v0.4.1

We don't know how to correctly use these identities. In particular, some
identities store parts of their private key material in certificate
extensions to work around hardware limitations. Not understanding these
extensions could lead to encrypting with the wrong protocol and
violating security assumptions.

.github/workflows/ci.yml

@@ -1,13 +1,10 @@
 name: CI checks
 
-on:
+on: [push, pull_request]
-  pull_request:
-  push:
-    branches: main
 
 jobs:
-  test-msrv:
+  test:
-    name: Test MSRV on ${{ matrix.name }}
+    name: Test on ${{ matrix.name }}
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
@@ -25,83 +22,37 @@ jobs:
             os: macos-latest
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
       - name: Install build dependencies
         run: sudo apt install ${{ matrix.build_deps }}
         if: matrix.build_deps != ''
-      - uses: dtolnay/rust-toolchain@stable
-        id: stable-toolchain
-      - name: Install test dependencies using latest stable Rust
-        run: cargo +${{steps.stable-toolchain.outputs.name}} install rage
-      - name: Run tests
-        run: cargo test
-      - name: Verify working directory is clean
-        run: git diff --exit-code
-
-  test-latest:
-    name: Test latest stable on ${{ matrix.name }}
-    runs-on: ${{ matrix.os }}
-    strategy:
-      matrix:
-        name: [linux, windows, macos]
-        include:
-          - name: linux
-            os: ubuntu-latest
-            build_deps: >
-              libpcsclite-dev
-
-          - name: windows
-            os: windows-latest
-
-          - name: macos
-            os: macos-latest
-
-    steps:
-      - uses: actions/checkout@v4
-      - name: Install build dependencies
-        run: sudo apt install ${{ matrix.build_deps }}
-        if: matrix.build_deps != ''
-      - uses: dtolnay/rust-toolchain@stable
-      - uses: dtolnay/rust-toolchain@stable
-        id: toolchain
-      - run: rustup override set ${{steps.toolchain.outputs.name}}
       - name: Install test dependencies
         run: cargo install rage
-      - name: Remove lockfile to build with latest dependencies
+      - run: cargo fetch
-        run: rm Cargo.lock
+      - name: Build tests
+        run: cargo build --verbose --tests
       - name: Run tests
-        run: cargo test
+        run: cargo test --verbose
-      - name: Verify working directory is clean (excluding lockfile)
-        run: git diff --exit-code ':!Cargo.lock'
 
   codecov:
     name: Code coverage
     runs-on: ubuntu-latest
-    container:
-      image: xd009642/tarpaulin:develop-nightly
-      options: --security-opt seccomp=unconfined
-
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
       - name: Install build dependencies
-        run: apt update && apt install -y libpcsclite-dev
+        run: sudo apt install libpcsclite-dev
+      - name: Install coverage dependencies
+        run: cargo install cargo-tarpaulin
       - name: Generate coverage report
-        run: >
+        run: cargo tarpaulin --engine llvm --all-features --release --timeout 600 --out Xml
-          cargo tarpaulin
-          --engine llvm
-          --timeout 180
-          --out xml
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@v4.5.0
+        uses: codecov/codecov-action@v3.1.1
-        with:
-          fail_ci_if_error: true
-          token: ${{ secrets.CODECOV_TOKEN }}
 
   doc-links:
     name: Intra-doc links
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
       - name: Install build dependencies
         run: sudo apt install libpcsclite-dev
       - run: cargo fetch
@@ -111,8 +62,9 @@ jobs:
 
   fmt:
     name: Rustfmt
+    timeout-minutes: 30
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
       - name: Check formatting
         run: cargo fmt -- --check

.github/workflows/lints-beta.yml

@@ -6,9 +6,10 @@ on: pull_request
 jobs:
   clippy-beta:
     name: Clippy (beta)
+    timeout-minutes: 30
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
       - uses: dtolnay/rust-toolchain@beta
         id: toolchain
       - run: rustup override set ${{steps.toolchain.outputs.name}}

.github/workflows/lints-stable.yml

@@ -6,9 +6,10 @@ on: pull_request
 jobs:
   clippy:
     name: Clippy (MSRV)
+    timeout-minutes: 30
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
       - name: Install build dependencies
         run: sudo apt install libpcsclite-dev
       - name: Run clippy

.github/workflows/release.yml

@@ -24,7 +24,7 @@ jobs:
           - windows
         include:
           - name: linux
-            os: ubuntu-20.04
+            os: ubuntu-18.04
             build_deps: >
               libpcsclite-dev
             archive_name: age-plugin-yubikey.tar.gz
@@ -48,10 +48,11 @@ jobs:
             asset_suffix: x86_64-darwin.tar.gz
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
-      - uses: dtolnay/rust-toolchain@stable
+      - uses: actions-rs/toolchain@v1
-        id: toolchain
+        with:
-      - run: rustup override set ${{steps.toolchain.outputs.name}}
+          toolchain: stable
+          override: true
       - name: Add target
         run: rustup target add ${{ matrix.target }}
         if: matrix.target != ''
@@ -86,7 +87,7 @@ jobs:
         if: matrix.name == 'windows'
 
       - name: Upload archive to release
-        uses: svenstaro/upload-release-action@2.6.1
+        uses: svenstaro/upload-release-action@2.5.0
         with:
           file: ${{ matrix.archive_name }}
           asset_name: age-plugin-yubikey-$tag-${{ matrix.asset_suffix }}
@@ -95,7 +96,7 @@ jobs:
 
   deb:
     name: Debian ${{ matrix.name }}
-    runs-on: ubuntu-20.04
+    runs-on: ubuntu-18.04
     strategy:
       matrix:
         name: [linux]
@@ -106,10 +107,11 @@ jobs:
               libpcsclite-dev
 
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v3
-      - uses: dtolnay/rust-toolchain@stable
+      - uses: actions-rs/toolchain@v1
-        id: toolchain
+        with:
-      - run: rustup override set ${{steps.toolchain.outputs.name}}
+          toolchain: stable
+          override: true
       - name: Add target
         run: rustup target add ${{ matrix.target }}
       - name: cargo install cargo-deb
@@ -144,7 +146,7 @@ jobs:
           args: --package age-plugin-yubikey --no-build --target ${{ matrix.target }}
 
       - name: Upload Debian package to release
-        uses: svenstaro/upload-release-action@2.6.1
+        uses: svenstaro/upload-release-action@2.5.0
         with:
           file: target/${{ matrix.target }}/debian/*.deb
           file_glob: true

CHANGELOG.md

@@ -8,12 +8,11 @@ to 0.3.0 are beta releases.
 
 ## [Unreleased]
 
-## [0.5.0] - 2024-08-04
+## [0.3.4], [0.4.1] - 2026-04-08
 ### Fixed
-- `age-plugin-yubikey` can now be compiled with Rust 1.80 and above.
+- `age-plugin-yubikey` now completely ignores any identity that has unrecognised
-
+  critical extensions in its certificate, to ensure it doesn't misuse a newer
-### Changed
+  identity type.
-- MSRV is now 1.67.0.
 
 ## [0.4.0] - 2023-04-09
 ### Changed

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
 name = "age-plugin-yubikey"
 description = "YubiKey plugin for age clients"
-version = "0.5.0"
+version = "0.4.1"
 authors = ["Jack Grigg <thestr4d@gmail.com>"]
 repository = "https://github.com/str4d/age-plugin-yubikey"
 readme = "README.md"
@@ -9,7 +9,7 @@ keywords = ["age", "cli", "encryption", "yubikey"]
 categories = ["command-line-utilities", "cryptography"]
 license = "MIT OR Apache-2.0"
 edition = "2021"
-rust-version = "1.67" # MSRV
+rust-version = "1.65" # MSRV
 
 [package.metadata.deb]
 extended-description = """\
@@ -22,12 +22,12 @@ assets = [
 ]
 
 [dependencies]
-age-core = "0.10"
+age-core = "0.9"
-age-plugin = "0.5"
+age-plugin = "0.4"
 base64 = "0.21"
 bech32 = "0.9"
 console = { version = "0.15", default-features = false }
-dialoguer = { version = "0.11", default-features = false, features = ["password"] }
+dialoguer = { version = "0.10", default-features = false, features = ["password"] }
 env_logger = "0.10"
 gumdrop = "0.8"
 hex = "0.4"
@@ -36,23 +36,23 @@ p256 = { version = "0.13", features = ["ecdh"] }
 pcsc = "2.4"
 rand = "0.8"
 sha2 = "0.10"
-which = "5"
+which = "4.1"
 x509 = "0.2"
 x509-parser = "0.14"
 yubikey = { version = "=0.8.0-pre.0", features = ["untested"] }
 
 # Translations
-i18n-embed = { version = "0.14", features = ["desktop-requester", "fluent-system"] }
+i18n-embed = { version = "0.13", features = ["desktop-requester", "fluent-system"] }
-i18n-embed-fl = "0.8"
+i18n-embed-fl = "0.6"
 lazy_static = "1"
-rust-embed = "8"
+rust-embed = "6"
 
 # GnuPG coexistence
-sysinfo = "0.29"
+sysinfo = "0.28"
 
 [dev-dependencies]
 flate2 = "1"
 man = "0.3"
 tempfile = "3"
-test-with = "0.11"
+test-with = "0.9"
-which = "5"
+which = "4"

README.md

@@ -8,13 +8,8 @@ which enables files to be encrypted to age identities stored on YubiKeys.
 
 | Environment | CLI command |
 |-------------|-------------|
-| Cargo (Rust 1.67+) | `cargo install age-plugin-yubikey` |
+| Cargo (Rust 1.65+) | `cargo install age-plugin-yubikey` |
 | Homebrew (macOS or Linux) | `brew install age-plugin-yubikey` |
-| Arch Linux | `pacman -S age-plugin-yubikey` |
-| Debian | [Debian package](https://github.com/str4d/age-plugin-yubikey/releases) |
-| NixOS | Add to config:<br>`environment.systemPackages = [`<br>`  pkgs.age-plugin-yubikey`<br>`];`<br>Or run `nix-env -i age-plugin-yubikey` |
-| Ubuntu 20.04+ | [Debian package](https://github.com/str4d/age-plugin-yubikey/releases) |
-| OpenBSD | `pkg_add age-plugin-yubikey` (security/age-plugin-yubikey) |
 
 On Windows, Linux, and macOS, you can use the
 [pre-built binaries](https://github.com/str4d/age-plugin-yubikey/releases).
@@ -29,10 +24,8 @@ is installed and running.
 | Environment | CLI command |
 |-------------|-------------|
 | Debian or Ubuntu | `sudo apt-get install pcscd` |
-| Fedora | `sudo dnf install pcsc-lite` |
 | 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` |
-| Arch | `sudo pacman -S pcsclite pcsc-tools yubikey-manager`<br>`sudo systemctl enable pcscd`<br>`sudo systemctl start pcscd`| 
 
 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
@@ -41,7 +34,6 @@ compiled.
 | Environment | CLI command |
 |-------------|-------------|
 | Debian or Ubuntu | `sudo apt-get install libpcsclite-dev` |
-| Fedora | `sudo dnf install pcsc-lite-devel` |
 
 ### Windows Subsystem for Linux (WSL)
 

examples/generate-docs.rs

@@ -6,7 +6,7 @@ use std::io::prelude::*;
 const MANPAGES_DIR: &str = "./target/manpages";
 
 fn generate_manpage(page: String, name: &str) {
-    let file = File::create(format!("{MANPAGES_DIR}/{name}.1.gz"))
+    let file = File::create(format!("{}/{}.1.gz", MANPAGES_DIR, name))
         .expect("Should be able to open file in target directory");
     let mut encoder = GzEncoder::new(file, Compression::best());
     encoder

i18n/en-US/age_plugin_yubikey.ftl

@@ -204,7 +204,6 @@ err-invalid-flag-tui     = Flag '{$flag}' cannot be used with the interactive in
 err-invalid-pin-policy   = Invalid PIN policy '{$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}]).
-err-io-user              = Failed to get input from user: {$err}
 err-io                   = Failed to set up {-yubikey}: {$err}
 err-multiple-commands    = Only one of {-cmd-generate}, {-cmd-identity}, {-cmd-list}, {-cmd-list-all} can be specified.
 err-multiple-yubikeys    = Multiple {-yubikeys} are plugged in. Use {-flag-serial} to select a single {-yubikey}.

rust-toolchain.toml

@@ -1,3 +1,3 @@
 [toolchain]
-channel = "1.67.0"
+channel = "1.65.0"
 components = ["clippy", "rustfmt"]

src/error.rs

@@ -15,7 +15,6 @@ macro_rules! wlnfl {
 
 pub enum Error {
     CustomManagementKey,
-    Dialog(dialoguer::Error),
     InvalidFlagCommand(String, String),
     InvalidFlagTui(String),
     InvalidPinPolicy(String),
@@ -36,12 +35,6 @@ pub enum Error {
     YubiKey(yubikey::Error),
 }
 
-impl From<dialoguer::Error> for Error {
-    fn from(e: dialoguer::Error) -> Self {
-        Error::Dialog(e)
-    }
-}
-
 impl From<io::Error> for Error {
     fn from(e: io::Error) -> Self {
         Error::Io(e)
@@ -72,7 +65,6 @@ impl fmt::Debug for Error {
                     url = CHANGE_MGMT_KEY_URL
                 )?;
             }
-            Error::Dialog(e) => wlnfl!(f, "err-io-user", err = e.to_string())?,
             Error::InvalidFlagCommand(flag, command) => wlnfl!(
                 f,
                 "err-invalid-flag-command",

src/key.rs

@@ -15,6 +15,7 @@ use std::io;
 use std::iter;
 use std::thread::sleep;
 use std::time::{Duration, Instant, SystemTime};
+use x509_parser::der_parser::oid::Oid;
 use yubikey::{
     certificate::Certificate,
     piv::{decrypt_data, AlgorithmId, RetiredSlotId, SlotId},
@@ -27,13 +28,16 @@ use crate::{
     fl,
     format::{RecipientLine, STANZA_KEY_LABEL},
     p256::{Recipient, TAG_BYTES},
-    util::{otp_serial_prefix, Metadata},
+    util::{otp_serial_prefix, Metadata, POLICY_EXTENSION_OID},
     IDENTITY_PREFIX,
 };
 
 const ONE_SECOND: Duration = Duration::from_secs(1);
 const FIFTEEN_SECONDS: Duration = Duration::from_secs(15);
 
+/// The set of OIDs that we understand and use when parsing YubiKey slot certificates.
+const KNOWN_OIDS: &[&[u64]] = &[POLICY_EXTENSION_OID];
+
 pub(crate) fn is_connected(reader: Reader) -> bool {
     filter_connected(&reader)
 }
@@ -274,10 +278,10 @@ pub(crate) fn disconnect_without_reset(yubikey: YubiKey) {
     let _ = yubikey.disconnect(pcsc::Disposition::LeaveCard);
 }
 
-fn request_pin<E, E2>(
+fn request_pin<E>(
-    mut prompt: impl FnMut(Option<String>) -> Result<Result<SecretString, E>, E2>,
+    mut prompt: impl FnMut(Option<String>) -> io::Result<Result<SecretString, E>>,
     serial: Serial,
-) -> Result<Result<SecretString, E>, E2> {
+) -> io::Result<Result<SecretString, E>> {
     let mut prev_error = None;
     loop {
         prev_error = Some(match prompt(prev_error)? {
@@ -326,7 +330,7 @@ pub(crate) fn manage(yubikey: &mut YubiKey) -> Result<(), Error> {
             let pin = request_pin(
                 |prev_error| {
                     if let Some(err) = prev_error {
-                        eprintln!("{err}");
+                        eprintln!("{}", err);
                     }
                     Password::new()
                         .with_prompt(fl!("mgr-choose-new-pin"))
@@ -388,6 +392,30 @@ pub(crate) fn manage(yubikey: &mut YubiKey) -> Result<(), Error> {
     Ok(())
 }
 
+/// Parses the certificate to identify the preferred recipient type it corresponds to.
+pub(crate) fn identify_recipient(cert: &Certificate) -> Option<Recipient> {
+    let known_oids = KNOWN_OIDS
+        .iter()
+        .map(|oid| Oid::from(oid).unwrap())
+        .collect::<Vec<_>>();
+
+    // If the certificate contains any unrecognised critical extensions, reject it: we
+    // don't know how to correctly use the identity. In particular, some identities store
+    // parts of their private key material in certificate extensions to work around
+    // hardware limitations. Not understanding these extensions could lead to encrypting
+    // with the wrong protocol and violating security assumptions.
+    let (_, c) = x509_parser::parse_x509_certificate(cert.as_ref()).ok()?;
+    if c.tbs_certificate
+        .extensions()
+        .iter()
+        .any(|ext| ext.critical && !known_oids.contains(&ext.oid))
+    {
+        return None;
+    }
+
+    Recipient::from_certificate(cert)
+}
+
 /// 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(
@@ -397,8 +425,7 @@ pub(crate) fn list_slots(
         // We only use the retired slots.
         match key.slot() {
             SlotId::Retired(slot) => {
-                // Only P-256 keys are compatible with us.
+                let recipient = identify_recipient(key.certificate());
-                let recipient = Recipient::from_certificate(key.certificate());
                 Some((key, slot, recipient))
             }
             _ => None,
@@ -605,9 +632,9 @@ impl Stub {
         let (cert, pk) = match Certificate::read(&mut yubikey, SlotId::Retired(self.slot))
             .ok()
             .and_then(|cert| {
-                Recipient::from_certificate(&cert)
+                identify_recipient(&cert)
-                    .filter(|pk| pk.tag() == self.tag)
+                    .filter(|recipient| recipient.tag() == self.tag)
-                    .map(|pk| (cert, pk))
+                    .map(|r| (cert, r))
             }) {
             Some(pk) => pk,
             None => {

src/main.rs

@@ -296,8 +296,8 @@ fn list(flags: PluginFlags, all: bool) -> Result<(), Error> {
         flags,
         all,
         |_, recipient, metadata| {
-            println!("{metadata}");
+            println!("{}", metadata);
-            println!("{recipient}");
+            println!("{}", recipient);
         },
     )
 }
@@ -329,8 +329,8 @@ fn main() -> Result<(), Error> {
     if let Some(state_machine) = opts.age_plugin {
         run_state_machine(
             &state_machine,
-            Some(plugin::RecipientPlugin::default),
+            plugin::RecipientPlugin::default,
-            Some(plugin::IdentityPlugin::default),
+            plugin::IdentityPlugin::default,
         )?;
         Ok(())
     } else if opts.version {
@@ -411,9 +411,9 @@ fn main() -> Result<(), Error> {
                                 .validity()
                                 .not_before
                                 .to_rfc2822()
-                                .unwrap_or_else(|e| format!("Invalid date: {e}"));
+                                .unwrap_or_else(|e| format!("Invalid date: {}", e));
 
-                            format!("{name}, created: {created}")
+                            format!("{}, created: {}", name, created)
                         })
                     })
             })
@@ -631,8 +631,14 @@ fn main() -> Result<(), Error> {
         // If `rage` binary is installed, use it in examples. Otherwise default to `age`.
         let age_binary = which::which("rage").map(|_| "rage").unwrap_or("age");
 
-        let encrypt_usage = format!("$ cat foo.txt | {age_binary} -r {recipient} -o foo.txt.age");
+        let encrypt_usage = format!(
-        let decrypt_usage = format!("$ cat foo.txt.age | {age_binary} -d -i {file_name} > foo.txt");
+            "$ cat foo.txt | {} -r {} -o foo.txt.age",
+            age_binary, recipient
+        );
+        let decrypt_usage = format!(
+            "$ cat foo.txt.age | {} -d -i {} > foo.txt",
+            age_binary, file_name
+        );
         let identity_usage = format!(
             "$ age-plugin-yubikey -i --serial {} --slot {} > {}",
             stub.serial,

src/util.rs

@@ -177,7 +177,7 @@ impl Metadata {
                     .validity()
                     .not_before
                     .to_rfc2822()
-                    .unwrap_or_else(|e| format!("Invalid date: {e}")),
+                    .unwrap_or_else(|e| format!("Invalid date: {}", e)),
                 pin_policy,
                 touch_policy,
             })