yubikey-piv v0.3.0 (#240)

* Add MgmKey::set_default method

This wipes any metadata related to derived and PIN-protected management
keys, returning the management key to its default state.

* Transaction::set_mgm_key: Take touch requirement as bool

The Option<u8> was inherited from the original C code's usage of an
unsigned char. We don't need that flexibility, because only two cases
are supported.

* Replace MgmKey::set with MgmKey::set_manual

MgmKey::set_default is now implemented as a wrapper around
MgmKey::set_manual, as they both require clearing metadata related to
derived and PIN-protected management keys.

.github/workflows/ci.yml

@@ -3,7 +3,7 @@ name: CI
 on:
   pull_request: {}
   push:
-    branches: develop
+    branches: main
 
 env:
   CARGO_INCREMENTAL: 0
@@ -36,13 +36,13 @@ jobs:
             toolchain: stable
             deps: true
           - platform: ubuntu-latest
-            toolchain: 1.44.0 # MSRV
+            toolchain: 1.46.0 # MSRV
             deps: sudo apt-get install libpcsclite-dev
           - platform: windows-latest
-            toolchain: 1.44.0 # MSRV
+            toolchain: 1.46.0 # MSRV
             deps: true
           - platform: macos-latest
-            toolchain: 1.44.0 # MSRV
+            toolchain: 1.46.0 # MSRV
             deps: true
     runs-on: ${{ matrix.platform }}
     steps:
@@ -82,7 +82,7 @@ jobs:
       - uses: actions-rs/toolchain@v1
         with:
           profile: minimal
-          toolchain: 1.44.0 # MSRV
+          toolchain: 1.46.0 # MSRV
           components: clippy
       - run: sudo apt-get install libpcsclite-dev
       - run: cargo clippy --all --exclude crypto_box --all-features -- -D warnings

.github/workflows/security_audit.yml

@@ -3,7 +3,7 @@ on:
   pull_request:
     paths: Cargo.lock
   push:
-    branches: develop
+    branches: main
     paths: Cargo.lock
   schedule:
     - cron: '0 0 * * *'

CHANGELOG.md

@@ -4,7 +4,35 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## 0.1.0 (2020-10-18)
+## 0.3.0 (2021-03-22)
+### Added
+- Typed structs for PIN-protected and admin metadata ([#223])
+- `MgmKey::set_default`/`MgmKey::set_manual` methods ([#224])
+
+### Changed
+- Have `Transaction::set_mgm_key` take touch requirement as bool ([#224])
+
+### Removed
+- `MgmKey::set` method ([#224])
+
+[#223]: https://github.com/iqlusioninc/yubikey-piv.rs/pull/223
+[#224]: https://github.com/iqlusioninc/yubikey-piv.rs/pull/224
+
+## 0.2.0 (2021-01-30)
+### Changed
+- Bump `der-parser` to v5.0 ([#194])
+- Improve self-signed certificates ([#207])
+- Bump `x509-parser` to v0.9 ([#208])
+- Bump elliptic-curve to 0.8. Also requires bumping p256 and p384 ([#208])
+- Bump MSRV to 1.46+ ([#208])
+- Bump `pbkdf2` dependency to v0.7 ([#219])
+
+[#194]: https://github.com/iqlusioninc/yubikey-piv.rs/pull/194
+[#207]: https://github.com/iqlusioninc/yubikey-piv.rs/pull/207
+[#208]: https://github.com/iqlusioninc/yubikey-piv.rs/pull/208
+[#219]: https://github.com/iqlusioninc/yubikey-piv.rs/pull/219
+
+## 0.1.0 (2020-10-19)
 ### Added
 - `Certificate::generate_self_signed` ([#80])
 - `YubiKey::open_by_serial` ([#69])

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name    = "yubikey-piv"
-version = "0.1.0" # Also update html_root_url in lib.rs when bumping this
+version = "0.3.0" # Also update html_root_url in lib.rs when bumping this
 description = """
 Pure Rust host-side driver for the YubiKey Personal Identity Verification (PIV)
 application providing general-purpose public-key signing and encryption
@@ -24,19 +24,19 @@ maintenance = { status = "experimental" }
 [dependencies]
 chrono = "0.4"
 cookie-factory = "0.3"
-der-parser = "4"
+der-parser = "5"
 des = "0.6"
-elliptic-curve = "0.6"
+elliptic-curve = "0.8"
 getrandom = "0.1"
 hmac = "0.10"
 log = "0.4"
-nom = "5"
+nom = "6"
 num-bigint = { version = "0.6", features = ["rand"], package = "num-bigint-dig" }
 num-traits = "0.2"
 num-integer = "0.1"
-pbkdf2 = "0.6"
-p256 = "0.5"
-p384 = "0.4"
+pbkdf2 = { version = "0.7", default-features = false }
+p256 = "0.7"
+p384 = "0.6"
 pcsc = "2"
 rsa = "0.3"
 secrecy = "0.7"
@@ -44,13 +44,13 @@ sha-1 = "0.9"
 sha2 = "0.9"
 subtle = "2"
 subtle-encoding = "0.5"
-x509 = "0.1.2"
-x509-parser = "0.8"
+x509 = "0.2"
+x509-parser = "0.9"
 zeroize = "1"
 
 [dev-dependencies]
 env_logger = "0.8"
-ring = "0.16.15"
+ring = "0.16.18"
 lazy_static = "1"
 
 [features]

README.md

@@ -1,4 +1,4 @@
-<img src="https://raw.githubusercontent.com/iqlusioninc/yubikey-piv.rs/develop/img/logo.png" width="150" height="110">
+<img src="https://raw.githubusercontent.com/iqlusioninc/yubikey-piv.rs/main/img/logo.png" width="150" height="110">
 
 # yubikey-piv.rs
 
@@ -36,7 +36,7 @@ endorsed by Yubico.
 
 ## Minimum Supported Rust Version
 
-- Rust **1.44** or newer
+- Rust **1.46** or newer
 
 ## Supported YubiKeys
 
@@ -193,12 +193,12 @@ or conditions.
 [docs-image]: https://docs.rs/yubikey-piv/badge.svg
 [docs-link]: https://docs.rs/yubikey-piv/
 [license-image]: https://img.shields.io/badge/license-BSD-blue.svg
-[license-link]: https://github.com/iqlusioninc/yubikey-piv.rs/blob/develop/COPYING
-[rustc-image]: https://img.shields.io/badge/rustc-1.44+-blue.svg
+[license-link]: https://github.com/iqlusioninc/yubikey-piv.rs/blob/main/COPYING
+[rustc-image]: https://img.shields.io/badge/rustc-1.46+-blue.svg
 [maintenance-image]: https://img.shields.io/badge/maintenance-experimental-blue.svg
 [safety-image]: https://img.shields.io/badge/unsafe-forbidden-success.svg
 [safety-link]: https://github.com/rust-secure-code/safety-dance/
-[build-image]: https://github.com/iqlusioninc/yubikey-piv.rs/workflows/CI/badge.svg?branch=develop&event=push
+[build-image]: https://github.com/iqlusioninc/yubikey-piv.rs/workflows/CI/badge.svg?branch=main&event=push
 [build-link]: https://github.com/iqlusioninc/yubikey-piv.rs/actions
 [gitter-image]: https://badges.gitter.im/badge.svg
 [gitter-link]: https://gitter.im/iqlusioninc/community
@@ -214,7 +214,7 @@ or conditions.
 [yubico-piv-tool]: https://github.com/Yubico/yubico-piv-tool/
 [Corrode]: https://github.com/jameysharp/corrode
 [cc-web]: https://contributor-covenant.org/
-[cc-md]: https://github.com/iqlusioninc/yubikey-piv.rs/blob/develop/CODE_OF_CONDUCT.md
+[cc-md]: https://github.com/iqlusioninc/yubikey-piv.rs/blob/main/CODE_OF_CONDUCT.md
 [BSDL]: https://opensource.org/licenses/BSD-2-Clause
 
 [//]: # (github issues)

cli/CHANGELOG.md

@@ -4,5 +4,30 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## 0.2.0 (2021-01-30)
+### Changed
+- Bump MSRV to 1.46+ ([#208])
+- Bump `yubikey-piv` dependency to v0.2.0 ([#220])
+
+[#208]: https://github.com/iqlusioninc/yubikey-piv.rs/pull/208
+[#220]: https://github.com/iqlusioninc/yubikey-piv.rs/pull/220
+
+## 0.1.0 (2020-10-19)
+### Added
+- `status` command ([#72], [#74])
+
+### Changed
+- Bump `yubikey-piv` to v0.1.0 ([#180])
+- Bump `x509-parser` to v0.8 ([#181])
+- Bump `sha2` to v0.9 ([#182])
+- Rename `list` command to `readers`; improve usage ([#71])
+
+[#182]: https://github.com/iqlusioninc/yubikey-piv.rs/pull/182
+[#181]: https://github.com/iqlusioninc/yubikey-piv.rs/pull/181
+[#180]: https://github.com/iqlusioninc/yubikey-piv.rs/pull/180
+[#74]: https://github.com/iqlusioninc/yubikey-piv.rs/pull/74
+[#72]: https://github.com/iqlusioninc/yubikey-piv.rs/pull/72
+[#71]: https://github.com/iqlusioninc/yubikey-piv.rs/pull/71
+
 ## 0.0.1 (2019-12-02)
 - Initial release

cli/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "yubikey-cli"
-version = "0.0.1"
+version = "0.2.0"
 description = """
 Command-line interface for performing encryption and signing using RSA/ECC keys
 stored on YubiKey devices.
@@ -18,8 +18,8 @@ gumdrop = "0.8"
 env_logger = "0.8"
 lazy_static = "1"
 log = "0.4"
-sha2 = "0.8"
+sha2 = "0.9"
 subtle-encoding = "0.5"
 termcolor = "1"
-x509-parser = "0.7"
-yubikey-piv = { version = "0.1", path = ".." }
+x509-parser = "0.9"
+yubikey-piv = { version = "0.3", path = ".." }

cli/README.md

@@ -1,4 +1,4 @@
-<img src="https://raw.githubusercontent.com/iqlusioninc/yubikey-piv.rs/develop/img/logo.png" width="150" height="110">
+<img src="https://raw.githubusercontent.com/iqlusioninc/yubikey-piv.rs/main/img/logo.png" width="150" height="110">
 
 # yubikey-cli.rs
 
@@ -92,7 +92,7 @@ or conditions.
 [maintenance-image]: https://img.shields.io/badge/maintenance-experimental-blue.svg
 [safety-image]: https://img.shields.io/badge/unsafe-forbidden-success.svg
 [safety-link]: https://github.com/rust-secure-code/safety-dance/
-[build-image]: https://github.com/iqlusioninc/yubikey-piv.rs/workflows/Rust/badge.svg?branch=develop&event=push
+[build-image]: https://github.com/iqlusioninc/yubikey-piv.rs/workflows/CI/badge.svg?branch=main&event=push
 [build-link]: https://github.com/iqlusioninc/yubikey-piv.rs/actions
 [gitter-image]: https://badges.gitter.im/badge.svg
 [gitter-link]: https://gitter.im/iqlusioninc/community
@@ -108,5 +108,5 @@ or conditions.
 [yubico-piv-tool]: https://github.com/Yubico/yubico-piv-tool/
 [Corrode]: https://github.com/jameysharp/corrode
 [cc-web]: https://contributor-covenant.org/
-[cc-md]: https://github.com/iqlusioninc/yubikey-cli.rs/blob/develop/CODE_OF_CONDUCT.md
+[cc-md]: https://github.com/iqlusioninc/yubikey-cli.rs/blob/main/CODE_OF_CONDUCT.md
 [BSDL]: https://opensource.org/licenses/BSD-2-Clause

cli/src/lib.rs

@@ -19,7 +19,7 @@ use std::io::{self, Write};
 use std::str;
 use subtle_encoding::hex;
 use termcolor::{ColorSpec, StandardStreamLock, WriteColor};
-use x509_parser::parse_x509_der;
+use x509_parser::parse_x509_certificate;
 use yubikey_piv::{certificate::Certificate, key::*, YubiKey};
 
 ///Write information about certificate found in slot a la yubico-piv-tool output.
@@ -41,7 +41,7 @@ pub fn print_cert_info(
         let fingerprint = Sha256::digest(&buf);
         let slot_id: u8 = slot.into();
         print_cert_attr(stream, "Slot", format!("{:x}", slot_id))?;
-        match parse_x509_der(&buf) {
+        match parse_x509_certificate(&buf) {
             Ok((_rem, cert)) => {
                 print_cert_attr(
                     stream,
@@ -59,12 +59,12 @@ pub fn print_cert_info(
                 print_cert_attr(
                     stream,
                     "Not Before",
-                    cert.tbs_certificate.validity.not_before.asctime(),
+                    cert.tbs_certificate.validity.not_before.to_rfc2822(),
                 )?;
                 print_cert_attr(
                     stream,
                     "Not After",
-                    cert.tbs_certificate.validity.not_after.asctime(),
+                    cert.tbs_certificate.validity.not_after.to_rfc2822(),
                 )?;
             }
             _ => {

src/certificate.rs

@@ -49,7 +49,8 @@ use sha2::{Digest, Sha256};
 use std::convert::TryFrom;
 use std::fmt;
 use std::ops::DerefMut;
-use x509_parser::{parse_x509_der, x509::SubjectPublicKeyInfo};
+use x509::{der::Oid, RelativeDistinguishedName};
+use x509_parser::{parse_x509_certificate, x509::SubjectPublicKeyInfo};
 use zeroize::Zeroizing;
 
 use crate::CB_OBJ_MAX;
@@ -205,7 +206,13 @@ impl PublicKeyInfo {
             }
             OID_EC_PUBLIC_KEY => {
                 let key_bytes = &subject_pki.subject_public_key.data;
-                match read_pki::ec_parameters(&subject_pki.algorithm.parameters)? {
+                let algorithm_parameters = subject_pki
+                    .algorithm
+                    .parameters
+                    .as_ref()
+                    .ok_or(Error::InvalidObject)?;
+
+                match read_pki::ec_parameters(algorithm_parameters)? {
                     AlgorithmId::EccP256 => EcPublicKey::from_bytes(key_bytes)
                         .map(PublicKeyInfo::EcP256)
                         .map_err(|_| Error::InvalidObject),
@@ -331,19 +338,21 @@ impl<'a> TryFrom<&'a [u8]> for Certificate {
 impl Certificate {
     /// Creates a new self-signed certificate for the given key. Writes the resulting
     /// certificate to the slot before returning it.
-    pub fn generate_self_signed(
+    ///
+    /// `extensions` is optional; if empty, no extensions will be included. Due to the
+    /// need for an `O: Oid` type parameter, users who do not have any extensions should
+    /// use the workaround `let extensions: &[x509::Extension<'_, &[u64]>] = &[];`.
+    pub fn generate_self_signed<O: Oid>(
         yubikey: &mut YubiKey,
         key: SlotId,
         serial: impl Into<Serial>,
         not_after: Option<DateTime<Utc>>,
-        subject: String,
+        subject: &[RelativeDistinguishedName<'_>],
         subject_pki: PublicKeyInfo,
+        extensions: &[x509::Extension<'_, O>],
     ) -> Result<Self, Error> {
         let serial = serial.into();
 
-        // Issuer and subject are the same in self-signed certificates
-        let issuer = subject.clone();
-
         let mut tbs_cert = Buffer::new(Vec::with_capacity(CB_OBJ_MAX));
 
         let signature_algorithm = match subject_pki.algorithm() {
@@ -355,11 +364,13 @@ impl Certificate {
             x509::write::tbs_certificate(
                 &serial.to_bytes(),
                 &signature_algorithm,
-                &issuer,
+                // Issuer and subject are the same in self-signed certificates.
+                &subject,
                 Utc::now(),
                 not_after,
                 &subject,
                 &subject_pki,
+                &extensions,
             ),
             tbs_cert.deref_mut(),
         )
@@ -419,6 +430,15 @@ impl Certificate {
         )
         .expect("can serialize to Vec");
 
+        let (issuer, subject) = parse_x509_certificate(&data)
+            .map(|(_, cert)| {
+                (
+                    cert.tbs_certificate.issuer.to_string(),
+                    cert.tbs_certificate.subject.to_string(),
+                )
+            })
+            .expect("We just serialized this correctly");
+
         let cert = Certificate {
             serial,
             issuer,
@@ -471,7 +491,7 @@ impl Certificate {
             return Err(Error::SizeError);
         }
 
-        let parsed_cert = match parse_x509_der(&cert) {
+        let parsed_cert = match parse_x509_certificate(&cert) {
             Ok((_, cert)) => cert,
             _ => return Err(Error::InvalidObject),
         };
@@ -631,12 +651,7 @@ mod read_pki {
     /// }
     /// ```
     pub(super) fn ec_parameters(parameters: &DerObject<'_>) -> Result<AlgorithmId, Error> {
-        let curve_oid = match parameters.as_context_specific() {
-            Ok((_, Some(named_curve))) => {
-                named_curve.as_oid_val().map_err(|_| Error::InvalidObject)
-            }
-            _ => Err(Error::InvalidObject),
-        }?;
+        let curve_oid = parameters.as_oid_val().map_err(|_| Error::InvalidObject)?;
 
         match curve_oid.to_string().as_str() {
             OID_NIST_P256 => Ok(AlgorithmId::EccP256),

src/config.rs

@@ -32,11 +32,11 @@
 
 use crate::{
     error::Error,
-    metadata,
+    metadata::{AdminData, ProtectedData},
     mgm::{MgmType, ADMIN_FLAGS_1_PROTECTED_MGM},
     yubikey::{YubiKey, ADMIN_FLAGS_1_PUK_BLOCKED},
-    TAG_ADMIN, TAG_ADMIN_FLAGS_1, TAG_ADMIN_SALT, TAG_ADMIN_TIMESTAMP, TAG_PROTECTED,
-    TAG_PROTECTED_FLAGS_1, TAG_PROTECTED_MGM,
+    TAG_ADMIN_FLAGS_1, TAG_ADMIN_SALT, TAG_ADMIN_TIMESTAMP, TAG_PROTECTED_FLAGS_1,
+    TAG_PROTECTED_MGM,
 };
 use log::error;
 use std::{
@@ -79,8 +79,8 @@ impl Config {
 
         let txn = yubikey.begin_transaction()?;
 
-        if let Ok(data) = metadata::read(&txn, TAG_ADMIN) {
-            if let Ok(item) = metadata::get_item(&data, TAG_ADMIN_FLAGS_1) {
+        if let Ok(admin_data) = AdminData::read(&txn) {
+            if let Ok(item) = admin_data.get_item(TAG_ADMIN_FLAGS_1) {
                 if item.is_empty() {
                     error!("empty response for admin flags metadata item! ignoring");
                 } else {
@@ -94,7 +94,7 @@ impl Config {
                 }
             }
 
-            if metadata::get_item(&data, TAG_ADMIN_SALT).is_ok() {
+            if admin_data.get_item(TAG_ADMIN_SALT).is_ok() {
                 if config.mgm_type != MgmType::Manual {
                     error!("conflicting types of MGM key administration configured");
                 } else {
@@ -102,7 +102,7 @@ impl Config {
                 }
             }
 
-            if let Ok(item) = metadata::get_item(&data, TAG_ADMIN_TIMESTAMP) {
+            if let Ok(item) = admin_data.get_item(TAG_ADMIN_TIMESTAMP) {
                 if item.len() != CB_ADMIN_TIMESTAMP {
                     error!("pin timestamp in admin metadata is an invalid size");
                 } else {
@@ -117,10 +117,10 @@ impl Config {
             }
         }
 
-        if let Ok(data) = metadata::read(&txn, TAG_PROTECTED) {
+        if let Ok(protected_data) = ProtectedData::read(&txn) {
             config.protected_data_available = true;
 
-            if let Ok(item) = metadata::get_item(&data, TAG_PROTECTED_FLAGS_1) {
+            if let Ok(item) = protected_data.get_item(TAG_PROTECTED_FLAGS_1) {
                 if item.is_empty() {
                     error!("empty response for protected flags metadata item! ignoring");
                 } else if item[0] & PROTECTED_FLAGS_1_PUK_NOBLOCK != 0 {
@@ -128,7 +128,7 @@ impl Config {
                 }
             }
 
-            if metadata::get_item(&data, TAG_PROTECTED_MGM).is_ok() {
+            if protected_data.get_item(TAG_PROTECTED_MGM).is_ok() {
                 if config.mgm_type != MgmType::Protected {
                     error!(
                         "conflicting types of mgm key administration configured: protected MGM exists"

src/lib.rs

@@ -83,12 +83,12 @@
 //! [YubiKey NEO]: https://support.yubico.com/support/solutions/articles/15000006494-yubikey-neo
 //! [YubiKey 4]: https://support.yubico.com/support/solutions/articles/15000006486-yubikey-4
 //! [YubiKey 5]: https://www.yubico.com/products/yubikey-5-overview/
-//! [status]: https://github.com/tarcieri/yubikey-piv.rs#status
+//! [status]: https://github.com/iqlusioninc/yubikey-piv.rs#status
 //! [yubico-piv-tool]: https://github.com/Yubico/yubico-piv-tool/
 //! [Corrode]: https://github.com/jameysharp/corrode
 //! [piv-tool-guide]: https://www.yubico.com/wp-content/uploads/2016/05/Yubico_PIV_Tool_Command_Line_Guide_en.pdf
 //! [cc-web]: https://contributor-covenant.org/
-//! [cc-md]: https://github.com/tarcieri/yubikey-piv.rs/blob/develop/CODE_OF_CONDUCT.md
+//! [cc-md]: https://github.com/iqlusioninc/yubikey-piv.rs/blob/main/CODE_OF_CONDUCT.md
 //! [BSDL]: https://opensource.org/licenses/BSD-2-Clause
 
 // Adapted from yubico-piv-tool:
@@ -122,8 +122,8 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #![doc(
-    html_logo_url = "https://raw.githubusercontent.com/iqlusioninc/yubikey-piv.rs/develop/img/logo.png",
-    html_root_url = "https://docs.rs/yubikey-piv/0.1.0"
+    html_logo_url = "https://raw.githubusercontent.com/iqlusioninc/yubikey-piv.rs/main/img/logo.png",
+    html_root_url = "https://docs.rs/yubikey-piv/0.3.0"
 )]
 #![forbid(unsafe_code)]
 #![warn(
@@ -178,11 +178,9 @@ pub(crate) const CB_OBJ_TAG_MIN: usize = 2; // 1 byte tag + 1 byte len
 #[cfg(feature = "untested")]
 pub(crate) const CB_OBJ_TAG_MAX: usize = CB_OBJ_TAG_MIN + 2; // 1 byte tag + 3 bytes len
 
-pub(crate) const TAG_ADMIN: u8 = 0x80;
 pub(crate) const TAG_ADMIN_FLAGS_1: u8 = 0x81;
 pub(crate) const TAG_ADMIN_SALT: u8 = 0x82;
 pub(crate) const TAG_ADMIN_TIMESTAMP: u8 = 0x83;
-pub(crate) const TAG_PROTECTED: u8 = 0x88;
 pub(crate) const TAG_PROTECTED_FLAGS_1: u8 = 0x81;
 pub(crate) const TAG_PROTECTED_MGM: u8 = 0x89;
 

src/metadata.rs

@@ -30,21 +30,89 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-use crate::{
-    error::Error, serialization::*, transaction::Transaction, Buffer, TAG_ADMIN, TAG_PROTECTED,
-};
+use std::marker::PhantomData;
+use zeroize::Zeroizing;
+
+use crate::{error::Error, serialization::*, transaction::Transaction, Buffer};
 
 #[cfg(feature = "untested")]
 use crate::{CB_OBJ_MAX, CB_OBJ_TAG_MAX};
 
 #[cfg(feature = "untested")]
-use zeroize::Zeroizing;
+use std::iter;
 
+const TAG_ADMIN: u8 = 0x80;
+const TAG_PROTECTED: u8 = 0x88;
 pub const OBJ_ADMIN_DATA: u32 = 0x005f_ff00;
 pub const OBJ_PRINTED: u32 = 0x005f_c109;
 
-/// Get metadata item
-pub(crate) fn get_item(mut data: &[u8], tag: u8) -> Result<&[u8], Error> {
+pub(crate) trait MetadataType: private::Sealed {}
+
+/// A type variable corresponding to PIN-protected metadata.
+pub(crate) enum Protected {}
+impl MetadataType for Protected {}
+
+/// A type variable corresponding to administrative metadata.
+pub(crate) enum Admin {}
+impl MetadataType for Admin {}
+
+/// Metadata stored in a YubiKey.
+pub(crate) struct Metadata<T: MetadataType> {
+    inner: Buffer,
+    _marker: PhantomData<T>,
+}
+
+/// PIN-protected metadata stored in a YubiKey.
+pub(crate) type ProtectedData = Metadata<Protected>;
+/// Administrative metadata stored in a YubiKey.
+pub(crate) type AdminData = Metadata<Admin>;
+
+impl<T: MetadataType> Default for Metadata<T> {
+    fn default() -> Self {
+        Metadata {
+            inner: Zeroizing::new(vec![]),
+            _marker: PhantomData::default(),
+        }
+    }
+}
+
+impl<T: MetadataType> Metadata<T> {
+    /// Read metadata
+    pub(crate) fn read(txn: &Transaction<'_>) -> Result<Self, Error> {
+        let data = txn.fetch_object(T::obj_id())?;
+        Ok(Metadata {
+            inner: Tlv::parse_single(data, T::tag())?,
+            _marker: PhantomData::default(),
+        })
+    }
+
+    /// Write metadata
+    #[cfg(feature = "untested")]
+    pub(crate) fn write(&self, txn: &Transaction<'_>) -> Result<(), Error> {
+        if self.inner.len() > CB_OBJ_MAX - CB_OBJ_TAG_MAX {
+            return Err(Error::GenericError);
+        }
+
+        if self.inner.is_empty() {
+            return Self::delete(txn);
+        }
+
+        let mut buf = Zeroizing::new(vec![0u8; CB_OBJ_MAX]);
+        let len = Tlv::write(&mut buf, T::tag(), &self.inner)?;
+
+        txn.save_object(T::obj_id(), &buf[..len])
+    }
+
+    /// Delete metadata
+    #[cfg(feature = "untested")]
+    pub(crate) fn delete(txn: &Transaction<'_>) -> Result<(), Error> {
+        txn.save_object(T::obj_id(), &[])
+    }
+
+    /// Get metadata item
+    pub(crate) fn get_item(&self, tag: u8) -> Result<&[u8], Error> {
+        let mut data = &self.inner[..];
+
         while !data.is_empty() {
             let (remaining, tlv) = Tlv::parse(data)?;
             data = remaining;
@@ -56,29 +124,22 @@ pub(crate) fn get_item(mut data: &[u8], tag: u8) -> Result<&[u8], Error> {
         }
 
         Err(Error::GenericError)
-}
+    }
 
-/// Set metadata item
-#[cfg(feature = "untested")]
-pub(crate) fn set_item(
-    data: &mut [u8],
-    pcb_data: &mut usize,
-    cb_data_max: usize,
-    tag: u8,
-    p_item: &[u8],
-) -> Result<(), Error> {
+    /// Set metadata item
+    #[cfg(feature = "untested")]
+    pub(crate) fn set_item(&mut self, tag: u8, item: &[u8]) -> Result<(), Error> {
         let mut cb_temp: usize = 0;
         let mut tag_temp: u8 = 0;
         let mut cb_len: usize = 0;
-    let cb_item = p_item.len();
 
         let mut offset = 0;
 
-    while offset < *pcb_data {
-        tag_temp = data[offset];
+        while offset < self.inner.len() {
+            tag_temp = self.inner[offset];
             offset += 1;
 
-        cb_len = get_length(&data[offset..], &mut cb_temp);
+            cb_len = get_length(&self.inner[offset..], &mut cb_temp);
             offset += cb_len;
 
             if tag_temp == tag {
@@ -89,13 +150,16 @@ pub(crate) fn set_item(
         }
 
         if tag_temp != tag {
-        if cb_item == 0 {
+            if item.is_empty() {
                 // We've been asked to delete an existing item that isn't in the blob
                 return Ok(());
             }
 
             // We did not find an existing tag, append
-        *pcb_data += Tlv::write(&mut data[*pcb_data..], tag, p_item)?;
+            assert_eq!(offset, self.inner.len());
+            self.inner
+                .extend(iter::repeat(0).take(1 + get_length_size(item.len()) + item.len()));
+            Tlv::write(&mut self.inner[offset..], tag, item)?;
 
             return Ok(());
         }
@@ -103,80 +167,50 @@ pub(crate) fn set_item(
         // Found tag
 
         // Check length, if it matches, overwrite
-    if cb_temp == cb_item {
-        data[offset..offset + cb_item].copy_from_slice(p_item);
+        if cb_temp == item.len() {
+            self.inner[offset..offset + item.len()].copy_from_slice(item);
             return Ok(());
         }
 
         // Length doesn't match, expand/shrink to fit
         let next_offset = offset + cb_temp;
         // Must be signed to have negative offsets
-    let cb_moved: isize = (cb_item as isize - cb_temp as isize)
-        + if cb_item != 0 {
-            get_length_size(cb_item) as isize
-        } else {
+        let cb_moved: isize = (item.len() as isize - cb_temp as isize)
+            + if item.is_empty() {
                 // For tag, if deleting
                 -1
+            } else {
+                get_length_size(item.len()) as isize
             }
             // Accounts for different length encoding
             - cb_len as isize;
 
         // If length would cause buffer overflow, return error
-    if (*pcb_data as isize + cb_moved) as usize > cb_data_max {
+        if (self.inner.len() as isize + cb_moved) as usize > CB_OBJ_MAX {
             return Err(Error::GenericError);
         }
 
         // Move remaining data
-    data.copy_within(
-        next_offset..*pcb_data,
+        let orig_len = self.inner.len();
+        if cb_moved > 0 {
+            self.inner.extend(iter::repeat(0).take(cb_moved as usize));
+        }
+        self.inner.copy_within(
+            next_offset..orig_len,
             (next_offset as isize + cb_moved) as usize,
         );
-    *pcb_data = (*pcb_data as isize + cb_moved) as usize;
+        self.inner
+            .resize((orig_len as isize + cb_moved) as usize, 0);
 
         // Re-encode item and insert
-    if cb_item != 0 {
+        if !item.is_empty() {
             offset -= cb_len;
-        offset += set_length(&mut data[offset..], cb_item)?;
-        data[offset..offset + cb_item].copy_from_slice(p_item);
+            offset += set_length(&mut self.inner[offset..], item.len())?;
+            self.inner[offset..offset + item.len()].copy_from_slice(item);
         }
 
         Ok(())
-}
-
-/// Read metadata
-pub(crate) fn read(txn: &Transaction<'_>, tag: u8) -> Result<Buffer, Error> {
-    let obj_id = match tag {
-        TAG_ADMIN => OBJ_ADMIN_DATA,
-        TAG_PROTECTED => OBJ_PRINTED,
-        _ => return Err(Error::InvalidObject),
-    };
-
-    let data = txn.fetch_object(obj_id)?;
-    Tlv::parse_single(data, tag)
-}
-
-/// Write metadata
-#[cfg(feature = "untested")]
-pub(crate) fn write(txn: &Transaction<'_>, tag: u8, data: &[u8]) -> Result<(), Error> {
-    if data.len() > CB_OBJ_MAX - CB_OBJ_TAG_MAX {
-        return Err(Error::GenericError);
     }
-
-    let obj_id = match tag {
-        TAG_ADMIN => OBJ_ADMIN_DATA,
-        TAG_PROTECTED => OBJ_PRINTED,
-        _ => return Err(Error::InvalidObject),
-    };
-
-    if data.is_empty() {
-        // Deleting metadata
-        return txn.save_object(obj_id, &[]);
-    }
-
-    let mut buf = Zeroizing::new(vec![0u8; CB_OBJ_MAX]);
-    let len = Tlv::write(&mut buf, tag, data)?;
-
-    txn.save_object(obj_id, &buf[..len])
 }
 
 /// Get the size of a length tag for the given length
@@ -190,3 +224,27 @@ fn get_length_size(length: usize) -> usize {
         3
     }
 }
+
+mod private {
+    use super::*;
+    pub trait Sealed {
+        fn tag() -> u8;
+        fn obj_id() -> u32;
+    }
+    impl Sealed for Protected {
+        fn tag() -> u8 {
+            TAG_PROTECTED
+        }
+        fn obj_id() -> u32 {
+            OBJ_PRINTED
+        }
+    }
+    impl Sealed for Admin {
+        fn tag() -> u8 {
+            TAG_ADMIN
+        }
+        fn obj_id() -> u32 {
+            OBJ_ADMIN_DATA
+        }
+    }
+}

src/mgm.rs

@@ -38,8 +38,9 @@ use zeroize::{Zeroize, Zeroizing};
 
 #[cfg(feature = "untested")]
 use crate::{
-    metadata, yubikey::YubiKey, CB_BUF_MAX, CB_OBJ_MAX, TAG_ADMIN, TAG_ADMIN_FLAGS_1,
-    TAG_ADMIN_SALT, TAG_PROTECTED, TAG_PROTECTED_MGM,
+    metadata::{AdminData, ProtectedData},
+    yubikey::YubiKey,
+    TAG_ADMIN_FLAGS_1, TAG_ADMIN_SALT, TAG_PROTECTED_MGM,
 };
 use des::{
     cipher::{generic_array::GenericArray, BlockCipher, NewBlockCipher},
@@ -135,8 +136,8 @@ impl MgmKey {
         let txn = yubikey.begin_transaction()?;
 
         // recover management key
-        let data = metadata::read(&txn, TAG_ADMIN)?;
-        let salt = metadata::get_item(&data, TAG_ADMIN_SALT)?;
+        let admin_data = AdminData::read(&txn)?;
+        let salt = admin_data.get_item(TAG_ADMIN_SALT)?;
 
         if salt.len() != CB_ADMIN_SALT {
             error!(
@@ -159,12 +160,12 @@ impl MgmKey {
     pub fn get_protected(yubikey: &mut YubiKey) -> Result<Self, Error> {
         let txn = yubikey.begin_transaction()?;
 
-        let data = metadata::read(&txn, TAG_PROTECTED).map_err(|e| {
+        let protected_data = ProtectedData::read(&txn).map_err(|e| {
             error!("could not read protected data (err: {:?})", e);
             e
         })?;
 
-        let item = metadata::get_item(&data, TAG_PROTECTED_MGM).map_err(|e| {
+        let item = protected_data.get_item(TAG_PROTECTED_MGM).map_err(|e| {
             error!("could not read protected MGM from metadata (err: {:?})", e);
             e
         })?;
@@ -182,21 +183,84 @@ impl MgmKey {
         MgmKey::from_bytes(item)
     }
 
-    /// Set the management key (MGM)
+    /// Resets the management key for the given YubiKey to the default value.
+    ///
+    /// This will wipe any metadata related to derived and PIN-protected management keys.
     #[cfg(feature = "untested")]
-    pub fn set(&self, yubikey: &mut YubiKey, touch: Option<u8>) -> Result<(), Error> {
-        let txn = yubikey.begin_transaction()?;
-        txn.set_mgm_key(&self, touch)
+    pub fn set_default(yubikey: &mut YubiKey) -> Result<(), Error> {
+        MgmKey::default().set_manual(yubikey, false)
     }
 
-    /// Set protected management key (MGM)
+    /// Configures the given YubiKey to use this management key.
+    ///
+    /// The management key must be stored by the user, and provided when performing key
+    /// management operations.
+    ///
+    /// This will wipe any metadata related to derived and PIN-protected management keys.
     #[cfg(feature = "untested")]
-    pub fn set_protected(&self, yubikey: &mut YubiKey) -> Result<(), Error> {
-        let mut data = Zeroizing::new(vec![0u8; CB_BUF_MAX]);
-
+    pub fn set_manual(&self, yubikey: &mut YubiKey, require_touch: bool) -> Result<(), Error> {
         let txn = yubikey.begin_transaction()?;
 
-        txn.set_mgm_key(self, None).map_err(|e| {
+        txn.set_mgm_key(&self, require_touch).map_err(|e| {
+            // Log a warning, since the device mgm key is corrupt or we're in a state
+            // where we can't set the mgm key.
+            error!("could not set new derived mgm key, err = {}", e);
+            e
+        })?;
+
+        // After this point, we've set the mgm key, so the function should succeed,
+        // regardless of being able to set the metadata.
+
+        if let Ok(mut admin_data) = AdminData::read(&txn) {
+            // Clear the protected mgm key bit.
+            if let Ok(item) = admin_data.get_item(TAG_ADMIN_FLAGS_1) {
+                let mut flags_1 = [0u8; 1];
+                if item.len() == flags_1.len() {
+                    flags_1.copy_from_slice(item);
+                    flags_1[0] &= !ADMIN_FLAGS_1_PROTECTED_MGM;
+
+                    if let Err(e) = admin_data.set_item(TAG_ADMIN_FLAGS_1, &flags_1) {
+                        error!("could not set admin flags item, err = {}", e);
+                    }
+                } else {
+                    error!(
+                        "admin data flags are an incorrect size: {} (expected {})",
+                        item.len(),
+                        flags_1.len()
+                    );
+                }
+            }
+
+            // Remove any existing salt for a derived mgm key.
+            if let Err(e) = admin_data.set_item(TAG_ADMIN_SALT, &[]) {
+                error!("could not unset derived mgm salt (err = {})", e)
+            }
+
+            if let Err(e) = admin_data.write(&txn) {
+                error!("could not write admin data, err = {}", e);
+            }
+        }
+
+        // Clear any prior mgm key from protected data.
+        if let Ok(mut protected_data) = ProtectedData::read(&txn) {
+            if let Err(e) = protected_data.set_item(TAG_PROTECTED_MGM, &[]) {
+                error!("could not clear protected mgm item, err = {:?}", e);
+            } else if let Err(e) = protected_data.write(&txn) {
+                error!("could not write protected data, err = {:?}", e);
+            }
+        }
+
+        Ok(())
+    }
+
+    /// Configures the given YubiKey to use this as a PIN-protected management key.
+    ///
+    /// This enables key management operations to be performed with access to the PIN.
+    #[cfg(feature = "untested")]
+    pub fn set_protected(&self, yubikey: &mut YubiKey) -> Result<(), Error> {
+        let txn = yubikey.begin_transaction()?;
+
+        txn.set_mgm_key(self, false).map_err(|e| {
             // log a warning, since the device mgm key is corrupt or we're in
             // a state where we can't set the mgm key
             error!("could not set new derived mgm key, err = {}", e);
@@ -206,39 +270,25 @@ impl MgmKey {
         // after this point, we've set the mgm key, so the function should
         // succeed, regardless of being able to set the metadata
 
-        // set the new mgm key in protected data
-        let buffer = match metadata::read(&txn, TAG_PROTECTED) {
-            Ok(b) => b,
-            Err(_) => {
-                // set current metadata blob size to zero, we'll add to the blank blob
-                Zeroizing::new(vec![])
-            }
-        };
-        let mut cb_data = buffer.len();
-        data[..cb_data].copy_from_slice(&buffer);
+        // Fetch the current protected data, or start a blank metadata blob.
+        let mut protected_data = ProtectedData::read(&txn).unwrap_or_default();
 
-        if let Err(e) = metadata::set_item(
-            data.as_mut_slice(),
-            &mut cb_data,
-            CB_OBJ_MAX,
-            TAG_PROTECTED_MGM,
-            self.as_ref(),
-        ) {
+        // Set the new mgm key in protected data.
+        if let Err(e) = protected_data.set_item(TAG_PROTECTED_MGM, self.as_ref()) {
             error!("could not set protected mgm item, err = {:?}", e);
         } else {
-            metadata::write(&txn, TAG_PROTECTED, &data).map_err(|e| {
+            protected_data.write(&txn).map_err(|e| {
                 error!("could not write protected data, err = {:?}", e);
                 e
             })?;
         }
 
         // set the protected mgm flag in admin data
-        cb_data = data.len();
 
         let mut flags_1 = [0u8; 1];
 
-        if let Ok(buffer) = metadata::read(&txn, TAG_ADMIN) {
-            if let Ok(item) = metadata::get_item(&buffer, TAG_ADMIN_FLAGS_1) {
+        let mut admin_data = if let Ok(mut admin_data) = AdminData::read(&txn) {
+            if let Ok(item) = admin_data.get_item(TAG_ADMIN_FLAGS_1) {
                 if item.len() == flags_1.len() {
                     flags_1.copy_from_slice(item);
                 } else {
@@ -254,26 +304,20 @@ impl MgmKey {
             }
 
             // remove any existing salt
-            if let Err(e) =
-                metadata::set_item(&mut data, &mut cb_data, CB_OBJ_MAX, TAG_ADMIN_SALT, &[])
-            {
+            if let Err(e) = admin_data.set_item(TAG_ADMIN_SALT, &[]) {
                 error!("could not unset derived mgm salt (err = {})", e)
             }
+
+            admin_data
         } else {
-            cb_data = 0;
-        }
+            AdminData::default()
+        };
 
         flags_1[0] |= ADMIN_FLAGS_1_PROTECTED_MGM;
 
-        if let Err(e) = metadata::set_item(
-            data.as_mut_slice(),
-            &mut cb_data,
-            CB_OBJ_MAX,
-            TAG_ADMIN_FLAGS_1,
-            &flags_1,
-        ) {
+        if let Err(e) = admin_data.set_item(TAG_ADMIN_FLAGS_1, &flags_1) {
             error!("could not set admin flags item, err = {}", e);
-        } else if let Err(e) = metadata::write(&txn, TAG_ADMIN, &data[..cb_data]) {
+        } else if let Err(e) = admin_data.write(&txn) {
             error!("could not write admin data, err = {}", e);
         }
 

src/transaction.rs

@@ -229,14 +229,8 @@ impl<'tx> Transaction<'tx> {
 
     /// Set the management key (MGM).
     #[cfg(feature = "untested")]
-    pub fn set_mgm_key(&self, new_key: &MgmKey, touch: Option<u8>) -> Result<(), Error> {
-        let p2 = match touch.unwrap_or_default() {
-            0 => 0xff,
-            1 => 0xfe,
-            _ => {
-                return Err(Error::GenericError);
-            }
-        };
+    pub fn set_mgm_key(&self, new_key: &MgmKey, require_touch: bool) -> Result<(), Error> {
+        let p2 = if require_touch { 0xfe } else { 0xff };
 
         let mut data = [0u8; DES_LEN_3DES + 3];
         data[0] = ALGO_3DES;

src/yubikey.rs

@@ -50,8 +50,8 @@ use std::{
 
 #[cfg(feature = "untested")]
 use crate::{
-    apdu::StatusWords, metadata, transaction::ChangeRefAction, Buffer, ObjectId, CB_BUF_MAX,
-    CB_OBJ_MAX, MGMT_AID, TAG_ADMIN, TAG_ADMIN_FLAGS_1, TAG_ADMIN_TIMESTAMP,
+    apdu::StatusWords, metadata::AdminData, transaction::ChangeRefAction, Buffer, ObjectId,
+    MGMT_AID, TAG_ADMIN_FLAGS_1, TAG_ADMIN_TIMESTAMP,
 };
 use getrandom::getrandom;
 #[cfg(feature = "untested")]
@@ -417,12 +417,9 @@ impl YubiKey {
     /// Set PIN last changed
     #[cfg(feature = "untested")]
     pub fn set_pin_last_changed(yubikey: &mut YubiKey) -> Result<(), Error> {
-        let mut data = [0u8; CB_BUF_MAX];
         let txn = yubikey.begin_transaction()?;
 
-        let buffer = metadata::read(&txn, TAG_ADMIN)?;
-        let mut cb_data = buffer.len();
-        data[..cb_data].copy_from_slice(&buffer);
+        let mut admin_data = AdminData::read(&txn)?;
 
         // TODO(tarcieri): double check this is little endian
         let tnow = SystemTime::now()
@@ -431,19 +428,14 @@ impl YubiKey {
             .as_secs()
             .to_le_bytes();
 
-        metadata::set_item(
-            &mut data,
-            &mut cb_data,
-            CB_OBJ_MAX,
-            TAG_ADMIN_TIMESTAMP,
-            &tnow,
-        )
+        admin_data
+            .set_item(TAG_ADMIN_TIMESTAMP, &tnow)
             .map_err(|e| {
                 error!("could not set pin timestamp, err = {}", e);
                 e
             })?;
 
-        metadata::write(&txn, TAG_ADMIN, &data).map_err(|e| {
+        admin_data.write(&txn).map_err(|e| {
             error!("could not write admin data, err = {}", e);
             e
         })?;
@@ -494,8 +486,10 @@ impl YubiKey {
             }
         }
 
-        if let Ok(data) = metadata::read(&txn, TAG_ADMIN) {
-            if let Ok(item) = metadata::get_item(&data, TAG_ADMIN_FLAGS_1) {
+        // Attempt to set the "PUK blocked" flag in admin data.
+
+        let mut admin_data = if let Ok(admin_data) = AdminData::read(&txn) {
+            if let Ok(item) = admin_data.get_item(TAG_ADMIN_FLAGS_1) {
                 if item.len() == flags.len() {
                     flags.copy_from_slice(item)
                 } else {
@@ -506,22 +500,16 @@ impl YubiKey {
                     );
                 }
             }
-        }
+
+            admin_data
+        } else {
+            AdminData::default()
+        };
 
         flags[0] |= ADMIN_FLAGS_1_PUK_BLOCKED;
-        let mut data = [0u8; CB_BUF_MAX];
-        let mut cb_data: usize = data.len();
 
-        if metadata::set_item(
-            &mut data,
-            &mut cb_data,
-            CB_OBJ_MAX,
-            TAG_ADMIN_FLAGS_1,
-            &flags,
-        )
-        .is_ok()
-        {
-            if metadata::write(&txn, TAG_ADMIN, &data[..cb_data]).is_err() {
+        if admin_data.set_item(TAG_ADMIN_FLAGS_1, &flags).is_ok() {
+            if admin_data.write(&txn).is_err() {
                 error!("could not write admin metadata");
             }
         } else {

tests/integration.rs

@@ -10,6 +10,7 @@ use rsa::{hash::Hash::SHA2_256, PaddingScheme, PublicKey};
 use sha2::{Digest, Sha256};
 use std::convert::TryInto;
 use std::{env, sync::Mutex};
+use x509::RelativeDistinguishedName;
 use yubikey_piv::{
     certificate::{Certificate, PublicKeyInfo},
     key::{self, AlgorithmId, Key, RetiredSlotId, SlotId},
@@ -106,6 +107,45 @@ fn test_verify_pin() {
     assert!(yubikey.verify_pin(b"123456").is_ok());
 }
 
+//
+// Management key support
+//
+
+#[cfg(feature = "untested")]
+#[test]
+#[ignore]
+fn test_set_mgmkey() {
+    let mut yubikey = YUBIKEY.lock().unwrap();
+
+    assert!(yubikey.verify_pin(b"123456").is_ok());
+    assert!(MgmKey::get_protected(&mut yubikey).is_err());
+    assert!(yubikey.authenticate(MgmKey::default()).is_ok());
+
+    // Set a protected management key.
+    assert!(MgmKey::generate()
+        .unwrap()
+        .set_protected(&mut yubikey)
+        .is_ok());
+    let protected = MgmKey::get_protected(&mut yubikey).unwrap();
+    assert!(yubikey.authenticate(MgmKey::default()).is_err());
+    assert!(yubikey.authenticate(protected.clone()).is_ok());
+
+    // Set a manual management key.
+    let manual = MgmKey::generate().unwrap();
+    assert!(manual.set_manual(&mut yubikey, false).is_ok());
+    assert!(MgmKey::get_protected(&mut yubikey).is_err());
+    assert!(yubikey.authenticate(MgmKey::default()).is_err());
+    assert!(yubikey.authenticate(protected.clone()).is_err());
+    assert!(yubikey.authenticate(manual.clone()).is_ok());
+
+    // Set back to the default management key.
+    assert!(MgmKey::set_default(&mut yubikey).is_ok());
+    assert!(MgmKey::get_protected(&mut yubikey).is_err());
+    assert!(yubikey.authenticate(protected).is_err());
+    assert!(yubikey.authenticate(manual).is_err());
+    assert!(yubikey.authenticate(MgmKey::default()).is_ok());
+}
+
 //
 // Certificate support
 //
@@ -132,13 +172,15 @@ fn generate_self_signed_cert(algorithm: AlgorithmId) -> Certificate {
     getrandom(&mut serial).unwrap();
 
     // Generate a self-signed certificate for the new key.
+    let extensions: &[x509::Extension<'_, &[u64]>] = &[];
     let cert_result = Certificate::generate_self_signed(
         &mut yubikey,
         slot,
         serial,
         None,
-        "testSubject".to_owned(),
+        &[RelativeDistinguishedName::common_name("testSubject")],
         generated,
+        extensions,
     );
 
     assert!(cert_result.is_ok());