Merge pull request #141 from str4d/release-0.4.0

Release 0.4.0

.github/workflows/ci.yml

@@ -23,116 +23,42 @@ jobs:
 
     steps:
       - uses: actions/checkout@v3
-      - uses: actions-rs/toolchain@v1
-        with:
-          toolchain: 1.56.0
-          override: true
       - name: Install build dependencies
         run: sudo apt install ${{ matrix.build_deps }}
         if: matrix.build_deps != ''
-      - name: cargo fetch
-        uses: actions-rs/cargo@v1
-        with:
-          command: fetch
+      - name: Install test dependencies
+        run: cargo install rage
+      - run: cargo fetch
       - name: Build tests
-        uses: actions-rs/cargo@v1
-        with:
-          command: build
-          args: --verbose --tests
+        run: cargo build --verbose --tests
       - name: Run tests
-        uses: actions-rs/cargo@v1
-        with:
-          command: test
-          args: --verbose
-
-  clippy:
-    name: Clippy (1.56.0)
-    timeout-minutes: 30
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v3
-      - uses: actions-rs/toolchain@v1
-        with:
-          toolchain: 1.56.0
-          components: clippy
-          override: true
-      - name: Install build dependencies
-        run: sudo apt install libpcsclite-dev
-      - name: Run clippy
-        uses: actions-rs/clippy-check@v1
-        with:
-          name: Clippy (1.56.0)
-          token: ${{ secrets.GITHUB_TOKEN }}
-          args: --all-features --all-targets -- -D warnings
-
-  clippy-nightly:
-    name: Clippy (nightly)
-    timeout-minutes: 30
-    runs-on: ubuntu-latest
-    continue-on-error: true
-    steps:
-      - uses: actions/checkout@v3
-      - uses: actions-rs/toolchain@v1
-        with:
-          toolchain: nightly
-          components: clippy
-          override: true
-      - name: Install build dependencies
-        run: sudo apt install libpcsclite-dev
-      - name: Run Clippy (nightly)
-        uses: actions-rs/clippy-check@v1
-        continue-on-error: true
-        with:
-          name: Clippy (nightly)
-          token: ${{ secrets.GITHUB_TOKEN }}
-          args: --all-features --all-targets
+        run: cargo test --verbose
 
   codecov:
     name: Code coverage
     runs-on: ubuntu-latest
-
     steps:
       - uses: actions/checkout@v3
-      # Use stable for this to ensure that cargo-tarpaulin can be built.
-      - uses: actions-rs/toolchain@v1
-        with:
-          toolchain: stable
-          override: true
       - name: Install build dependencies
         run: sudo apt install libpcsclite-dev
+      - name: Install coverage dependencies
+        run: cargo install cargo-tarpaulin
       - name: Generate coverage report
-        uses: actions-rs/tarpaulin@v0.1
-        with:
-          args: --release --timeout 180 --out Xml
+        run: cargo tarpaulin --engine llvm --all-features --release --timeout 600 --out Xml
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v3.1.0
-        with:
-          token: ${{secrets.CODECOV_TOKEN}}
+        uses: codecov/codecov-action@v3.1.1
 
   doc-links:
     name: Intra-doc links
     runs-on: ubuntu-latest
-
     steps:
       - uses: actions/checkout@v3
-      - uses: actions-rs/toolchain@v1
-        with:
-          toolchain: 1.56.0
-          override: true
       - name: Install build dependencies
         run: sudo apt install libpcsclite-dev
-      - name: cargo fetch
-        uses: actions-rs/cargo@v1
-        with:
-          command: fetch
-
-      # Ensure intra-documentation links all resolve correctly
-      # Requires #![deny(intra_doc_link_resolution_failure)] in crates.
+      - run: cargo fetch
+      # Requires #![deny(rustdoc::broken_intra_doc_links)] in crates.
       - name: Check intra-doc links
-        uses: actions-rs/cargo@v1
-        with:
-          command: doc
-          args: --document-private-items
+        run: cargo doc --document-private-items
 
   fmt:
     name: Rustfmt
@@ -140,13 +66,5 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v3
-      - uses: actions-rs/toolchain@v1
-        with:
-          toolchain: 1.56.0
-          components: rustfmt
-          override: true
       - name: Check formatting
-        uses: actions-rs/cargo@v1
-        with:
-          command: fmt
-          args: -- --check
+        run: cargo fmt -- --check

.github/workflows/lints-beta.yml

@@ -0,0 +1,23 @@
+name: Beta lints
+
+# We only run these lints on trial-merges of PRs to reduce noise.
+on: pull_request
+
+jobs:
+  clippy-beta:
+    name: Clippy (beta)
+    timeout-minutes: 30
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: dtolnay/rust-toolchain@beta
+        id: toolchain
+      - run: rustup override set ${{steps.toolchain.outputs.name}}
+      - name: Install build dependencies
+        run: sudo apt install libpcsclite-dev
+      - name: Clippy (beta)
+        uses: actions-rs/clippy-check@v1
+        with:
+          name: Clippy (beta)
+          token: ${{ secrets.GITHUB_TOKEN }}
+          args: --all-features --all-targets -- -W clippy::all

.github/workflows/lints-stable.yml

@@ -0,0 +1,20 @@
+name: Stable lints
+
+# We only run these lints on trial-merges of PRs to reduce noise.
+on: pull_request
+
+jobs:
+  clippy:
+    name: Clippy (MSRV)
+    timeout-minutes: 30
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - name: Install build dependencies
+        run: sudo apt install libpcsclite-dev
+      - name: Run clippy
+        uses: actions-rs/clippy-check@v1
+        with:
+          name: Clippy (MSRV)
+          token: ${{ secrets.GITHUB_TOKEN }}
+          args: --all-features --all-targets -- -D warnings

.github/workflows/release.yml

@@ -17,7 +17,11 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        name: [linux, windows, macos]
+        name:
+          - linux
+          - macos-arm64
+          - macos-x86_64
+          - windows
         include:
           - name: linux
             os: ubuntu-18.04
@@ -31,7 +35,14 @@ jobs:
             archive_name: age-plugin-yubikey.zip
             asset_suffix: x86_64-windows.zip
 
-          - name: macos
+          - name: macos-arm64
+            os: macos-latest
+            target: aarch64-apple-darwin
+            build_flags: --target aarch64-apple-darwin
+            archive_name: age-plugin-yubikey.tar.gz
+            asset_suffix: arm64-darwin.tar.gz
+
+          - name: macos-x86_64
             os: macos-latest
             archive_name: age-plugin-yubikey.tar.gz
             asset_suffix: x86_64-darwin.tar.gz
@@ -76,12 +87,10 @@ jobs:
         if: matrix.name == 'windows'
 
       - name: Upload archive to release
-        uses: svenstaro/upload-release-action@2.2.1
+        uses: svenstaro/upload-release-action@2.5.0
         with:
-          repo_token: ${{ secrets.GITHUB_TOKEN }}
           file: ${{ matrix.archive_name }}
           asset_name: age-plugin-yubikey-$tag-${{ matrix.asset_suffix }}
-          tag: ${{ github.ref }}
           prerelease: true
         if: github.event.inputs.test != 'true'
 
@@ -137,11 +146,9 @@ jobs:
           args: --package age-plugin-yubikey --no-build --target ${{ matrix.target }}
 
       - name: Upload Debian package to release
-        uses: svenstaro/upload-release-action@2.2.1
+        uses: svenstaro/upload-release-action@2.5.0
         with:
-          repo_token: ${{ secrets.GITHUB_TOKEN }}
           file: target/${{ matrix.target }}/debian/*.deb
-          tag: ${{ github.ref }}
           file_glob: true
           prerelease: true
         if: github.event.inputs.test != 'true'

CHANGELOG.md

@@ -8,6 +8,53 @@ to 0.3.0 are beta releases.
 
 ## [Unreleased]
 
+## [0.4.0] - 2023-04-09
+### Changed
+- MSRV is now 1.65.0.
+- The YubiKey PIV PIN and touch caches are now preserved across processes in
+  most cases. See [README.md](README.md#agent-support) for exceptions. This has
+  several usability effects (not applicable to YubiKey 4 series):
+  - If a YubiKey's PIN is cached by an agent like `yubikey-agent`, and then
+    `age-plugin-yubikey` is run (either directly or as a plugin), the agent
+    won't request a PIN entry on its next use.
+  - If a YubiKey's PIN was requested by either a previous invocation of
+    `age-plugin-yubikey` or an agent like `yubikey-agent`, subsequent calls to
+    `age-plugin-yubikey` won't request a PIN entry to decrypt a file with an
+    identity that has a PIN policy of `once`.
+
+### Fixed
+- Identities can now be generated with a PIN policy of "always" (in previous
+  versions of `age-plugin-yubikey` this would cause an error).
+
+## [0.3.3] - 2023-02-11
+### Fixed
+- When `age-plugin-yubikey` assists the user in changing their PIN from the
+  default PIN, it no longer tells the user that PINs shorter than 6 characters
+  are allowed, and instead loops until the user enters a PIN of valid length.
+  It also now prevents the user from setting their PIN to the default PIN, to
+  avoid creating a cycle.
+- More kinds of SmartCard readers are ignored when they have no SmartCard
+  inserted.
+
+## [0.3.2] - 2023-01-01
+### Changed
+- The "sharing violation" logic now also sends SIGHUP to any `yubikey-agent`
+  that is running, to have them release any YubiKey locks they are holding.
+
+### Fixed
+- The "sharing violation" logic now runs during plugin mode as intended. In the
+  previous release it only ran during direct `age-plugin-yubikey` usage.
+
+## [0.3.1] - 2022-12-30
+### Changed
+- If a "sharing violation" error is encountered while opening a connection to a
+  YubiKey, and `scdaemon` is running (which can hold exclusive access to a
+  YubiKey indefinitely), `age-plugin-yubikey` now attempts to stop `scdaemon` by
+  interrupting it (or killing it on Windows), and then tries again to open the
+  connection.
+- Several error messages were enhanced with guidance on how to resolve their
+  respective issue.
+
 ## [0.3.0] - 2022-05-02
 First non-beta release!
 

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "age-plugin-yubikey"
 description = "YubiKey plugin for age clients"
-version = "0.3.0"
+version = "0.4.0"
 authors = ["Jack Grigg <thestr4d@gmail.com>"]
 repository = "https://github.com/str4d/age-plugin-yubikey"
 readme = "README.md"
@@ -9,6 +9,7 @@ keywords = ["age", "cli", "encryption", "yubikey"]
 categories = ["command-line-utilities", "cryptography"]
 license = "MIT OR Apache-2.0"
 edition = "2021"
+rust-version = "1.65" # MSRV
 
 [package.metadata.deb]
 extended-description = """\
@@ -21,24 +22,24 @@ assets = [
 ]
 
 [dependencies]
-age-core = "0.8"
-age-plugin = "0.3"
-base64 = "0.13"
-bech32 = "0.8"
+age-core = "0.9"
+age-plugin = "0.4"
+base64 = "0.21"
+bech32 = "0.9"
 console = { version = "0.15", default-features = false }
-dialoguer = { version = "0.9", default-features = false, features = ["password"] }
-env_logger = "0.9"
+dialoguer = { version = "0.10", default-features = false, features = ["password"] }
+env_logger = "0.10"
 gumdrop = "0.8"
 hex = "0.4"
 log = "0.4"
-p256 = { version = "0.9", features = ["ecdh"] }
+p256 = { version = "0.13", features = ["ecdh"] }
 pcsc = "2.4"
 rand = "0.8"
-sha2 = "0.9"
+sha2 = "0.10"
 which = "4.1"
 x509 = "0.2"
-x509-parser = "0.12"
-yubikey = { version = "0.5", features = ["untested"] }
+x509-parser = "0.14"
+yubikey = { version = "=0.8.0-pre.0", features = ["untested"] }
 
 # Translations
 i18n-embed = { version = "0.13", features = ["desktop-requester", "fluent-system"] }
@@ -46,6 +47,12 @@ i18n-embed-fl = "0.6"
 lazy_static = "1"
 rust-embed = "6"
 
+# GnuPG coexistence
+sysinfo = "0.28"
+
 [dev-dependencies]
 flate2 = "1"
 man = "0.3"
+tempfile = "3"
+test-with = "0.9"
+which = "4"

README.md

@@ -6,18 +6,35 @@ which enables files to be encrypted to age identities stored on YubiKeys.
 
 ## Installation
 
+| Environment | CLI command |
+|-------------|-------------|
+| Cargo (Rust 1.65+) | `cargo install age-plugin-yubikey` |
+| Homebrew (macOS or Linux) | `brew install age-plugin-yubikey` |
+
 On Windows, Linux, and macOS, you can use the
 [pre-built binaries](https://github.com/str4d/age-plugin-yubikey/releases).
 
-If your system has Rust 1.56+ installed (either via `rustup` or a system
-package), you can build directly from source:
-
-```
-cargo install age-plugin-yubikey
-```
-
 Help from new packagers is very welcome.
 
+### Linux, BSD, etc.
+
+On non-Windows, non-macOS systems, you need to ensure that the `pcscd` service
+is installed and running. 
+
+| Environment | CLI command |
+|-------------|-------------|
+| Debian or Ubuntu | `sudo apt-get install pcscd` |
+| OpenBSD | As ```root``` do:<br>`pkg_add pcsc-lite ccid`<br>`rcctl enable pcscd`<br>`rcctl start pcscd` |
+| FreeBSD | As ```root``` do:<br>`pkg install pcsc-lite libccid`<br>`service pcscd enable`<br>`service pcscd start` |
+
+When installing via Cargo, you also need to ensure that the development headers
+for the `pcsc-lite` library are available, so that the `pcsc-sys` crate can be
+compiled.
+
+| Environment | CLI command |
+|-------------|-------------|
+| Debian or Ubuntu | `sudo apt-get install libpcsclite-dev` |
+
 ### Windows Subsystem for Linux (WSL)
 
 WSL does not currently provide native support for USB devices. However, Windows
@@ -35,7 +52,12 @@ YubiKey:
 
 ## Configuration
 
-There are two ways to configure a YubiKey as an `age` identity. You can run the
+`age-plugin-yubikey` identities have two parts:
+- The secret key material, which is stored inside a YubiKey.
+- An age identity file, which contains information that an age client can use to
+  figure out which YubiKey secret key should be used.
+
+There are two ways to configure a YubiKey as an age identity. You can run the
 plugin binary directly to use a simple text interface, which will create an age
 identity file:
 
@@ -61,6 +83,14 @@ Once an identity has been created, you can regenerate it later:
 $ age-plugin-yubikey --identity [--serial SERIAL] --slot SLOT
 ```
 
+To use the identity with an age client, it needs to be stored in a file. When
+using the above programmatic flags, you can do this by redirecting standard
+output to a file. On a Unix system like macOS or Ubuntu:
+
+```
+$ age-plugin-yubikey --identity --slot SLOT > yubikey-identity.txt
+```
+
 ## Usage
 
 The age recipients contained in all connected YubiKeys can be printed on
@@ -85,13 +115,27 @@ age client as normal (e.g. `rage -d -i yubikey-identity.txt`).
 ### Agent support
 
 `age-plugin-yubikey` does not provide or interact with an agent for decryption.
-As age plugin binaries have short lifetimes (they only run while the age client
-is running), this means that YubiKey identities configured with a PIN policy of
-`once` will actually prompt for the PIN on every decryption.
+It does however attempt to preserve the PIN cache by not soft-resetting the
+YubiKey after a decryption or read-only operation, which enables YubiKey
+identities configured with a PIN policy of `once` to not prompt for the PIN on
+every decryption. **This does not work for YubiKey 4 series.**
 
-A decryption agent will most likely be implemented as a separate age plugin that
-interacts with [`yubikey-agent`](https://github.com/FiloSottile/yubikey-agent),
-enabling YubiKeys to be used simultaneously with age and SSH.
+The session that corresponds to the `once` policy can be ended in several ways,
+not all of which are necessarily intuitive:
+
+- Unplugging the YubiKey (the obvious way).
+- Using a different applet (e.g. FIDO2). This causes the PIV applet to be closed
+  which clears its state.
+  - This is why the YubiKey 4 series does not support PIN cache preservation:
+    their serial can only be obtained by switching to the OTP applet.
+- Generating a new age identity via `age-plugin-yubikey --generate` or the CLI
+  interface. This is to avoid leaving the YubiKey authenticated with the
+  management key.
+
+If the current PIN UX proves to be insufficient, a decryption agent will most
+likely be implemented as a separate age plugin that interacts with
+[`yubikey-agent`](https://github.com/FiloSottile/yubikey-agent), enabling
+YubiKeys to be used simultaneously with age and SSH.
 
 ### Manual setup and technical details
 

i18n/en-US/age_plugin_yubikey.ftl

@@ -12,6 +12,7 @@
 -yubikey = YubiKey
 -yubikeys = YubiKeys
 -age-plugin-yubikey = age-plugin-yubikey
+-pcscd = pcscd
 
 ## CLI commands and flags
 
@@ -75,6 +76,14 @@ cli-setup-name-identity       = 📛 Name this identity
 cli-setup-select-pin-policy   = 🔤 Select a PIN policy
 cli-setup-select-touch-policy = 👆 Select a touch policy
 
+cli-setup-yk4-pin-policy =
+    ⚠️ Your {-yubikey} is a {-yubikey} 4 series. With ephemeral applications like
+    {-age-plugin-yubikey}, a PIN policy of "Once" behaves like a PIN policy of
+    "Always", and your PIN will be requested for every decryption. However, you
+    might still benefit from a PIN policy of "Once" in long-running applications
+    like agents.
+cli-setup-yk4-pin-policy-confirm = Use PIN policy of "Once" with {-yubikey} 4?
+
 cli-setup-generate-new = Generate new identity in slot {$slot_index}?
 cli-setup-use-existing = Use existing identity in slot {$slot_index}?
 
@@ -111,6 +120,7 @@ cli-setup-finished =
 open-yk-with-serial    = ⏳ Please insert the {-yubikey} with serial {$yubikey_serial}.
 open-yk-without-serial = ⏳ Please insert the {-yubikey}.
 warn-yk-not-connected  = Ignoring {$yubikey_name}: not connected
+warn-yk-missing-applet = Ignoring {$yubikey_name}: Missing {$applet_name} applet
 
 print-recipient = Recipient: {$recipient}
 
@@ -126,13 +136,15 @@ mgr-change-default-pin =
     ✨ Your {-yubikey} is using the default PIN. Let's change it!
     ✨ We'll also set the PUK equal to the PIN.
 
-    🔐 The PIN is up to 8 numbers, letters, or symbols. Not just numbers!
+    🔐 The PIN can be numbers, letters, or symbols. Not just numbers!
+    📏 The PIN must be at least 6 and at most 8 characters in length.
     ❌ Your keys will be lost if the PIN and PUK are locked after 3 incorrect tries.
 
 mgr-enter-current-puk = Enter current PUK (default is {$default_puk})
 mgr-choose-new-pin    = Choose a new PIN/PUK
 mgr-repeat-new-pin    = Repeat the PIN/PUK
 mgr-pin-mismatch      = PINs don't match
+mgr-nope-default-pin  = You entered the default PIN again. You need to change it.
 
 mgr-changing-mgmt-key =
     ✨ Your {-yubikey} is using the default management key.
@@ -143,6 +155,12 @@ mgr-changing-mgmt-key-error =
     {"  "}{$management_key}
 mgr-changing-mgmt-key-success = Success!
 
+## YubiKey keygen
+
+builder-gen-key  = 🎲 Generating key...
+builder-gen-cert = 🔏 Generating certificate...
+builder-touch-yk = 👆 Please touch the {-yubikey}
+
 ## Plugin usage
 
 plugin-err-invalid-recipient = Invalid recipient
@@ -169,10 +187,20 @@ plugin-err-pin-required     = A PIN is required for {-yubikey} with serial {$yub
 
 ## Errors
 
-err-custom-mgmt-key      = Custom unprotected management keys are not supported.
+err-mgmt-key-auth = Failed to authenticate with the PIN-protected management key.
+rec-mgmt-key-auth =
+    Check whether your management key is using the TDES algorithm.
+    AES is not supported yet: {$aes_url}
+err-custom-mgmt-key = Custom unprotected non-TDES management keys are not supported.
+rec-change-mgmt-key =
+    You can use the {-yubikey} Manager CLI to change to a protected management key:
+    {"  "}{$cmd}
+
+    See here for more information about {-yubikey} Manager:
+    {"  "}{$url}
+
 err-invalid-flag-command = Flag '{$flag}' cannot be used with '{$command}'.
 err-invalid-flag-tui     = Flag '{$flag}' cannot be used with the interactive interface.
-err-invalid-pin-length   = The PIN needs to be 1-8 characters.
 err-invalid-pin-policy   = Invalid PIN policy '{$policy}' (expected [{$expected}]).
 err-invalid-slot         = Invalid slot '{$slot}' (expected number between 1 and 20).
 err-invalid-touch-policy = Invalid touch policy '{$policy}' (expected [{$expected}]).
@@ -185,11 +213,38 @@ err-slot-has-no-identity = Slot {$slot} does not contain an {-age} identity or c
 err-slot-is-not-empty    = Slot {$slot} is not empty. Use {-flag-force} to overwrite the slot.
 err-timed-out            = Timed out while waiting for a {-yubikey} to be inserted.
 err-use-list-for-single  = Use {-cmd-list} to print the recipient for a single slot.
+
+err-yk-no-service-macos = The Crypto Token Kit service is not running.
+rec-yk-no-service-macos =
+    You may need to restart it. See this Stack Exchange answer for more help:
+    {"  "}{$url}
+
+err-yk-no-service-pcscd = {-pcscd} is not running.
+rec-yk-no-service-pcscd =
+    If you are on Debian or Ubuntu, you can install it with:
+    {"  "}{$apt}
+
+rec-yk-no-service-pcscd-bsd =
+    You can install and run it as root with:
+    {"  "}{$pkg}
+    {"  "}{$service_enable}
+    {"  "}{$service_start}
+
+err-yk-no-service-win = The Smart Cards for Windows service is not running.
+rec-yk-no-service-win =
+    See this troubleshooting guide for more help:
+    {"  "}{$url}
+
 err-yk-not-found         = Please insert the {-yubikey} you want to set up
-err-yk-wrong-pin         = Invalid PIN ({$tries} tries remaining before it is blocked)
 err-yk-general           = Error while communicating with {-yubikey}: {$err}
 err-yk-general-cause     = Cause: {$inner_err}
 
+err-yk-wrong-pin = Invalid {$pin_kind} ({$tries ->
+    [one] {$tries} try remaining
+   *[other] {$tries} tries remaining
+} before it is blocked)
+err-yk-pin-locked = {$pin_kind} locked
+
 err-ux-A = Did this not do what you expected? Could an error be more useful?
 err-ux-B = Tell us
 # Put (len(A) - len(B) - 46) spaces here.

rust-toolchain

@@ -1 +0,0 @@
-1.56.0

rust-toolchain.toml

@@ -0,0 +1,3 @@
+[toolchain]
+channel = "1.65.0"
+components = ["clippy", "rustfmt"]

src/builder.rs

@@ -1,13 +1,15 @@
+use dialoguer::Password;
 use rand::{rngs::OsRng, RngCore};
 use x509::RelativeDistinguishedName;
 use yubikey::{
-    certificate::{Certificate, PublicKeyInfo},
+    certificate::Certificate,
     piv::{generate as yubikey_generate, AlgorithmId, RetiredSlotId, SlotId},
     Key, PinPolicy, TouchPolicy, YubiKey,
 };
 
 use crate::{
     error::Error,
+    fl,
     key::{self, Stub},
     p256::Recipient,
     util::{Metadata, POLICY_EXTENSION_OID},
@@ -86,17 +88,13 @@ impl IdentityBuilder {
         let pin_policy = self.pin_policy.unwrap_or(DEFAULT_PIN_POLICY);
         let touch_policy = self.touch_policy.unwrap_or(DEFAULT_TOUCH_POLICY);
 
+        eprintln!("{}", fl!("builder-gen-key"));
+
         // No need to ask for users to enter their PIN if the PIN policy requires it,
         // because here we _always_ require them to enter their PIN in order to access the
         // protected management key (which is necessary in order to generate identities).
         key::manage(yubikey)?;
 
-        if let TouchPolicy::Never = touch_policy {
-            // No need to touch YubiKey
-        } else {
-            eprintln!("👆 Please touch the YubiKey");
-        }
-
         // Generate a new key in the selected slot.
         let generated = yubikey_generate(
             yubikey,
@@ -106,14 +104,12 @@ impl IdentityBuilder {
             touch_policy,
         )?;
 
-        let recipient = match &generated {
-            PublicKeyInfo::EcP256(pubkey) => {
-                Recipient::from_encoded(pubkey).expect("YubiKey generates a valid pubkey")
-            }
-            _ => unreachable!(),
-        };
+        let recipient = Recipient::from_spki(&generated).expect("YubiKey generates a valid pubkey");
         let stub = Stub::new(yubikey.serial(), slot, &recipient);
 
+        eprintln!();
+        eprintln!("{}", fl!("builder-gen-cert"));
+
         // Pick a random serial for the new self-signed certificate.
         let mut serial = [0; 20];
         OsRng.fill_bytes(&mut serial);
@@ -122,6 +118,23 @@ impl IdentityBuilder {
             .name
             .unwrap_or(format!("age identity {}", hex::encode(stub.tag)));
 
+        if let PinPolicy::Always = pin_policy {
+            // We need to enter the PIN again.
+            let pin = Password::new()
+                .with_prompt(fl!(
+                    "plugin-enter-pin",
+                    yubikey_serial = yubikey.serial().to_string(),
+                ))
+                .report(true)
+                .interact()?;
+            yubikey.verify_pin(pin.as_bytes())?;
+        }
+        if let TouchPolicy::Never = touch_policy {
+            // No need to touch YubiKey
+        } else {
+            eprintln!("{}", fl!("builder-touch-yk"));
+        }
+
         let cert = Certificate::generate_self_signed(
             yubikey,
             SlotId::Retired(slot),
@@ -139,7 +152,6 @@ impl IdentityBuilder {
             )],
         )?;
 
-        let (_, cert) = x509_parser::parse_x509_certificate(cert.as_ref()).unwrap();
         let metadata = Metadata::extract(yubikey, slot, &cert, false).unwrap();
 
         Ok((

src/error.rs

@@ -1,4 +1,3 @@
-use i18n_embed_fl::fl;
 use std::fmt;
 use std::io;
 use yubikey::{piv::RetiredSlotId, Serial};
@@ -9,25 +8,30 @@ macro_rules! wlnfl {
     ($f:ident, $message_id:literal) => {
         writeln!($f, "{}", $crate::fl!($message_id))
     };
+    ($f:ident, $message_id:literal, $($kwarg:expr),* $(,)*) => {{
+        writeln!($f, "{}", $crate::fl!($message_id, $($kwarg,)*))
+    }};
 }
 
 pub enum Error {
     CustomManagementKey,
     InvalidFlagCommand(String, String),
     InvalidFlagTui(String),
-    InvalidPinLength,
     InvalidPinPolicy(String),
     InvalidSlot(u8),
     InvalidTouchPolicy(String),
     Io(io::Error),
+    ManagementKeyAuth,
     MultipleCommands,
     MultipleYubiKeys,
     NoEmptySlots(Serial),
     NoMatchingSerial(Serial),
+    PukLocked,
     SlotHasNoIdentity(RetiredSlotId),
     SlotIsNotEmpty(RetiredSlotId),
     TimedOut,
     UseListForSingleSlot,
+    WrongPuk(u8),
     YubiKey(yubikey::Error),
 }
 
@@ -47,126 +51,124 @@ impl From<yubikey::Error> for Error {
 // manually to provide the error output we want.
 impl fmt::Debug for Error {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        const CHANGE_MGMT_KEY_CMD: &str =
+            "ykman piv access change-management-key -a TDES --protect";
+        const CHANGE_MGMT_KEY_URL: &str = "https://developers.yubico.com/yubikey-manager/";
+
         match self {
-            Error::CustomManagementKey => wlnfl!(f, "err-custom-mgmt-key")?,
-            Error::InvalidFlagCommand(flag, command) => writeln!(
+            Error::CustomManagementKey => {
+                wlnfl!(f, "err-custom-mgmt-key")?;
+                wlnfl!(
+                    f,
+                    "rec-change-mgmt-key",
+                    cmd = CHANGE_MGMT_KEY_CMD,
+                    url = CHANGE_MGMT_KEY_URL
+                )?;
+            }
+            Error::InvalidFlagCommand(flag, command) => wlnfl!(
                 f,
-                "{}",
-                fl!(
-                    crate::LANGUAGE_LOADER,
-                    "err-invalid-flag-command",
-                    flag = flag.as_str(),
-                    command = command.as_str(),
-                ),
+                "err-invalid-flag-command",
+                flag = flag.as_str(),
+                command = command.as_str(),
             )?,
-            Error::InvalidFlagTui(flag) => writeln!(
+            Error::InvalidFlagTui(flag) => wlnfl!(f, "err-invalid-flag-tui", flag = flag.as_str())?,
+            Error::InvalidPinPolicy(s) => wlnfl!(
                 f,
-                "{}",
-                fl!(
-                    crate::LANGUAGE_LOADER,
-                    "err-invalid-flag-tui",
-                    flag = flag.as_str(),
-                ),
+                "err-invalid-pin-policy",
+                policy = s.as_str(),
+                expected = "always, once, never",
             )?,
-            Error::InvalidPinLength => wlnfl!(f, "err-invalid-pin-length")?,
-            Error::InvalidPinPolicy(s) => writeln!(
+            Error::InvalidSlot(slot) => wlnfl!(f, "err-invalid-slot", slot = slot)?,
+            Error::InvalidTouchPolicy(s) => wlnfl!(
                 f,
-                "{}",
-                fl!(
-                    crate::LANGUAGE_LOADER,
-                    "err-invalid-pin-policy",
-                    policy = s.as_str(),
-                    expected = "always, once, never",
-                ),
-            )?,
-            Error::InvalidSlot(slot) => writeln!(
-                f,
-                "{}",
-                fl!(crate::LANGUAGE_LOADER, "err-invalid-slot", slot = slot),
-            )?,
-            Error::InvalidTouchPolicy(s) => writeln!(
-                f,
-                "{}",
-                fl!(
-                    crate::LANGUAGE_LOADER,
-                    "err-invalid-touch-policy",
-                    policy = s.as_str(),
-                    expected = "always, cached, never",
-                ),
-            )?,
-            Error::Io(e) => writeln!(
-                f,
-                "{}",
-                fl!(crate::LANGUAGE_LOADER, "err-io", err = e.to_string()),
+                "err-invalid-touch-policy",
+                policy = s.as_str(),
+                expected = "always, cached, never",
             )?,
+            Error::Io(e) => wlnfl!(f, "err-io", err = e.to_string())?,
+            Error::ManagementKeyAuth => {
+                let aes_url = "https://github.com/str4d/age-plugin-yubikey/issues/92";
+                wlnfl!(f, "err-mgmt-key-auth")?;
+                wlnfl!(f, "rec-mgmt-key-auth", aes_url = aes_url)?;
+                wlnfl!(
+                    f,
+                    "rec-change-mgmt-key",
+                    cmd = CHANGE_MGMT_KEY_CMD,
+                    url = CHANGE_MGMT_KEY_URL
+                )?;
+            }
             Error::MultipleCommands => wlnfl!(f, "err-multiple-commands")?,
             Error::MultipleYubiKeys => wlnfl!(f, "err-multiple-yubikeys")?,
-            Error::NoEmptySlots(serial) => writeln!(
-                f,
-                "{}",
-                fl!(
-                    crate::LANGUAGE_LOADER,
-                    "err-no-empty-slots",
-                    serial = serial.to_string(),
-                ),
-            )?,
-            Error::NoMatchingSerial(serial) => writeln!(
-                f,
-                "{}",
-                fl!(
-                    crate::LANGUAGE_LOADER,
-                    "err-no-matching-serial",
-                    serial = serial.to_string(),
-                ),
-            )?,
-            Error::SlotHasNoIdentity(slot) => writeln!(
-                f,
-                "{}",
-                fl!(
-                    crate::LANGUAGE_LOADER,
-                    "err-slot-has-no-identity",
-                    slot = slot_to_ui(slot),
-                ),
-            )?,
-            Error::SlotIsNotEmpty(slot) => writeln!(
-                f,
-                "{}",
-                fl!(
-                    crate::LANGUAGE_LOADER,
-                    "err-slot-is-not-empty",
-                    slot = slot_to_ui(slot),
-                ),
-            )?,
+            Error::NoEmptySlots(serial) => {
+                wlnfl!(f, "err-no-empty-slots", serial = serial.to_string())?
+            }
+            Error::NoMatchingSerial(serial) => {
+                wlnfl!(f, "err-no-matching-serial", serial = serial.to_string())?
+            }
+            Error::PukLocked => wlnfl!(f, "err-yk-pin-locked", pin_kind = "PUK")?,
+            Error::SlotHasNoIdentity(slot) => {
+                wlnfl!(f, "err-slot-has-no-identity", slot = slot_to_ui(slot))?
+            }
+            Error::SlotIsNotEmpty(slot) => {
+                wlnfl!(f, "err-slot-is-not-empty", slot = slot_to_ui(slot))?
+            }
             Error::TimedOut => wlnfl!(f, "err-timed-out")?,
             Error::UseListForSingleSlot => wlnfl!(f, "err-use-list-for-single")?,
+            Error::WrongPuk(tries) => {
+                wlnfl!(f, "err-yk-wrong-pin", pin_kind = "PUK", tries = tries)?
+            }
             Error::YubiKey(e) => match e {
                 yubikey::Error::NotFound => wlnfl!(f, "err-yk-not-found")?,
-                yubikey::Error::WrongPin { tries } => writeln!(
-                    f,
-                    "{}",
-                    fl!(crate::LANGUAGE_LOADER, "err-yk-wrong-pin", tries = tries),
-                )?,
+                yubikey::Error::PcscError {
+                    inner: Some(pcsc::Error::NoService),
+                } => {
+                    if cfg!(windows) {
+                        wlnfl!(f, "err-yk-no-service-win")?;
+                        let url = "https://learn.microsoft.com/en-us/windows/security/identity-protection/smart-cards/smart-card-debugging-information#smart-card-service";
+                        wlnfl!(f, "rec-yk-no-service-win", url = url)?;
+                    } else if cfg!(target_os = "macos") {
+                        wlnfl!(f, "err-yk-no-service-macos")?;
+                        let url = "https://apple.stackexchange.com/a/438198";
+                        wlnfl!(f, "rec-yk-no-service-macos", url = url)?;
+                    } else if cfg!(target_os = "openbsd") {
+                        wlnfl!(f, "err-yk-no-service-pcscd")?;
+                        let pkg = "pkg_add pcsc-lite ccid";
+                        let service_enable = "rcctl enable pcscd";
+                        let service_start = "rcctl start pcscd";
+                        wlnfl!(
+                            f,
+                            "rec-yk-no-service-pcscd-bsd",
+                            pkg = pkg,
+                            service_enable = service_enable,
+                            service_start = service_start
+                        )?;
+                    } else if cfg!(target_os = "freebsd") {
+                        wlnfl!(f, "err-yk-no-service-pcscd")?;
+                        let pkg = "pkg install pcsc-lite libccid";
+                        let service_enable = "service pcscd enable";
+                        let service_start = "service pcscd start";
+                        wlnfl!(
+                            f,
+                            "rec-yk-no-service-pcscd-bsd",
+                            pkg = pkg,
+                            service_enable = service_enable,
+                            service_start = service_start
+                        )?;
+                    } else {
+                        wlnfl!(f, "err-yk-no-service-pcscd")?;
+                        let apt = "sudo apt-get install pcscd";
+                        wlnfl!(f, "rec-yk-no-service-pcscd", apt = apt)?;
+                    }
+                }
+                yubikey::Error::PinLocked => wlnfl!(f, "err-yk-pin-locked", pin_kind = "PIN")?,
+                yubikey::Error::WrongPin { tries } => {
+                    wlnfl!(f, "err-yk-wrong-pin", pin_kind = "PIN", tries = tries)?
+                }
                 e => {
-                    writeln!(
-                        f,
-                        "{}",
-                        fl!(
-                            crate::LANGUAGE_LOADER,
-                            "err-yk-general",
-                            err = e.to_string(),
-                        ),
-                    )?;
+                    wlnfl!(f, "err-yk-general", err = e.to_string())?;
                     use std::error::Error;
                     if let Some(inner) = e.source() {
-                        writeln!(
-                            f,
-                            "{}",
-                            fl!(
-                                crate::LANGUAGE_LOADER,
-                                "err-yk-general-cause",
-                                inner_err = inner.to_string(),
-                            ),
-                        )?;
+                        wlnfl!(f, "err-yk-general-cause", inner_err = inner.to_string())?;
                     }
                 }
             },

src/format.rs

@@ -1,10 +1,15 @@
 use age_core::{
     format::{FileKey, Stanza},
-    primitives::{aead_encrypt, hkdf},
+    primitives::aead_encrypt,
     secrecy::ExposeSecret,
 };
-use p256::{ecdh::EphemeralSecret, elliptic_curve::sec1::ToEncodedPoint};
+use base64::{prelude::BASE64_STANDARD_NO_PAD, Engine};
+use p256::{
+    ecdh::EphemeralSecret,
+    elliptic_curve::sec1::{FromEncodedPoint, ToEncodedPoint},
+};
 use rand::rngs::OsRng;
+use sha2::Sha256;
 
 use crate::{p256::Recipient, STANZA_TAG};
 
@@ -22,8 +27,12 @@ pub(crate) struct EphemeralKeyBytes(p256::EncodedPoint);
 
 impl EphemeralKeyBytes {
     fn from_bytes(bytes: [u8; EPK_BYTES]) -> Option<Self> {
-        let encoded = p256::EncodedPoint::from_bytes(&bytes).ok()?;
-        if encoded.is_compressed() && encoded.decompress().is_some() {
+        let encoded = p256::EncodedPoint::from_bytes(bytes).ok()?;
+        if encoded.is_compressed()
+            && p256::PublicKey::from_encoded_point(&encoded)
+                .is_some()
+                .into()
+        {
             Some(EphemeralKeyBytes(encoded))
         } else {
             None
@@ -39,9 +48,9 @@ impl EphemeralKeyBytes {
     }
 
     pub(crate) fn decompress(&self) -> p256::EncodedPoint {
-        self.0
-            .decompress()
-            .expect("EphemeralKeyBytes is a valid compressed encoding by construction")
+        // EphemeralKeyBytes is a valid compressed encoding by construction.
+        let p = p256::PublicKey::from_encoded_point(&self.0).unwrap();
+        p.to_encoded_point(false)
     }
 }
 
@@ -57,8 +66,8 @@ impl From<RecipientLine> for Stanza {
         Stanza {
             tag: STANZA_TAG.to_owned(),
             args: vec![
-                base64::encode_config(&r.tag, base64::STANDARD_NO_PAD),
-                base64::encode_config(r.epk_bytes.as_bytes(), base64::STANDARD_NO_PAD),
+                BASE64_STANDARD_NO_PAD.encode(r.tag),
+                BASE64_STANDARD_NO_PAD.encode(r.epk_bytes.as_bytes()),
             ],
             body: r.encrypted_file_key.to_vec(),
         }
@@ -76,9 +85,10 @@ impl RecipientLine {
                 return None;
             }
 
-            base64::decode_config_slice(arg, base64::STANDARD_NO_PAD, buf.as_mut())
+            BASE64_STANDARD_NO_PAD
+                .decode_slice_unchecked(arg, buf.as_mut())
                 .ok()
-                .map(|_| buf)
+                .and_then(|len| (len == buf.as_mut().len()).then_some(buf))
         }
 
         let (tag, epk_bytes) = match &s.args[..] {
@@ -101,7 +111,7 @@ impl RecipientLine {
     }
 
     pub(crate) fn wrap_file_key(file_key: &FileKey, pk: &Recipient) -> Self {
-        let esk = EphemeralSecret::random(OsRng);
+        let esk = EphemeralSecret::random(&mut OsRng);
         let epk = esk.public_key();
         let epk_bytes = EphemeralKeyBytes::from_public_key(&epk);
 
@@ -111,7 +121,14 @@ impl RecipientLine {
         salt.extend_from_slice(epk_bytes.as_bytes());
         salt.extend_from_slice(pk.to_encoded().as_bytes());
 
-        let enc_key = hkdf(&salt, STANZA_KEY_LABEL, shared_secret.as_bytes());
+        let enc_key = {
+            let mut okm = [0; 32];
+            shared_secret
+                .extract::<Sha256>(Some(&salt))
+                .expand(STANZA_KEY_LABEL, &mut okm)
+                .expect("okm is the correct length");
+            okm
+        };
 
         let encrypted_file_key = {
             let mut key = [0; ENCRYPTED_FILE_KEY_BYTES];

src/key.rs

@@ -3,22 +3,23 @@
 use age_core::{
     format::{FileKey, FILE_KEY_BYTES},
     primitives::{aead_decrypt, hkdf},
-    secrecy::ExposeSecret,
+    secrecy::{ExposeSecret, SecretString},
 };
 use age_plugin::{identity, Callbacks};
 use bech32::{ToBase32, Variant};
 use dialoguer::Password;
-use log::warn;
+use log::{debug, error, warn};
+use std::convert::Infallible;
 use std::fmt;
 use std::io;
 use std::iter;
 use std::thread::sleep;
 use std::time::{Duration, Instant, SystemTime};
 use yubikey::{
-    certificate::{Certificate, PublicKeyInfo},
+    certificate::Certificate,
     piv::{decrypt_data, AlgorithmId, RetiredSlotId, SlotId},
     reader::{Context, Reader},
-    MgmKey, PinPolicy, Serial, TouchPolicy, YubiKey,
+    Key, MgmKey, PinPolicy, Serial, TouchPolicy, YubiKey,
 };
 
 use crate::{
@@ -39,24 +40,32 @@ pub(crate) fn is_connected(reader: Reader) -> bool {
 
 pub(crate) fn filter_connected(reader: &Reader) -> bool {
     match reader.open() {
-        Ok(_) => true,
-        Err(e) => {
-            use std::error::Error;
-            if let Some(pcsc::Error::RemovedCard) =
-                e.source().and_then(|inner| inner.downcast_ref())
-            {
-                warn!(
-                    "{}",
-                    i18n_embed_fl::fl!(
-                        crate::LANGUAGE_LOADER,
-                        "warn-yk-not-connected",
-                        yubikey_name = reader.name(),
-                    )
-                );
-                false
-            } else {
-                true
-            }
+        Err(yubikey::Error::PcscError {
+            inner: Some(pcsc::Error::NoSmartcard | pcsc::Error::RemovedCard),
+        }) => {
+            warn!(
+                "{}",
+                fl!("warn-yk-not-connected", yubikey_name = reader.name())
+            );
+            false
+        }
+        Err(yubikey::Error::AppletNotFound { applet_name }) => {
+            warn!(
+                "{}",
+                fl!(
+                    "warn-yk-missing-applet",
+                    yubikey_name = reader.name(),
+                    applet_name = applet_name,
+                ),
+            );
+            false
+        }
+        Err(_) => true,
+        Ok(yubikey) => {
+            // We only connected as a side-effect of confirming that we can connect, so
+            // avoid resetting the YubiKey.
+            disconnect_without_reset(yubikey);
+            true
         }
     }
 }
@@ -77,16 +86,139 @@ pub(crate) fn wait_for_readers() -> Result<Context, Error> {
     }
 }
 
+/// Looks for agent processes that might be holding exclusive access to a YubiKey, and
+/// asks them as nicely as possible to release it.
+///
+/// Returns `true` if any known agent was running and was successfully interrupted (or
+/// killed if the platform doesn't support interrupts).
+fn hunt_agents() -> bool {
+    debug!("Sharing violation encountered, looking for agent processes");
+
+    use sysinfo::{ProcessExt, ProcessRefreshKind, RefreshKind, Signal, System, SystemExt};
+
+    let mut interrupted = false;
+
+    let sys =
+        System::new_with_specifics(RefreshKind::new().with_processes(ProcessRefreshKind::new()));
+
+    for process in sys.processes().values() {
+        match process.name() {
+            "scdaemon" | "scdaemon.exe" => {
+                // gpg-agent runs scdaemon to interact with smart cards. The canonical way
+                // to reload it is `gpgconf --reload scdaemon`, which kills and restarts
+                // the process. We emulate that here with SIGINT (which it listens to).
+                if process
+                    .kill_with(Signal::Interrupt)
+                    .unwrap_or_else(|| process.kill())
+                {
+                    debug!("Stopped scdaemon (PID {})", process.pid());
+                    interrupted = true;
+                }
+            }
+            "yubikey-agent" | "yubikey-agent.exe" => {
+                // yubikey-agent releases all YubiKey locks when it receives a SIGHUP.
+                match process.kill_with(Signal::Hangup) {
+                    Some(true) => {
+                        debug!("Sent SIGHUP to yubikey-agent (PID {})", process.pid());
+                        interrupted = true;
+                    }
+                    Some(false) => (),
+                    None => debug!(
+                        "Found yubikey-agent (PID {}) but platform doesn't support SIGHUP",
+                        process.pid(),
+                    ),
+                }
+            }
+            _ => (),
+        }
+    }
+
+    // If we did interrupt an agent, pause briefly to allow it to finish up.
+    if interrupted {
+        sleep(Duration::from_millis(100));
+    }
+
+    interrupted
+}
+
+fn open_sesame(
+    op: impl Fn() -> Result<YubiKey, yubikey::Error>,
+) -> Result<YubiKey, yubikey::Error> {
+    op().or_else(|e| match e {
+        yubikey::Error::PcscError {
+            inner: Some(pcsc::Error::SharingViolation),
+        } if hunt_agents() => op(),
+        _ => Err(e),
+    })
+}
+
+/// Opens a connection to this reader, returning a `YubiKey` if successful.
+///
+/// This is equivalent to [`Reader::open`], but additionally handles the presence of
+/// agents (which can indefinitely hold exclusive access to a YubiKey).
+pub(crate) fn open_connection(reader: &Reader) -> Result<YubiKey, yubikey::Error> {
+    open_sesame(|| reader.open())
+}
+
+/// Opens a YubiKey with a specific serial number.
+///
+/// This is equivalent to [`YubiKey::open_by_serial`], but additionally handles the
+/// presence of agents (which can indefinitely hold exclusive access to a YubiKey).
+fn open_by_serial(serial: Serial) -> Result<YubiKey, yubikey::Error> {
+    // `YubiKey::open_by_serial` has a bug where it ignores all opening errors, even if
+    // it potentially could have found a matching YubiKey if not for an error, and thus
+    // returns `Error::NotFound` if another agent is holding exclusive access to the
+    // required YubiKey. This gives misleading UX behaviour where age-plugin-yubikey asks
+    // the user to insert a YubiKey they have already inserted.
+    //
+    // For now, we instead implement the correct behaviour manually. Once MSRV has been
+    // raised to 1.60, we can upstream this into the `yubikey` crate.
+    open_sesame(|| {
+        let mut readers = Context::open()?;
+
+        let mut open_error = None;
+
+        for reader in readers.iter()? {
+            let yubikey = match reader.open() {
+                Ok(yk) => yk,
+                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 yubikey::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.
+                disconnect_without_reset(yubikey);
+            }
+        }
+
+        Err(if let Some(e) = open_error {
+            e
+        } else {
+            error!("no YubiKey detected with serial: {}", serial);
+            yubikey::Error::NotFound
+        })
+    })
+}
+
 pub(crate) fn open(serial: Option<Serial>) -> Result<YubiKey, Error> {
     if !Context::open()?.iter()?.any(is_connected) {
         if let Some(serial) = serial {
             eprintln!(
                 "{}",
-                i18n_embed_fl::fl!(
-                    crate::LANGUAGE_LOADER,
-                    "open-yk-with-serial",
-                    yubikey_serial = serial.to_string(),
-                )
+                fl!("open-yk-with-serial", yubikey_serial = serial.to_string())
             );
         } else {
             eprintln!("{}", fl!("open-yk-without-serial"));
@@ -99,9 +231,9 @@ pub(crate) fn open(serial: Option<Serial>) -> Result<YubiKey, Error> {
     // connected, an error is returned.
     let yubikey = match (readers_iter.next(), readers_iter.next(), serial) {
         (None, _, _) => unreachable!(),
-        (Some(reader), None, None) => reader.open()?,
+        (Some(reader), None, None) => open_connection(&reader)?,
         (Some(reader), None, Some(serial)) => {
-            let yubikey = reader.open()?;
+            let yubikey = open_connection(&reader)?;
             if yubikey.serial() != serial {
                 return Err(Error::NoMatchingSerial(serial));
             }
@@ -112,12 +244,12 @@ pub(crate) fn open(serial: Option<Serial>) -> Result<YubiKey, Error> {
                 .chain(Some(a))
                 .chain(Some(b))
                 .chain(readers_iter)
-                .find(|reader| match reader.open() {
+                .find(|reader| match open_connection(reader) {
                     Ok(yk) => yk.serial() == serial,
                     _ => false,
                 })
                 .ok_or(Error::NoMatchingSerial(serial))?;
-            reader.open()?
+            open_connection(&reader)?
         }
         (Some(_), Some(_), None) => return Err(Error::MultipleYubiKeys),
     };
@@ -125,18 +257,60 @@ pub(crate) fn open(serial: Option<Serial>) -> Result<YubiKey, Error> {
     Ok(yubikey)
 }
 
+/// Disconnect from the YubiKey without resetting it.
+///
+/// This can be used to preserve the YubiKey's PIN and touch caches. There are two cases
+/// where we want to do this:
+///
+/// - We connected to this YubiKey in a read-only context, so we have not made any changes
+///   to the YubiKey's state. However, we might have asked an agent to release the YubiKey
+///   in `key::open_connection`, and we want to allow any state it may have left behind
+///   (such as cached PINs or touches) to persist beyond our execution, for usability.
+/// - We opened this connection in a decryption context, so the only changes to the
+///   YubiKey's state were to potentially cache the PIN and/or touch (depending on the
+///   policies of the slot). We want to allow these to persist beyond our execution, for
+///   usability.
+pub(crate) fn disconnect_without_reset(yubikey: YubiKey) {
+    let _ = yubikey.disconnect(pcsc::Disposition::LeaveCard);
+}
+
+fn request_pin<E>(
+    mut prompt: impl FnMut(Option<String>) -> io::Result<Result<SecretString, E>>,
+    serial: Serial,
+) -> io::Result<Result<SecretString, E>> {
+    let mut prev_error = None;
+    loop {
+        prev_error = Some(match prompt(prev_error)? {
+            Ok(pin) => match pin.expose_secret().len() {
+                // A PIN must be between 6 and 8 characters.
+                6..=8 => break Ok(Ok(pin)),
+                // If the string is 44 bytes and starts with the YubiKey's serial
+                // encoded as 12-byte modhex, the user probably touched the YubiKey
+                // early and "typed" an OTP.
+                44 if pin.expose_secret().starts_with(&otp_serial_prefix(serial)) => {
+                    fl!("plugin-err-accidental-touch")
+                }
+                // Otherwise, the PIN is either too short or too long.
+                0..=5 => fl!("plugin-err-pin-too-short"),
+                _ => fl!("plugin-err-pin-too-long"),
+            },
+            Err(e) => break Ok(Err(e)),
+        });
+    }
+}
+
 pub(crate) fn manage(yubikey: &mut YubiKey) -> Result<(), Error> {
     const DEFAULT_PIN: &str = "123456";
     const DEFAULT_PUK: &str = "12345678";
 
     eprintln!();
     let pin = Password::new()
-        .with_prompt(i18n_embed_fl::fl!(
-            crate::LANGUAGE_LOADER,
+        .with_prompt(fl!(
             "mgr-enter-pin",
             yubikey_serial = yubikey.serial().to_string(),
             default_pin = DEFAULT_PIN,
         ))
+        .report(true)
         .interact()?;
     yubikey.verify_pin(pin.as_bytes())?;
 
@@ -146,53 +320,100 @@ pub(crate) fn manage(yubikey: &mut YubiKey) -> Result<(), Error> {
         eprintln!("{}", fl!("mgr-change-default-pin"));
         eprintln!();
         let current_puk = Password::new()
-            .with_prompt(i18n_embed_fl::fl!(
-                crate::LANGUAGE_LOADER,
-                "mgr-enter-current-puk",
-                default_puk = DEFAULT_PUK,
-            ))
+            .with_prompt(fl!("mgr-enter-current-puk", default_puk = DEFAULT_PUK))
             .interact()?;
-        let new_pin = Password::new()
-            .with_prompt(fl!("mgr-choose-new-pin"))
-            .with_confirmation(fl!("mgr-repeat-new-pin"), fl!("mgr-pin-mismatch"))
-            .interact()?;
-        if new_pin.len() > 8 {
-            return Err(Error::InvalidPinLength);
-        }
-        yubikey.change_puk(current_puk.as_bytes(), new_pin.as_bytes())?;
+        let new_pin = loop {
+            let pin = request_pin(
+                |prev_error| {
+                    if let Some(err) = prev_error {
+                        eprintln!("{}", err);
+                    }
+                    Password::new()
+                        .with_prompt(fl!("mgr-choose-new-pin"))
+                        .with_confirmation(fl!("mgr-repeat-new-pin"), fl!("mgr-pin-mismatch"))
+                        .interact()
+                        .map(|pin| Result::<_, Infallible>::Ok(SecretString::new(pin)))
+                },
+                yubikey.serial(),
+            )?
+            .unwrap();
+            if pin.expose_secret() == DEFAULT_PIN {
+                eprintln!("{}", fl!("mgr-nope-default-pin"));
+            } else {
+                break pin;
+            }
+        };
+        let new_pin = new_pin.expose_secret();
+        yubikey
+            .change_puk(current_puk.as_bytes(), new_pin.as_bytes())
+            .map_err(|e| match e {
+                yubikey::Error::PinLocked => Error::PukLocked,
+                yubikey::Error::WrongPin { tries } => Error::WrongPuk(tries),
+                _ => Error::YubiKey(e),
+            })?;
         yubikey.change_pin(pin.as_bytes(), new_pin.as_bytes())?;
     }
 
-    if let Ok(mgm_key) = MgmKey::get_protected(yubikey) {
-        yubikey.authenticate(mgm_key)?;
-    } else {
-        // Try to authenticate with the default management key.
-        yubikey
-            .authenticate(MgmKey::default())
-            .map_err(|_| Error::CustomManagementKey)?;
+    match MgmKey::get_protected(yubikey) {
+        Ok(mgm_key) => yubikey.authenticate(mgm_key).map_err(|e| match e {
+            yubikey::Error::AuthenticationError => Error::ManagementKeyAuth,
+            _ => e.into(),
+        })?,
+        Err(yubikey::Error::AuthenticationError) => Err(Error::ManagementKeyAuth)?,
+        _ => {
+            // Try to authenticate with the default management key.
+            yubikey
+                .authenticate(MgmKey::default())
+                .map_err(|_| Error::CustomManagementKey)?;
 
-        // Migrate to a PIN-protected management key.
-        let mgm_key = MgmKey::generate();
-        eprintln!();
-        eprintln!("{}", fl!("mgr-changing-mgmt-key"));
-        eprint!("... ");
-        mgm_key.set_protected(yubikey).map_err(|e| {
-            eprintln!(
-                "{}",
-                i18n_embed_fl::fl!(
-                    crate::LANGUAGE_LOADER,
-                    "mgr-changing-mgmt-key-error",
-                    management_key = hex::encode(mgm_key.as_ref()),
-                )
-            );
-            e
-        })?;
-        eprintln!("{}", fl!("mgr-changing-mgmt-key-success"));
+            // Migrate to a PIN-protected management key.
+            let mgm_key = MgmKey::generate();
+            eprintln!();
+            eprintln!("{}", fl!("mgr-changing-mgmt-key"));
+            eprint!("... ");
+            mgm_key.set_protected(yubikey).map_err(|e| {
+                eprintln!(
+                    "{}",
+                    fl!(
+                        "mgr-changing-mgmt-key-error",
+                        management_key = hex::encode(mgm_key.as_ref()),
+                    )
+                );
+                e
+            })?;
+            eprintln!("{}", fl!("mgr-changing-mgmt-key-success"));
+        }
     }
 
     Ok(())
 }
 
+/// Returns an iterator of keys that are occupying plugin-compatible slots, along with the
+/// corresponding recipient if the key is compatible with this plugin.
+pub(crate) fn list_slots(
+    yubikey: &mut YubiKey,
+) -> Result<impl Iterator<Item = (Key, RetiredSlotId, Option<Recipient>)>, Error> {
+    Ok(Key::list(yubikey)?.into_iter().filter_map(|key| {
+        // We only use the retired slots.
+        match key.slot() {
+            SlotId::Retired(slot) => {
+                // Only P-256 keys are compatible with us.
+                let recipient = Recipient::from_certificate(key.certificate());
+                Some((key, slot, recipient))
+            }
+            _ => None,
+        }
+    }))
+}
+
+/// Returns an iterator of keys that are compatible with this plugin.
+pub(crate) fn list_compatible(
+    yubikey: &mut YubiKey,
+) -> Result<impl Iterator<Item = (Key, RetiredSlotId, Recipient)>, Error> {
+    list_slots(yubikey)
+        .map(|iter| iter.filter_map(|(key, slot, res)| res.map(|recipient| (key, slot, recipient))))
+}
+
 /// A reference to an age key stored in a YubiKey.
 #[derive(Debug)]
 pub struct Stub {
@@ -272,14 +493,10 @@ impl Stub {
         &self,
         callbacks: &mut dyn Callbacks<E>,
     ) -> io::Result<Result<Option<Connection>, identity::Error>> {
-        let mut yubikey = match YubiKey::open_by_serial(self.serial) {
+        let mut yubikey = match open_by_serial(self.serial) {
             Ok(yk) => yk,
             Err(yubikey::Error::NotFound) => {
-                let mut message = i18n_embed_fl::fl!(
-                    crate::LANGUAGE_LOADER,
-                    "plugin-insert-yk",
-                    yubikey_serial = self.serial.to_string(),
-                );
+                let mut message = fl!("plugin-insert-yk", yubikey_serial = self.serial.to_string());
 
                 // If the `confirm` command is available, we loop until either the YubiKey
                 // we want is inserted, or the used explicitly skips.
@@ -294,14 +511,13 @@ impl Stub {
                         // User told us to skip this key.
                         Ok(false) => return Ok(Ok(None)),
                         // User said they plugged it in; try it.
-                        Ok(true) => match YubiKey::open_by_serial(self.serial) {
+                        Ok(true) => match open_by_serial(self.serial) {
                             Ok(yubikey) => break Some(yubikey),
                             Err(yubikey::Error::NotFound) => (),
                             Err(_) => {
                                 return Ok(Err(identity::Error::Identity {
                                     index: self.identity_index,
-                                    message: i18n_embed_fl::fl!(
-                                        crate::LANGUAGE_LOADER,
+                                    message: fl!(
                                         "plugin-err-yk-opening",
                                         yubikey_serial = self.serial.to_string(),
                                     ),
@@ -312,8 +528,7 @@ impl Stub {
                         Err(age_core::plugin::Error::Fail) => {
                             return Ok(Err(identity::Error::Identity {
                                 index: self.identity_index,
-                                message: i18n_embed_fl::fl!(
-                                    crate::LANGUAGE_LOADER,
+                                message: fl!(
                                     "plugin-err-yk-opening",
                                     yubikey_serial = self.serial.to_string(),
                                 ),
@@ -323,8 +538,7 @@ impl Stub {
 
                     // We're going to loop around, meaning that the first attempt failed.
                     // Change the message to indicate this to the user.
-                    message = i18n_embed_fl::fl!(
-                        crate::LANGUAGE_LOADER,
+                    message = fl!(
                         "plugin-insert-yk-retry",
                         yubikey_serial = self.serial.to_string(),
                     );
@@ -337,8 +551,7 @@ impl Stub {
                     if callbacks.message(&message)?.is_err() {
                         return Ok(Err(identity::Error::Identity {
                             index: self.identity_index,
-                            message: i18n_embed_fl::fl!(
-                                crate::LANGUAGE_LOADER,
+                            message: fl!(
                                 "plugin-err-yk-not-found",
                                 yubikey_serial = self.serial.to_string(),
                             ),
@@ -348,14 +561,13 @@ impl Stub {
                     // Start a 15-second timer waiting for the YubiKey to be inserted
                     let start = SystemTime::now();
                     loop {
-                        match YubiKey::open_by_serial(self.serial) {
+                        match open_by_serial(self.serial) {
                             Ok(yubikey) => break yubikey,
                             Err(yubikey::Error::NotFound) => (),
                             Err(_) => {
                                 return Ok(Err(identity::Error::Identity {
                                     index: self.identity_index,
-                                    message: i18n_embed_fl::fl!(
-                                        crate::LANGUAGE_LOADER,
+                                    message: fl!(
                                         "plugin-err-yk-opening",
                                         yubikey_serial = self.serial.to_string(),
                                     ),
@@ -367,8 +579,7 @@ impl Stub {
                             Ok(end) if end >= FIFTEEN_SECONDS => {
                                 return Ok(Err(identity::Error::Identity {
                                     index: self.identity_index,
-                                    message: i18n_embed_fl::fl!(
-                                        crate::LANGUAGE_LOADER,
+                                    message: fl!(
                                         "plugin-err-yk-timed-out",
                                         yubikey_serial = self.serial.to_string(),
                                     ),
@@ -382,8 +593,7 @@ impl Stub {
             Err(_) => {
                 return Ok(Err(identity::Error::Identity {
                     index: self.identity_index,
-                    message: i18n_embed_fl::fl!(
-                        crate::LANGUAGE_LOADER,
+                    message: fl!(
                         "plugin-err-yk-opening",
                         yubikey_serial = self.serial.to_string(),
                     ),
@@ -394,11 +604,10 @@ impl Stub {
         // Read the pubkey from the YubiKey slot and check it still matches.
         let (cert, pk) = match Certificate::read(&mut yubikey, SlotId::Retired(self.slot))
             .ok()
-            .and_then(|cert| match cert.subject_pki() {
-                PublicKeyInfo::EcP256(pubkey) => Recipient::from_encoded(pubkey)
+            .and_then(|cert| {
+                Recipient::from_certificate(&cert)
                     .filter(|pk| pk.tag() == self.tag)
-                    .map(|pk| (cert, pk)),
-                _ => None,
+                    .map(|pk| (cert, pk))
             }) {
             Some(pk) => pk,
             None => {
@@ -444,9 +653,8 @@ impl Connection {
     ) -> io::Result<Result<(), identity::Error>> {
         // Check if we can skip requesting a PIN.
         if self.cached_metadata.is_none() {
-            let (_, cert) = x509_parser::parse_x509_certificate(self.cert.as_ref()).unwrap();
             self.cached_metadata =
-                match Metadata::extract(&mut self.yubikey, self.slot, &cert, true) {
+                match Metadata::extract(&mut self.yubikey, self.slot, &self.cert, true) {
                     None => {
                         return Ok(Err(identity::Error::Identity {
                             index: self.identity_index,
@@ -456,48 +664,37 @@ impl Connection {
                     metadata => metadata,
                 };
         }
-        if let Some(PinPolicy::Never) = self.cached_metadata.as_ref().and_then(|m| m.pin_policy) {
-            return Ok(Ok(()));
+        match self.cached_metadata.as_ref().and_then(|m| m.pin_policy) {
+            Some(PinPolicy::Never) => return Ok(Ok(())),
+            Some(PinPolicy::Once) if self.yubikey.verify_pin(&[]).is_ok() => return Ok(Ok(())),
+            _ => (),
         }
 
         // The policy requires a PIN, so request it.
-        // Note that we can't distinguish between PinPolicy::Once and PinPolicy::Always
-        // because this plugin is ephemeral, so we always request the PIN.
-        let enter_pin_msg = i18n_embed_fl::fl!(
-            crate::LANGUAGE_LOADER,
-            "plugin-enter-pin",
-            yubikey_serial = self.yubikey.serial().to_string(),
-        );
-        let mut message = enter_pin_msg.clone();
-        let pin = loop {
-            message = match callbacks.request_secret(&message)? {
-                Ok(pin) => match pin.expose_secret().len() {
-                    // A PIN must be between 6 and 8 characters.
-                    6..=8 => break pin,
-                    // If the string is 44 bytes and starts with the YubiKey's serial
-                    // encoded as 12-byte modhex, the user probably touched the YubiKey
-                    // early and "typed" an OTP.
-                    44 if pin
-                        .expose_secret()
-                        .starts_with(&otp_serial_prefix(self.yubikey.serial())) =>
-                    {
-                        format!("{} {}", fl!("plugin-err-accidental-touch"), enter_pin_msg)
-                    }
-                    // Otherwise, the PIN is either too short or too long.
-                    0..=5 => format!("{} {}", fl!("plugin-err-pin-too-short"), enter_pin_msg),
-                    _ => format!("{} {}", fl!("plugin-err-pin-too-long"), enter_pin_msg),
-                },
-                Err(_) => {
-                    return Ok(Err(identity::Error::Identity {
-                        index: self.identity_index,
-                        message: i18n_embed_fl::fl!(
-                            crate::LANGUAGE_LOADER,
-                            "plugin-err-pin-required",
-                            yubikey_serial = self.yubikey.serial().to_string(),
-                        ),
-                    }))
-                }
-            };
+        let pin = match request_pin(
+            |prev_error| {
+                callbacks.request_secret(&format!(
+                    "{}{}{}",
+                    prev_error.as_deref().unwrap_or(""),
+                    prev_error.as_deref().map(|_| " ").unwrap_or(""),
+                    fl!(
+                        "plugin-enter-pin",
+                        yubikey_serial = self.yubikey.serial().to_string(),
+                    )
+                ))
+            },
+            self.yubikey.serial(),
+        )? {
+            Ok(pin) => pin,
+            Err(_) => {
+                return Ok(Err(identity::Error::Identity {
+                    index: self.identity_index,
+                    message: fl!(
+                        "plugin-err-pin-required",
+                        yubikey_serial = self.yubikey.serial().to_string(),
+                    ),
+                }))
+            }
         };
         if let Err(e) = self.yubikey.verify_pin(pin.expose_secret().as_bytes()) {
             return Ok(Err(identity::Error::Identity {
@@ -557,6 +754,13 @@ impl Connection {
             Err(_) => Err(()),
         }
     }
+
+    /// Close this connection without resetting the YubiKey.
+    ///
+    /// This can be used to preserve the YubiKey's PIN and touch caches.
+    pub(crate) fn disconnect_without_reset(self) {
+        disconnect_without_reset(self.yubikey);
+    }
 }
 
 #[cfg(test)]

src/main.rs

@@ -12,12 +12,7 @@ use i18n_embed::{
 };
 use lazy_static::lazy_static;
 use rust_embed::RustEmbed;
-use yubikey::{
-    certificate::PublicKeyInfo,
-    piv::{RetiredSlotId, SlotId},
-    reader::Context,
-    Key, PinPolicy, Serial, TouchPolicy,
-};
+use yubikey::{piv::RetiredSlotId, reader::Context, PinPolicy, Serial, TouchPolicy};
 
 mod builder;
 mod error;
@@ -73,6 +68,9 @@ macro_rules! fl {
     ($message_id:literal) => {{
         i18n_embed_fl::fl!($crate::LANGUAGE_LOADER, $message_id)
     }};
+    ($message_id:literal, $($kwarg:expr),* $(,)*) => {{
+        i18n_embed_fl::fl!($crate::LANGUAGE_LOADER, $message_id, $($kwarg,)*)
+    }};
 }
 
 #[derive(Debug, Options)]
@@ -183,6 +181,13 @@ fn generate(flags: PluginFlags) -> Result<(), Error> {
 
     util::print_identity(stub, recipient, metadata);
 
+    // We have written to the YubiKey, which means we've authenticated with the management
+    // key. Out of an abundance of caution, we let the YubiKey be reset on disconnect,
+    // which will clear its PIN and touch caches. This has as small negative UX effect,
+    // but identity generation is a relatively infrequent occurrence, and users are more
+    // likely to see their cached PINs reset due to switching applets (e.g. from PIV to
+    // FIDO2).
+
     Ok(())
 }
 
@@ -193,29 +198,17 @@ fn print_single(
 ) -> Result<(), Error> {
     let mut yubikey = key::open(serial)?;
 
-    let mut keys = Key::list(&mut yubikey)?.into_iter().filter_map(|key| {
-        // - We only use the retired slots.
-        // - Only P-256 keys are compatible with us.
-        match (key.slot(), key.certificate().subject_pki()) {
-            (SlotId::Retired(slot), PublicKeyInfo::EcP256(pubkey)) => {
-                p256::Recipient::from_encoded(pubkey).map(|r| (key, slot, r))
-            }
-            _ => None,
-        }
-    });
-
-    let (key, slot, recipient) = keys
+    let (key, slot, recipient) = key::list_compatible(&mut yubikey)?
         .find(|(_, s, _)| s == &slot)
         .ok_or(Error::SlotHasNoIdentity(slot))?;
 
     let stub = key::Stub::new(yubikey.serial(), slot, &recipient);
-    let metadata = x509_parser::parse_x509_certificate(key.certificate().as_ref())
-        .ok()
-        .and_then(|(_, cert)| util::Metadata::extract(&mut yubikey, slot, &cert, true))
-        .unwrap();
+    let metadata = util::Metadata::extract(&mut yubikey, slot, key.certificate(), true).unwrap();
 
     printer(stub, recipient, metadata);
 
+    key::disconnect_without_reset(yubikey);
+
     Ok(())
 }
 
@@ -229,33 +222,16 @@ fn print_multiple(
 
     let mut printed = 0;
     for reader in readers.iter()?.filter(key::filter_connected) {
-        let mut yubikey = reader.open()?;
+        let mut yubikey = key::open_connection(&reader)?;
         if let Some(serial) = serial {
             if yubikey.serial() != serial {
                 continue;
             }
         }
 
-        for key in Key::list(&mut yubikey)? {
-            // We only use the retired slots.
-            let slot = match key.slot() {
-                SlotId::Retired(slot) => slot,
-                _ => continue,
-            };
-
-            // Only P-256 keys are compatible with us.
-            let recipient = match key.certificate().subject_pki() {
-                PublicKeyInfo::EcP256(pubkey) => match p256::Recipient::from_encoded(pubkey) {
-                    Some(recipient) => recipient,
-                    None => continue,
-                },
-                _ => continue,
-            };
-
+        for (key, slot, recipient) in key::list_compatible(&mut yubikey)? {
             let stub = key::Stub::new(yubikey.serial(), slot, &recipient);
-            let metadata = match x509_parser::parse_x509_certificate(key.certificate().as_ref())
-                .ok()
-                .and_then(|(_, cert)| util::Metadata::extract(&mut yubikey, slot, &cert, all))
+            let metadata = match util::Metadata::extract(&mut yubikey, slot, key.certificate(), all)
             {
                 Some(res) => res,
                 None => continue,
@@ -266,17 +242,11 @@ fn print_multiple(
             println!();
         }
         println!();
+
+        key::disconnect_without_reset(yubikey);
     }
     if printed > 1 {
-        eprintln!(
-            "{}",
-            i18n_embed_fl::fl!(
-                LANGUAGE_LOADER,
-                "printed-multiple",
-                kind = kind,
-                count = printed,
-            )
-        );
+        eprintln!("{}", fl!("printed-multiple", kind = kind, count = printed));
     }
 
     Ok(())
@@ -327,7 +297,7 @@ fn list(flags: PluginFlags, all: bool) -> Result<(), Error> {
         all,
         |_, recipient, metadata| {
             println!("{}", metadata);
-            println!("{}", recipient.to_string());
+            println!("{}", recipient);
         },
     )
 }
@@ -382,8 +352,7 @@ fn main() -> Result<(), Error> {
 
         eprintln!(
             "{}",
-            i18n_embed_fl::fl!(
-                LANGUAGE_LOADER,
+            fl!(
                 "cli-setup-intro",
                 generate_usage = "age-plugin-yubikey --generate",
             )
@@ -401,13 +370,14 @@ fn main() -> Result<(), Error> {
         let reader_names = readers_list
             .iter()
             .map(|reader| {
-                reader.open().map(|yk| {
-                    i18n_embed_fl::fl!(
-                        LANGUAGE_LOADER,
+                key::open_connection(reader).map(|yk| {
+                    let name = fl!(
                         "cli-setup-yk-name",
                         yubikey_name = reader.name(),
                         yubikey_serial = yk.serial().to_string(),
-                    )
+                    );
+                    key::disconnect_without_reset(yk);
+                    name
                 })
             })
             .collect::<Result<Vec<_>, _>>()?;
@@ -415,34 +385,36 @@ fn main() -> Result<(), Error> {
             .with_prompt(fl!("cli-setup-select-yk"))
             .items(&reader_names)
             .default(0)
+            .report(true)
             .interact_opt()?
         {
             Some(yk) => readers_list[yk].open()?,
             None => return Ok(()),
         };
 
-        let keys = Key::list(&mut yubikey)?;
+        let keys = key::list_slots(&mut yubikey)?.collect::<Vec<_>>();
 
         // Identify slots that we can't allow the user to select.
         let slot_details: Vec<_> = USABLE_SLOTS
             .iter()
             .map(|&slot| {
                 keys.iter()
-                    .find(|key| key.slot() == SlotId::Retired(slot))
-                    .map(|key| match key.certificate().subject_pki() {
-                        PublicKeyInfo::EcP256(pubkey) => {
-                            p256::Recipient::from_encoded(pubkey).map(|_| {
-                                // Cache the details we need to display to the user.
-                                let (_, cert) =
-                                    x509_parser::parse_x509_certificate(key.certificate().as_ref())
-                                        .unwrap();
-                                let (name, _) = util::extract_name(&cert, true).unwrap();
-                                let created = cert.validity().not_before.to_rfc2822();
+                    .find(|(_, s, _)| s == &slot)
+                    .map(|(key, _, recipient)| {
+                        recipient.as_ref().map(|_| {
+                            // Cache the details we need to display to the user.
+                            let (_, cert) =
+                                x509_parser::parse_x509_certificate(key.certificate().as_ref())
+                                    .unwrap();
+                            let (name, _) = util::extract_name(&cert, true).unwrap();
+                            let created = cert
+                                .validity()
+                                .not_before
+                                .to_rfc2822()
+                                .unwrap_or_else(|e| format!("Invalid date: {}", e));
 
-                                format!("{}, created: {}", name, created)
-                            })
-                        }
-                        _ => None,
+                            format!("{}, created: {}", name, created)
+                        })
                     })
             })
             .collect();
@@ -455,20 +427,13 @@ fn main() -> Result<(), Error> {
                 let i = i + 1;
 
                 match occupied {
-                    Some(Some(name)) => i18n_embed_fl::fl!(
-                        LANGUAGE_LOADER,
+                    Some(Some(name)) => fl!(
                         "cli-setup-slot-usable",
                         slot_index = i,
                         slot_name = name.as_str(),
                     ),
-                    Some(None) => i18n_embed_fl::fl!(
-                        LANGUAGE_LOADER,
-                        "cli-setup-slot-unusable",
-                        slot_index = i,
-                    ),
-                    None => {
-                        i18n_embed_fl::fl!(LANGUAGE_LOADER, "cli-setup-slot-empty", slot_index = i)
-                    }
+                    Some(None) => fl!("cli-setup-slot-unusable", slot_index = i),
+                    None => fl!("cli-setup-slot-empty", slot_index = i),
                 }
             })
             .collect();
@@ -479,6 +444,7 @@ fn main() -> Result<(), Error> {
                     .with_prompt(fl!("cli-setup-select-slot"))
                     .items(&slots)
                     .default(0)
+                    .report(true)
                     .interact_opt()?
                 {
                     Some(slot) => {
@@ -491,30 +457,23 @@ fn main() -> Result<(), Error> {
                 }
             };
 
-            if let Some(key) = keys.iter().find(|key| key.slot() == SlotId::Retired(slot)) {
-                let recipient = match key.certificate().subject_pki() {
-                    PublicKeyInfo::EcP256(pubkey) => {
-                        p256::Recipient::from_encoded(pubkey).expect("We checked this above")
-                    }
-                    _ => unreachable!(),
-                };
+            if let Some((key, _, recipient)) = keys.into_iter().find(|(_, s, _)| s == &slot) {
+                let recipient = recipient.expect("We checked this above");
 
                 if Confirm::new()
-                    .with_prompt(i18n_embed_fl::fl!(
-                        LANGUAGE_LOADER,
-                        "cli-setup-use-existing",
-                        slot_index = slot_index,
-                    ))
+                    .with_prompt(fl!("cli-setup-use-existing", slot_index = slot_index))
+                    .report(true)
                     .interact()?
                 {
                     let stub = key::Stub::new(yubikey.serial(), slot, &recipient);
-                    let (_, cert) =
-                        x509_parser::parse_x509_certificate(key.certificate().as_ref()).unwrap();
                     let metadata =
-                        util::Metadata::extract(&mut yubikey, slot, &cert, true).unwrap();
+                        util::Metadata::extract(&mut yubikey, slot, key.certificate(), true)
+                            .unwrap();
 
+                    key::disconnect_without_reset(yubikey);
                     ((stub, recipient, metadata), false)
                 } else {
+                    key::disconnect_without_reset(yubikey);
                     return Ok(());
                 }
             } else {
@@ -525,30 +484,57 @@ fn main() -> Result<(), Error> {
                         flags.name.as_deref().unwrap_or("age identity TAG_HEX")
                     ))
                     .allow_empty(true)
+                    .report(true)
                     .interact_text()?;
 
-                let pin_policy = match Select::new()
-                    .with_prompt(fl!("cli-setup-select-pin-policy"))
-                    .items(&[
-                        fl!("pin-policy-always"),
-                        fl!("pin-policy-once"),
-                        fl!("pin-policy-never"),
-                    ])
-                    .default(
-                        [PinPolicy::Always, PinPolicy::Once, PinPolicy::Never]
-                            .iter()
-                            .position(|p| {
-                                p == &flags.pin_policy.unwrap_or(builder::DEFAULT_PIN_POLICY)
-                            })
-                            .unwrap(),
-                    )
-                    .interact_opt()?
-                {
-                    Some(0) => PinPolicy::Always,
-                    Some(1) => PinPolicy::Once,
-                    Some(2) => PinPolicy::Never,
-                    Some(_) => unreachable!(),
-                    None => return Ok(()),
+                let mut displayed_yk4_warning = false;
+                let pin_policy = loop {
+                    let pin_policy = match Select::new()
+                        .with_prompt(fl!("cli-setup-select-pin-policy"))
+                        .items(&[
+                            fl!("pin-policy-always"),
+                            fl!("pin-policy-once"),
+                            fl!("pin-policy-never"),
+                        ])
+                        .default(
+                            [PinPolicy::Always, PinPolicy::Once, PinPolicy::Never]
+                                .iter()
+                                .position(|p| {
+                                    p == &flags.pin_policy.unwrap_or(builder::DEFAULT_PIN_POLICY)
+                                })
+                                .unwrap(),
+                        )
+                        .report(true)
+                        .interact_opt()?
+                    {
+                        Some(0) => PinPolicy::Always,
+                        Some(1) => PinPolicy::Once,
+                        Some(2) => PinPolicy::Never,
+                        Some(_) => unreachable!(),
+                        None => return Ok(()),
+                    };
+
+                    // We can't preserve the PIN cache for YubiKey 4 series, because to
+                    // retrieve the serial we switch to the OTP applet.
+                    match (pin_policy, yubikey.version().major) {
+                        (PinPolicy::Once, 4) => {
+                            if !displayed_yk4_warning {
+                                eprintln!();
+                                eprintln!("{}", fl!("cli-setup-yk4-pin-policy"));
+                                eprintln!();
+                                displayed_yk4_warning = true;
+                            }
+
+                            if Confirm::new()
+                                .with_prompt(fl!("cli-setup-yk4-pin-policy-confirm"))
+                                .report(true)
+                                .interact()?
+                            {
+                                break pin_policy;
+                            }
+                        }
+                        _ => break pin_policy,
+                    }
                 };
 
                 let touch_policy = match Select::new()
@@ -566,6 +552,7 @@ fn main() -> Result<(), Error> {
                             })
                             .unwrap(),
                     )
+                    .report(true)
                     .interact_opt()?
                 {
                     Some(0) => TouchPolicy::Always,
@@ -576,11 +563,8 @@ fn main() -> Result<(), Error> {
                 };
 
                 if Confirm::new()
-                    .with_prompt(i18n_embed_fl::fl!(
-                        LANGUAGE_LOADER,
-                        "cli-setup-generate-new",
-                        slot_index = slot_index,
-                    ))
+                    .with_prompt(fl!("cli-setup-generate-new", slot_index = slot_index))
+                    .report(true)
                     .interact()?
                 {
                     eprintln!();
@@ -596,6 +580,7 @@ fn main() -> Result<(), Error> {
                         true,
                     )
                 } else {
+                    key::disconnect_without_reset(yubikey);
                     return Ok(());
                 }
             }
@@ -608,6 +593,7 @@ fn main() -> Result<(), Error> {
                 "age-yubikey-identity-{}.txt",
                 hex::encode(stub.tag)
             ))
+            .report(true)
             .interact_text()?;
 
         let mut file = match OpenOptions::new()
@@ -619,6 +605,7 @@ fn main() -> Result<(), Error> {
             Err(e) if e.kind() == io::ErrorKind::AlreadyExists => {
                 if Confirm::new()
                     .with_prompt(fl!("cli-setup-identity-file-exists"))
+                    .report(true)
                     .interact()?
                 {
                     File::create(&file_name)?
@@ -632,8 +619,7 @@ fn main() -> Result<(), Error> {
         writeln!(
             file,
             "{}",
-            i18n_embed_fl::fl!(
-                LANGUAGE_LOADER,
+            fl!(
                 "yubikey-identity",
                 yubikey_metadata = metadata.to_string(),
                 recipient = recipient.to_string(),
@@ -668,8 +654,7 @@ fn main() -> Result<(), Error> {
         eprintln!();
         eprintln!(
             "{}",
-            i18n_embed_fl::fl!(
-                LANGUAGE_LOADER,
+            fl!(
                 "cli-setup-finished",
                 is_new = if is_new { "true" } else { "false" },
                 recipient = recipient.to_string(),

src/p256.rs

@@ -1,6 +1,8 @@
 use bech32::{ToBase32, Variant};
 use p256::elliptic_curve::sec1::{FromEncodedPoint, ToEncodedPoint};
 use sha2::{Digest, Sha256};
+use yubikey::{certificate::PublicKeyInfo, Certificate};
+
 use std::fmt;
 
 use crate::RECIPIENT_PREFIX;
@@ -42,12 +44,23 @@ impl Recipient {
         }
     }
 
+    pub(crate) fn from_certificate(cert: &Certificate) -> Option<Self> {
+        Self::from_spki(cert.subject_pki())
+    }
+
+    pub(crate) fn from_spki(spki: &PublicKeyInfo) -> Option<Self> {
+        match spki {
+            PublicKeyInfo::EcP256(pubkey) => Self::from_encoded(pubkey),
+            _ => None,
+        }
+    }
+
     /// Attempts to parse a valid YubiKey recipient from its SEC-1 encoding.
     ///
     /// This accepts both compressed (as used by the plugin) and uncompressed (as used in
     /// the YubiKey certificate) encodings.
-    pub(crate) fn from_encoded(encoded: &p256::EncodedPoint) -> Option<Self> {
-        p256::PublicKey::from_encoded_point(encoded).map(Recipient)
+    fn from_encoded(encoded: &p256::EncodedPoint) -> Option<Self> {
+        Option::from(p256::PublicKey::from_encoded_point(encoded)).map(Recipient)
     }
 
     /// Returns the compressed SEC-1 encoding of this recipient.

src/plugin.rs

@@ -71,8 +71,7 @@ impl RecipientPluginV1 for RecipientPlugin {
                 Ok(Some(conn)) => yk_recipients.push(conn.recipient().clone()),
                 Ok(None) => yk_errors.push(recipient::Error::Identity {
                     index: stub.identity_index,
-                    message: i18n_embed_fl::fl!(
-                        crate::LANGUAGE_LOADER,
+                    message: fl!(
                         "plugin-err-yk-opening",
                         yubikey_serial = stub.serial.to_string(),
                     ),
@@ -250,6 +249,8 @@ impl IdentityPluginV1 for IdentityPlugin {
                     }
                 }
             }
+
+            conn.disconnect_without_reset();
         }
         Ok(file_keys)
     }

src/util.rs

@@ -4,7 +4,7 @@ use std::iter;
 use x509_parser::{certificate::X509Certificate, der_parser::oid::Oid};
 use yubikey::{
     piv::{RetiredSlotId, SlotId},
-    PinPolicy, Serial, TouchPolicy, YubiKey,
+    Certificate, PinPolicy, Serial, TouchPolicy, YubiKey,
 };
 
 use crate::fl;
@@ -112,15 +112,20 @@ impl Metadata {
     pub(crate) fn extract(
         yubikey: &mut YubiKey,
         slot: RetiredSlotId,
-        cert: &X509Certificate,
+        cert: &Certificate,
         all: bool,
     ) -> Option<Self> {
+        let (_, cert) = x509_parser::parse_x509_certificate(cert.as_ref()).ok()?;
+
         // We store the PIN and touch policies for identities in their certificates
         // using the same certificate extension as PIV attestations.
         // https://developers.yubico.com/PIV/Introduction/PIV_attestation.html
         let policies = |c: &X509Certificate| {
             c.tbs_certificate
-                .find_extension(&Oid::from(POLICY_EXTENSION_OID).unwrap())
+                .get_extension_unique(&Oid::from(POLICY_EXTENSION_OID).unwrap())
+                // If the extension is duplicated, we assume it is invalid.
+                .ok()
+                .flatten()
                 // If the encoded extension doesn't have 2 bytes, we assume it is invalid.
                 .filter(|policy| policy.value.len() >= 2)
                 .map(|policy| {
@@ -143,10 +148,10 @@ impl Metadata {
                 .unwrap_or((None, None))
         };
 
-        extract_name(cert, all)
+        extract_name(&cert, all)
             .map(|(name, ours)| {
                 if ours {
-                    let (pin_policy, touch_policy) = policies(cert);
+                    let (pin_policy, touch_policy) = policies(&cert);
                     (name, pin_policy, touch_policy)
                 } else {
                     // We can extract the PIN and touch policies via an attestation. This
@@ -168,7 +173,11 @@ impl Metadata {
                 serial: yubikey.serial(),
                 slot,
                 name,
-                created: cert.validity().not_before.to_rfc2822(),
+                created: cert
+                    .validity()
+                    .not_before
+                    .to_rfc2822()
+                    .unwrap_or_else(|e| format!("Invalid date: {}", e)),
                 pin_policy,
                 touch_policy,
             })
@@ -180,8 +189,7 @@ impl fmt::Display for Metadata {
         write!(
             f,
             "{}",
-            i18n_embed_fl::fl!(
-                crate::LANGUAGE_LOADER,
+            fl!(
                 "yubikey-metadata",
                 serial = self.serial.to_string(),
                 slot = slot_to_ui(&self.slot),
@@ -197,20 +205,13 @@ impl fmt::Display for Metadata {
 pub(crate) fn print_identity(stub: Stub, recipient: Recipient, metadata: Metadata) {
     let recipient = recipient.to_string();
     if !console::user_attended() {
-        eprintln!(
-            "{}",
-            i18n_embed_fl::fl!(
-                crate::LANGUAGE_LOADER,
-                "print-recipient",
-                recipient = recipient.as_str(),
-            )
-        );
+        let recipient = recipient.as_str();
+        eprintln!("{}", fl!("print-recipient", recipient = recipient));
     }
 
     println!(
         "{}",
-        i18n_embed_fl::fl!(
-            crate::LANGUAGE_LOADER,
+        fl!(
             "yubikey-identity",
             yubikey_metadata = metadata.to_string(),
             recipient = recipient,

tests/integration.rs

@@ -0,0 +1,125 @@
+use std::env;
+use std::io::Write;
+use std::path::Path;
+use std::process::{Command, Stdio};
+
+const PLUGIN_BIN: &str = env!("CARGO_BIN_EXE_age-plugin-yubikey");
+
+#[test_with::env(YUBIKEY_SERIAL, YUBIKEY_SLOT)]
+#[cfg_attr(all(unix, not(target_os = "macos")), test_with::executable(pcscd))]
+#[test]
+fn recipient_and_identity_match() {
+    let recipient = Command::new(PLUGIN_BIN)
+        .arg("--list")
+        .arg("--serial")
+        .arg(env::var("YUBIKEY_SERIAL").unwrap())
+        .arg("--slot")
+        .arg(env::var("YUBIKEY_SLOT").unwrap())
+        .output()
+        .unwrap();
+    assert_eq!(recipient.status.code(), Some(0));
+
+    let identity = Command::new(PLUGIN_BIN)
+        .arg("--identity")
+        .arg("--serial")
+        .arg(env::var("YUBIKEY_SERIAL").unwrap())
+        .arg("--slot")
+        .arg(env::var("YUBIKEY_SLOT").unwrap())
+        .output()
+        .unwrap();
+    assert_eq!(identity.status.code(), Some(0));
+
+    let recipient_file = String::from_utf8_lossy(&recipient.stdout);
+    let recipient = recipient_file.lines().last().unwrap();
+    let identity = String::from_utf8_lossy(&identity.stdout);
+    assert!(identity.contains(recipient));
+}
+
+#[test_with::executable(rage)]
+#[test]
+fn plugin_encrypt() {
+    let enc_file = tempfile::NamedTempFile::new_in(env!("CARGO_TARGET_TMPDIR")).unwrap();
+
+    let mut process = Command::new(which::which("rage").unwrap())
+        .arg("-r")
+        .arg("age1yubikey1q2w7u3vpya839jxxuq8g0sedh3d740d4xvn639sqhr95ejj8vu3hyfumptt")
+        .arg("-o")
+        .arg(enc_file.path())
+        .stdin(Stdio::piped())
+        .env("PATH", Path::new(PLUGIN_BIN).parent().unwrap())
+        .spawn()
+        .unwrap();
+
+    // Scope to ensure stdin is closed.
+    {
+        let mut stdin = process.stdin.take().unwrap();
+        stdin.write_all(b"Testing YubiKey encryption").unwrap();
+        stdin.flush().unwrap();
+    }
+
+    let status = process.wait().unwrap();
+    assert_eq!(status.code(), Some(0));
+}
+
+#[test_with::env(YUBIKEY_SERIAL, YUBIKEY_SLOT)]
+#[test_with::executable(rage)]
+#[cfg_attr(all(unix, not(target_os = "macos")), test_with::executable(pcscd))]
+#[test]
+fn plugin_decrypt() {
+    let mut identity_file = tempfile::NamedTempFile::new_in(env!("CARGO_TARGET_TMPDIR")).unwrap();
+    let enc_file = tempfile::NamedTempFile::new_in(env!("CARGO_TARGET_TMPDIR")).unwrap();
+    let plaintext = "Testing YubiKey encryption";
+
+    // Write an identity file corresponding to this YubiKey slot.
+    let identity = Command::new(PLUGIN_BIN)
+        .arg("--identity")
+        .arg("--serial")
+        .arg(env::var("YUBIKEY_SERIAL").unwrap())
+        .arg("--slot")
+        .arg(env::var("YUBIKEY_SLOT").unwrap())
+        .output()
+        .unwrap();
+    assert_eq!(identity.status.code(), Some(0));
+    identity_file.write_all(&identity.stdout).unwrap();
+    identity_file.flush().unwrap();
+
+    // Encrypt to the YubiKey slot.
+    let mut enc_process = Command::new(which::which("rage").unwrap())
+        .arg("-e")
+        .arg("-i")
+        .arg(identity_file.path())
+        .arg("-o")
+        .arg(enc_file.path())
+        .stdin(Stdio::piped())
+        .env("PATH", Path::new(PLUGIN_BIN).parent().unwrap())
+        .spawn()
+        .unwrap();
+
+    // Scope to ensure stdin is closed.
+    {
+        let mut stdin = enc_process.stdin.take().unwrap();
+        stdin.write_all(plaintext.as_bytes()).unwrap();
+        stdin.flush().unwrap();
+    }
+
+    let enc_status = enc_process.wait().unwrap();
+    assert_eq!(enc_status.code(), Some(0));
+
+    // Decrypt with the YubiKey.
+    let dec_process = Command::new(which::which("rage").unwrap())
+        .arg("-d")
+        .arg("-i")
+        .arg(identity_file.path())
+        .arg(enc_file.path())
+        .stdin(Stdio::piped())
+        .env("PATH", Path::new(PLUGIN_BIN).parent().unwrap())
+        .output()
+        .unwrap();
+
+    let stderr = String::from_utf8_lossy(&dec_process.stderr);
+    if !stderr.is_empty() {
+        assert!(stderr.contains("age-plugin-yubikey"));
+        assert!(stderr.ends_with("...\n"));
+    }
+    assert_eq!(String::from_utf8_lossy(&dec_process.stdout), plaintext);
+}