Fix docstring for Certificate::generate_self_signed (#632)

Co-authored-by: roblabla <robin@harfanglab.fr>

.cargo/audit.toml

@@ -0,0 +1,6 @@
+[advisories]
+ignore = [
+    "RUSTSEC-2020-0071", # chrono
+    "RUSTSEC-2021-0145", # atty
+    "RUSTSEC-2023-0071", # rsa: Marvin Attack: potential key recovery
+] # advisory IDs to ignore e.g. ["RUSTSEC-2019-0001", ...]

.github/dependabot.yml

@@ -1,8 +1,19 @@
 version: 2
 updates:
   - package-ecosystem: cargo
+    versioning-strategy: lockfile-only
+    directory: "/"
+    allow:
+      - dependency-type: "all"
+    groups:
+      all-deps:
+        patterns:
+          - "*"
+    schedule:
+      interval: weekly
+    open-pull-requests-limit: 10
+  - package-ecosystem: github-actions
     directory: "/"
     schedule:
       interval: weekly
-    time: '13:00'
     open-pull-requests-limit: 10

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
   check:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v6
       - uses: actions-rs/toolchain@v1
         with:
           profile: minimal
@@ -36,17 +36,17 @@ jobs:
             toolchain: stable
             deps: true
           - platform: ubuntu-latest
-            toolchain: 1.51.0 # MSRV
+            toolchain: 1.85.0 # MSRV
             deps: sudo apt-get install libpcsclite-dev
           - platform: windows-latest
-            toolchain: 1.51.0 # MSRV
+            toolchain: 1.85.0 # MSRV
             deps: true
           - platform: macos-latest
-            toolchain: 1.51.0 # MSRV
+            toolchain: 1.85.0 # MSRV
             deps: true
     runs-on: ${{ matrix.platform }}
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v6
       - uses: actions-rs/toolchain@v1
         with:
           profile: minimal
@@ -60,7 +60,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout sources
-        uses: actions/checkout@v1
+        uses: actions/checkout@v6
 
       - name: Install stable toolchain
         uses: actions-rs/toolchain@v1
@@ -78,11 +78,11 @@ jobs:
   clippy:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v1
+      - uses: actions/checkout@v6
       - uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: 1.51.0 # MSRV
+          toolchain: 1.85.0 # MSRV
           components: clippy
           override: true
       - run: sudo apt-get install libpcsclite-dev

.github/workflows/security_audit.yml

@@ -15,16 +15,16 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout sources
-        uses: actions/checkout@v1
+        uses: actions/checkout@v6
 
       - name: Cache cargo registry
-        uses: actions/cache@v1
+        uses: actions/cache@v5
         with:
           path: ~/.cargo/registry
           key: ${{ runner.os }}-cargo-registry-${{ hashFiles('Cargo.lock') }}
 
       - name: Cache cargo index
-        uses: actions/cache@v1
+        uses: actions/cache@v5
         with:
           path: ~/.cargo/git
           key: ${{ runner.os }}-cargo-index-${{ hashFiles('Cargo.lock') }}
@@ -42,4 +42,4 @@ jobs:
         uses: actions-rs/cargo@v1
         with:
           command: audit
-          args: --deny warnings --ignore RUSTSEC-2019-0031 # spin
+          args: --deny warnings

CHANGELOG.md

@@ -4,7 +4,170 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## 0.4.0 (2021-07-12)
+## Unreleased
+### Added
+- `yubikey::certificate::SelfSigned`
+- `yubikey::Error::CertificateBuilder`
+- `yubikey::MgmAlgorithmId`
+- `yubikey::mgm`:
+  - `MgmKey::generate_for`
+  - `MgmKey::get_default`
+  - `impl AsRef<[u8]> for MgmKey`
+
+### Changed
+- MSRV is now 1.81.
+- Migrated the public API to the following (pre-release) dependencies:
+  - `der 0.8.0-rc.1`
+  - `ecdsa 0.17.0-pre.9`
+  - `p256 0.14.0-pre.2`
+  - `p384 0.14.0-pre.2`
+  - `rsa 0.10.0-pre.3`
+  - `sha2 0.11.0-pre.4`
+  - `x509-cert 0.3.0-pre.0`
+- `yubikey::mgm`:
+  - `MgmKey::generate` now takes a `rand::TryCryptoRng` argument.
+  - `MgmKey::generate` now requires the caller to specify the key algorithm via
+    an `MgmAlgorithmId` parameter.
+    - Use `MgmKey::generate_for` if you want to generate a key using the
+      preferred algorithm for a given Yubikey's firmware version.
+  - `MgmKey::from_bytes` now takes an `Option<MgmAlgorithmId>` argument, to
+    disambiguate algorithms with the same key length.
+- `yubikey::piv`:
+  - `ManagementAlgorithmId` has been renamed to `SlotAlgorithmId`, and its
+    `ThreeDes` variant has been replaced by `SlotAlgorithmId::Management`
+    containing a `yubikey::MgmAlgorithmId`.
+- Metadata command returns `Error:NotFound` instead of `Error::GenericError` when the object doesn't exist ([#558]).
+
+### Removed
+- `yubikey::mgm`:
+  - `MgmKey::new` (use `MgmKey::from_bytes(_, Some(MgmAlgorithmId::ThreeDes))`
+    instead).
+  - `impl AsRef<[u8; DES_LEN_3DES]> for MgmKey` (use
+    `impl AsRef<[u8]> for MgmKey` instead).
+  - `impl Default for MgmKey` (use `MgmKey::get_default` instead).
+  - `impl TryFrom<&[u8]> for MgmKey` (use `MgmKey::from_bytes` instead).
+
+## 0.8.0 (2023-08-15)
+### Added
+- `impl Debug for {Context, YubiKey}` ([#457])
+- `YubiKey::disconnect` ([#462])
+- `Error::AppletNotFound` ([#476])
+
+### Changed
+- `Reader::open` now returns `Error::AppletNotFound` instead of `Error::Generic`
+  if the PIV applet is not present on the device. This is returned by non-PIV
+  virtual smart cards like Windows Hello for Business, as well as some smart
+  card readers when no card is present.
+- `Reader::open` now avoids resetting the card if an error occurs (equivalent to
+  calling `YubiKey::disconnect(pcsc::Disposition::LeaveCard)` if `Reader::open`
+  succeeds).
+- Raise minimum `pcsc` version to 2.3.1 and remove workaround ([#478])
+- Bump asymmetric crypto dependencies; MSRV 1.65 ([#490])
+  - `elliptic-curve` v0.13
+  - `k256` v0.13
+  - `p256` v0.13
+  - `p384` v0.13
+  - `pbkdf2` v0.12
+  - `rsa` v0.9 ([#502])
+  - `signature` v2
+- Use `x509-cert` certificate builder ([#495])
+- Make `RsaKeyData::new` fallible ([#517])
+
+### Fixed
+- `StatusWords::code` now returns the correct code (including embedded `tries`
+  count) for `StatusWords::VerifyFailError`. Previously the returned code lost
+  information and was not round-trip compatible with `StatusWords::from(u16)`.
+- Parsing of serial numbers ([#466])
+- Make `YubiKey::open()` more robust ([#504])
+
+[#457]: https://github.com/iqlusioninc/yubikey.rs/pull/457
+[#462]: https://github.com/iqlusioninc/yubikey.rs/pull/462
+[#466]: https://github.com/iqlusioninc/yubikey.rs/pull/466
+[#476]: https://github.com/iqlusioninc/yubikey.rs/pull/476
+[#478]: https://github.com/iqlusioninc/yubikey.rs/pull/478
+[#490]: https://github.com/iqlusioninc/yubikey.rs/pull/490
+[#495]: https://github.com/iqlusioninc/yubikey.rs/pull/495
+[#502]: https://github.com/iqlusioninc/yubikey.rs/pull/502
+[#504]: https://github.com/iqlusioninc/yubikey.rs/pull/504
+[#517]: https://github.com/iqlusioninc/yubikey.rs/pull/517
+
+## 0.7.0 (2022-11-14)
+### Added
+- Display inner PC/SC errors ([#420])
+- Support for metadata command ([#371])
+- Better `certificate::Serial` inspection ([#437])
+
+### Changed
+- MSRV 1.60.0 ([#423])
+- Bump `rsa` to v0.7.1 ([#440])
+- Switch from `lazy_static` to `once_cell` ([#442])
+- Switch from `subtle-encoding` to `base16ct` ([#443])
+
+### Fixed
+- Use `chrono` v0.4.23 or newer ([#436])
+- `Certificate::issuer` was returning the subject instead ([#437])
+
+[#371]: https://github.com/iqlusioninc/yubikey.rs/pull/371
+[#420]: https://github.com/iqlusioninc/yubikey.rs/pull/420
+[#423]: https://github.com/iqlusioninc/yubikey.rs/pull/423
+[#436]: https://github.com/iqlusioninc/yubikey.rs/pull/436
+[#437]: https://github.com/iqlusioninc/yubikey.rs/pull/437
+[#440]: https://github.com/iqlusioninc/yubikey.rs/pull/440
+[#442]: https://github.com/iqlusioninc/yubikey.rs/pull/442
+[#443]: https://github.com/iqlusioninc/yubikey.rs/pull/443
+
+## 0.6.0 (2022-08-10)
+### Changed
+- 2021 edition upgrade ([#343])
+- RustCrypto crate upgrades; MSRV 1.57 ([#378])
+  - `des` v0.8
+  - `elliptic-curve` v0.12
+  - `hmac` v0.12
+  - `num-bigint-dig` v0.8
+  - `pbkdf2` v0.11
+  - `p256` v0.11
+  - `p384` v0.11
+  - `rsa` v0.6
+  - `sha1` v0.10 (replacing `sha-1`)
+  - `sha2` v0.10
+- Bump `uuid` to v1.0 ([#376])
+- Bump `der-parser` to v8.0 ([#402])
+- Bump `x509-parser` to v0.14 ([#402])
+
+[#343]: https://github.com/iqlusioninc/yubikey.rs/pull/343
+[#376]: https://github.com/iqlusioninc/yubikey.rs/pull/376
+[#378]: https://github.com/iqlusioninc/yubikey.rs/pull/378
+[#402]: https://github.com/iqlusioninc/yubikey.rs/pull/402
+
+## 0.5.0 (2021-11-21)
+### Changed
+- Update `rsa` dependency to 0.5 ([#315])
+- Update `pbkdf2` dependency to 0.9 ([#315])
+- Update `x509-parser` dependency to 0.12 ([#315], [#322])
+- Update `nom` to v7.0 ([#322])
+
+[#315]: https://github.com/iqlusioninc/yubikey.rs/pull/315
+[#322]: https://github.com/iqlusioninc/yubikey.rs/pull/322
+
+## 0.4.2 (2021-07-13)
+### Added
+- Make `yubikey::Buffer` a pub type ([#290])
+
+### Changed
+- Have `YubiKey::block_puk` take `&mut self` as argument ([#289])
+
+[#289]: https://github.com/iqlusioninc/yubikey.rs/pull/289
+[#290]: https://github.com/iqlusioninc/yubikey.rs/pull/290
+
+## 0.4.1 (2021-07-12)
+### Changed
+- Rename `SettingValue` to `Setting` ([#286])
+- Rename `Ccc` to `CccId` ([#287])
+
+[#286]: https://github.com/iqlusioninc/yubikey.rs/pull/286
+[#287]: https://github.com/iqlusioninc/yubikey.rs/pull/287
+
+## 0.4.0 (2021-07-12) [YANKED]
 ### Added
 - `Result` alias ([#271])
 

Cargo.toml

@@ -1,58 +1,68 @@
 [package]
 name = "yubikey"
-version = "0.4.0" # Also update html_root_url in lib.rs when bumping this
+version = "0.9.0-pre.0"
 description = """
 Pure Rust cross-platform host-side driver for YubiKey devices from Yubico with
 support for hardware-backed public-key decryption and digital signatures using
-the Personal Identity Verification (PIV) application. Supports RSA (1024/2048)
+the Personal Identity Verification (PIV) application. Supports RSA (1024/2048/3072/4096)
 or ECC (NIST P-256/P-384) algorithms e.g, PKCS#1v1.5, ECDSA
 """
 authors = ["Tony Arcieri <tony@iqlusion.io>", "Yubico AB"]
-edition    = "2018"
 license = "BSD-2-Clause"
 repository = "https://github.com/iqlusioninc/yubikey.rs"
 readme = "README.md"
-categories = ["api-bindings", "cryptography", "hardware-support"]
+categories = ["api-bindings", "authentication", "cryptography", "hardware-support"]
 keywords = ["ecdsa", "encryption", "rsa", "piv", "signature"]
+edition = "2021"
+rust-version = "1.85"
 
 [workspace]
 members = [".", "cli"]
 
+[workspace.dependencies]
+sha2 = "0.11"
+x509-cert = { version = "0.3.0-rc.4", features = ["builder", "hazmat"] }
+
 [dependencies]
-chrono = "0.4"
-cookie-factory = "0.3"
-der-parser = "5"
-des = "0.7"
-elliptic-curve = "0.10"
-hmac = "0.11"
+aes = { version = "0.9.0-rc.4", features = ["zeroize"] }
+bitflags = "2.5.0"
+cipher = { version = "0.5", features = ["getrandom", "rand_core"] }
+curve25519-dalek = "5.0.0-pre.6"
+der = "0.8"
+des = "0.9.0-rc.3"
+ecdsa = { version = "0.17.0-rc.16", features = ["digest", "pem"] }
+ed25519-dalek = { version = "3.0.0-pre.6", features = ["alloc", "pkcs8"] }
+elliptic-curve = "0.14.0-rc.29"
+hex = { package = "base16ct", version = "0.2", features = ["alloc"] }
 log = "0.4"
-nom = "6"
-num-bigint-dig = { version = "0.7", features = ["rand"] }
-num-traits = "0.2"
-num-integer = "0.1"
-pbkdf2 = { version = "0.8", default-features = false }
-p256 = "0.9"
-p384 = "0.8"
-pcsc = "2"
-rand_core = { version = "0.6", features = ["std"] }
-rsa = "0.4"
-secrecy = "0.7"
-sha-1 = "0.9"
-sha2 = "0.9"
+nom = "8"
+p256 = "0.14.0-rc.8"
+p384 = "0.14.0-rc.8"
+pbkdf2 = { version = "0.13.0-rc.10", default-features = false, features = ["hmac"] }
+pcsc = "2.3.1"
+rand = "0.10"
+rand_core = "0.10"
+rsa = { version = "0.10.0-rc.17", features = ["sha2"] }
+sha1 = { version = "0.11", features = ["oid"] }
+sha2 = { workspace = true, features = ["oid"] }
+signature = "3.0.0-rc.10"
 subtle = "2"
-subtle-encoding = "0.5"
-uuid = { version = "0.8", features = ["v4"] }
-x509 = "0.2"
-x509-parser = "0.9"
+uuid = { version = "1.2", features = ["v4"] }
+x25519-dalek = "3.0.0-pre.6"
+x509-cert.workspace = true
 zeroize = "1"
 
 [dev-dependencies]
-env_logger = "0.8"
-lazy_static = "1"
+env_logger = "0.11"
+once_cell = "1"
 
 [features]
 untested = []
 
+[[example]]
+name = "change-mode"
+required-features = ["untested"]
+
 [package.metadata.docs.rs]
 all-features = true
 rustdoc-args = ["--cfg", "docsrs"]

README.md

@@ -4,48 +4,80 @@
 
 [![crate][crate-image]][crate-link]
 [![Docs][docs-image]][docs-link]
-[![2-Clause BSD Licensed][license-image]][license-link]
-![Rust Version][rustc-image]
-![Maintenance Status: Experimental][maintenance-image]
-[![Safety Dance][safety-image]][safety-link]
 [![Build Status][build-image]][build-link]
-[![Gitter Chat][gitter-image]][gitter-link]
+[![Safety Dance][safety-image]][safety-link]
+[![Dependency Status][deps-image]][deps-link]
+[![2-Clause BSD Licensed][license-image]][license-link]
+![MSRV][msrv-image]
 
 Pure Rust cross-platform host-side driver for [YubiKey] devices from [Yubico]
 with support for public-key encryption and digital signatures using the
 [Personal Identity Verification (PIV)][PIV] application.
 
+Uses the Personal Computer/Smart Card ([PC/SC]) interface with cross-platform
+access provided by the [`pcsc` crate].
+
 [Documentation][docs-link]
 
 ## About
 
 YubiKeys are versatile devices and through their PIV support, you can use them
-to store a number of RSA (2048/1024) and ECC (NIST P-256/P-384) private keys
+to store a number of RSA (1024/2048/3072/4096) and ECC (NIST P-256/P-384) private keys
 with configurable access control policies. Both the signing (RSASSA/ECDSA) and
 encryption (PKCS#1v1.5/ECIES) use cases are supported for either key type.
 
 See [Yubico's guide to PIV-enabled YubiKeys][yk-guide] for more information
 on which devices support PIV and the available functionality.
 
-If you've been wanting to use Rust to sign and/or encrypt stuff using a
-private key generated and stored on a Yubikey (with option PIN-based access),
+If you've been wanting to use Rust to sign and/or encrypt data using a
+private key generated and stored on a YubiKey (with option PIN-based access),
 this is the crate you've been after!
 
 Note that while this project started as a fork of a [Yubico] project,
 this fork is **NOT** an official Yubico project and is in no way supported or
 endorsed by Yubico.
 
+## Features
+
+### Personal Identity Verification (PIV)
+
+[PIV] is a [NIST] standard for both *signing* and *encryption*
+using SmartCards and SmartCard-based hardware tokens like YubiKeys.
+
+PIV-related functionality can be found in the [`piv`] module.
+
+This library natively implements the protocol used to manage and
+utilize PIV encryption and signing keys which can be generated, imported,
+and stored on YubiKey devices.
+
+See [Yubico's guide to PIV-enabled YubiKeys][yk-guide] for more information
+on which devices support PIV and the available functionality.
+
+### Supported Algorithms
+
+- **Authentication**: `3DES`
+- **Encryption**:
+    - RSA: `RSA1024`, `RSA2048`, `RSA3072`, `RSA4096`
+    - ECC: `ECCP256`, `ECCP384` (NIST curves: P-256, P-384)
+- **Signatures**:
+    - RSASSA-PKCS#1v1.5: `RSA1024`, `RSA2048`, `RSA3072`, `RSA4096`
+    - ECDSA: `ECCP256`, `ECCP384` (NIST curves: P-256, P-384)
+
+NOTE:
+
+- RSASSA-PSS signatures and RSA-OAEP encryption may be supportable (TBD)
+- `RSA3072` and `RSA4096` require a YubiKey with firmware 5.7 or newer.
+
 ## Minimum Supported Rust Version
 
-Rust **1.51** or newer.
+Rust **1.60** or newer.
 
 ## Supported YubiKeys
 
 - [YubiKey 4] series
 - [YubiKey 5] series
 
-NOTE: Nano and USB-C variants of the above are also supported.
-      Pre-YK4 [YubiKey NEO] series is **NOT** supported (see [#18]).
+NOTE: Nano and USB-C variants of the above are also supported. NEO series is NOT supported.
 
 ## Supported Operating Systems
 
@@ -60,16 +92,27 @@ an experimental stage and may still contain high-severity issues.
 
 USE AT YOUR OWN RISK!
 
+## Status
+
+Functionality which has been successfully tested is available by default.
+
+Any functionality which is gated on the `untested` feature has not been
+properly tested and is not known to function correctly.
+
+Please see the [`untested` functionality tracking issue] for current status.
+We would appreciate any help testing this functionality and removing the
+`untested` gating as well as writing more automated tests.
+
 ## Testing
 
-To run the full test suite, you'll need a connected YubiKey NEO/4/5 device in
-the default state (i.e. default PIN/PUK).
+To run the full test suite, you'll need a supported YubiKey device connected
+which is in the default state (i.e. default PIN/PUK).
 
 Tests which run live against a YubiKey device are marked as `#[ignore]` by
 default in order to pass when running in a CI environment. To run these
 tests locally, invoke the following command:
 
-```
+```shell
 cargo test -- --ignored
 ```
 
@@ -78,14 +121,14 @@ information about what is happening. If you'd like to print this logging
 information while running the tests, set the `RUST_LOG` environment variable
 to a relevant loglevel (e.g. `error`, `warn`, `info`, `debug`, `trace`):
 
-```
+```shell
 RUST_LOG=info cargo test -- --ignored
 ```
 
 To trace every message sent to/from the card i.e. the raw
 Application Protocol Data Unit (APDU) messages, use the `trace` log level:
 
-```
+```text
 running 1 test
 [INFO  yubikey::yubikey] trying to connect to reader 'Yubico YubiKey OTP+FIDO+CCID'
 [INFO  yubikey::yubikey] connected to 'Yubico YubiKey OTP+FIDO+CCID' successfully
@@ -111,6 +154,14 @@ Yubico, which was originally written in C. It was mechanically translated
 from C into Rust using [Corrode], and then subsequently heavily
 refactored into safer, more idiomatic Rust.
 
+For more information on [yubico-piv-tool] and background information on how
+the YubiKey implementation of PIV works in general, see the
+[Yubico PIV Tool Command Line Guide][piv-tool-guide].
+
+## ⚠️ Security Warning
+
+No security audits of this crate have ever been performed.
+
 ## Code of Conduct
 
 We abide by the [Contributor Covenant][cc-md] and ask that you do as well.
@@ -124,7 +175,7 @@ Yubico's [yubico-piv-tool], a C library/CLI program. The original library
 was licensed under a [2-Clause BSD License][BSDL], which this library inherits
 as a derived work.
 
-Copyright (c) 2014-2021 Yubico AB, Tony Arcieri
+Copyright (c) 2014-2025 Yubico AB, Tony Arcieri
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -160,35 +211,38 @@ or conditions.
 
 [//]: # (badges)
 
-[crate-image]: https://img.shields.io/crates/v/yubikey.svg
+[crate-image]: https://img.shields.io/crates/v/yubikey?logo=rust
 [crate-link]: https://crates.io/crates/yubikey
 [docs-image]: https://docs.rs/yubikey/badge.svg
 [docs-link]: https://docs.rs/yubikey/
 [license-image]: https://img.shields.io/badge/license-BSD-blue.svg
 [license-link]: https://github.com/iqlusioninc/yubikey.rs/blob/main/COPYING
-[rustc-image]: https://img.shields.io/badge/rustc-1.51+-blue.svg
-[maintenance-image]: https://img.shields.io/badge/maintenance-experimental-blue.svg
+[msrv-image]: https://img.shields.io/badge/rustc-1.85+-blue.svg
 [safety-image]: https://img.shields.io/badge/unsafe-forbidden-success.svg
 [safety-link]: https://github.com/rust-secure-code/safety-dance/
-[build-image]: https://github.com/iqlusioninc/yubikey.rs/workflows/CI/badge.svg?branch=main&event=push
+[build-image]: https://github.com/iqlusioninc/yubikey.rs/actions/workflows/ci.yml/badge.svg
 [build-link]: https://github.com/iqlusioninc/yubikey.rs/actions
-[gitter-image]: https://badges.gitter.im/badge.svg
-[gitter-link]: https://gitter.im/iqlusioninc/community
+[deps-image]: https://deps.rs/repo/github/iqlusioninc/yubikey.rs/status.svg
+[deps-link]: https://deps.rs/repo/github/iqlusioninc/yubikey.rs
 
 [//]: # (general links)
 
 [YubiKey]: https://www.yubico.com/products/yubikey-hardware/
-[PIV]: https://piv.idmanagement.gov/
-[yk-guide]: https://developers.yubico.com/PIV/Introduction/YubiKey_and_PIV.html
 [Yubico]: https://www.yubico.com/
-[YubiKey NEO]: https://support.yubico.com/support/solutions/articles/15000006494-yubikey-neo
+[PIV]: https://piv.idmanagement.gov/
+[NIST]: https://www.nist.gov/
+[PC/SC]: https://en.wikipedia.org/wiki/PC/SC
+[`pcsc` crate]: https://github.com/bluetech/pcsc-rust
+[yk-guide]: https://developers.yubico.com/PIV/Introduction/YubiKey_and_PIV.html
 [YubiKey 4]: https://support.yubico.com/support/solutions/articles/15000006486-yubikey-4
 [YubiKey 5]: https://www.yubico.com/products/yubikey-5-overview/
 [yubico-piv-tool]: https://github.com/Yubico/yubico-piv-tool/
+[piv-tool-guide]: https://docs.yubico.com/software/yubikey/tools/pivtool/Introduction.html
 [Corrode]: https://github.com/jameysharp/corrode
 [cc-web]: https://contributor-covenant.org/
 [cc-md]: https://github.com/iqlusioninc/yubikey.rs/blob/main/CODE_OF_CONDUCT.md
 [BSDL]: https://opensource.org/licenses/BSD-2-Clause
+[`untested` functionality tracking issue]: https://github.com/iqlusioninc/yubikey.rs/issues/280
 
 [//]: # (github issues)
 

cli/CHANGELOG.md

@@ -4,16 +4,57 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+### Changed
+- MSRV is now 1.81.
+
+## 0.7.0 (2022-11-14)
+### Changed
+- Bump `clap` to v4.0 ([#438])
+- Bump `x509-parser` to v0.14 ([#441])
+- Switch from `lazy_static` to `once_cell` ([#442])
+- Switch from `subtle-encoding` to `base16ct` ([#443])
+- Bump `yubikey` dependency to v0.7 ([#444])
+
+[#438]: https://github.com/iqlusioninc/yubikey.rs/pull/438
+[#441]: https://github.com/iqlusioninc/yubikey.rs/pull/441
+[#442]: https://github.com/iqlusioninc/yubikey.rs/pull/442
+[#443]: https://github.com/iqlusioninc/yubikey.rs/pull/443
+[#444]: https://github.com/iqlusioninc/yubikey.rs/pull/444
+
+## 0.6.0 (2022-08-10)
+### Changed
+- 2021 edition upgrade; MSRV 1.57 ([#343])
+- Migrate from `gumdrop` to `clap` v3 ([#379])
+- Bump `yubikey` dependency to v0.6 ([#403])
+
+[#343]: https://github.com/iqlusioninc/yubikey.rs/pull/343
+[#379]: https://github.com/iqlusioninc/yubikey.rs/pull/379
+[#403]: https://github.com/iqlusioninc/yubikey.rs/pull/403
+
+## 0.5.0 (2021-11-21)
+### Changed
+- Bump `yubikey` dependency to v0.5 ([#327])
+
+[#327]: https://github.com/iqlusioninc/yubikey.rs/pull/327
+ 
+## 0.4.0 (2021-07-12)
+### Changed
+- Switch to renamed `yubikey` crate ([#283])
+- Bump MSRV to 1.51+ ([#283])
+
+[#283]: https://github.com/iqlusioninc/yubikey.rs/pull/283
+
 ## 0.3.0 (2021-03-22)
 ### Changed
-- Bump `yubikey` dependency to v0.3 ([#240])
+- Bump `yubikey-piv` dependency to v0.3 ([#240])
 
 [#240]: https://github.com/iqlusioninc/yubikey.rs/pull/240
 
 ## 0.2.0 (2021-01-30)
 ### Changed
 - Bump MSRV to 1.46+ ([#208])
-- Bump `yubikey` dependency to v0.2 ([#220])
+- Bump `yubikey-piv` dependency to v0.2 ([#220])
 
 [#208]: https://github.com/iqlusioninc/yubikey.rs/pull/208
 [#220]: https://github.com/iqlusioninc/yubikey.rs/pull/220
@@ -23,7 +64,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - `status` command ([#72], [#74])
 
 ### Changed
-- Bump `yubikey` to v0.1.0 ([#180])
+- Bump `yubikey-piv` to v0.1 ([#180])
 - Bump `x509-parser` to v0.8 ([#181])
 - Bump `sha2` to v0.9 ([#182])
 - Rename `list` command to `readers`; improve usage ([#71])

cli/Cargo.toml

@@ -1,25 +1,26 @@
 [package]
 name = "yubikey-cli"
-version = "0.4.0-pre"
+version = "0.9.0-pre"
 description = """
 Command-line interface for performing encryption and signing using RSA/ECC keys
 stored on YubiKey devices.
 """
 authors = ["Tony Arcieri <tony@iqlusion.io>"]
-edition    = "2018"
 license = "BSD-2-Clause"
 repository = "https://github.com/iqlusioninc/yubikey.rs"
 readme = "README.md"
 categories = ["command-line-utilities", "cryptography", "hardware-support"]
 keywords = ["ecdsa", "rsa", "piv", "pcsc", "yubikey"]
+edition = "2021"
+rust-version = "1.85"
 
 [dependencies]
-gumdrop = "0.8"
-env_logger = "0.8"
-lazy_static = "1"
+clap = { version = "4", features = ["derive"] }
+env_logger = "0.11"
+hex = { package = "base16ct", version = "0.2", features = ["alloc"] }
 log = "0.4"
-sha2 = "0.9"
-subtle-encoding = "0.5"
+once_cell = "1"
+sha2.workspace = true
 termcolor = "1"
-x509-parser = "0.9"
-yubikey = { version = "0.4", path = ".." }
+x509-cert.workspace = true
+yubikey = { version = "=0.9.0-pre.0", path = ".." }

cli/README.md

@@ -18,15 +18,14 @@ utility with general-purpose public-key encryption and signing support.
 
 ## Minimum Supported Rust Version
 
-Rust **1.51** or newer.
+Rust **1.60** or newer.
 
 ## Supported YubiKeys
 
 - [YubiKey 4] series
 - [YubiKey 5] series
 
-NOTE: Nano and USB-C variants of the above are also supported.
-      Pre-YK4 [YubiKey NEO] series is **NOT** supported (see [#18]).
+NOTE: Nano and USB-C variants of the above are also supported. NEO series is NOT supported.
 
 ## Security Warning
 
@@ -35,10 +34,6 @@ an experimental stage and may still contain high-severity issues.
 
 USE AT YOUR OWN RISK!
 
-## Status
-
-WIP. Check back later.
-
 ## Code of Conduct
 
 We abide by the [Contributor Covenant][cc-md] and ask that you do as well.
@@ -47,7 +42,7 @@ For more information, please see [CODE_OF_CONDUCT.md][cc-md].
 
 ## License
 
-Copyright (c) 2014-2021 Yubico AB, Tony Arcieri
+Copyright (c) 2014-2023 Yubico AB, Tony Arcieri
 All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -88,7 +83,7 @@ or conditions.
 [docs-image]: https://docs.rs/yubikey-cli/badge.svg
 [docs-link]: https://docs.rs/yubikey-cli/
 [license-image]: https://img.shields.io/badge/license-BSD-blue.svg
-[rustc-image]: https://img.shields.io/badge/rustc-1.39+-blue.svg
+[rustc-image]: https://img.shields.io/badge/rustc-1.85+-blue.svg
 [maintenance-image]: https://img.shields.io/badge/maintenance-experimental-blue.svg
 [safety-image]: https://img.shields.io/badge/unsafe-forbidden-success.svg
 [safety-link]: https://github.com/rust-secure-code/safety-dance/
@@ -102,7 +97,6 @@ or conditions.
 [PIV]: https://piv.idmanagement.gov/
 [yk-guide]: https://developers.yubico.com/PIV/Introduction/YubiKey_and_PIV.html
 [Yubico]: https://www.yubico.com/
-[YubiKey NEO]: https://support.yubico.com/support/solutions/articles/15000006494-yubikey-neo
 [YubiKey 4]: https://support.yubico.com/support/solutions/articles/15000006486-yubikey-4
 [YubiKey 5]: https://www.yubico.com/products/yubikey-5-overview/
 [yubico-piv-tool]: https://github.com/Yubico/yubico-piv-tool/

cli/src/bin/yubikey/main.rs

@@ -8,9 +8,9 @@
     unused_qualifications
 )]
 
-use gumdrop::Options;
+use clap::Parser;
 use yubikey_cli::commands::YubiKeyCli;
 
 fn main() {
-    YubiKeyCli::parse_args_default_or_exit().run();
+    YubiKeyCli::parse().run()
 }

cli/src/commands.rs

@@ -4,62 +4,25 @@ pub mod readers;
 pub mod status;
 
 use self::{readers::ReadersCmd, status::StatusCmd};
-use crate::terminal::{self, STDOUT};
-use gumdrop::Options;
-use std::{
-    env,
-    io::{self, Write},
-    process::exit,
-};
-use termcolor::{ColorChoice, ColorSpec, WriteColor};
+use crate::terminal;
+use clap::Parser;
+use std::{env, process::exit};
+use termcolor::ColorChoice;
 use yubikey::{Serial, YubiKey};
 
 /// The `yubikey` CLI utility
-#[derive(Debug, Options)]
+#[derive(Debug, Parser)]
 pub struct YubiKeyCli {
-    /// Obtain help about the current command
-    #[options(short = "h", help = "print help message")]
-    pub help: bool,
-
-    /// Specify the serial number of the YubiKey to connect to
-    #[options(
-        short = "s",
-        long = "serial",
-        help = "serial number of the YubiKey to connect to"
-    )]
+    /// Serial number of the YubiKey to connect to
+    #[clap(short = 's', long = "serial")]
     pub serial: Option<Serial>,
 
     /// Subcommand to execute.
-    #[options(command)]
-    pub command: Option<Commands>,
+    #[clap(subcommand)]
+    pub command: Commands,
 }
 
 impl YubiKeyCli {
-    /// Print usage information
-    pub fn print_usage() -> io::Result<()> {
-        let mut stdout = STDOUT.lock();
-        stdout.reset()?;
-
-        let mut bold = ColorSpec::new();
-        bold.set_bold(true);
-
-        stdout.set_color(&bold)?;
-        writeln!(
-            stdout,
-            "{} {}",
-            env!("CARGO_PKG_NAME"),
-            env!("CARGO_PKG_VERSION")
-        )?;
-        stdout.reset()?;
-
-        writeln!(stdout, "{}", env!("CARGO_PKG_AUTHORS"))?;
-        writeln!(stdout, "{}", env!("CARGO_PKG_DESCRIPTION").trim())?;
-        writeln!(stdout)?;
-        writeln!(stdout, "{}", Commands::usage())?;
-
-        Ok(())
-    }
-
     /// Run the underlying command type or print usage info and exit
     pub fn run(&self) {
         // TODO(tarcieri): make this more configurable
@@ -70,10 +33,7 @@ impl YubiKeyCli {
             env_logger::builder().format_timestamp(None).init();
         }
 
-        match &self.command {
-            Some(cmd) => cmd.run(self.yubikey_init()),
-            None => Self::print_usage().unwrap(),
-        }
+        self.command.run(self.yubikey_init())
     }
 
     /// Initialize the YubiKey client driver
@@ -92,22 +52,18 @@ impl YubiKeyCli {
 }
 
 /// Subcommands of this application
-#[derive(Debug, Options)]
+#[derive(Debug, Parser)]
 pub enum Commands {
-    /// `help` subcommand
-    #[options(help = "show help for a command")]
-    Help(HelpOpts),
-
     /// `version` subcommand
-    #[options(help = "display version information")]
+    #[clap(about = "display version information")]
     Version(VersionOpts),
 
     /// `readers` subcommand
-    #[options(help = "list detected readers")]
+    #[clap(about = "list detected readers")]
     Readers(ReadersCmd),
 
     /// `status` subcommand
-    #[options(help = "show yubikey status")]
+    #[clap(about = "show yubikey status")]
     Status(StatusCmd),
 }
 
@@ -115,7 +71,6 @@ impl Commands {
     /// Run the given command
     pub fn run(&self, yubikey: YubiKey) {
         match self {
-            Commands::Help(help) => help.run(),
             Commands::Version(version) => version.run(),
             Commands::Readers(list) => list.run(),
             Commands::Status(status) => status.run(yubikey),
@@ -123,28 +78,8 @@ impl Commands {
     }
 }
 
-/// Help options
-#[derive(Debug, Options)]
-pub struct HelpOpts {
-    #[options(free, help = "subcommand to get help for")]
-    free: Vec<String>,
-}
-
-impl HelpOpts {
-    fn run(&self) {
-        if let Some(command) = self.free.first() {
-            if let Some(usage) = Commands::command_usage(command) {
-                println!("{}", usage);
-                exit(1);
-            }
-        }
-
-        println!("{}", Commands::usage());
-    }
-}
-
 /// Version options
-#[derive(Debug, Options)]
+#[derive(Debug, Parser)]
 pub struct VersionOpts {}
 
 impl VersionOpts {

cli/src/commands/readers.rs

@@ -1,7 +1,7 @@
 //! List detected readers
 
 use crate::terminal::STDOUT;
-use gumdrop::Options;
+use clap::Parser;
 use std::{
     io::{self, Write},
     process::exit,
@@ -10,7 +10,7 @@ use termcolor::{ColorSpec, StandardStreamLock, WriteColor};
 use yubikey::{Context, Serial};
 
 /// The `readers` subcommand
-#[derive(Debug, Options)]
+#[derive(Debug, Parser)]
 pub struct ReadersCmd {}
 
 impl ReadersCmd {

cli/src/commands/status.rs

@@ -1,18 +1,16 @@
 //! Print device status
 
-use crate::terminal::STDOUT;
-use gumdrop::Options;
+use crate::terminal::{print_cert_info, STDOUT};
+use clap::Parser;
 use std::io::{self, Write};
 use termcolor::{ColorSpec, StandardStreamLock, WriteColor};
 use yubikey::{piv::*, YubiKey};
 
-use crate::print_cert_info;
-
 // String to use for `None`
 const NONE_STR: &str = "<none>";
 
 /// The `status` subcommand
-#[derive(Debug, Options)]
+#[derive(Debug, Parser)]
 pub struct StatusCmd {}
 
 impl StatusCmd {

cli/src/lib.rs

@@ -1,92 +1,13 @@
 //! `yubikey` command-line utility.
+//!
+//! The goal of this tool is to provide functionality similar to `yubico-piv-tool`
+//! but implemented in pure Rust.
+//!
+//! It also serves as a demonstration/example of how to use the `yubikey` crate.
 
 #![forbid(unsafe_code)]
-#![warn(
-    missing_docs,
-    rust_2018_idioms,
-    unused_lifetimes,
-    unused_qualifications
-)]
+#![warn(missing_docs, rust_2018_idioms, unused_qualifications)]
 
 #[macro_use]
 pub mod terminal;
-
 pub mod commands;
-
-use log::debug;
-use sha2::{Digest, Sha256};
-use std::io::{self, Write};
-use std::str;
-use subtle_encoding::hex;
-use termcolor::{ColorSpec, StandardStreamLock, WriteColor};
-use x509_parser::parse_x509_certificate;
-use yubikey::{certificate::Certificate, piv::*, YubiKey};
-
-/// Write information about certificate found in slot a la yubico-piv-tool output.
-pub fn print_cert_info(
-    yubikey: &mut YubiKey,
-    slot: SlotId,
-    stream: &mut StandardStreamLock<'_>,
-) -> io::Result<()> {
-    let cert = match Certificate::read(yubikey, slot) {
-        Ok(c) => c,
-        Err(e) => {
-            debug!("error reading certificate in slot {:?}: {}", slot, e);
-            return Ok(());
-        }
-    };
-    let buf = cert.into_buffer();
-
-    if !buf.is_empty() {
-        let fingerprint = Sha256::digest(&buf);
-        let slot_id: u8 = slot.into();
-        print_cert_attr(stream, "Slot", format!("{:x}", slot_id))?;
-        match parse_x509_certificate(&buf) {
-            Ok((_rem, cert)) => {
-                print_cert_attr(
-                    stream,
-                    "Algorithm",
-                    cert.tbs_certificate.subject_pki.algorithm.algorithm,
-                )?;
-
-                print_cert_attr(stream, "Subject", cert.tbs_certificate.subject)?;
-                print_cert_attr(stream, "Issuer", cert.tbs_certificate.issuer)?;
-                print_cert_attr(
-                    stream,
-                    "Fingerprint",
-                    str::from_utf8(hex::encode(fingerprint).as_slice()).unwrap(),
-                )?;
-                print_cert_attr(
-                    stream,
-                    "Not Before",
-                    cert.tbs_certificate.validity.not_before.to_rfc2822(),
-                )?;
-                print_cert_attr(
-                    stream,
-                    "Not After",
-                    cert.tbs_certificate.validity.not_after.to_rfc2822(),
-                )?;
-            }
-            _ => {
-                println!("Failed to parse certificate");
-                return Ok(());
-            }
-        };
-    }
-
-    Ok(())
-}
-
-/// Print a status attribute
-fn print_cert_attr(
-    stream: &mut StandardStreamLock<'_>,
-    name: &str,
-    value: impl ToString,
-) -> io::Result<()> {
-    stream.set_color(ColorSpec::new().set_bold(true))?;
-    write!(stream, "{:>12}:", name)?;
-    stream.reset()?;
-    writeln!(stream, " {}", value.to_string())?;
-    stream.flush()?;
-    Ok(())
-}

cli/src/terminal.rs

@@ -1,9 +1,16 @@
 //! Status messages
 
-use lazy_static::lazy_static;
-use std::io::{self, Write};
-use std::sync::Mutex;
-use termcolor::{Color, ColorChoice, ColorSpec, StandardStream, WriteColor};
+use log::debug;
+use once_cell::sync::Lazy;
+use sha2::{Digest, Sha256};
+use std::{
+    io::{self, Write},
+    str,
+    sync::Mutex,
+};
+use termcolor::{Color, ColorChoice, ColorSpec, StandardStream, StandardStreamLock, WriteColor};
+use x509_cert::der::Encode;
+use yubikey::{certificate::Certificate, piv::*, YubiKey};
 
 /// Print a success status message (in green if colors are enabled)
 #[macro_export]
@@ -51,16 +58,14 @@ macro_rules! status_err {
     };
 }
 
-lazy_static! {
 /// Color configuration
-    static ref COLOR_CHOICE: Mutex<Option<ColorChoice>> = Mutex::new(None);
+static COLOR_CHOICE: Lazy<Mutex<Option<ColorChoice>>> = Lazy::new(|| Mutex::new(None));
 
 /// Standard output
-    pub static ref STDOUT: StandardStream = StandardStream::stdout(get_color_choice());
+pub static STDOUT: Lazy<StandardStream> = Lazy::new(|| StandardStream::stdout(get_color_choice()));
 
 /// Standard error
-    pub static ref STDERR: StandardStream = StandardStream::stderr(get_color_choice());
-}
+pub static STDERR: Lazy<StandardStream> = Lazy::new(|| StandardStream::stderr(get_color_choice()));
 
 /// Obtain the color configuration.
 ///
@@ -132,14 +137,12 @@ impl Status {
 
     /// Print the given message to stdout
     pub fn print_stdout(self, msg: impl AsRef<str>) {
-        self.print(&*STDOUT, msg)
-            .expect("error printing to stdout!")
+        self.print(&STDOUT, msg).expect("error printing to stdout!")
     }
 
     /// Print the given message to stderr
     pub fn print_stderr(self, msg: impl AsRef<str>) {
-        self.print(&*STDERR, msg)
-            .expect("error printing to stderr!")
+        self.print(&STDERR, msg).expect("error printing to stderr!")
     }
 
     /// Print the given message
@@ -163,3 +166,65 @@ impl Status {
         Ok(())
     }
 }
+
+/// Write information about certificate found in slot a la yubico-piv-tool output.
+pub fn print_cert_info(
+    yubikey: &mut YubiKey,
+    slot: SlotId,
+    stream: &mut StandardStreamLock<'_>,
+) -> io::Result<()> {
+    let cert = match Certificate::read(yubikey, slot) {
+        Ok(c) => c,
+        Err(e) => {
+            debug!("error reading certificate in slot {:?}: {}", slot, e);
+            return Ok(());
+        }
+    };
+    let cert = &cert.cert;
+
+    let fingerprint = Sha256::digest(cert.to_der().unwrap());
+    let slot_id: u8 = slot.into();
+    print_cert_attr(stream, "Slot", format!("{:x}", slot_id))?;
+    print_cert_attr(
+        stream,
+        "Algorithm",
+        cert.tbs_certificate()
+            .subject_public_key_info()
+            .algorithm
+            .oid,
+    )?;
+
+    print_cert_attr(stream, "Subject", cert.tbs_certificate().subject())?;
+    print_cert_attr(stream, "Issuer", cert.tbs_certificate().issuer())?;
+    print_cert_attr(
+        stream,
+        "Fingerprint",
+        hex::upper::encode_string(&fingerprint),
+    )?;
+    print_cert_attr(
+        stream,
+        "Not Before",
+        cert.tbs_certificate().validity().not_before,
+    )?;
+    print_cert_attr(
+        stream,
+        "Not After",
+        cert.tbs_certificate().validity().not_after,
+    )?;
+
+    Ok(())
+}
+
+/// Print a status attribute
+fn print_cert_attr(
+    stream: &mut StandardStreamLock<'_>,
+    name: &str,
+    value: impl ToString,
+) -> io::Result<()> {
+    stream.set_color(ColorSpec::new().set_bold(true))?;
+    write!(stream, "{:>12}:", name)?;
+    stream.reset()?;
+    writeln!(stream, " {}", value.to_string())?;
+    stream.flush()?;
+    Ok(())
+}

examples/change-mode.rs

@@ -0,0 +1,10 @@
+#![cfg(feature = "untested")]
+
+use yubikey::{mgm, YubiKey};
+
+fn main() {
+    let yubikey = YubiKey::open().unwrap();
+
+    let mut mgmt = mgm::Manager::new(yubikey).unwrap();
+    mgmt.enable_yubihsm().unwrap();
+}

src/apdu.rs

@@ -82,6 +82,12 @@ impl Apdu {
         self
     }
 
+    /// Set this APDU's second parameter only
+    pub(crate) fn p2(&mut self, value: u8) -> &mut Self {
+        self.p2 = value;
+        self
+    }
+
     /// Set both parameters for this APDU
     pub fn params(&mut self, p1: u8, p2: u8) -> &mut Self {
         self.p1 = p1;
@@ -108,11 +114,31 @@ impl Apdu {
         self
     }
 
-    /// Transmit this APDU using the given card transaction
+    /// Transmit this APDU using the given card transaction.
+    ///
+    /// Handles ISO 7816-4 `SW1=61` (bytes remaining) responses by issuing
+    /// [`Ins::GetResponseApdu`] commands until all response data is collected.
     pub fn transmit(&self, txn: &Transaction<'_>, recv_len: usize) -> Result<Response> {
         trace!(">>> {:?}", self);
-        let response = Response::from(txn.transmit(&self.to_bytes(), recv_len)?);
+        let mut response = Response::from(txn.transmit(&self.to_bytes(), recv_len)?);
         trace!("<<< {:?}", &response);
+
+        if let StatusWords::BytesRemaining { .. } = response.status_words() {
+            let mut data = response.data().to_vec();
+            let mut sw = response.status_words();
+
+            while let StatusWords::BytesRemaining { .. } = sw {
+                let next = Response::from(
+                    txn.transmit(&Apdu::new(Ins::GetResponseApdu).to_bytes(), recv_len)?,
+                );
+                trace!("<<< {:?}", &next);
+                data.extend_from_slice(next.data());
+                sw = next.status_words();
+            }
+
+            response = Response::new(sw, data);
+        }
+
         Ok(response)
     }
 
@@ -195,6 +221,18 @@ pub enum Ins {
     /// Get device serial
     GetSerial,
 
+    /// Get slot metadata
+    GetMetadata,
+
+    /// Management // Read Config
+    ReadConfig,
+
+    /// Management // Write Config
+    WriteConfig,
+
+    /// Management // DeviceReset
+    DeviceReset,
+
     /// Other/unrecognized instruction codes
     Other(u8),
 }
@@ -219,6 +257,13 @@ impl Ins {
             Ins::SetPinRetries => 0xfa,
             Ins::Attest => 0xf9,
             Ins::GetSerial => 0xf8,
+            Ins::GetMetadata => 0xf7,
+
+            // Management
+            Ins::ReadConfig => 0x1d,
+            Ins::WriteConfig => 0x1c,
+            Ins::DeviceReset => 0x1f,
+
             Ins::Other(code) => code,
         }
     }
@@ -227,6 +272,11 @@ impl Ins {
 impl From<u8> for Ins {
     fn from(code: u8) -> Self {
         match code {
+            // Management
+            0x1d => Ins::ReadConfig,
+            0x1c => Ins::WriteConfig,
+            0x1f => Ins::DeviceReset,
+
             0x20 => Ins::Verify,
             0x24 => Ins::ChangeReference,
             0x2c => Ins::ResetRetry,
@@ -243,6 +293,7 @@ impl From<u8> for Ins {
             0xfa => Ins::SetPinRetries,
             0xf9 => Ins::Attest,
             0xf8 => Ins::GetSerial,
+            0xf7 => Ins::GetMetadata,
             code => Ins::Other(code),
         }
     }
@@ -313,7 +364,7 @@ impl From<Vec<u8>> for Response {
         }
 
         let sw = StatusWords::from(
-            (bytes[bytes.len() - 2] as u16) << 8 | (bytes[bytes.len() - 1] as u16),
+            ((bytes[bytes.len() - 2] as u16) << 8) | (bytes[bytes.len() - 1] as u16),
         );
 
         let len = bytes.len() - 2;
@@ -348,6 +399,12 @@ pub(crate) enum StatusWords {
     /// Successful execution
     Success,
 
+    /// The requested data was too large for the response, and there is data remaining.
+    BytesRemaining {
+        /// The number of bytes remaining, as indicated in the response.
+        len: u8,
+    },
+
     /// https://github.com/Yubico/yubikey-manager/blob/1f22620b623c6b345dd9f9193ec765a542dddc80/ykman/driver_ccid.py#L53
     NoInputDataError,
 
@@ -384,6 +441,9 @@ pub(crate) enum StatusWords {
     /// Not enough memory
     NoSpaceError,
 
+    /// Referenced data or reference data not found
+    ReferenceDataNotFoundError,
+
     //
     // Custom Yubico Status Word extensions
     //
@@ -405,8 +465,9 @@ impl StatusWords {
     pub fn code(self) -> u16 {
         match self {
             StatusWords::None => 0,
+            StatusWords::BytesRemaining { len } => 0x6100 | len as u16,
             StatusWords::NoInputDataError => 0x6285,
-            StatusWords::VerifyFailError { tries } => 0x63c0 & tries as u16,
+            StatusWords::VerifyFailError { tries } => 0x63c0 | tries as u16,
             StatusWords::WrongLengthError => 0x6700,
             StatusWords::SecurityStatusError => 0x6982,
             StatusWords::AuthBlockedError => 0x6983,
@@ -416,6 +477,7 @@ impl StatusWords {
             StatusWords::IncorrectParamError => 0x6a80,
             StatusWords::NotFoundError => 0x6a82,
             StatusWords::NoSpaceError => 0x6a84,
+            StatusWords::ReferenceDataNotFoundError => 0x6a88,
             StatusWords::IncorrectSlotError => 0x6b00,
             StatusWords::NotSupportedError => 0x6d00,
             StatusWords::CommandAbortedError => 0x6f00,
@@ -434,6 +496,9 @@ impl From<u16> for StatusWords {
     fn from(sw: u16) -> Self {
         match sw {
             0x0000 => StatusWords::None,
+            sw if sw & 0xff00 == 0x6100 => Self::BytesRemaining {
+                len: (sw & 0x00ff) as u8,
+            },
             0x6285 => StatusWords::NoInputDataError,
             sw if sw & 0xfff0 == 0x63c0 => StatusWords::VerifyFailError {
                 tries: (sw & 0x000f) as u8,
@@ -447,6 +512,7 @@ impl From<u16> for StatusWords {
             0x6a80 => StatusWords::IncorrectParamError,
             0x6a82 => StatusWords::NotFoundError,
             0x6a84 => StatusWords::NoSpaceError,
+            0x6a88 => StatusWords::ReferenceDataNotFoundError,
             0x6b00 => StatusWords::IncorrectSlotError,
             0x6d00 => StatusWords::NotSupportedError,
             0x6f00 => StatusWords::CommandAbortedError,
@@ -461,3 +527,40 @@ impl From<StatusWords> for u16 {
         sw.code()
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::StatusWords;
+
+    #[test]
+    fn status_words_round_trip() {
+        let round_trip = |sw: StatusWords| {
+            assert_eq!(StatusWords::from(sw.code()), sw);
+        };
+
+        round_trip(StatusWords::None);
+        round_trip(StatusWords::BytesRemaining { len: 1 });
+        round_trip(StatusWords::BytesRemaining { len: 10 });
+        round_trip(StatusWords::BytesRemaining { len: 0xFF });
+        round_trip(StatusWords::Success);
+        round_trip(StatusWords::NoInputDataError);
+        round_trip(StatusWords::VerifyFailError { tries: 0x0F });
+        round_trip(StatusWords::VerifyFailError { tries: 3 });
+        round_trip(StatusWords::VerifyFailError { tries: 2 });
+        round_trip(StatusWords::VerifyFailError { tries: 1 });
+        round_trip(StatusWords::VerifyFailError { tries: 0 });
+        round_trip(StatusWords::WrongLengthError);
+        round_trip(StatusWords::SecurityStatusError);
+        round_trip(StatusWords::AuthBlockedError);
+        round_trip(StatusWords::DataInvalidError);
+        round_trip(StatusWords::ConditionsNotSatisfiedError);
+        round_trip(StatusWords::CommandNotAllowedError);
+        round_trip(StatusWords::IncorrectParamError);
+        round_trip(StatusWords::NotFoundError);
+        round_trip(StatusWords::NoSpaceError);
+        round_trip(StatusWords::IncorrectSlotError);
+        round_trip(StatusWords::NotSupportedError);
+        round_trip(StatusWords::CommandAbortedError);
+        round_trip(StatusWords::Other(0x1337));
+    }
+}

src/cccid.rs

@@ -30,14 +30,10 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-use crate::{Error, Result, YubiKey};
-use rand_core::{OsRng, RngCore};
-use std::{
-    convert::TryInto,
-    fmt::{self, Debug, Display},
-    str,
-};
-use subtle_encoding::hex;
+use crate::{Result, YubiKey};
+use cipher::common::Generate;
+use rand_core::CryptoRng;
+use std::fmt::{self, Debug, Display};
 
 /// CCCID offset
 const CCC_ID_OFFS: usize = 9;
@@ -53,6 +49,7 @@ const OBJ_CAPABILITY: u32 = 0x005f_c107;
 ///  - 0xff == Manufacturer ID (dummy)
 ///  - 0x02 == Card type (javaCard)
 ///  - next 14 bytes: card ID
+#[allow(dead_code)]
 const CCC_TMPL: &[u8] = &[
     0xf0, 0x15, 0xa0, 0x00, 0x00, 0x01, 0x16, 0xff, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
     0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf1, 0x01, 0x21, 0xf2, 0x01, 0x21, 0xf3, 0x00, 0xf4,
@@ -70,17 +67,20 @@ impl CardId {
 
     /// Generate a random CCC Card ID
     pub fn generate() -> Self {
-        let mut id = [0u8; Self::BYTE_SIZE];
-        OsRng.fill_bytes(&mut id);
-        Self(id)
+        Self(Generate::generate())
+    }
+
+    /// Generate a random CCC Card ID from an [`Rng`]
+    pub fn generate_from_rng<R: CryptoRng + ?Sized>(rng: &mut R) -> Self {
+        Self(Generate::generate_from_rng(rng))
     }
 }
 
 /// Cardholder Capability Container (CCC) Identifier.
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
-pub struct Ccc(pub [u8; Self::BYTE_SIZE]);
+pub struct CccId(pub [u8; Self::BYTE_SIZE]);
 
-impl Ccc {
+impl CccId {
     /// CCC size in bytes
     pub const BYTE_SIZE: usize = 51;
 
@@ -95,17 +95,11 @@ impl Ccc {
     pub fn get(yubikey: &mut YubiKey) -> Result<Self> {
         let txn = yubikey.begin_transaction()?;
         let response = txn.fetch_object(OBJ_CAPABILITY)?;
-
-        if response.len() != CCC_TMPL.len() {
-            return Err(Error::GenericError);
-        }
-
-        Ok(Self(response[..Self::BYTE_SIZE].try_into().unwrap()))
+        Ok(response[..Self::BYTE_SIZE].try_into().map(Self)?)
     }
 
     /// Set Cardholder Capability Container (CCC) ID
     #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub fn set(&self, yubikey: &mut YubiKey) -> Result<()> {
         let mut buf = CCC_TMPL.to_vec();
         buf[0..self.0.len()].copy_from_slice(&self.0);
@@ -115,8 +109,14 @@ impl Ccc {
     }
 }
 
-impl Display for Ccc {
+impl AsRef<[u8]> for CccId {
+    fn as_ref(&self) -> &[u8] {
+        &self.0
+    }
+}
+
+impl Display for CccId {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.write_str(str::from_utf8(&hex::encode(&self.0[..])).unwrap())
+        f.write_str(&hex::upper::encode_string(self.as_ref()))
     }
 }

src/certificate.rs

@@ -33,73 +33,29 @@
 use crate::{
     consts::CB_OBJ_MAX,
     error::{Error, Result},
-    piv::{sign_data, AlgorithmId, SlotId},
+    piv::SlotId,
     serialization::*,
     transaction::Transaction,
     yubikey::YubiKey,
     Buffer,
 };
-use chrono::{DateTime, Utc};
-use elliptic_curve::sec1::EncodedPoint as EcPublicKey;
 use log::error;
-use num_bigint_dig::BigUint;
-use p256::NistP256;
-use p384::NistP384;
-use rsa::{PublicKeyParts, RSAPublicKey};
-use sha2::{Digest, Sha256};
-use std::convert::TryFrom;
-use std::fmt;
-use std::ops::DerefMut;
-use x509::{der::Oid, RelativeDistinguishedName};
-use x509_parser::{parse_x509_certificate, x509::SubjectPublicKeyInfo};
+use x509_cert::{
+    builder::{profile::BuilderProfile, Builder, CertificateBuilder},
+    der::{referenced::OwnedToRef, Decode, Encode},
+    name::Name,
+    serial_number::SerialNumber,
+    spki::{SubjectPublicKeyInfoOwned, SubjectPublicKeyInfoRef},
+    time::Validity,
+};
 use zeroize::Zeroizing;
 
-// TODO: Make these der_parser::oid::Oid constants when it has const fn support.
-const OID_RSA_ENCRYPTION: &str = "1.2.840.113549.1.1.1";
-const OID_EC_PUBLIC_KEY: &str = "1.2.840.10045.2.1";
-const OID_NIST_P256: &str = "1.2.840.10045.3.1.7";
-const OID_NIST_P384: &str = "1.3.132.0.34";
-
 const TAG_CERT: u8 = 0x70;
 const TAG_CERT_COMPRESS: u8 = 0x71;
 const TAG_CERT_LRC: u8 = 0xFE;
 
-/// A serial number for a [`Certificate`].
-#[derive(Clone, Debug)]
-pub struct Serial(BigUint);
-
-impl From<BigUint> for Serial {
-    fn from(num: BigUint) -> Serial {
-        Serial(num)
-    }
-}
-
-impl From<[u8; 20]> for Serial {
-    fn from(bytes: [u8; 20]) -> Serial {
-        Serial(BigUint::from_bytes_be(&bytes))
-    }
-}
-
-impl TryFrom<&[u8]> for Serial {
-    type Error = Error;
-
-    fn try_from(bytes: &[u8]) -> Result<Serial> {
-        if bytes.len() <= 20 {
-            Ok(Serial(BigUint::from_bytes_be(&bytes)))
-        } else {
-            Err(Error::ParseError)
-        }
-    }
-}
-
-impl Serial {
-    fn to_bytes(&self) -> Vec<u8> {
-        self.0.to_bytes_be()
-    }
-}
-
 /// Information about how a [`Certificate`] is stored within a YubiKey.
-#[derive(Clone, Copy, Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub enum CertInfo {
     /// The certificate is uncompressed.
     Uncompressed,
@@ -129,323 +85,42 @@ impl From<CertInfo> for u8 {
     }
 }
 
-impl x509::AlgorithmIdentifier for AlgorithmId {
-    type AlgorithmOid = &'static [u64];
-
-    fn algorithm(&self) -> Self::AlgorithmOid {
-        match self {
-            // RSA encryption
-            AlgorithmId::Rsa1024 | AlgorithmId::Rsa2048 => &[1, 2, 840, 113_549, 1, 1, 1],
-            // EC Public Key
-            AlgorithmId::EccP256 | AlgorithmId::EccP384 => &[1, 2, 840, 10045, 2, 1],
-        }
-    }
-
-    fn parameters<W: std::io::Write>(
-        &self,
-        w: cookie_factory::WriteContext<W>,
-    ) -> cookie_factory::GenResult<W> {
-        use x509::der::write::der_oid;
-
-        // From [RFC 5480](https://tools.ietf.org/html/rfc5480#section-2.1.1):
-        // ```text
-        // ECParameters ::= CHOICE {
-        //   namedCurve         OBJECT IDENTIFIER
-        //   -- implicitCurve   NULL
-        //   -- specifiedCurve  SpecifiedECDomain
-        // }
-        // ```
-        match self {
-            AlgorithmId::EccP256 => der_oid(&[1, 2, 840, 10045, 3, 1, 7][..])(w),
-            AlgorithmId::EccP384 => der_oid(&[1, 3, 132, 0, 34][..])(w),
-            _ => Ok(w),
-        }
-    }
-}
-
-/// Information about a public key within a [`Certificate`].
-#[derive(Clone, Eq, PartialEq)]
-pub enum PublicKeyInfo {
-    /// RSA keys
-    Rsa {
-        /// RSA algorithm
-        algorithm: AlgorithmId,
-
-        /// Public key
-        pubkey: RSAPublicKey,
-    },
-
-    /// EC P-256 keys
-    EcP256(EcPublicKey<NistP256>),
-
-    /// EC P-384 keys
-    EcP384(EcPublicKey<NistP384>),
-}
-
-impl fmt::Debug for PublicKeyInfo {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "PublicKeyInfo({:?})", self.algorithm())
-    }
-}
-
-impl PublicKeyInfo {
-    fn parse(subject_pki: &SubjectPublicKeyInfo<'_>) -> Result<Self> {
-        match subject_pki.algorithm.algorithm.to_string().as_str() {
-            OID_RSA_ENCRYPTION => {
-                let pubkey = read_pki::rsa_pubkey(subject_pki.subject_public_key.data)?;
-
-                Ok(PublicKeyInfo::Rsa {
-                    algorithm: match pubkey.n().bits() {
-                        1024 => AlgorithmId::Rsa1024,
-                        2048 => AlgorithmId::Rsa2048,
-                        _ => return Err(Error::AlgorithmError),
-                    },
-                    pubkey,
-                })
-            }
-            OID_EC_PUBLIC_KEY => {
-                let key_bytes = &subject_pki.subject_public_key.data;
-                let algorithm_parameters = subject_pki
-                    .algorithm
-                    .parameters
-                    .as_ref()
-                    .ok_or(Error::InvalidObject)?;
-
-                match read_pki::ec_parameters(algorithm_parameters)? {
-                    AlgorithmId::EccP256 => EcPublicKey::from_bytes(key_bytes)
-                        .map(PublicKeyInfo::EcP256)
-                        .map_err(|_| Error::InvalidObject),
-                    AlgorithmId::EccP384 => EcPublicKey::from_bytes(key_bytes)
-                        .map(PublicKeyInfo::EcP384)
-                        .map_err(|_| Error::InvalidObject),
-                    _ => Err(Error::AlgorithmError),
-                }
-            }
-            _ => Err(Error::InvalidObject),
-        }
-    }
-
-    /// Returns the algorithm that this public key can be used with.
-    pub fn algorithm(&self) -> AlgorithmId {
-        match self {
-            PublicKeyInfo::Rsa { algorithm, .. } => *algorithm,
-            PublicKeyInfo::EcP256(_) => AlgorithmId::EccP256,
-            PublicKeyInfo::EcP384(_) => AlgorithmId::EccP384,
-        }
-    }
-}
-
-impl x509::SubjectPublicKeyInfo for PublicKeyInfo {
-    type AlgorithmId = AlgorithmId;
-    type SubjectPublicKey = Vec<u8>;
-
-    fn algorithm_id(&self) -> AlgorithmId {
-        self.algorithm()
-    }
-
-    fn public_key(&self) -> Vec<u8> {
-        match self {
-            PublicKeyInfo::Rsa { pubkey, .. } => {
-                cookie_factory::gen_simple(write_pki::rsa_pubkey(pubkey), vec![])
-                    .expect("can write to Vec")
-            }
-            PublicKeyInfo::EcP256(pubkey) => pubkey.as_bytes().to_vec(),
-            PublicKeyInfo::EcP384(pubkey) => pubkey.as_bytes().to_vec(),
-        }
-    }
-}
-
-/// Digest algorithms.
-///
-/// See RFC 4055 and RFC 8017.
-enum DigestId {
-    /// Secure Hash Algorithm 256 (SHA256)
-    Sha256,
-}
-
-impl x509::AlgorithmIdentifier for DigestId {
-    type AlgorithmOid = &'static [u64];
-
-    fn algorithm(&self) -> Self::AlgorithmOid {
-        match self {
-            // See https://tools.ietf.org/html/rfc4055#section-2.1
-            DigestId::Sha256 => &[2, 16, 840, 1, 101, 3, 4, 2, 1],
-        }
-    }
-
-    fn parameters<W: std::io::Write>(
-        &self,
-        w: cookie_factory::WriteContext<W>,
-    ) -> cookie_factory::GenResult<W> {
-        // Parameters are an explicit NULL
-        // See https://tools.ietf.org/html/rfc8017#appendix-A.2.4
-        x509::der::write::der_null()(w)
-    }
-}
-
-enum SignatureId {
-    /// Public-Key Cryptography Standards (PKCS) #1 version 1.5 signature algorithm with
-    /// Secure Hash Algorithm 256 (SHA256) and Rivest, Shamir and Adleman (RSA) encryption
-    ///
-    /// See RFC 4055 and RFC 8017.
-    Sha256WithRsaEncryption,
-
-    /// Elliptic Curve Digital Signature Algorithm (DSA) coupled with the Secure Hash
-    /// Algorithm 256 (SHA256) algorithm
-    ///
-    /// See RFC 5758.
-    EcdsaWithSha256,
-}
-
-impl x509::AlgorithmIdentifier for SignatureId {
-    type AlgorithmOid = &'static [u64];
-
-    fn algorithm(&self) -> Self::AlgorithmOid {
-        match self {
-            SignatureId::Sha256WithRsaEncryption => &[1, 2, 840, 113_549, 1, 1, 11],
-            SignatureId::EcdsaWithSha256 => &[1, 2, 840, 10045, 4, 3, 2],
-        }
-    }
-
-    fn parameters<W: std::io::Write>(
-        &self,
-        w: cookie_factory::WriteContext<W>,
-    ) -> cookie_factory::GenResult<W> {
-        // No parameters for any SignatureId
-        Ok(w)
-    }
-}
-
 /// Certificates
 #[derive(Clone, Debug)]
 pub struct Certificate {
-    serial: Serial,
-    issuer: String,
-    subject: String,
-    subject_pki: PublicKeyInfo,
-    data: Buffer,
-}
-
-impl<'a> TryFrom<&'a [u8]> for Certificate {
-    type Error = Error;
-
-    fn try_from(bytes: &'a [u8]) -> Result<Self> {
-        Self::from_bytes(bytes.to_vec())
-    }
+    /// Inner certificate
+    pub cert: x509_cert::Certificate,
 }
 
 impl Certificate {
     /// Creates a new self-signed certificate for the given key. Writes the resulting
     /// certificate to the slot before returning it.
     ///
-    /// `extensions` is optional; if empty, no extensions will be included. Due to the
-    /// need for an `O: Oid` type parameter, users who do not have any extensions should
-    /// use the workaround `let extensions: &[x509::Extension<'_, &[u64]>] = &[];`.
-    pub fn generate_self_signed<O: Oid>(
+    /// `extensions` is a required argument; users who do not have any extensions
+    /// should set the `extensions` argument to `|_| Ok(())`.
+    pub fn generate_self_signed<F, KT: yubikey_signer::KeyType>(
         yubikey: &mut YubiKey,
         key: SlotId,
-        serial: impl Into<Serial>,
-        not_after: Option<DateTime<Utc>>,
-        subject: &[RelativeDistinguishedName<'_>],
-        subject_pki: PublicKeyInfo,
-        extensions: &[x509::Extension<'_, O>],
-    ) -> Result<Self> {
-        let serial = serial.into();
+        serial: SerialNumber,
+        validity: Validity,
+        subject: Name,
+        subject_pki: SubjectPublicKeyInfoOwned,
+        extensions: F,
+    ) -> Result<Self>
+    where
+        F: FnOnce(&mut CertificateBuilder<SelfSigned>) -> der::Result<()>,
+    {
+        let signer =
+            yubikey_signer::Signer::<'_, KT>::new(yubikey, key, subject_pki.owned_to_ref())?;
+        let mut builder =
+            CertificateBuilder::new(SelfSigned { subject }, serial, validity, subject_pki)
+                .map_err(|_| Error::KeyError)?;
 
-        let mut tbs_cert = Buffer::new(Vec::with_capacity(CB_OBJ_MAX));
-
-        let signature_algorithm = match subject_pki.algorithm() {
-            AlgorithmId::Rsa1024 | AlgorithmId::Rsa2048 => SignatureId::Sha256WithRsaEncryption,
-            AlgorithmId::EccP256 | AlgorithmId::EccP384 => SignatureId::EcdsaWithSha256,
-        };
-
-        cookie_factory::gen(
-            x509::write::tbs_certificate(
-                &serial.to_bytes(),
-                &signature_algorithm,
-                // Issuer and subject are the same in self-signed certificates.
-                &subject,
-                Utc::now(),
-                not_after,
-                &subject,
-                &subject_pki,
-                &extensions,
-            ),
-            tbs_cert.deref_mut(),
-        )
-        .expect("can serialize to Vec");
-
-        let signature = match signature_algorithm {
-            SignatureId::Sha256WithRsaEncryption => {
-                use cookie_factory::{combinator::slice, sequence::tuple};
-                use x509::{
-                    der::write::{der_octet_string, der_sequence},
-                    write::algorithm_identifier,
-                };
-
-                let em_len = if let AlgorithmId::Rsa1024 = subject_pki.algorithm() {
-                    128
-                } else {
-                    256
-                };
-
-                let h = Sha256::digest(&tbs_cert);
-
-                let t = cookie_factory::gen_simple(
-                    der_sequence((
-                        algorithm_identifier(&DigestId::Sha256),
-                        der_octet_string(&h),
-                    )),
-                    vec![],
-                )
-                .expect("can serialize into Vec");
-
-                let em = cookie_factory::gen_simple(
-                    tuple((
-                        slice(&[0x00, 0x01]),
-                        slice(&vec![0xff; em_len - t.len() - 3]),
-                        slice(&[0x00]),
-                        slice(t),
-                    )),
-                    vec![],
-                )
-                .expect("can serialize to Vec");
-
-                sign_data(yubikey, &em, subject_pki.algorithm(), key)
-            }
-            SignatureId::EcdsaWithSha256 => sign_data(
-                yubikey,
-                &Sha256::digest(&tbs_cert),
-                subject_pki.algorithm(),
-                key,
-            ),
-        }?;
-
-        let mut data = Buffer::new(Vec::with_capacity(CB_OBJ_MAX));
-
-        cookie_factory::gen(
-            x509::write::certificate(&tbs_cert, &signature_algorithm, &signature),
-            data.deref_mut(),
-        )
-        .expect("can serialize to Vec");
-
-        let (issuer, subject) = parse_x509_certificate(&data)
-            .map(|(_, cert)| {
-                (
-                    cert.tbs_certificate.issuer.to_string(),
-                    cert.tbs_certificate.subject.to_string(),
-                )
-            })
-            .expect("We just serialized this correctly");
-
-        let cert = Certificate {
-            serial,
-            issuer,
-            subject,
-            subject_pki,
-            data,
-        };
+        // Add custom extensions
+        extensions(&mut builder)?;
 
+        let cert = builder.build(&signer).map_err(|_| Error::KeyError)?;
+        let cert = Self { cert };
         cert.write(yubikey, key, CertInfo::Uncompressed)?;
 
         Ok(cert)
@@ -460,18 +135,18 @@ impl Certificate {
             return Err(Error::InvalidObject);
         }
 
-        Certificate::from_bytes(buf)
+        Self::from_bytes(buf)
     }
 
     /// Write this certificate into the YubiKey in the given slot
     pub fn write(&self, yubikey: &mut YubiKey, slot: SlotId, certinfo: CertInfo) -> Result<()> {
         let txn = yubikey.begin_transaction()?;
-        write_certificate(&txn, slot, Some(&self.data), certinfo)
+        let data = self.cert.to_der().map_err(|_| Error::InvalidObject)?;
+        write_certificate(&txn, slot, Some(&data), certinfo)
     }
 
     /// Delete a certificate located at the given slot of the given YubiKey
     #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub fn delete(yubikey: &mut YubiKey, slot: SlotId) -> Result<()> {
         let txn = yubikey.begin_transaction()?;
         write_certificate(&txn, slot, None, CertInfo::Uncompressed)
@@ -486,55 +161,59 @@ impl Certificate {
             return Err(Error::SizeError);
         }
 
-        let parsed_cert = match parse_x509_certificate(&cert) {
-            Ok((_, cert)) => cert,
-            _ => return Err(Error::InvalidObject),
-        };
-
-        let serial = Serial::try_from(parsed_cert.tbs_certificate.serial.to_bytes_be().as_slice())
-            .map_err(|_| Error::InvalidObject)?;
-        let issuer = parsed_cert.tbs_certificate.issuer.to_string();
-        let subject = parsed_cert.tbs_certificate.subject.to_string();
-        let subject_pki = PublicKeyInfo::parse(&parsed_cert.tbs_certificate.subject_pki)?;
-
-        Ok(Certificate {
-            serial,
-            issuer,
-            subject,
-            subject_pki,
-            data: cert,
-        })
-    }
-
-    /// Returns the serial number of the certificate.
-    pub fn serial(&self) -> &Serial {
-        &self.serial
+        x509_cert::Certificate::from_der(&cert)
+            .map(|cert| Self { cert })
+            .map_err(|_| Error::InvalidObject)
     }
 
     /// Returns the Issuer field of the certificate.
-    pub fn issuer(&self) -> &str {
-        &self.subject
+    pub fn issuer(&self) -> String {
+        self.cert.tbs_certificate().issuer().to_string()
     }
 
     /// Returns the SubjectName field of the certificate.
-    pub fn subject(&self) -> &str {
-        &self.subject
+    pub fn subject(&self) -> String {
+        self.cert.tbs_certificate().subject().to_string()
     }
 
     /// Returns the SubjectPublicKeyInfo field of the certificate.
-    pub fn subject_pki(&self) -> &PublicKeyInfo {
-        &self.subject_pki
-    }
-
-    /// Extract the inner buffer
-    pub fn into_buffer(self) -> Buffer {
-        self.data
+    pub fn subject_pki(&self) -> SubjectPublicKeyInfoRef<'_> {
+        self.cert
+            .tbs_certificate()
+            .subject_public_key_info()
+            .owned_to_ref()
     }
 }
 
-impl AsRef<[u8]> for Certificate {
-    fn as_ref(&self) -> &[u8] {
-        self.data.as_ref()
+/// A [`BuilderProfile`] for self-signed certificates.
+///
+/// This profile has no default extensions.
+pub struct SelfSigned {
+    subject: Name,
+}
+
+impl BuilderProfile for SelfSigned {
+    fn get_issuer(&self, subject: &Name) -> Name {
+        // RFC 5280 Section 3.2:
+        //
+        // > Self-issued certificates are CA certificates in which the issuer and subject
+        // > are the same entity. [..] Self-signed certificates are self-issued
+        // > certificates where the digital signature may be verified by the public key
+        // > bound into the certificate.
+        subject.clone()
+    }
+
+    fn get_subject(&self) -> Name {
+        self.subject.clone()
+    }
+
+    fn build_extensions(
+        &self,
+        _spk: SubjectPublicKeyInfoRef<'_>,
+        _issuer_spk: SubjectPublicKeyInfoRef<'_>,
+        _tbs: &x509_cert::TbsCertificate,
+    ) -> x509_cert::builder::Result<Vec<x509_cert::ext::Extension>> {
+        Ok(vec![])
     }
 }
 
@@ -570,12 +249,7 @@ pub(crate) fn write_certificate(
 ) -> Result<()> {
     let object_id = slot.object_id();
 
-    if data.is_none() {
-        return txn.save_object(object_id, &[]);
-    }
-
-    let data = data.unwrap();
-
+    if let Some(data) = data {
         let mut buf = [0u8; CB_OBJ_MAX];
         let mut offset = Tlv::write(&mut buf, TAG_CERT, data)?;
 
@@ -584,102 +258,291 @@ pub(crate) fn write_certificate(
         offset += Tlv::write(&mut buf[offset..], TAG_CERT_LRC, &[])?;
 
         txn.save_object(object_id, &buf[..offset])
+    } else {
+        txn.save_object(object_id, &[])
+    }
 }
 
-mod read_pki {
-    use der_parser::{
-        ber::BerObjectContent,
-        der::{parse_der_integer, DerObject},
-        error::BerError,
-        *,
+pub mod yubikey_signer {
+    //! Signer implementation for yubikey
+
+    use crate::{
+        error::{Error, Result},
+        piv::AlgorithmId,
+        piv::{sign_data, SlotId},
+        YubiKey,
     };
-    use nom::{combinator, IResult};
-    use rsa::{BigUint, RSAPublicKey};
-
-    use super::{OID_NIST_P256, OID_NIST_P384};
-    use crate::{piv::AlgorithmId, Error, Result};
-
-    /// From [RFC 8017](https://tools.ietf.org/html/rfc8017#appendix-A.1.1):
-    /// ```text
-    /// RSAPublicKey ::= SEQUENCE {
-    ///     modulus           INTEGER,  -- n
-    ///     publicExponent    INTEGER   -- e
-    /// }
-    /// ```
-    pub(super) fn rsa_pubkey(encoded: &[u8]) -> Result<RSAPublicKey> {
-        fn parse_rsa_pubkey(i: &[u8]) -> IResult<&[u8], DerObject<'_>, BerError> {
-            parse_der_sequence_defined!(i, parse_der_integer >> parse_der_integer)
-        }
-
-        fn rsa_pubkey_parts(i: &[u8]) -> IResult<&[u8], (BigUint, BigUint), BerError> {
-            combinator::map(parse_rsa_pubkey, |object| {
-                let seq = object.as_sequence().expect("is DER sequence");
-                assert_eq!(seq.len(), 2);
-
-                let n = match seq[0].content {
-                    BerObjectContent::Integer(s) => BigUint::from_bytes_be(s),
-                    _ => panic!("expected DER integer"),
+    use der::{
+        asn1::{Any, OctetString},
+        oid::db::rfc5912,
+        Encode, Sequence,
     };
-                let e = match seq[1].content {
-                    BerObjectContent::Integer(s) => BigUint::from_bytes_be(s),
-                    _ => panic!("expected DER integer"),
+    use sha2::{Digest, Sha256, Sha384, Sha512};
+    use signature::Keypair;
+    use std::{cell::RefCell, fmt, io::Write, marker::PhantomData};
+    use x509_cert::spki::{
+        self, AlgorithmIdentifierOwned, DynSignatureAlgorithmIdentifier, EncodePublicKey,
+        SignatureBitStringEncoding, SubjectPublicKeyInfoRef,
     };
 
-                (n, e)
-            })(i)
+    type SigResult<T> = core::result::Result<T, signature::Error>;
+
+    /// Key to be used to sign certificates
+    pub trait KeyType {
+        /// Error returned when working with signature
+        type Error: Into<signature::Error> + fmt::Debug;
+        /// The signature type returned by the signer
+        type Signature: SignatureBitStringEncoding
+            + for<'s> TryFrom<&'s [u8], Error = Self::Error>
+            + fmt::Debug;
+        /// The public key used to verify signature
+        type VerifyingKey: EncodePublicKey
+            + DynSignatureAlgorithmIdentifier
+            + Clone
+            + From<Self::PublicKey>;
+        /// Public key type used to load the SPKI formatted key
+        type PublicKey: for<'a> TryFrom<SubjectPublicKeyInfoRef<'a>, Error = spki::Error>;
+
+        /// The algorithm used when talking with the yubikey
+        const ALGORITHM: AlgorithmId;
+
+        /// Prepare buffer before submitting it for signature
+        fn prepare(input: &[u8]) -> SigResult<Vec<u8>>;
+
+        /// Prepare a prehashed message before submitting it for signature
+        fn prepare_prehash(hashed: &[u8]) -> SigResult<Vec<u8>>;
+
+        /// Read back the signature from the device
+        fn read_signature(input: &[u8]) -> SigResult<Self::Signature>;
     }
 
-        let (n, e) = match rsa_pubkey_parts(encoded) {
-            Ok((_, res)) => res,
-            _ => return Err(Error::InvalidObject),
+    impl KeyType for ed25519_dalek::SigningKey {
+        const ALGORITHM: AlgorithmId = AlgorithmId::Ed25519;
+        type Error = ed25519_dalek::SignatureError;
+        type Signature = ed25519_dalek::Signature;
+        type VerifyingKey = ed25519_dalek::VerifyingKey;
+        type PublicKey = ed25519_dalek::VerifyingKey;
+
+        fn prepare(input: &[u8]) -> SigResult<Vec<u8>> {
+            Ok(Sha512::digest(input).to_vec())
+        }
+
+        fn read_signature(input: &[u8]) -> SigResult<Self::Signature> {
+            Self::Signature::try_from(input)
+        }
+    }
+
+    impl KeyType for p256::NistP256 {
+        const ALGORITHM: AlgorithmId = AlgorithmId::EccP256;
+        type Error = ecdsa::Error;
+        type Signature = p256::ecdsa::DerSignature;
+        type VerifyingKey = p256::ecdsa::VerifyingKey;
+        type PublicKey = p256::ecdsa::VerifyingKey;
+
+        fn prepare(input: &[u8]) -> SigResult<Vec<u8>> {
+            Ok(Sha256::digest(input).to_vec())
+        }
+
+        fn prepare_prehash(hashed: &[u8]) -> SigResult<Vec<u8>> {
+            Ok(hashed.to_vec())
+        }
+
+        fn read_signature(input: &[u8]) -> SigResult<Self::Signature> {
+            Self::Signature::from_bytes(input)
+        }
+    }
+
+    impl KeyType for p384::NistP384 {
+        const ALGORITHM: AlgorithmId = AlgorithmId::EccP384;
+        type Error = ecdsa::Error;
+        type Signature = p384::ecdsa::DerSignature;
+        type VerifyingKey = p384::ecdsa::VerifyingKey;
+        type PublicKey = p384::ecdsa::VerifyingKey;
+
+        fn prepare(input: &[u8]) -> SigResult<Vec<u8>> {
+            Ok(Sha384::digest(input).to_vec())
+        }
+
+        fn prepare_prehash(hashed: &[u8]) -> SigResult<Vec<u8>> {
+            Ok(hashed.to_vec())
+        }
+
+        fn read_signature(input: &[u8]) -> SigResult<Self::Signature> {
+            Self::Signature::from_bytes(input)
+        }
+    }
+
+    /// Trait used to handle subtypes of RSA keys
+    pub trait RsaLength {
+        /// The length of the RSA key in bits
+        const BIT_LENGTH: usize;
+        /// The algorithm to use when talking with the Yubikey.
+        const ALGORITHM: AlgorithmId;
+    }
+
+    /// RSA 1024 bits key
+    pub struct Rsa1024;
+
+    impl RsaLength for Rsa1024 {
+        const BIT_LENGTH: usize = 1024;
+        const ALGORITHM: AlgorithmId = AlgorithmId::Rsa1024;
+    }
+
+    /// RSA 2048 bits key
+    pub struct Rsa2048;
+
+    impl RsaLength for Rsa2048 {
+        const BIT_LENGTH: usize = 2048;
+        const ALGORITHM: AlgorithmId = AlgorithmId::Rsa2048;
+    }
+
+    /// RSA 3072 bits key
+    pub struct Rsa3072;
+
+    impl RsaLength for Rsa3072 {
+        const BIT_LENGTH: usize = 3072;
+        const ALGORITHM: AlgorithmId = AlgorithmId::Rsa3072;
+    }
+
+    /// RSA 4096 bits key
+    pub struct Rsa4096;
+
+    impl RsaLength for Rsa4096 {
+        const BIT_LENGTH: usize = 4096;
+        const ALGORITHM: AlgorithmId = AlgorithmId::Rsa4096;
+    }
+
+    /// RSA keys used to sign certificates
+    pub struct YubiRsa<N: RsaLength> {
+        _len: PhantomData<N>,
+    }
+
+    impl<N: RsaLength> KeyType for YubiRsa<N> {
+        type Error = signature::Error;
+        type Signature = rsa::pkcs1v15::Signature;
+        type VerifyingKey = rsa::pkcs1v15::VerifyingKey<Sha256>;
+        type PublicKey = rsa::RsaPublicKey;
+        const ALGORITHM: AlgorithmId = N::ALGORITHM;
+
+        fn prepare(input: &[u8]) -> SigResult<Vec<u8>> {
+            let hashed = Sha256::digest(input).to_vec();
+            Self::prepare_prehash(&hashed)
+        }
+
+        fn prepare_prehash(hashed: &[u8]) -> SigResult<Vec<u8>> {
+            OctetString::new(hashed)
+                .map_err(|e| e.into())
+                .and_then(Self::emsa_pkcs1_1_5)
+                .map_err(signature::Error::from_source)
+        }
+
+        fn read_signature(input: &[u8]) -> SigResult<Self::Signature> {
+            Self::Signature::try_from(input)
+        }
+    }
+
+    impl<N: RsaLength> YubiRsa<N> {
+        /// https://www.rfc-editor.org/rfc/rfc8017#section-9.2
+        fn emsa_pkcs1_1_5(digest: OctetString) -> Result<Vec<u8>> {
+            /// https://www.rfc-editor.org/rfc/rfc8017#appendix-A.2.4
+            #[derive(Debug, Sequence)]
+            struct DigestInfo {
+                digest_algorithm: AlgorithmIdentifierOwned,
+                digest: OctetString,
+            }
+
+            let em_len = N::BIT_LENGTH / 8;
+
+            let null = Any::null();
+
+            let t = DigestInfo {
+                digest_algorithm: AlgorithmIdentifierOwned {
+                    oid: rfc5912::ID_SHA_256,
+                    parameters: Some(null),
+                },
+                digest,
             };
+            let t = t.to_der()?;
 
-        RSAPublicKey::new(n, e).map_err(|_| Error::InvalidObject)
-    }
+            let ps = vec![0xff; em_len - t.len() - 3];
+            assert!(ps.len() >= 8, "spec violation");
 
-    /// From [RFC 5480](https://tools.ietf.org/html/rfc5480#section-2.1.1):
-    /// ```text
-    /// ECParameters ::= CHOICE {
-    ///   namedCurve         OBJECT IDENTIFIER
-    ///   -- implicitCurve   NULL
-    ///   -- specifiedCurve  SpecifiedECDomain
-    /// }
-    /// ```
-    pub(super) fn ec_parameters(parameters: &DerObject<'_>) -> Result<AlgorithmId> {
-        let curve_oid = parameters.as_oid_val().map_err(|_| Error::InvalidObject)?;
-
-        match curve_oid.to_string().as_str() {
-            OID_NIST_P256 => Ok(AlgorithmId::EccP256),
-            OID_NIST_P384 => Ok(AlgorithmId::EccP384),
-            _ => Err(Error::AlgorithmError),
-        }
+            let mut out = Vec::with_capacity(em_len);
+            out.write(&[0x00, 0x01]).map_err(|_| Error::MemoryError)?;
+            out.write(&ps).map_err(|_| Error::MemoryError)?;
+            out.write(&[0x00]).map_err(|_| Error::MemoryError)?;
+            out.write(&t).map_err(|_| Error::MemoryError)?;
+            Ok(out)
         }
     }
 
-mod write_pki {
-    use cookie_factory::{SerializeFn, WriteContext};
-    use rsa::{BigUint, PublicKeyParts, RSAPublicKey};
-    use std::io::Write;
-    use x509::der::write::{der_integer, der_sequence};
-
-    /// Encodes a usize as an ASN.1 integer using DER.
-    fn der_integer_biguint<'a, W: Write + 'a>(num: &'a BigUint) -> impl SerializeFn<W> + 'a {
-        move |w: WriteContext<W>| der_integer(&num.to_bytes_be())(w)
+    /// The entrypoint to sign data with the yubikey.
+    pub struct Signer<'y, KT: KeyType> {
+        yubikey: RefCell<&'y mut YubiKey>,
+        key: SlotId,
+        public_key: KT::VerifyingKey,
     }
 
-    /// From [RFC 8017](https://tools.ietf.org/html/rfc8017#appendix-A.1.1):
-    /// ```text
-    /// RSAPublicKey ::= SEQUENCE {
-    ///     modulus           INTEGER,  -- n
-    ///     publicExponent    INTEGER   -- e
-    /// }
-    /// ```
-    pub(super) fn rsa_pubkey<'a, W: Write + 'a>(
-        pubkey: &'a RSAPublicKey,
-    ) -> impl SerializeFn<W> + 'a {
-        der_sequence((
-            der_integer_biguint(pubkey.n()),
-            der_integer_biguint(pubkey.e()),
-        ))
+    impl<'y, KT: KeyType> Signer<'y, KT> {
+        /// Create new Signer
+        pub fn new(
+            yubikey: &'y mut YubiKey,
+            key: SlotId,
+            subject_pki: SubjectPublicKeyInfoRef<'_>,
+        ) -> Result<Self> {
+            let public_key = KT::PublicKey::try_from(subject_pki).map_err(|_| Error::ParseError)?;
+            let public_key = public_key.into();
+
+            Ok(Self {
+                yubikey: RefCell::new(yubikey),
+                key,
+                public_key,
+            })
+        }
+    }
+
+    impl<KT: KeyType> Keypair for Signer<'_, KT> {
+        type VerifyingKey = KT::VerifyingKey;
+        fn verifying_key(&self) -> <Self as Keypair>::VerifyingKey {
+            self.public_key.clone()
+        }
+    }
+
+    impl<KT: KeyType> DynSignatureAlgorithmIdentifier for Signer<'_, KT> {
+        fn signature_algorithm_identifier(&self) -> spki::Result<AlgorithmIdentifierOwned> {
+            self.verifying_key().signature_algorithm_identifier()
+        }
+    }
+
+    impl<KT: KeyType> signature::Signer<KT::Signature> for Signer<'_, KT> {
+        fn try_sign(&self, msg: &[u8]) -> SigResult<KT::Signature> {
+            let data = KT::prepare(msg)?;
+
+            let out = sign_data(
+                &mut self.yubikey.borrow_mut(),
+                &data,
+                KT::ALGORITHM,
+                self.key,
+            )
+            .map_err(signature::Error::from_source)?;
+            let out = KT::read_signature(&out)?;
+            Ok(out)
+        }
+    }
+
+    impl<KT: KeyType> signature::hazmat::PrehashSigner<KT::Signature> for Signer<'_, KT> {
+        fn sign_prehash(&self, hashed: &[u8]) -> SigResult<KT::Signature> {
+            let data = KT::prepare_prehash(hashed)?;
+
+            let out = sign_data(
+                &mut self.yubikey.borrow_mut(),
+                &data,
+                KT::ALGORITHM,
+                self.key,
+            )
+            .map_err(signature::Error::from_source)?;
+            let out = KT::read_signature(&out)?;
+            Ok(out)
+        }
     }
 }

src/chuid.rs

@@ -30,13 +30,8 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-use crate::{Error, Result, YubiKey};
-use std::{
-    convert::TryInto,
-    fmt::{self, Debug, Display},
-    str,
-};
-use subtle_encoding::hex;
+use crate::{Result, YubiKey};
+use std::fmt::{self, Debug, Display};
 use uuid::Uuid;
 
 /// FASC-N offset
@@ -66,6 +61,7 @@ const OBJ_CHUID: u32 = 0x005f_c102;
 /// - 0x35: Exp. Date (hard-coded)
 /// - 0x3e: Signature (hard-coded, empty)
 /// - 0xfe: Error Detection Code (hard-coded)
+#[allow(dead_code)]
 const CHUID_TMPL: &[u8] = &[
     0x30, 0x19, 0xd4, 0xe7, 0x39, 0xda, 0x73, 0x9c, 0xed, 0x39, 0xce, 0x73, 0x9d, 0x83, 0x68, 0x58,
     0x21, 0x08, 0x42, 0x10, 0x84, 0x21, 0xc8, 0x42, 0x10, 0xc3, 0xeb, 0x34, 0x10, 0x00, 0x00, 0x00,
@@ -91,12 +87,13 @@ impl ChuId {
     pub fn fascn(&self) -> [u8; Self::FASCN_SIZE] {
         self.0[CHUID_FASCN_OFFS..(CHUID_FASCN_OFFS + Self::FASCN_SIZE)]
             .try_into()
-            .unwrap()
+            .expect("should be FASCN_SIZE")
     }
 
     /// Return Card UUID/GUID component of CHUID
     pub fn uuid(&self) -> Uuid {
-        Uuid::from_slice(&self.0[CHUID_GUID_OFFS..(CHUID_GUID_OFFS + 16)]).unwrap()
+        Uuid::from_slice(&self.0[CHUID_GUID_OFFS..(CHUID_GUID_OFFS + 16)])
+            .expect("should be UUID-sized")
     }
 
     /// Return expiration date component of CHUID
@@ -104,24 +101,18 @@ impl ChuId {
     pub fn expiration(&self) -> [u8; Self::EXPIRATION_SIZE] {
         self.0[CHUID_EXPIRATION_OFFS..(CHUID_EXPIRATION_OFFS + Self::EXPIRATION_SIZE)]
             .try_into()
-            .unwrap()
+            .expect("should be EXPIRATION_SIZE")
     }
 
     /// Get Cardholder Unique Identifier (CHUID)
     pub fn get(yubikey: &mut YubiKey) -> Result<ChuId> {
         let txn = yubikey.begin_transaction()?;
         let response = txn.fetch_object(OBJ_CHUID)?;
-
-        if response.len() != CHUID_TMPL.len() {
-            return Err(Error::GenericError);
-        }
-
-        Ok(ChuId(response[..Self::BYTE_SIZE].try_into().unwrap()))
+        Ok(response[..Self::BYTE_SIZE].try_into().map(Self)?)
     }
 
     /// Set Cardholder Unique Identifier (CHUID)
     #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub fn set(&self, yubikey: &mut YubiKey) -> Result<()> {
         let mut buf = CHUID_TMPL.to_vec();
         buf[..Self::BYTE_SIZE].copy_from_slice(&self.0);
@@ -131,8 +122,14 @@ impl ChuId {
     }
 }
 
+impl AsRef<[u8]> for ChuId {
+    fn as_ref(&self) -> &[u8] {
+        &self.0
+    }
+}
+
 impl Display for ChuId {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.write_str(str::from_utf8(&hex::encode(&self.0[..])).unwrap())
+        f.write_str(&hex::upper::encode_string(self.as_ref()))
     }
 }

src/config.rs

@@ -41,10 +41,7 @@ use crate::{
     Result,
 };
 use log::error;
-use std::{
-    convert::TryInto,
-    time::{Duration, SystemTime, UNIX_EPOCH},
-};
+use std::time::{Duration, SystemTime, UNIX_EPOCH};
 
 const CB_ADMIN_TIMESTAMP: usize = 0x04;
 const PROTECTED_FLAGS_1_PUK_NOBLOCK: u8 = 0x01;
@@ -114,7 +111,7 @@ impl Config {
                     error!("pin timestamp in admin metadata is an invalid size");
                 } else {
                     // TODO(tarcieri): double-check endianness is correct
-                    let pin_last_changed = u32::from_le_bytes(item.try_into().unwrap());
+                    let pin_last_changed = u32::from_le_bytes([item[0], item[1], item[2], item[3]]);
 
                     if pin_last_changed != 0 {
                         config.pin_last_changed =

src/consts.rs

@@ -1,5 +1,7 @@
 //! Miscellaneous constant values
 
+#![allow(dead_code)]
+
 /// YubiKey max buffer size
 pub(crate) const CB_BUF_MAX: usize = 3072;
 
@@ -7,7 +9,6 @@ pub(crate) const CB_BUF_MAX: usize = 3072;
 pub(crate) const CB_OBJ_MAX: usize = CB_BUF_MAX - 9;
 
 pub(crate) const CB_OBJ_TAG_MIN: usize = 2; // 1 byte tag + 1 byte len
-#[cfg(feature = "untested")]
 pub(crate) const CB_OBJ_TAG_MAX: usize = CB_OBJ_TAG_MIN + 2; // 1 byte tag + 3 bytes len
 
 // Admin tags
@@ -18,3 +19,19 @@ pub(crate) const TAG_ADMIN_TIMESTAMP: u8 = 0x83;
 // Protected tags
 pub(crate) const TAG_PROTECTED_FLAGS_1: u8 = 0x81;
 pub(crate) const TAG_PROTECTED_MGM: u8 = 0x89;
+
+// Management
+pub(crate) const TAG_USB_SUPPORTED: u8 = 0x01;
+pub(crate) const TAG_SERIAL: u8 = 0x02;
+pub(crate) const TAG_USB_ENABLED: u8 = 0x03;
+pub(crate) const TAG_FORM_FACTOR: u8 = 0x04;
+pub(crate) const TAG_VERSION: u8 = 0x05;
+pub(crate) const TAG_AUTO_EJECT_TIMEOUT: u8 = 0x06;
+pub(crate) const TAG_CHALRESP_TIMEOUT: u8 = 0x07;
+pub(crate) const TAG_DEVICE_FLAGS: u8 = 0x08;
+pub(crate) const TAG_APP_VERSIONS: u8 = 0x09;
+pub(crate) const TAG_CONFIG_LOCK: u8 = 0x0A;
+pub(crate) const TAG_UNLOCK: u8 = 0x0B;
+pub(crate) const TAG_REBOOT: u8 = 0x0C;
+pub(crate) const TAG_NFC_SUPPORTED: u8 = 0x0D;
+pub(crate) const TAG_NFC_ENABLED: u8 = 0x0E;

src/error.rs

@@ -45,12 +45,21 @@ pub enum Error {
     /// Applet error
     AppletError,
 
+    /// We tried to select an applet that could not be found.
+    AppletNotFound {
+        /// Human-readable name of the applet.
+        applet_name: &'static str,
+    },
+
     /// Argument error
     ArgumentError,
 
     /// Authentication error
     AuthenticationError,
 
+    /// Error while building a certificate
+    CertificateBuilder,
+
     /// Generic error
     GenericError,
 
@@ -121,31 +130,53 @@ impl Error {
     }
 
     /// Error message
-    pub fn msg(self) -> &'static str {
+    pub fn msg(self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         match self {
-            Error::AlgorithmError => "algorithm error",
-            Error::AppletError => "applet error",
-            Error::ArgumentError => "argument error",
-            Error::AuthenticationError => "authentication error",
-            Error::GenericError => "generic error",
-            Error::InvalidObject => "invalid object",
-            Error::KeyError => "key error",
-            Error::MemoryError => "memory error",
-            Error::NotSupported => "not supported",
-            Error::NotFound => "not found",
-            Error::ParseError => "parse error",
-            Error::PcscError { .. } => "PC/SC error",
-            Error::PinLocked => "PIN locked",
-            Error::RangeError => "range error",
-            Error::SizeError => "size error",
-            Error::WrongPin { .. } => "wrong pin",
+            Error::AlgorithmError => f.write_str("algorithm error"),
+            Error::AppletError => f.write_str("applet error"),
+            Error::AppletNotFound { applet_name } => {
+                f.write_str(&format!("{applet_name} applet not found"))
+            }
+            Error::ArgumentError => f.write_str("argument error"),
+            Error::AuthenticationError => f.write_str("authentication error"),
+            Error::CertificateBuilder => f.write_str("certificate builder error"),
+            Error::GenericError => f.write_str("generic error"),
+            Error::InvalidObject => f.write_str("invalid object"),
+            Error::KeyError => f.write_str("key error"),
+            Error::MemoryError => f.write_str("memory error"),
+            Error::NotSupported => f.write_str("not supported"),
+            Error::NotFound => f.write_str("not found"),
+            Error::ParseError => f.write_str("parse error"),
+
+            Error::PcscError {
+                inner: Some(pcsc_error),
+            } => f.write_fmt(format_args!("PC/SC error: {pcsc_error}")),
+
+            Error::PcscError { .. } => f.write_str("PC/SC error"),
+
+            Error::PinLocked => f.write_str("PIN locked"),
+            Error::RangeError => f.write_str("range error"),
+            Error::SizeError => f.write_str("size error"),
+            Error::WrongPin { .. } => f.write_str("wrong pin"),
         }
     }
 }
 
 impl Display for Error {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.write_str(self.msg())
+        self.msg(f)
+    }
+}
+
+impl From<std::array::TryFromSliceError> for Error {
+    fn from(_: std::array::TryFromSliceError) -> Error {
+        Error::SizeError
+    }
+}
+
+impl From<std::time::SystemTimeError> for Error {
+    fn from(_: std::time::SystemTimeError) -> Error {
+        Error::GenericError
     }
 }
 
@@ -164,3 +195,15 @@ impl std::error::Error for Error {
         }
     }
 }
+
+impl From<der::Error> for Error {
+    fn from(_err: der::Error) -> Error {
+        Error::ParseError
+    }
+}
+
+impl From<x509_cert::builder::Error> for Error {
+    fn from(_err: x509_cert::builder::Error) -> Error {
+        Error::CertificateBuilder
+    }
+}

src/lib.rs

@@ -1,102 +1,17 @@
-//! **yubikey.rs**: pure Rust cross-platform host-side driver for [YubiKey]
-//! devices from [Yubico] using the Personal Computer/Smart Card ([PC/SC])
-//! interface as provided by the [`pcsc` crate].
-//!
-//! # Features
-//! ## Personal Identity Verification (PIV)
-//! [PIV] is a [NIST] standard for both *signing* and *encryption*
-//! using SmartCards and SmartCard-based hardware tokens like YubiKeys.
-//!
-//! PIV-related functionality can be found in the [`piv`] module.
-//!
-//! This library natively implements the protocol used to manage and
-//! utilize PIV encryption and signing keys which can be generated, imported,
-//! and stored on YubiKey devices.
-//!
-//! See [Yubico's guide to PIV-enabled YubiKeys][yk-guide] for more information
-//! on which devices support PIV and the available functionality.
-//!
-//! # Minimum Supported Rust Version
-//! Rust **1.51** or newer.
-//!
-//! # Supported YubiKeys
-//! - [YubiKey 4] series
-//! - [YubiKey 5] series
-//!
-//! NOTE: Nano and USB-C variants of the above are also supported.
-//!       Pre-YK4 [YubiKey NEO] series is **NOT** supported.
-//!
-//! # Supported Operating Systems
-//! - Linux
-//! - macOS
-//! - Windows
-//!
-//! # Supported Algorithms
-//! - **Authentication**: `3DES`
-//! - **Encryption**:
-//!   - RSA: `RSA1024`, `RSA2048`
-//!   - ECC: `ECCP256`, `ECCP384` (NIST curves: P-256, P-384)
-//! - **Signatures**:
-//!   - RSASSA-PKCS#1v1.5: `RSA1024`, `RSA2048`
-//!   - ECDSA: `ECCP256`, `ECCP384` (NIST curves: P-256, P-384)
-//!
-//! NOTE: RSASSA-PSS signatures and RSA-OAEP encryption may be supportable (TBD)
-//!
-//! # Status
-//! Functionality which has been successfully tested is available by default.
-//!
-//! Any functionality which is gated on the `untested` feature has not been
-//! properly tested and is not known to function correctly.
-//!
-//! Please see the [`untested` functionality tracking issue] for current status.
-//! We would appreciate any help testing this functionality and removing the
-//! `untested` gating as well as writing more automated tests.
-//!
-//! # History
-//! This library is a Rust translation of the [yubico-piv-tool] utility by
-//! Yubico, which was originally written in C. It was mechanically translated
-//! from C into Rust using [Corrode], and then subsequently heavily
-//! refactored into safer, more idiomatic Rust.
-//!
-//! For more information on [yubico-piv-tool] and background information on how
-//! the YubiKey implementation of PIV works in general, see the
-//! [Yubico PIV Tool Command Line Guide][piv-tool-guide].
-//!
-//! # Security Warning
-//! No security audits of this crate have ever been performed. Presently it is in
-//! an experimental stage and may still contain high-severity issues.
-//!
-//! USE AT YOUR OWN RISK!
-//!
-//! # Code of Conduct
-//! We abide by the [Contributor Covenant][cc-md] and ask that you do as well.
-//!
-//! For more information, please see [CODE_OF_CONDUCT.md][cc-md].
-//!
-//! # License
-//! **yubikey.rs** is a fork of and originally a mechanical translation from
-//! Yubico's [yubico-piv-tool], a C library/CLI program.
-//!
-//! The original library was licensed under a [2-Clause BSD License][BSDL],
-//! which this library inherits as a derived work.
-//!
-//! [YubiKey]: https://www.yubico.com/products/yubikey-hardware/
-//! [PIV]: https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-73-4.pdf
-//! [Yubico]: https://www.yubico.com/
-//! [PC/SC]: https://en.wikipedia.org/wiki/PC/SC
-//! [`pcsc` crate]: https://github.com/bluetech/pcsc-rust
-//! [NIST]: https://www.nist.gov/
-//! [yk-guide]: https://developers.yubico.com/PIV/Introduction/YubiKey_and_PIV.html
-//! [YubiKey NEO]: https://support.yubico.com/support/solutions/articles/15000006494-yubikey-neo
-//! [YubiKey 4]: https://support.yubico.com/support/solutions/articles/15000006486-yubikey-4
-//! [YubiKey 5]: https://www.yubico.com/products/yubikey-5-overview/
-//! [`untested` functionality tracking issue]: https://github.com/iqlusioninc/yubikey.rs/issues/280
-//! [yubico-piv-tool]: https://github.com/Yubico/yubico-piv-tool/
-//! [Corrode]: https://github.com/jameysharp/corrode
-//! [piv-tool-guide]: https://www.yubico.com/wp-content/uploads/2016/05/Yubico_PIV_Tool_Command_Line_Guide_en.pdf
-//! [cc-web]: https://contributor-covenant.org/
-//! [cc-md]: https://github.com/iqlusioninc/yubikey.rs/blob/main/CODE_OF_CONDUCT.md
-//! [BSDL]: https://opensource.org/licenses/BSD-2-Clause
+#![doc = include_str!("../README.md")]
+#![doc(
+    html_logo_url = "https://raw.githubusercontent.com/iqlusioninc/yubikey.rs/main/img/logo-sq.png"
+)]
+#![cfg_attr(docsrs, feature(doc_cfg))]
+#![forbid(unsafe_code)]
+#![warn(
+    clippy::mod_module_files,
+    clippy::unwrap_used,
+    missing_docs,
+    rust_2018_idioms,
+    unused_lifetimes,
+    unused_qualifications
+)]
 
 // Adapted from yubico-piv-tool:
 // <https://github.com/Yubico/yubico-piv-tool/>
@@ -128,14 +43,6 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#![cfg_attr(docsrs, feature(doc_cfg))]
-#![doc(
-    html_logo_url = "https://raw.githubusercontent.com/iqlusioninc/yubikey.rs/main/img/logo.png",
-    html_root_url = "https://docs.rs/yubikey/0.4.0"
-)]
-#![forbid(unsafe_code)]
-#![warn(missing_docs, rust_2018_idioms, trivial_casts, unused_qualifications)]
-
 mod apdu;
 mod cccid;
 pub mod certificate;
@@ -144,30 +51,31 @@ mod config;
 mod consts;
 mod error;
 mod metadata;
-mod mgm;
+pub mod mgm;
 #[cfg(feature = "untested")]
 mod mscmap;
 #[cfg(feature = "untested")]
 mod msroots;
+mod otp;
 pub mod piv;
 mod policy;
 pub mod reader;
 mod serialization;
-mod settings;
+mod setting;
 mod transaction;
 mod yubikey;
 
 pub use crate::{
-    cccid::{CardId, Ccc},
+    cccid::{CardId, CccId},
     certificate::Certificate,
     chuid::ChuId,
     config::Config,
     error::{Error, Result},
-    mgm::{MgmKey, MgmType},
+    mgm::{MgmAlgorithmId, MgmKey, MgmType},
     piv::Key,
     policy::{PinPolicy, TouchPolicy},
     reader::Context,
-    settings::{SettingSource, SettingValue},
+    setting::{Setting, SettingSource},
     yubikey::{CachedPin, Serial, Version, YubiKey},
 };
 
@@ -180,4 +88,4 @@ pub use uuid::Uuid;
 pub type ObjectId = u32;
 
 /// Buffer type (self-zeroizing byte vector)
-pub(crate) type Buffer = zeroize::Zeroizing<Vec<u8>>;
+pub type Buffer = zeroize::Zeroizing<Vec<u8>>;

src/metadata.rs

@@ -30,16 +30,15 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-use std::marker::PhantomData;
+use std::{iter, marker::PhantomData};
 use zeroize::Zeroizing;
 
-use crate::{serialization::*, transaction::Transaction, Buffer, Error, Result};
-
-#[cfg(feature = "untested")]
-use crate::consts::{CB_OBJ_MAX, CB_OBJ_TAG_MAX};
-
-#[cfg(feature = "untested")]
-use std::iter;
+use crate::{
+    consts::{CB_OBJ_MAX, CB_OBJ_TAG_MAX},
+    serialization::*,
+    transaction::Transaction,
+    Buffer, Error, Result,
+};
 
 const TAG_ADMIN: u8 = 0x80;
 const TAG_PROTECTED: u8 = 0x88;
@@ -71,7 +70,7 @@ impl<T: MetadataType> Default for Metadata<T> {
     fn default() -> Self {
         Metadata {
             inner: Zeroizing::new(vec![]),
-            _marker: PhantomData::default(),
+            _marker: PhantomData,
         }
     }
 }
@@ -82,13 +81,11 @@ impl<T: MetadataType> Metadata<T> {
         let data = txn.fetch_object(T::obj_id())?;
         Ok(Metadata {
             inner: Tlv::parse_single(data, T::tag())?,
-            _marker: PhantomData::default(),
+            _marker: PhantomData,
         })
     }
 
     /// Write metadata
-    #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub(crate) fn write(&self, txn: &Transaction<'_>) -> Result<()> {
         if self.inner.len() > CB_OBJ_MAX - CB_OBJ_TAG_MAX {
             return Err(Error::GenericError);
@@ -105,8 +102,6 @@ impl<T: MetadataType> Metadata<T> {
     }
 
     /// Delete metadata
-    #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub(crate) fn delete(txn: &Transaction<'_>) -> Result<()> {
         txn.save_object(T::obj_id(), &[])
     }
@@ -129,8 +124,6 @@ impl<T: MetadataType> Metadata<T> {
     }
 
     /// Set metadata item
-    #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub(crate) fn set_item(&mut self, tag: u8, item: &[u8]) -> Result<()> {
         let mut cb_temp: usize = 0;
         let mut tag_temp: u8 = 0;
@@ -160,8 +153,10 @@ impl<T: MetadataType> Metadata<T> {
 
             // We did not find an existing tag, append
             assert_eq!(offset, self.inner.len());
-            self.inner
-                .extend(iter::repeat(0).take(1 + get_length_size(item.len()) + item.len()));
+            self.inner.extend(iter::repeat_n(
+                0,
+                1 + get_length_size(item.len()) + item.len(),
+            ));
             Tlv::write(&mut self.inner[offset..], tag, item)?;
 
             return Ok(());
@@ -196,7 +191,7 @@ impl<T: MetadataType> Metadata<T> {
         // Move remaining data
         let orig_len = self.inner.len();
         if cb_moved > 0 {
-            self.inner.extend(iter::repeat(0).take(cb_moved as usize));
+            self.inner.extend(iter::repeat_n(0, cb_moved as usize));
         }
         self.inner.copy_within(
             next_offset..orig_len,
@@ -217,7 +212,6 @@ impl<T: MetadataType> Metadata<T> {
 }
 
 /// Get the size of a length tag for the given length
-#[cfg(feature = "untested")]
 fn get_length_size(length: usize) -> usize {
     if length < 0x80 {
         1

src/mscmap.rs

@@ -32,7 +32,6 @@
 
 use crate::{consts::CB_OBJ_MAX, piv::SlotId, serialization::*, Error, Result, YubiKey};
 use log::error;
-use std::convert::{TryFrom, TryInto};
 
 const OBJ_MSCMAP: u32 = 0x005f_ff10;
 
@@ -42,7 +41,6 @@ const TAG_MSCMAP: u8 = 0x81;
 ///
 /// Defined in Microsoft's Smart Card Minidriver Specification:
 /// <https://docs.microsoft.com/en-us/previous-versions/windows/hardware/design/dn631754(v=vs.85)>
-#[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
 #[derive(Clone, Debug)]
 pub struct MsContainer {
     /// Container name.
@@ -142,7 +140,7 @@ impl MsContainer {
         let name_bytes_len = Self::NAME_LEN * 2;
 
         for (i, chunk) in bytes[..name_bytes_len].chunks_exact(2).enumerate() {
-            name[i] = u16::from_le_bytes(chunk.try_into().unwrap());
+            name[i] = u16::from_le_bytes([chunk[0], chunk[1]]);
         }
 
         let mut cert_fingerprint = [0u8; 20];
@@ -152,11 +150,10 @@ impl MsContainer {
             name,
             slot: bytes[name_bytes_len].try_into()?,
             key_spec: bytes[name_bytes_len + 1],
-            key_size_bits: u16::from_le_bytes(
-                bytes[(name_bytes_len + 2)..(name_bytes_len + 4)]
-                    .try_into()
-                    .unwrap(),
-            ),
+            key_size_bits: u16::from_le_bytes([
+                bytes[name_bytes_len + 2],
+                bytes[name_bytes_len + 3],
+            ]),
             flags: bytes[name_bytes_len + 4],
             pin_id: bytes[name_bytes_len + 5],
             associated_echd_container: bytes[name_bytes_len + 6],
@@ -185,7 +182,10 @@ impl MsContainer {
         bytes.push(self.pin_id);
         bytes.push(self.associated_echd_container);
         bytes.extend_from_slice(&self.cert_fingerprint);
-        bytes.as_slice().try_into().unwrap()
+        bytes
+            .as_slice()
+            .try_into()
+            .expect("should be REC_LEN-sized")
     }
 }
 

src/msroots.rs

@@ -57,7 +57,6 @@ const TAG_MSROOTS_MID: u8 = 0x83;
 ///
 /// For more information, see:
 /// <https://docs.microsoft.com/en-us/windows-hardware/drivers/smartcard/developer-guidelines#-interoperability-with-msroots>
-#[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
 pub struct MsRoots(Vec<u8>);
 
 impl MsRoots {
@@ -97,10 +96,9 @@ impl MsRoots {
             }
         }
 
-        MsRoots::new(&data).map(Some).map_err(|e| {
-            error!("error parsing msroots: {:?}", e);
-            e
-        })
+        MsRoots::new(&data)
+            .map(Some)
+            .inspect_err(|e| error!("error parsing msroots: {:?}", e))
     }
 
     /// Write `msroots` file to YubiKey
@@ -111,7 +109,7 @@ impl MsRoots {
         let mut data_chunk: usize;
         let data = &self.0;
         let data_len = data.len();
-        let n_objs: usize;
+
         let txn = yubikey.begin_transaction()?;
 
         if data_len == 0 {
@@ -119,7 +117,7 @@ impl MsRoots {
         }
 
         // Calculate number of objects required to store blob
-        n_objs = (data_len / (CB_OBJ_MAX - CB_OBJ_TAG_MAX)) + 1;
+        let n_objs: usize = (data_len / (CB_OBJ_MAX - CB_OBJ_TAG_MAX)) + 1;
 
         if n_objs > 5 {
             return Err(Error::SizeError);

src/otp.rs

@@ -0,0 +1,5 @@
+/// YubiKey OTP Applet Name
+pub(crate) const APPLET_NAME: &str = "YubiKey OTP";
+
+/// YubiKey OTP Applet ID. Needed to query serial on YK4.
+pub(crate) const APPLET_ID: &[u8] = &[0xa0, 0x00, 0x00, 0x05, 0x27, 0x20, 0x01, 0x01];

src/policy.rs

@@ -1,12 +1,12 @@
 //! Enums representing key policies.
 
-use crate::{serialization::Tlv, Result};
+use crate::{serialization::Tlv, Error, Result};
 
 /// Specifies how often the PIN needs to be entered for access to the credential in a
 /// given slot.
 ///
 /// This policy must be set when keys are generated or imported, and cannot be changed later.
-#[derive(Clone, Copy, Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub enum PinPolicy {
     /// Use the default PIN policy for the slot. See the slot's documentation for details.
     Default,
@@ -35,6 +35,20 @@ impl From<PinPolicy> for u8 {
     }
 }
 
+impl TryFrom<u8> for PinPolicy {
+    type Error = Error;
+
+    fn try_from(value: u8) -> Result<Self> {
+        match value {
+            0 => Ok(PinPolicy::Default),
+            1 => Ok(PinPolicy::Never),
+            2 => Ok(PinPolicy::Once),
+            3 => Ok(PinPolicy::Always),
+            _ => Err(Error::GenericError),
+        }
+    }
+}
+
 impl PinPolicy {
     /// Writes the `PinPolicy` in the format the YubiKey expects during key generation or
     /// importation.
@@ -50,7 +64,7 @@ impl PinPolicy {
 /// addition to the [`PinPolicy`].
 ///
 /// This policy must be set when keys are generated or imported, and cannot be changed later.
-#[derive(Clone, Copy, Debug, PartialEq)]
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub enum TouchPolicy {
     /// Use the default touch policy for the slot.
     Default,
@@ -90,3 +104,17 @@ impl TouchPolicy {
         }
     }
 }
+
+impl TryFrom<u8> for TouchPolicy {
+    type Error = Error;
+
+    fn try_from(value: u8) -> Result<Self> {
+        match value {
+            0 => Ok(TouchPolicy::Default),
+            1 => Ok(TouchPolicy::Never),
+            2 => Ok(TouchPolicy::Always),
+            3 => Ok(TouchPolicy::Cached),
+            _ => Err(Error::GenericError),
+        }
+    }
+}

src/reader.rs

@@ -1,10 +1,10 @@
 //! Support for enumerating available PC/SC card readers.
 
-use crate::{Result, YubiKey};
+use crate::{Error, Result, YubiKey};
 use std::{
     borrow::Cow,
-    convert::TryInto,
     ffi::CStr,
+    fmt,
     sync::{Arc, Mutex},
 };
 
@@ -20,6 +20,12 @@ pub struct Context {
     reader_names: Vec<u8>,
 }
 
+impl fmt::Debug for Context {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("Context").finish_non_exhaustive()
+    }
+}
+
 impl Context {
     /// Open a PC/SC context, which can be used to enumerate available PC/SC
     /// readers (which can be used to connect to YubiKeys).
@@ -37,7 +43,8 @@ impl Context {
         let Self { ctx, reader_names } = self;
 
         let reader_cstrs: Vec<_> = {
-            let c = ctx.lock().unwrap();
+            // TODO(tarcieri): better error?
+            let c = ctx.lock().map_err(|_| Error::GenericError)?;
 
             // ensure PC/SC context is valid
             c.is_valid()?;
@@ -45,6 +52,7 @@ impl Context {
             c.list_readers(reader_names)?.collect()
         };
 
+        #[allow(clippy::needless_collect)]
         let readers: Vec<_> = reader_cstrs
             .iter()
             .map(|name| Reader::new(name, Arc::clone(ctx)))
@@ -83,7 +91,8 @@ impl<'ctx> Reader<'ctx> {
 
     /// Connect to this reader, returning its `pcsc::Card`.
     pub(crate) fn connect(&self) -> Result<pcsc::Card> {
-        let ctx = self.ctx.lock().unwrap();
+        // TODO(tarcieri): better error?
+        let ctx = self.ctx.lock().map_err(|_| Error::GenericError)?;
         Ok(ctx.connect(self.name, pcsc::ShareMode::Shared, pcsc::Protocols::T1)?)
     }
 }

src/setting.rs

@@ -41,7 +41,7 @@ use std::{
 };
 
 /// Source of how a setting was configured.
-#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+#[derive(Clone, Copy, Debug, Default, Eq, PartialEq)]
 pub enum SettingSource {
     /// User-specified setting: sourced via `YUBIKEY_PIV_*` environment vars.
     User,
@@ -51,22 +51,17 @@ pub enum SettingSource {
     Admin,
 
     /// Default setting.
+    #[default]
     Default,
 }
 
-impl Default for SettingSource {
-    fn default() -> Self {
-        Self::Default
-    }
-}
-
 /// Setting booleans: configuration values sourced from a file or the environment.
 ///
 /// These can be configured globally in `/etc/yubico/yubikeypiv.conf` by a
 /// system administrator, or by the local user via `YUBIKEY_PIV_*` environment
 /// variables.
-#[derive(Copy, Clone, Debug)]
-pub struct SettingValue {
+#[derive(Copy, Clone, Debug, Default)]
+pub struct Setting {
     /// Boolean value
     pub value: bool,
 
@@ -74,8 +69,8 @@ pub struct SettingValue {
     pub source: SettingSource,
 }
 
-impl SettingValue {
-    /// Get a [`SettingValue`] value by name.
+impl Setting {
+    /// Get a setting by name.
     pub fn get(key: &str, default: bool) -> Self {
         Self::from_file(key)
             .or_else(|| Self::from_env(key))
@@ -99,7 +94,7 @@ impl SettingValue {
                 }
 
                 let (name, value) = {
-                    let mut parts = line.splitn(1, '=');
+                    let mut parts = line.splitn(2, '=');
                     let name = parts.next();
                     let value = parts.next();
                     match (name, value, parts.next()) {
@@ -109,7 +104,7 @@ impl SettingValue {
                 };
 
                 if name == key {
-                    return Some(SettingValue {
+                    return Some(Setting {
                         source: SettingSource::Admin,
                         value: value == "1" || value == "true",
                     });
@@ -122,20 +117,11 @@ impl SettingValue {
 
     /// Get a setting boolean from an environment variable
     fn from_env(key: &str) -> Option<Self> {
-        env::var(format!("YUBIKEY_PIV_{}", key))
+        env::var(format!("YUBIKEY_PIV_{key}"))
             .ok()
-            .map(|value| SettingValue {
+            .map(|value| Setting {
                 source: SettingSource::User,
                 value: value == "1" || value == "true",
             })
     }
 }
-
-impl Default for SettingValue {
-    fn default() -> Self {
-        Self {
-            value: false,
-            source: SettingSource::default(),
-        }
-    }
-}

src/transaction.rs

@@ -5,23 +5,18 @@ use crate::{
     apdu::{Apdu, Ins, StatusWords},
     consts::{CB_BUF_MAX, CB_OBJ_MAX},
     error::{Error, Result},
-    piv::{AlgorithmId, SlotId},
+    mgm::MgmKey,
+    otp,
+    piv::{self, AlgorithmId, SlotId},
     serialization::*,
     yubikey::*,
     Buffer, ObjectId,
 };
 use log::{error, trace};
-use std::convert::TryInto;
 use zeroize::Zeroizing;
 
 #[cfg(feature = "untested")]
-use crate::mgm::{MgmKey, DES_LEN_3DES};
-
-/// PIV Applet ID
-const PIV_AID: [u8; 5] = [0xa0, 0x00, 0x00, 0x03, 0x08];
-
-/// YubiKey OTP Applet ID. Needed to query serial on YK4.
-const YK_AID: [u8; 8] = [0xa0, 0x00, 0x00, 0x05, 0x27, 0x20, 0x01, 0x01];
+use crate::mgm::{DeviceConfig, DeviceInfo, Lock};
 
 const CB_PIN_MAX: usize = 8;
 
@@ -66,23 +61,34 @@ impl<'tx> Transaction<'tx> {
         Ok(recv_buffer)
     }
 
+    /// Select PIV application.
+    pub fn select_piv_application(&self) -> Result<()> {
+        self.select_application(
+            piv::APPLET_ID,
+            piv::APPLET_NAME,
+            "failed selecting application",
+        )
+    }
+
     /// Select application.
-    pub fn select_application(&self) -> Result<()> {
+    pub fn select_application(
+        &self,
+        applet: &[u8],
+        applet_name: &'static str,
+        error: &'static str,
+    ) -> Result<()> {
         let response = Apdu::new(Ins::SelectApplication)
             .p1(0x04)
-            .data(&PIV_AID)
+            .data(applet)
             .transmit(self, 0xFF)
-            .map_err(|e| {
-                error!("failed communicating with card: '{}'", e);
-                e
-            })?;
+            .inspect_err(|e| error!("failed communicating with card: '{}'", e))?;
 
         if !response.is_success() {
-            error!(
-                "failed selecting application: {:04x}",
-                response.status_words().code()
-            );
-            return Err(Error::GenericError);
+            error!("{}: {:04x}", error, response.status_words().code());
+            return Err(match response.status_words() {
+                StatusWords::NotFoundError => Error::AppletNotFound { applet_name },
+                _ => Error::GenericError,
+            });
         }
 
         Ok(())
@@ -93,74 +99,81 @@ impl<'tx> Transaction<'tx> {
         // get version from device
         let response = Apdu::new(Ins::GetVersion).transmit(self, 261)?;
 
-        if !response.is_success() {
+        if !response.is_success() || response.data().is_empty() {
             return Err(Error::GenericError);
         }
 
-        if response.data().len() < 3 {
-            return Err(Error::SizeError);
-        }
-
-        Ok(Version::new(response.data()[..3].try_into().unwrap()))
+        Ok(response.data()[..3].try_into().map(Version::new)?)
     }
 
     /// Get YubiKey device serial number.
     pub fn get_serial(&self, version: Version) -> Result<Serial> {
-        let response = if version.major < 5 {
-            // YK4 requires switching to the yk applet to retrieve the serial
-            let sw = Apdu::new(Ins::SelectApplication)
-                .p1(0x04)
-                .data(&YK_AID)
-                .transmit(self, 0xFF)?
-                .status_words();
+        match version.major {
+            // YK4 requires switching to the YK applet to retrieve the serial
+            4 => {
+                self.select_application(
+                    otp::APPLET_ID,
+                    otp::APPLET_NAME,
+                    "failed selecting yk application",
+                )?;
 
-            if !sw.is_success() {
-                error!("failed selecting yk application: {:04x}", sw.code());
-                return Err(Error::GenericError);
-            }
+                let response = Apdu::new(0x01).p1(0x10).transmit(self, 0xFF)?;
 
-            let resp = Apdu::new(0x01).p1(0x10).transmit(self, 0xFF)?;
-
-            if !resp.is_success() {
+                if !response.is_success() {
+                    // TODO(tarcieri): still reselect the PIV applet in this case?
                     error!(
                         "failed retrieving serial number: {:04x}",
-                    resp.status_words().code()
+                        response.status_words().code()
                     );
                     return Err(Error::GenericError);
                 }
 
                 // reselect the PIV applet
-            let sw = Apdu::new(Ins::SelectApplication)
-                .p1(0x04)
-                .data(&PIV_AID)
-                .transmit(self, 0xFF)?
-                .status_words();
+                self.select_application(
+                    piv::APPLET_ID,
+                    piv::APPLET_NAME,
+                    "failed selecting application",
+                )?;
 
-            if !sw.is_success() {
-                error!("failed selecting application: {:04x}", sw.code());
-                return Err(Error::GenericError);
+                response.data().try_into()
             }
 
-            resp
-        } else {
             // YK5 implements getting the serial as a PIV applet command (0xf8)
-            let resp = Apdu::new(Ins::GetSerial).transmit(self, 0xFF)?;
+            5 => {
+                let response = Apdu::new(Ins::GetSerial).transmit(self, 0xFF)?;
 
-            if !resp.is_success() {
+                if !response.is_success() {
                     error!(
                         "failed retrieving serial number: {:04x}",
-                    resp.status_words().code()
+                        response.status_words().code()
                     );
                     return Err(Error::GenericError);
                 }
 
-            resp
-        };
+                response.data().try_into()
+            }
 
-        response.data()[..4]
-            .try_into()
-            .map(|serial| Serial::from(u32::from_be_bytes(serial)))
-            .map_err(|_| Error::SizeError)
+            // Other versions unsupported
+            _ => Err(Error::NotSupported),
+        }
+    }
+
+    /// Read metadata
+    pub(crate) fn get_metadata(&self, slot: SlotId) -> Result<piv::SlotMetadata> {
+        let response = Apdu::new(Ins::GetMetadata)
+            .p2(slot.into())
+            .transmit(self, CB_OBJ_MAX)?;
+
+        match response.status_words() {
+            StatusWords::Success => {
+                let buf = Buffer::new(response.data().into());
+                piv::SlotMetadata::try_from(buf)
+            }
+            StatusWords::ReferenceDataNotFoundError => Err(Error::NotFound),
+            // Requires firmware 5.2.3
+            StatusWords::NotSupportedError => Err(Error::NotSupported),
+            _ => Err(Error::GenericError),
+        }
     }
 
     /// Verify device PIN.
@@ -178,7 +191,7 @@ impl<'tx> Transaction<'tx> {
         if !pin.is_empty() {
             let mut data = Zeroizing::new([0xff; CB_PIN_MAX]);
             data[0..pin.len()].copy_from_slice(pin);
-            query.data(data.as_ref());
+            query.data(data.as_slice());
         }
 
         let response = query.transmit(self, 261)?;
@@ -235,19 +248,18 @@ impl<'tx> Transaction<'tx> {
     }
 
     /// Set the management key (MGM).
-    #[cfg(feature = "untested")]
     pub fn set_mgm_key(&self, new_key: &MgmKey, require_touch: bool) -> Result<()> {
         let p2 = if require_touch { 0xfe } else { 0xff };
 
-        let mut data = [0u8; DES_LEN_3DES + 3];
-        data[0] = ALGO_3DES;
-        data[1] = KEY_CARDMGM;
-        data[2] = DES_LEN_3DES as u8;
-        data[3..3 + DES_LEN_3DES].copy_from_slice(new_key.as_ref());
+        let mut data = Vec::with_capacity(usize::from(new_key.key_size()) + 3);
+        data.push(new_key.algorithm_id().into());
+        data.push(KEY_CARDMGM);
+        data.push(new_key.key_size());
+        data.extend_from_slice(new_key.as_ref());
 
         let status_words = Apdu::new(Ins::SetMgmKey)
             .params(0xff, p2)
-            .data(&data)
+            .data(data)
             .transmit(self, 261)?
             .status_words();
 
@@ -276,14 +288,23 @@ impl<'tx> Transaction<'tx> {
         let templ = [0, Ins::Authenticate.code(), algorithm.into(), key.into()];
 
         match algorithm {
-            AlgorithmId::Rsa1024 | AlgorithmId::Rsa2048 => {
-                let key_len = if let AlgorithmId::Rsa1024 = algorithm {
-                    128
-                } else {
-                    256
-                };
-
-                if in_len != key_len {
+            AlgorithmId::Rsa1024 => {
+                if in_len != 128 {
+                    return Err(Error::SizeError);
+                }
+            }
+            AlgorithmId::Rsa2048 => {
+                if in_len != 256 {
+                    return Err(Error::SizeError);
+                }
+            }
+            AlgorithmId::Rsa3072 => {
+                if in_len != 384 {
+                    return Err(Error::SizeError);
+                }
+            }
+            AlgorithmId::Rsa4096 => {
+                if in_len != 512 {
                     return Err(Error::SizeError);
                 }
             }
@@ -299,6 +320,19 @@ impl<'tx> Transaction<'tx> {
                     return Err(Error::SizeError);
                 }
             }
+            AlgorithmId::X25519 => {
+                if !decipher {
+                    return Err(Error::NotSupported);
+                }
+                if in_len != 32 {
+                    return Err(Error::SizeError);
+                }
+            }
+            AlgorithmId::Ed25519 => {
+                if decipher {
+                    return Err(Error::NotSupported);
+                }
+            }
         }
 
         let bytes = if in_len < 0x80 {
@@ -315,7 +349,9 @@ impl<'tx> Transaction<'tx> {
                 Tlv::write(
                     &mut buf[2..],
                     match (algorithm, decipher) {
-                        (AlgorithmId::EccP256, true) | (AlgorithmId::EccP384, true) => 0x85,
+                        (AlgorithmId::EccP256, true)
+                        | (AlgorithmId::EccP384, true)
+                        | (AlgorithmId::X25519, true) => 0x85,
                         _ => 0x81,
                     },
                     sign_in
@@ -327,10 +363,7 @@ impl<'tx> Transaction<'tx> {
 
         let response = self
             .transfer_data(&templ, &indata[..offset], 1024)
-            .map_err(|e| {
-                error!("sign command failed to communicate: {}", e);
-                e
-            })?;
+            .inspect_err(|e| error!("sign command failed to communicate: {}", e))?;
 
         if !response.is_success() {
             error!("failed sign command with code {:x}", response.code());
@@ -388,11 +421,12 @@ impl<'tx> Transaction<'tx> {
                 .data(&in_data[in_offset..(in_offset + this_size)])
                 .transmit(self, 261)?;
 
-            sw = response.status_words().code();
+            sw = response.status_words();
 
-            if !response.is_success() && (sw >> 8 != 0x61) {
+            match sw {
+                StatusWords::Success | StatusWords::BytesRemaining { .. } => (),
                 // TODO(tarcieri): is this really OK?
-                return Ok(Response::new(sw.into(), out_data));
+                _ => return Ok(Response::new(sw, out_data)),
             }
 
             if !out_data.is_empty() && (out_data.len() - response.data().len() > max_out) {
@@ -413,17 +447,15 @@ impl<'tx> Transaction<'tx> {
             }
         }
 
-        while sw >> 8 == 0x61 {
-            trace!(
-                "The card indicates there is {} bytes more data for us",
-                sw & 0xff
-            );
+        while let StatusWords::BytesRemaining { len } = sw {
+            trace!("The card indicates there is {} bytes more data for us", len);
 
             let response = Apdu::new(Ins::GetResponseApdu).transmit(self, 261)?;
-            sw = response.status_words().code();
+            sw = response.status_words();
 
-            if sw != StatusWords::Success.code() && (sw >> 8 != 0x61) {
-                return Ok(Response::new(sw.into(), vec![]));
+            match sw {
+                StatusWords::Success | StatusWords::BytesRemaining { .. } => (),
+                _ => return Ok(Response::new(sw, vec![])),
             }
 
             if out_data.len() + response.data().len() > max_out {
@@ -439,7 +471,7 @@ impl<'tx> Transaction<'tx> {
             out_data.extend_from_slice(&response.data()[..response.data().len()]);
         }
 
-        Ok(Response::new(sw.into(), out_data))
+        Ok(Response::new(sw, out_data))
     }
 
     /// Fetch an object.
@@ -504,4 +536,66 @@ impl<'tx> Transaction<'tx> {
             _ => Err(Error::GenericError),
         }
     }
+
+    /// Write configuration to the YubiKey
+    #[cfg(feature = "untested")]
+    pub fn write_config(
+        &mut self,
+        version: Version,
+        config: DeviceConfig,
+        current_lock: Option<Lock>,
+        new_lock: Option<Lock>,
+    ) -> Result<()> {
+        if version
+            < (Version {
+                major: 5,
+                minor: 0,
+                patch: 0,
+            })
+        {
+            return Err(Error::NotSupported);
+        }
+
+        let data = config.as_tlv(true, current_lock, new_lock)?;
+
+        let response = Apdu::new(Ins::WriteConfig)
+            .params(0x00, 0x00)
+            .data(&data)
+            .transmit(self, 2)?;
+
+        if !response.is_success() {
+            error!(
+                "Unable to write_config: {:04x}",
+                response.status_words().code()
+            );
+            return Err(Error::GenericError);
+        }
+
+        Ok(())
+    }
+
+    /// Write configuration to the YubiKey
+    #[cfg(feature = "untested")]
+    pub fn read_config(&mut self) -> Result<DeviceInfo> {
+        let mut data = [0u8; CB_BUF_MAX];
+        let mut len = data.len();
+        let data_remaining = &mut data[..];
+
+        len -= data_remaining.len();
+        let response = Apdu::new(Ins::ReadConfig)
+            .params(0x00, 0x00)
+            .data(&data[..len])
+            .transmit(self, CB_BUF_MAX + 2)?;
+
+        if !response.is_success() {
+            error!(
+                "Unable to read configuration: {:04x}",
+                response.status_words().code()
+            );
+            return Err(Error::GenericError);
+        }
+
+        let data = response.data();
+        DeviceInfo::parse(data)
+    }
 }

src/yubikey.rs

@@ -32,7 +32,7 @@
 
 use crate::{
     apdu::{Apdu, Ins},
-    cccid::Ccc,
+    cccid::CccId,
     chuid::ChuId,
     config::Config,
     error::{Error, Result},
@@ -41,11 +41,12 @@ use crate::{
     reader::{Context, Reader},
     transaction::Transaction,
 };
+use cipher::common::getrandom::SysRng;
 use log::{error, info};
 use pcsc::Card;
-use rand_core::{OsRng, RngCore};
+use rand_core::TryRng;
 use std::{
-    convert::{TryFrom, TryInto},
+    cmp::{Ord, Ordering},
     fmt::{self, Display},
     str::FromStr,
 };
@@ -56,10 +57,10 @@ use {
         apdu::StatusWords,
         consts::{TAG_ADMIN_FLAGS_1, TAG_ADMIN_TIMESTAMP},
         metadata::AdminData,
+        mgm,
         transaction::ChangeRefAction,
         Buffer, ObjectId,
     },
-    secrecy::ExposeSecret,
     std::time::{SystemTime, UNIX_EPOCH},
 };
 
@@ -67,24 +68,20 @@ use {
 pub(crate) const ADMIN_FLAGS_1_PUK_BLOCKED: u8 = 0x01;
 
 /// 3DES authentication
+#[cfg(feature = "untested")]
 pub(crate) const ALGO_3DES: u8 = 0x03;
 
 /// Card management key
 pub(crate) const KEY_CARDMGM: u8 = 0x9b;
 
-/// MGMT Applet ID.
-///
-/// <https://developers.yubico.com/PIV/Introduction/Admin_access.html>
-#[cfg(feature = "untested")]
-const MGMT_AID: [u8; 8] = [0xa0, 0x00, 0x00, 0x05, 0x27, 0x47, 0x11, 0x17];
-
 const TAG_DYN_AUTH: u8 = 0x7c;
 
 /// Cached YubiKey PIN.
-pub type CachedPin = secrecy::SecretVec<u8>;
+// TODO(tarcieri): add a newtype for this with a zeroize impl
+pub type CachedPin = Vec<u8>;
 
 /// YubiKey serial number.
-#[derive(Copy, Clone, Debug, Eq, PartialEq, PartialOrd, Ord)]
+#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash, PartialOrd, Ord)]
 pub struct Serial(pub u32);
 
 impl From<u32> for Serial {
@@ -99,6 +96,20 @@ impl From<Serial> for u32 {
     }
 }
 
+impl TryFrom<&[u8]> for Serial {
+    type Error = Error;
+
+    fn try_from(bytes: &[u8]) -> Result<Self> {
+        if bytes.len() > 4 {
+            return Err(Error::SizeError);
+        }
+
+        let mut arr = [0u8; 4];
+        arr[(4 - bytes.len())..].copy_from_slice(bytes);
+        Ok(Self(u32::from_be_bytes(arr)))
+    }
+}
+
 impl FromStr for Serial {
     type Err = Error;
 
@@ -135,6 +146,22 @@ impl Version {
             patch: bytes[2],
         }
     }
+
+    #[cfg(feature = "untested")]
+    pub(crate) fn parse(input: &[u8]) -> Result<Self> {
+        use nom::{combinator::eof, number::complete::u8};
+
+        let (i, major) = u8(input).map_err(|_: nom::Err<()>| Error::ParseError)?;
+        let (i, minor) = u8(i).map_err(|_: nom::Err<()>| Error::ParseError)?;
+        let (i, patch) = u8(i).map_err(|_: nom::Err<()>| Error::ParseError)?;
+        let (_i, _) = eof(i).map_err(|_: nom::Err<()>| Error::ParseError)?;
+
+        Ok(Self {
+            major,
+            minor,
+            patch,
+        })
+    }
 }
 
 impl Display for Version {
@@ -143,6 +170,39 @@ impl Display for Version {
     }
 }
 
+impl Ord for Version {
+    fn cmp(&self, other: &Self) -> Ordering {
+        if self.major > other.major {
+            return Ordering::Greater;
+        }
+        if self.major < other.major {
+            return Ordering::Less;
+        }
+
+        if self.minor > other.minor {
+            return Ordering::Greater;
+        }
+        if self.minor < other.minor {
+            return Ordering::Less;
+        }
+
+        if self.patch > other.patch {
+            return Ordering::Greater;
+        }
+        if self.patch < other.patch {
+            return Ordering::Less;
+        }
+
+        Ordering::Equal
+    }
+}
+
+impl PartialOrd for Version {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
 /// YubiKey device: primary API for opening a session and performing various operations.
 ///
 /// Almost all functionality in this library will require an open session
@@ -157,64 +217,101 @@ pub struct YubiKey {
     pub(crate) serial: Serial,
 }
 
+impl fmt::Debug for YubiKey {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.debug_struct("YubiKey")
+            .field("name", &self.name)
+            .field("version", &self.version)
+            .field("serial", &self.serial)
+            .finish_non_exhaustive()
+    }
+}
+
 impl YubiKey {
     /// Open a connection to a YubiKey.
     ///
-    /// Returns an error if there is more than one YubiKey detected.
+    /// Returns an error if more than one YubiKey is detected (or none at all).
+    ///
+    /// NOTE: If multiple YubiKeys are connected, but we are only able to
+    /// open one of them (e.g. because the other one is in use, and the
+    /// connection doesn't allow sharing), the YubiKey that we were able to
+    /// open is returned.
     ///
     /// If you need to operate in environments with more than one YubiKey
     /// attached to the same system, use [`YubiKey::open_by_serial`] or
     /// [`yubikey::reader::Context`][`Context`] to select from the available
     /// PC/SC readers.
     pub fn open() -> Result<Self> {
-        let mut readers = Context::open().map_err(|e| match e {
-            Error::PcscError {
-                inner: Some(pcsc::Error::NoReadersAvailable),
-            } => Error::NotFound,
-            other => other,
-        })?;
-        let mut reader_iter = readers.iter()?;
+        let mut yubikey: Option<Self> = None;
+
+        let mut readers = Context::open()?;
+        for reader in readers.iter()? {
+            if let Ok(yk_found) = reader.open() {
+                if let Some(yk_stored) = yubikey {
+                    // We found two YubiKeys, so we won't use either.
+                    // Don't reset them.
+                    let _ = yk_stored.disconnect(pcsc::Disposition::LeaveCard);
+                    let _ = yk_found.disconnect(pcsc::Disposition::LeaveCard);
 
-        if let Some(reader) = reader_iter.next() {
-            if reader_iter.next().is_some() {
                     error!("multiple YubiKeys detected!");
                     return Err(Error::PcscError { inner: None });
+                } else {
+                    yubikey = Some(yk_found);
+                }
+            }
         }
 
-            return reader.open();
-        }
-
+        if let Some(yubikey) = yubikey {
+            // We found exactly one YubiKey that we could open, so we return it.
+            Ok(yubikey)
+        } else {
             error!("no YubiKey detected!");
             Err(Error::NotFound)
         }
+    }
 
     /// Open a YubiKey with a specific serial number.
     pub fn open_by_serial(serial: Serial) -> Result<Self> {
-        let mut readers = Context::open().map_err(|e| match e {
-            Error::PcscError {
-                inner: Some(pcsc::Error::NoReadersAvailable),
-            } => Error::NotFound,
-            other => other,
-        })?;
+        let mut readers = Context::open()?;
+
+        let mut open_error = None;
 
         for reader in readers.iter()? {
             let yubikey = match reader.open() {
                 Ok(yk) => yk,
-                Err(_) => continue,
+                Err(e) => {
+                    // Save the first error we see that indicates we might have been able
+                    // to find a matching YubiKey.
+                    if open_error.is_none() {
+                        if let Error::PcscError {
+                            inner: Some(pcsc::Error::SharingViolation),
+                        } = e
+                        {
+                            open_error = Some(e);
+                        }
+                    }
+                    continue;
+                }
             };
 
             if serial == yubikey.serial() {
                 return Ok(yubikey);
+            } else {
+                // We didn't want this YubiKey; don't reset it.
+                let _ = yubikey.disconnect(pcsc::Disposition::LeaveCard);
             }
         }
 
+        Err(if let Some(e) = open_error {
+            e
+        } else {
             error!("no YubiKey detected with serial: {}", serial);
-        Err(Error::NotFound)
+            Error::NotFound
+        })
     }
 
     /// Reconnect to a YubiKey.
     #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub fn reconnect(&mut self) -> Result<()> {
         info!("trying to reconnect to current reader");
 
@@ -224,13 +321,10 @@ impl YubiKey {
             pcsc::Disposition::ResetCard,
         )?;
 
-        let pin = self
-            .pin
-            .as_ref()
-            .map(|p| Buffer::new(p.expose_secret().clone()));
+        let pin = self.pin.as_ref().map(|p| Buffer::new(p.clone()));
 
         let txn = Transaction::new(&mut self.card)?;
-        txn.select_application()?;
+        txn.select_piv_application()?;
 
         if let Some(p) = &pin {
             txn.verify_pin(p)?;
@@ -239,6 +333,41 @@ impl YubiKey {
         Ok(())
     }
 
+    /// Disconnect from the YubiKey.
+    ///
+    /// In case of error, ownership of the YubiKey is returned to the caller.
+    ///
+    /// # Note
+    ///
+    /// `YubiKey` implements `Drop` which automatically disconnects the card using
+    /// `Disposition::ResetCard`; you only need to call this function if you want to
+    /// handle errors or use a different disposition method.
+    pub fn disconnect(
+        self,
+        disposition: pcsc::Disposition,
+    ) -> core::result::Result<(), (Self, Error)> {
+        let Self {
+            card,
+            name,
+            pin,
+            version,
+            serial,
+        } = self;
+
+        card.disconnect(disposition).map_err(|(card, e)| {
+            (
+                Self {
+                    card,
+                    name,
+                    pin,
+                    version,
+                    serial,
+                },
+                e.into(),
+            )
+        })
+    }
+
     /// Begin a transaction.
     pub(crate) fn begin_transaction(&mut self) -> Result<Transaction<'_>> {
         // TODO(tarcieri): reconnect support
@@ -275,43 +404,52 @@ impl YubiKey {
     }
 
     /// Get Cardholder Capability Container (CCC) Identifier.
-    pub fn cccid(&mut self) -> Result<Ccc> {
-        Ccc::get(self)
+    pub fn cccid(&mut self) -> Result<CccId> {
+        CccId::get(self)
     }
 
     /// Authenticate to the card using the provided management key (MGM).
-    pub fn authenticate(&mut self, mgm_key: MgmKey) -> Result<()> {
+    pub fn authenticate(&mut self, mgm_key: &MgmKey) -> Result<()> {
         let txn = self.begin_transaction()?;
 
         // get a challenge from the card
-        let challenge = Apdu::new(Ins::Authenticate)
-            .params(ALGO_3DES, KEY_CARDMGM)
-            .data(&[TAG_DYN_AUTH, 0x02, 0x80, 0x00])
+        let card_response = Apdu::new(Ins::Authenticate)
+            .params(mgm_key.algorithm_id().into(), KEY_CARDMGM)
+            .data([TAG_DYN_AUTH, 0x02, 0x80, 0x00])
             .transmit(&txn, 261)?;
 
-        if !challenge.is_success() || challenge.data().len() < 12 {
+        if !card_response.is_success() || card_response.data().len() < 5 {
             return Err(Error::AuthenticationError);
         }
 
         // send a response to the cards challenge and a challenge of our own.
-        let response = mgm_key.decrypt(challenge.data()[4..12].try_into().unwrap());
+        let card_challenge = mgm_key.card_challenge(&card_response.data()[4..])?;
+        let challenge_len = card_challenge.len();
 
-        let mut data = [0u8; 22];
-        data[0] = TAG_DYN_AUTH;
-        data[1] = 20; // 2 + 8 + 2 +8
-        data[2] = 0x80;
-        data[3] = 8;
-        data[4..12].copy_from_slice(&response);
-        data[12] = 0x81;
-        data[13] = 8;
-        OsRng.fill_bytes(&mut data[14..22]);
+        // If this exceeds a `u8` then the card is giving us unexpected data.
+        let auth_len = (2 + challenge_len + 2 + challenge_len)
+            .try_into()
+            .map_err(|_| Error::AuthenticationError)?;
 
-        let mut challenge = [0u8; 8];
-        challenge.copy_from_slice(&data[14..22]);
+        let mut data = Vec::with_capacity(4 + challenge_len + 2 + challenge_len);
+        data.push(TAG_DYN_AUTH);
+        data.push(auth_len);
+        data.push(0x80);
+        data.push(challenge_len as u8);
+        data.extend_from_slice(&card_challenge);
+        data.push(0x81);
+        data.push(challenge_len as u8);
+
+        let mut host_challenge = vec![0u8; challenge_len];
+        SysRng
+            .try_fill_bytes(&mut host_challenge)
+            .map_err(|_| Error::GenericError)?;
+
+        data.extend_from_slice(&host_challenge);
 
         let authentication = Apdu::new(Ins::Authenticate)
-            .params(ALGO_3DES, KEY_CARDMGM)
-            .data(&data)
+            .params(mgm_key.algorithm_id().into(), KEY_CARDMGM)
+            .data(data)
             .transmit(&txn, 261)?;
 
         if !authentication.is_success() {
@@ -319,14 +457,7 @@ impl YubiKey {
         }
 
         // compare the response from the card with our challenge
-        let response = mgm_key.encrypt(&challenge);
-
-        use subtle::ConstantTimeEq;
-        if response.ct_eq(&authentication.data()[4..12]).unwrap_u8() != 1 {
-            return Err(Error::AuthenticationError);
-        }
-
-        Ok(())
+        mgm_key.check_challenge(&host_challenge, &authentication.data()[4..])
     }
 
     /// Get the PIV keys contained in this YubiKey.
@@ -336,13 +467,12 @@ impl YubiKey {
 
     /// Deauthenticate.
     #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub fn deauthenticate(&mut self) -> Result<()> {
         let txn = self.begin_transaction()?;
 
         let status_words = Apdu::new(Ins::SelectApplication)
             .p1(0x04)
-            .data(MGMT_AID)
+            .data(mgm::APPLET_ID)
             .transmit(&txn, 255)?
             .status_words();
 
@@ -351,7 +481,12 @@ impl YubiKey {
                 "Failed selecting mgmt application: {:04x}",
                 status_words.code()
             );
-            return Err(Error::GenericError);
+            return Err(match status_words {
+                StatusWords::NotFoundError => Error::AppletNotFound {
+                    applet_name: mgm::APPLET_NAME,
+                },
+                _ => Error::GenericError,
+            });
         }
 
         Ok(())
@@ -365,7 +500,7 @@ impl YubiKey {
         }
 
         if !pin.is_empty() {
-            self.pin = Some(CachedPin::new(pin.into()))
+            self.pin = Some(pin.into())
         }
 
         Ok(())
@@ -378,7 +513,7 @@ impl YubiKey {
         // Force a re-select to unverify, because once verified the spec dictates that
         // subsequent verify calls will return a "verification not needed" instead of
         // the number of tries left...
-        txn.select_application()?;
+        txn.select_piv_application()?;
 
         // WRONG_PIN is expected on successful query.
         match txn.verify_pin(&[]) {
@@ -390,7 +525,6 @@ impl YubiKey {
 
     /// Set the number of PIN retries.
     #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub fn set_pin_retries(&mut self, pin_tries: u8, puk_tries: u8) -> Result<()> {
         // Special case: if either retry count is 0, it's a successful no-op
         if pin_tries == 0 || puk_tries == 0 {
@@ -415,7 +549,6 @@ impl YubiKey {
     ///
     /// The default PIN code is `123456`.
     #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub fn change_pin(&mut self, current_pin: &[u8], new_pin: &[u8]) -> Result<()> {
         {
             let txn = self.begin_transaction()?;
@@ -423,7 +556,7 @@ impl YubiKey {
         }
 
         if !new_pin.is_empty() {
-            self.pin = Some(CachedPin::new(new_pin.into()));
+            self.pin = Some(new_pin.into());
         }
 
         Ok(())
@@ -431,7 +564,6 @@ impl YubiKey {
 
     /// Set PIN last changed.
     #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub fn set_pin_last_changed(yubikey: &mut YubiKey) -> Result<()> {
         let txn = yubikey.begin_transaction()?;
 
@@ -439,22 +571,17 @@ impl YubiKey {
 
         // TODO(tarcieri): double check this is little endian
         let tnow = SystemTime::now()
-            .duration_since(UNIX_EPOCH)
-            .unwrap()
+            .duration_since(UNIX_EPOCH)?
             .as_secs()
             .to_le_bytes();
 
         admin_data
             .set_item(TAG_ADMIN_TIMESTAMP, &tnow)
-            .map_err(|e| {
-                error!("could not set pin timestamp, err = {}", e);
-                e
-            })?;
+            .inspect_err(|e| error!("could not set pin timestamp, err = {}", e))?;
 
-        admin_data.write(&txn).map_err(|e| {
-            error!("could not write admin data, err = {}", e);
-            e
-        })?;
+        admin_data
+            .write(&txn)
+            .inspect_err(|e| error!("could not write admin data, err = {}", e))?;
 
         Ok(())
     }
@@ -467,7 +594,6 @@ impl YubiKey {
     ///
     /// The default PUK code is `12345678`.
     #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub fn change_puk(&mut self, current_puk: &[u8], new_puk: &[u8]) -> Result<()> {
         let txn = self.begin_transaction()?;
         txn.change_ref(ChangeRefAction::ChangePuk, current_puk, new_puk)
@@ -475,13 +601,12 @@ impl YubiKey {
 
     /// Block PUK: permanently prevent the PIN from becoming unblocked.
     #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
-    pub fn block_puk(yubikey: &mut YubiKey) -> Result<()> {
+    pub fn block_puk(&mut self) -> Result<()> {
         let mut puk = [0x30, 0x42, 0x41, 0x44, 0x46, 0x30, 0x30, 0x44];
         let mut tries_remaining: i32 = -1;
         let mut flags = [0];
 
-        let txn = yubikey.begin_transaction()?;
+        let txn = self.begin_transaction()?;
 
         while tries_remaining != 0 {
             // 2 -> change puk
@@ -506,7 +631,7 @@ impl YubiKey {
 
         // Attempt to set the "PUK blocked" flag in admin data.
         let mut admin_data = AdminData::read(&txn)
-            .map(|data| {
+            .inspect(|data| {
                 if let Ok(item) = data.get_item(TAG_ADMIN_FLAGS_1) {
                     if item.len() == flags.len() {
                         flags.copy_from_slice(item)
@@ -518,8 +643,6 @@ impl YubiKey {
                         );
                     }
                 }
-
-                data
             })
             .unwrap_or_default();
 
@@ -539,7 +662,6 @@ impl YubiKey {
     /// Unblock a Personal Identification Number (PIN) using a previously
     /// configured PIN Unblocking Key (PUK).
     #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub fn unblock_pin(&mut self, puk: &[u8], new_pin: &[u8]) -> Result<()> {
         let txn = self.begin_transaction()?;
         txn.change_ref(ChangeRefAction::UnblockPin, puk, new_pin)
@@ -547,7 +669,6 @@ impl YubiKey {
 
     /// Fetch an object from the YubiKey.
     #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub fn fetch_object(&mut self, object_id: ObjectId) -> Result<Buffer> {
         let txn = self.begin_transaction()?;
         txn.fetch_object(object_id)
@@ -555,7 +676,6 @@ impl YubiKey {
 
     /// Save an object.
     #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub fn save_object(&mut self, object_id: ObjectId, indata: &mut [u8]) -> Result<()> {
         let txn = self.begin_transaction()?;
         txn.save_object(object_id, indata)
@@ -563,25 +683,27 @@ impl YubiKey {
 
     /// Get an auth challenge.
     #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub fn get_auth_challenge(&mut self) -> Result<[u8; 8]> {
         let txn = self.begin_transaction()?;
 
         let response = Apdu::new(Ins::Authenticate)
             .params(ALGO_3DES, KEY_CARDMGM)
-            .data(&[0x7c, 0x02, 0x81, 0x00])
+            .data([0x7c, 0x02, 0x81, 0x00])
             .transmit(&txn, 261)?;
 
         if !response.is_success() {
             return Err(Error::AuthenticationError);
         }
 
-        Ok(response.data()[4..12].try_into().unwrap())
+        Ok(response
+            .data()
+            .get(4..12)
+            .ok_or(Error::SizeError)?
+            .try_into()?)
     }
 
     /// Verify an auth response.
     #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub fn verify_auth_response(&mut self, response: [u8; 8]) -> Result<()> {
         let mut data = [0u8; 12];
         data[0] = 0x7c;
@@ -595,7 +717,7 @@ impl YubiKey {
         // send the response to the card and a challenge of our own.
         let status_words = Apdu::new(Ins::Authenticate)
             .params(ALGO_3DES, KEY_CARDMGM)
-            .data(&data)
+            .data(data)
             .transmit(&txn, 261)?
             .status_words();
 
@@ -612,7 +734,6 @@ impl YubiKey {
     ///
     /// The reset function is only available when both pins are blocked.
     #[cfg(feature = "untested")]
-    #[cfg_attr(docsrs, doc(cfg(feature = "untested")))]
     pub fn reset_device(&mut self) -> Result<()> {
         let templ = [0, Ins::Reset.code(), 0, 0];
         let txn = self.begin_transaction()?;
@@ -630,22 +751,36 @@ impl<'a> TryFrom<&'a Reader<'_>> for YubiKey {
     type Error = Error;
 
     fn try_from(reader: &'a Reader<'_>) -> Result<Self> {
-        let mut card = reader.connect().map_err(|e| {
-            error!("error connecting to reader '{}': {}", reader.name(), e);
-            e
-        })?;
+        let mut card = reader
+            .connect()
+            .inspect_err(|e| error!("error connecting to reader '{}': {}", reader.name(), e))?;
 
         info!("connected to reader: {}", reader.name());
 
-        let (version, serial) = {
+        let mut app_version_serial = || -> Result<(Version, Serial)> {
             let txn = Transaction::new(&mut card)?;
-            txn.select_application()?;
+            txn.select_piv_application()?;
 
             let v = txn.get_version()?;
             let s = txn.get_serial(v)?;
-            (v, s)
+            Ok((v, s))
         };
 
+        match app_version_serial() {
+            Err(e) => {
+                error!("Could not use reader: {}", e);
+
+                // We were unable to use the card, so we've effectively only connected as
+                // a side-effect of determining this. Avoid disrupting its internal state
+                // any further (e.g. preserve the PIN cache of whatever applet is selected
+                // currently).
+                if let Err((_, e)) = card.disconnect(pcsc::Disposition::LeaveCard) {
+                    error!("Failed to disconnect gracefully from card: {}", e);
+                }
+
+                Err(e)
+            }
+            Ok((version, serial)) => {
                 let yubikey = YubiKey {
                     card,
                     name: String::from(reader.name()),
@@ -657,3 +792,5 @@ impl<'a> TryFrom<&'a Reader<'_>> for YubiKey {
                 Ok(yubikey)
             }
         }
+    }
+}

tests/assets/Bob.crt

@@ -0,0 +1,85 @@
+Certificate:
+    Data:
+        Version: 3 (0x2)
+        Serial Number:
+            d4:29:8f:df:8a:af:7b:c0:d7:bf:19:9d:90:d5:ef:ca
+    Signature Algorithm: sha256WithRSAEncryption
+        Issuer: CN=Ferdinand Linnenberg CA
+        Validity
+            Not Before: Feb 10 12:25:37 2022 GMT
+            Not After : May 15 12:25:37 2024 GMT
+        Subject: CN=Bob
+        Subject Public Key Info:
+            Public Key Algorithm: rsaEncryption
+                Public-Key: (2048 bit)
+                Modulus:
+                    00:d5:27:9b:99:1b:3a:36:64:36:c8:e5:78:64:b6:
+                    9d:70:9d:29:6c:0e:85:91:4b:78:3b:dc:16:c3:09:
+                    8c:d3:74:20:8c:6f:ed:c3:90:c9:1b:4d:80:d5:46:
+                    da:52:7f:d2:2f:bc:b2:f7:40:8d:ad:dd:24:b9:5c:
+                    dc:a2:21:2f:48:ec:06:93:8b:89:f0:cd:63:ff:a1:
+                    fd:ce:36:d5:07:7a:1e:0e:cf:68:a8:c1:b3:7f:62:
+                    84:b7:e1:cf:25:7b:3f:a8:3c:ac:07:1a:fd:c2:e1:
+                    e0:9e:26:24:c1:0d:6d:9d:c6:57:6a:b4:39:28:3d:
+                    88:3e:c9:6a:89:90:72:4a:7b:75:c5:5e:1b:5e:5c:
+                    32:54:a3:ff:eb:01:68:7f:89:b4:4c:01:3f:08:8e:
+                    6c:61:49:60:26:0b:26:58:81:d7:1a:57:ee:52:5c:
+                    05:47:de:da:eb:b5:92:9d:5b:ce:26:18:44:59:3e:
+                    27:d0:61:86:e2:f4:c6:d9:c7:2b:1f:cb:ea:78:f0:
+                    a1:a9:57:d7:98:4c:c1:2f:ae:6a:38:b4:34:53:2e:
+                    5a:9e:f8:58:c7:51:e7:fd:b8:27:cd:87:72:26:c1:
+                    7d:14:c7:cd:fb:f2:04:8a:c4:8f:61:cf:a8:78:bd:
+                    21:be:28:cb:e8:a8:65:29:28:82:46:2f:18:e6:ff:
+                    6f:53
+                Exponent: 65537 (0x10001)
+        X509v3 extensions:
+            X509v3 Basic Constraints: 
+                CA:FALSE
+            X509v3 Subject Key Identifier: 
+                B5:A5:F0:37:25:97:AD:BE:F1:43:52:45:4D:8B:A0:5E:E9:78:21:B8
+            X509v3 Authority Key Identifier: 
+                keyid:26:4E:EB:B0:A5:1B:08:A8:90:2A:85:04:73:84:B5:A5:2C:61:D6:91
+                DirName:/CN=Ferdinand Linnenberg CA
+                serial:8C:E0:40:D9:D8:60:E5:77
+
+            X509v3 Extended Key Usage: 
+                TLS Web Client Authentication
+            X509v3 Key Usage: 
+                Digital Signature
+    Signature Algorithm: sha256WithRSAEncryption
+         19:f3:eb:c1:95:e6:d5:a9:33:d7:2e:02:d8:3a:91:84:81:14:
+         93:fc:03:4d:b1:4b:9d:0b:9b:94:93:9f:1a:0d:87:31:a1:fa:
+         a6:c7:3a:6b:18:24:12:ab:28:fb:c8:e3:09:a2:5d:50:49:00:
+         d9:18:e6:4a:09:18:e0:1c:da:d3:19:96:3d:74:72:fe:e0:8f:
+         ee:59:54:66:2e:57:72:b8:91:55:06:13:e5:9e:89:a2:3a:13:
+         3b:45:30:d3:cd:15:0e:81:eb:4f:b0:6a:a4:6d:00:7d:5b:c0:
+         4a:7f:97:d0:27:27:31:ae:3e:72:f1:74:fe:86:8e:29:a9:42:
+         23:26:22:db:08:8b:df:e9:d3:83:8d:81:10:36:d7:33:68:5e:
+         cb:93:cb:1e:12:c8:cb:be:5e:5c:8e:58:b0:1d:06:5e:c9:98:
+         b7:f1:49:fe:c4:03:de:b4:2b:da:9d:2c:7d:98:37:1c:6c:a8:
+         95:21:6f:23:e3:2e:09:bc:6c:e5:ed:e2:50:d8:f7:da:45:39:
+         d8:34:8a:57:0c:4f:d0:0d:80:06:d6:34:63:72:27:d1:50:d1:
+         d2:21:2c:97:57:17:98:02:95:3a:96:ed:75:9f:cc:f3:b8:f1:
+         3a:85:f9:58:08:9b:a0:75:fd:9b:fd:31:dd:08:dc:14:3d:f4:
+         68:aa:d4:30
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

tests/assets/Bob.key

@@ -0,0 +1,30 @@
+-----BEGIN ENCRYPTED PRIVATE KEY-----
+MIIFHDBOBgkqhkiG9w0BBQ0wQTApBgkqhkiG9w0BBQwwHAQIi6DixMpf5PQCAggA
+MAwGCCqGSIb3DQIJBQAwFAYIKoZIhvcNAwcECLgvCsIAjjXRBIIEyDAss0V4NrI5
+W7KXPRgRJ1tqvQrWZQTIFu4Crzs9Inb4TtSv5mATI9ZU2RMFF6MYXlhIxJng861P
+5IWcU6VeOjRFej8wcB3uTvD2z7NB2cyA5BZSojrZfX5OIEKL9sBzn0vinqmm5N1z
+oXhLMgf0FZssA3+zjIf04vtvmk5pxTCE6dq6vlsEIJyQ0xGc39bStIwk2a4E9wvi
+XayKNJnRFSrTahuI3DvQJPd9TdmM6sBKnrcJrDa6LvH51SrGzW8bBEjDAmC7yJdi
+mBckFTjZ6rGrSxOI6HdnF9RP+y9OiLE4ou5OJ9MbBtngq9OrTImAMZ5ftWowaqX/
+Do1UTqixi4ecWrr5fr1+A2Vch0I1drds2e/mmLR+5GEQXQXZPZKjtPMwxM/AYnTZ
+w/M3T9KtwSj0s5G6Saz4WpzaUL7wATb/UNqMr8Ifl8mHEVoFZhvoRpMWA7Yj1oPb
+cHz8lsfoSrTnK+zLR8ZK3HRu4MtpdCNVwQIJ67T6Feb8YLwYSccTNHBSqUmWRD95
+wOOqY33xcfplaQ2Y+/8+mHScGSEPNmC4f7EggDeUnG3ow0f4n95DENO+aYqGLjSF
++XdCjhD+NTNdlV0z50B6P2XWUoBZOOnPfgFf4nAgn7xQbkZZOk5bQDKo2Zu9jW9/
+uJyTHqI58tcopI3cjd5iQXOJUrM4OWpPIu3p+VWaIAA8JzJIfDN6fyQ3qsMr305L
+30JcjrH6if/6J+2g+DpMAK928JY2hfE8VNWH7096ZnArp42/hLYsNuYnSrL1eS+g
+F/4mvyZyLLTFyB0Frnic4I1QTuNkNmwSrm/B5wIWLqkS7XAyyDDXAcaTHdZCN6nM
+O2OuF7DfBsFcNMM4VagG5adPS9CYkvz0EEh6ho5XiP2yL3tZfsHyuB4njAsV3aFi
+D0Yq7QiCf5iA2d4KsYO6yr1wPfVhlsmPi3++mrHulBwwCQWHTlPgRZnjj1xgmPcQ
+00KsUVh+CMWlf20O5sKhzjvkzbwUj1K+ZfMDuuq1RbzFRSx+Gx8vIaThFg9kVyoP
+zuvzsT6qc3BGNHmaGZ3d5Re25AuGRTF4cTpDfjW0UL7Wnvnis7iMrUasDhyF7CFn
+/KG7eKzxqS08o6D4AM5S/fzZEtszoEgAga6DS2R75FVskDweWuEIsar9UGg3UlmW
+q3+rRPRf1CzrLtyYenkkLg/ajr8JOnFGqZVaLmMnegZQH6rF3aEzlQLNgbNepcuA
+ObSmAO6MR3MlQgdsH/lNzOPdj1gKcE25hOjGfmwgbOXSJv9Cz0bcBLFEyLZSNpRk
+HhNejj6BEz/Cmqg1wm7SOBHsXJGcOTnLO1Y3FBt0I7heWvWmj9rOLG9tvvx9dtrP
+pQyDbIcWonuXLrXYSPyOjmeWoQSzdH3NsCswBV4G+iOiLCJDkElR+mrwKbhtS88T
+3YeZnsCTsmH+jZpxGgPTObjIG91U4UE4Pnkwc2df355VuOKrf0rB/NK0A9hZGqsV
+nxtodjn92P6UFzmfEdt95pMcmurK9wkm1kRkP7cIyAs2lCOIdbgGsszz6Mk16Xqy
+49RdhLxJrJ4gkYZIAbY+KNGVc7uPhm/T9xGrIstbEsoUM7jy7nHMOCCDgdbwX/4X
+caMeSMZcZ+RvraDDBEbSbg==
+-----END ENCRYPTED PRIVATE KEY-----

tests/integration.rs

@@ -3,37 +3,38 @@
 #![forbid(unsafe_code)]
 #![warn(missing_docs, rust_2018_idioms, trivial_casts, unused_qualifications)]
 
-use lazy_static::lazy_static;
+use cipher::common::{getrandom::SysRng, Generate};
 use log::trace;
-use rand_core::{OsRng, RngCore};
-use rsa::{hash::Hash::SHA2_256, PaddingScheme, PublicKey};
+use once_cell::sync::Lazy;
+use rsa::{pkcs1v15, RsaPublicKey};
 use sha2::{Digest, Sha256};
-use std::{convert::TryInto, env, sync::Mutex};
-use x509::RelativeDistinguishedName;
+use signature::hazmat::PrehashVerifier;
+use std::{env, str::FromStr, sync::Mutex, time::Duration};
+use x509_cert::{der::Encode, name::Name, serial_number::SerialNumber, time::Validity};
 use yubikey::{
-    certificate::{Certificate, PublicKeyInfo},
-    piv::{self, AlgorithmId, Key, RetiredSlotId, SlotId},
-    Error, MgmKey, PinPolicy, TouchPolicy, YubiKey,
+    certificate::{yubikey_signer, Certificate},
+    piv::{self, AlgorithmId, Key, ManagementSlotId, RetiredSlotId, SlotId},
+    Error, MgmKey, PinPolicy, Serial, TouchPolicy, YubiKey,
 };
 
-lazy_static! {
-    /// Provide thread-safe access to a YubiKey
-    static ref YUBIKEY: Mutex<YubiKey> = init_yubikey();
-}
-
-/// One-time test initialization and setup
-fn init_yubikey() -> Mutex<YubiKey> {
+static YUBIKEY: Lazy<Mutex<YubiKey>> = Lazy::new(|| {
     // Only show logs if `RUST_LOG` is set
     if env::var("RUST_LOG").is_ok() {
         env_logger::builder().format_timestamp(None).init();
     }
 
-    let yubikey = YubiKey::open().unwrap();
+    let yubikey = if let Ok(serial) = env::var("YUBIKEY_SERIAL") {
+        let serial = Serial::from_str(&serial).unwrap();
+        YubiKey::open_by_serial(serial).unwrap()
+    } else {
+        YubiKey::open().unwrap()
+    };
+
     trace!("serial: {}", yubikey.serial());
     trace!("version: {}", yubikey.version());
 
     Mutex::new(yubikey)
-}
+});
 
 //
 // CCCID support
@@ -42,12 +43,15 @@ fn init_yubikey() -> Mutex<YubiKey> {
 #[test]
 #[ignore]
 fn test_get_cccid() {
-    let mut yubikey = YUBIKEY.lock().unwrap();
+    let mut yubikey = match YUBIKEY.lock() {
+        Ok(yubikey) => yubikey,
+        Err(poison) => poison.into_inner(),
+    };
 
     match yubikey.cccid() {
         Ok(cccid) => trace!("CCCID: {:?}", cccid),
         Err(Error::NotFound) => trace!("CCCID not found"),
-        Err(err) => panic!("error getting CCCID: {:?}", err),
+        Err(err) => panic!("error getting CCCID: {err:?}"),
     }
 }
 
@@ -58,12 +62,15 @@ fn test_get_cccid() {
 #[test]
 #[ignore]
 fn test_get_chuid() {
-    let mut yubikey = YUBIKEY.lock().unwrap();
+    let mut yubikey = match YUBIKEY.lock() {
+        Ok(yubikey) => yubikey,
+        Err(poison) => poison.into_inner(),
+    };
 
     match yubikey.chuid() {
         Ok(chuid) => trace!("CHUID: {:?}", chuid),
         Err(Error::NotFound) => trace!("CHUID not found"),
-        Err(err) => panic!("error getting CHUID: {:?}", err),
+        Err(err) => panic!("error getting CHUID: {err:?}"),
     }
 }
 
@@ -74,7 +81,10 @@ fn test_get_chuid() {
 #[test]
 #[ignore]
 fn test_get_config() {
-    let mut yubikey = YUBIKEY.lock().unwrap();
+    let mut yubikey = match YUBIKEY.lock() {
+        Ok(yubikey) => yubikey,
+        Err(poison) => poison.into_inner(),
+    };
     let config_result = yubikey.config();
     assert!(config_result.is_ok());
     trace!("config: {:?}", config_result.unwrap());
@@ -87,7 +97,10 @@ fn test_get_config() {
 #[test]
 #[ignore]
 fn test_list_keys() {
-    let mut yubikey = YUBIKEY.lock().unwrap();
+    let mut yubikey = match YUBIKEY.lock() {
+        Ok(yubikey) => yubikey,
+        Err(poison) => poison.into_inner(),
+    };
     let keys_result = Key::list(&mut yubikey);
     assert!(keys_result.is_ok());
     trace!("keys: {:?}", keys_result.unwrap());
@@ -100,7 +113,10 @@ fn test_list_keys() {
 #[test]
 #[ignore]
 fn test_verify_pin() {
-    let mut yubikey = YUBIKEY.lock().unwrap();
+    let mut yubikey = match YUBIKEY.lock() {
+        Ok(yubikey) => yubikey,
+        Err(poison) => poison.into_inner(),
+    };
     assert!(yubikey.verify_pin(b"000000").is_err());
     assert!(yubikey.verify_pin(b"123456").is_ok());
 }
@@ -113,43 +129,52 @@ fn test_verify_pin() {
 #[test]
 #[ignore]
 fn test_set_mgmkey() {
-    let mut yubikey = YUBIKEY.lock().unwrap();
+    let mut rng = SysRng;
+    let mut yubikey = match YUBIKEY.lock() {
+        Ok(yubikey) => yubikey,
+        Err(poison) => poison.into_inner(),
+    };
+    let default_key = MgmKey::get_default(&yubikey).unwrap();
 
     assert!(yubikey.verify_pin(b"123456").is_ok());
     assert!(MgmKey::get_protected(&mut yubikey).is_err());
-    assert!(yubikey.authenticate(MgmKey::default()).is_ok());
+    assert!(yubikey.authenticate(&default_key).is_ok());
 
     // Set a protected management key.
-    assert!(MgmKey::generate().set_protected(&mut yubikey).is_ok());
+    assert!(MgmKey::generate_for(&yubikey, &mut rng)
+        .unwrap()
+        .set_protected(&mut yubikey)
+        .is_ok());
     let protected = MgmKey::get_protected(&mut yubikey).unwrap();
-    assert!(yubikey.authenticate(MgmKey::default()).is_err());
-    assert!(yubikey.authenticate(protected.clone()).is_ok());
+    assert!(yubikey.authenticate(&default_key).is_err());
+    assert!(yubikey.authenticate(&protected).is_ok());
 
     // Set a manual management key.
-    let manual = MgmKey::generate();
+    let manual = MgmKey::generate_for(&yubikey, &mut rng).unwrap();
     assert!(manual.set_manual(&mut yubikey, false).is_ok());
     assert!(MgmKey::get_protected(&mut yubikey).is_err());
-    assert!(yubikey.authenticate(MgmKey::default()).is_err());
-    assert!(yubikey.authenticate(protected.clone()).is_err());
-    assert!(yubikey.authenticate(manual.clone()).is_ok());
+    assert!(yubikey.authenticate(&default_key).is_err());
+    assert!(yubikey.authenticate(&protected).is_err());
+    assert!(yubikey.authenticate(&manual).is_ok());
 
     // Set back to the default management key.
     assert!(MgmKey::set_default(&mut yubikey).is_ok());
     assert!(MgmKey::get_protected(&mut yubikey).is_err());
-    assert!(yubikey.authenticate(protected).is_err());
-    assert!(yubikey.authenticate(manual).is_err());
-    assert!(yubikey.authenticate(MgmKey::default()).is_ok());
+    assert!(yubikey.authenticate(&protected).is_err());
+    assert!(yubikey.authenticate(&manual).is_err());
+    assert!(yubikey.authenticate(&default_key).is_ok());
 }
 
 //
 // Certificate support
 //
 
-fn generate_self_signed_cert(algorithm: AlgorithmId) -> Certificate {
+fn generate_self_signed_cert<KT: yubikey_signer::KeyType>() -> Certificate {
     let mut yubikey = YUBIKEY.lock().unwrap();
+    let default_key = MgmKey::get_default(&yubikey).unwrap();
 
     assert!(yubikey.verify_pin(b"123456").is_ok());
-    assert!(yubikey.authenticate(MgmKey::default()).is_ok());
+    assert!(yubikey.authenticate(&default_key).is_ok());
 
     let slot = SlotId::Retired(RetiredSlotId::R1);
 
@@ -157,25 +182,27 @@ fn generate_self_signed_cert(algorithm: AlgorithmId) -> Certificate {
     let generated = piv::generate(
         &mut yubikey,
         slot,
-        algorithm,
+        KT::ALGORITHM,
         PinPolicy::Default,
         TouchPolicy::Default,
     )
     .unwrap();
 
-    let mut serial = [0u8; 20];
-    OsRng.fill_bytes(&mut serial);
+    // 0x80 0x00 ... (20bytes) is invalid because of high MSB (serial will keep the sign)
+    // we'll limit ourselves to 19 bytes serial.
+    let serial = <[u8; 19]>::generate();
+    let serial = SerialNumber::new(&serial[..]).expect("serial can't be more than 20 bytes long");
+    let validity = Validity::from_now(Duration::new(500000, 0)).unwrap();
 
     // Generate a self-signed certificate for the new key.
-    let extensions: &[x509::Extension<'_, &[u64]>] = &[];
-    let cert_result = Certificate::generate_self_signed(
+    let cert_result = Certificate::generate_self_signed::<_, KT>(
         &mut yubikey,
         slot,
         serial,
-        None,
-        &[RelativeDistinguishedName::common_name("testSubject")],
+        validity,
+        Name::from_str("CN=testSubject").expect("parse name"),
         generated,
-        extensions,
+        |_builder| Ok(()),
     );
 
     assert!(cert_result.is_ok());
@@ -187,57 +214,247 @@ fn generate_self_signed_cert(algorithm: AlgorithmId) -> Certificate {
 #[test]
 #[ignore]
 fn generate_self_signed_rsa_cert() {
-    let cert = generate_self_signed_cert(AlgorithmId::Rsa1024);
+    let cert = generate_self_signed_cert::<yubikey_signer::YubiRsa<yubikey_signer::Rsa1024>>();
 
     //
     // Verify that the certificate is signed correctly
     //
 
-    let pubkey = match cert.subject_pki() {
-        PublicKeyInfo::Rsa { pubkey, .. } => pubkey,
-        _ => unreachable!(),
-    };
+    let pubkey = RsaPublicKey::try_from(cert.subject_pki()).expect("valid rsa key");
+    let pubkey = pkcs1v15::VerifyingKey::<Sha256>::new(pubkey);
 
-    let data = cert.as_ref();
+    let data = cert.cert.to_der().expect("serialize certificate");
     let tbs_cert_len = u16::from_be_bytes(data[6..8].try_into().unwrap()) as usize;
     let msg = &data[4..8 + tbs_cert_len];
-    let sig = &data[data.len() - 128..];
-
+    let sig = pkcs1v15::Signature::try_from(&data[data.len() - 128..]).unwrap();
     let hash = Sha256::digest(msg);
 
-    assert!(pubkey
-        .verify(
-            PaddingScheme::PKCS1v15Sign {
-                hash: Some(SHA2_256)
-            },
-            &hash,
-            sig
-        )
-        .is_ok());
+    assert!(pubkey.verify_prehash(&hash, &sig).is_ok());
+}
+
+#[test]
+#[ignore]
+fn generate_rsa3072() {
+    let mut yubikey = YUBIKEY.lock().unwrap();
+    let version = yubikey.version();
+    let default_key = MgmKey::get_default(&yubikey).unwrap();
+
+    assert!(yubikey.authenticate(&default_key).is_ok());
+
+    let slot = SlotId::Retired(RetiredSlotId::R1);
+
+    // Generate a new key in the selected slot.
+    let generated = piv::generate(
+        &mut yubikey,
+        slot,
+        AlgorithmId::Rsa3072,
+        PinPolicy::Default,
+        TouchPolicy::Default,
+    );
+
+    match generated {
+        Ok(key) => {
+            let pubkey = key.subject_public_key;
+            assert!(pubkey.bit_len() > 3072)
+        }
+        Err(e) => assert!((version.major, version.minor) < (5, 7) && e == Error::AlgorithmError),
+    }
 }
 
 #[test]
 #[ignore]
 fn generate_self_signed_ec_cert() {
-    let cert = generate_self_signed_cert(AlgorithmId::EccP256);
+    let cert = generate_self_signed_cert::<p256::NistP256>();
 
     //
     // Verify that the certificate is signed correctly
     //
 
-    let pubkey = match cert.subject_pki() {
-        PublicKeyInfo::EcP256(pubkey) => pubkey,
-        _ => unreachable!(),
-    };
+    let vk = p256::ecdsa::VerifyingKey::try_from(cert.subject_pki()).expect("ecdsa key expected");
 
-    let data = cert.as_ref();
+    let data = cert.cert.to_der().expect("serialize certificate");
     let tbs_cert_len = data[6] as usize;
     let sig_algo_len = data[7 + tbs_cert_len + 1] as usize;
     let sig_start = 7 + tbs_cert_len + 2 + sig_algo_len + 3;
     let msg = &data[4..7 + tbs_cert_len];
     let sig = p256::ecdsa::Signature::from_der(&data[sig_start..]).unwrap();
-    let vk = p256::ecdsa::VerifyingKey::from_sec1_bytes(pubkey.as_bytes()).unwrap();
 
     use p256::ecdsa::signature::Verifier;
     assert!(vk.verify(msg, &sig).is_ok());
 }
+
+#[test]
+#[ignore]
+fn generate_self_signed_cv_cert() {
+    let cert = generate_self_signed_cert::<ed25519_dalek::SigningKey>();
+
+    //
+    // Verify that the certificate is signed correctly
+    //
+
+    let pubkey =
+        ed25519_dalek::VerifyingKey::try_from(cert.subject_pki()).expect("ed25519 key expected");
+
+    let data = cert.cert.to_der().expect("serialize certificate");
+    let cert_len = data[2] as usize;
+    let tbs_cert_len = data[5] as usize;
+    let sig_algo_len: usize = 64;
+    let sig_start = cert_len - sig_algo_len + 3;
+    let msg = &data[3..6 + tbs_cert_len];
+    let sig =
+        ed25519_dalek::Signature::from_slice(&data[sig_start..sig_start + sig_algo_len]).unwrap();
+
+    use ed25519_dalek::Verifier;
+    assert!(pubkey.verify(msg, &sig).is_ok());
+}
+
+#[test]
+#[ignore]
+fn test_slot_id_display() {
+    assert_eq!(format!("{}", SlotId::Authentication), "Authentication");
+    assert_eq!(format!("{}", SlotId::Signature), "Signature");
+    assert_eq!(format!("{}", SlotId::KeyManagement), "KeyManagement");
+    assert_eq!(
+        format!("{}", SlotId::CardAuthentication),
+        "CardAuthentication"
+    );
+    assert_eq!(format!("{}", SlotId::Attestation), "Attestation");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R1)), "R1");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R2)), "R2");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R3)), "R3");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R4)), "R4");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R5)), "R5");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R6)), "R6");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R7)), "R7");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R8)), "R8");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R9)), "R9");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R10)), "R10");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R11)), "R11");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R12)), "R12");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R13)), "R13");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R14)), "R14");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R15)), "R15");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R16)), "R16");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R17)), "R17");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R18)), "R18");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R19)), "R19");
+    assert_eq!(format!("{}", SlotId::Retired(RetiredSlotId::R20)), "R20");
+
+    assert_eq!(
+        format!("{}", SlotId::Management(ManagementSlotId::Pin)),
+        "Pin"
+    );
+    assert_eq!(
+        format!("{}", SlotId::Management(ManagementSlotId::Puk)),
+        "Puk"
+    );
+    assert_eq!(
+        format!("{}", SlotId::Management(ManagementSlotId::Management)),
+        "Management"
+    );
+}
+
+//
+// Metadata
+//
+
+#[test]
+#[ignore]
+fn test_read_metadata() {
+    let mut yubikey = match YUBIKEY.lock() {
+        Ok(yubikey) => yubikey,
+        Err(poison) => poison.into_inner(),
+    };
+    let default_key = MgmKey::get_default(&yubikey).unwrap();
+
+    assert!(yubikey.verify_pin(b"123456").is_ok());
+    assert!(yubikey.authenticate(&default_key).is_ok());
+
+    let slot = SlotId::Retired(RetiredSlotId::R1);
+
+    // Generate a new key in the selected slot.
+    let generated = piv::generate(
+        &mut yubikey,
+        slot,
+        AlgorithmId::EccP256,
+        PinPolicy::Default,
+        TouchPolicy::Default,
+    )
+    .unwrap();
+
+    match piv::metadata(&mut yubikey, slot) {
+        Ok(metadata) => assert_eq!(metadata.public, Some(generated)),
+        Err(Error::NotSupported) => {
+            // Some YubiKeys don't support metadata
+            eprintln!("metadata not supported by this YubiKey");
+        }
+        Err(err) => panic!("{}", err),
+    }
+}
+
+#[test]
+#[ignore]
+fn test_read_metadata_missing_key() {
+    let mut yubikey = YUBIKEY.lock().unwrap();
+    let default_key = MgmKey::get_default(&yubikey).unwrap();
+
+    assert!(yubikey.verify_pin(b"123456").is_ok());
+    assert!(yubikey.authenticate(&default_key).is_ok());
+
+    // we assume that at least one of these slots is empty
+    let slots_to_check = [
+        RetiredSlotId::R10,
+        RetiredSlotId::R11,
+        RetiredSlotId::R12,
+        RetiredSlotId::R13,
+        RetiredSlotId::R14,
+        RetiredSlotId::R15,
+        RetiredSlotId::R16,
+        RetiredSlotId::R17,
+        RetiredSlotId::R18,
+        RetiredSlotId::R19,
+        RetiredSlotId::R20,
+    ];
+
+    for slot in slots_to_check {
+        let slot = SlotId::Retired(slot);
+
+        match piv::metadata(&mut yubikey, slot) {
+            Ok(_) => {
+                eprintln!("Key {} exists", slot);
+            }
+            Err(Error::NotSupported) => {
+                // Some YubiKeys don't support metadata
+                eprintln!("metadata not supported by this YubiKey");
+                return;
+            }
+            Err(Error::NotFound) => {
+                eprintln!("Key {} doesn't exist, ok.", slot);
+                return;
+            }
+            Err(err) => panic!("{}", err),
+        }
+    }
+
+    panic!("No empty slots to check");
+}
+
+#[test]
+#[ignore]
+fn test_parse_cert_from_der() {
+    let bob_der = std::fs::read("tests/assets/Bob.der").expect(".der file not found");
+    let cert = Certificate::from_bytes(bob_der).expect("Failed to parse valid certificate");
+    assert_eq!(
+        cert.subject(),
+        "CN=Bob",
+        "Subject is {} should be CN=Bob",
+        cert.subject()
+    );
+    assert_eq!(
+        cert.issuer(),
+        "CN=Ferdinand Linnenberg CA",
+        "Issuer is {} should be {}",
+        cert.issuer(),
+        "CN=Ferdinand Linnenberg CA"
+    );
+}