pkcs11-check

See how any PKCS#11 module really behaves - a broad, vendor-neutral test client for providers, HSMs, tokens, and cloud KMS.

What this is

pkcs11-check is a broad, vendor-neutral test client for any PKCS#11 module - software tokens, HSMs, smart cards, cloud-KMS bridges, and internal or proprietary providers. It drives the module through >100k behavioral checks - a large hand-written suite of spec-conformance, CKR/API-negative, security, and fuzz tests, plus the major public crypto vector corpora (Wycheproof, NIST ACVP, CCTV, x509-limbo) - all with crash-survival, and shows what it supports, where it diverges from the spec or its peers, and where it breaks.

It maximizes coverage instead of stopping at the first incompatibility, and records every difference as evidence to investigate and compare - not a verdict. Large xfail/fail counts are normal: PKCS#11 cannot express many constraints (for example, there is no per-curve capability flag), so one capability gap multiplies across thousands of vectors. Both xfail and fail are recorded findings - how the module differed from the checked expectation - not defects in pkcs11-check. See docs/interpreting-results.md.

What it is not

It does not replace your module's own tests - keep those; they are faster and know your internals. Think of pkcs11-check as an extra, exceptionally wide external client that exercises your module the way the real world will. It is not a compliance certification (no FIPS/CC), and its findings are hardening observations under a software-token threat model - not CVE claims against any project.

Who it's for

• Building a PKCS#11 module? Point pkcs11-check at it during development for a broad, independent second opinion on how it behaves (it complements your own unit tests, it does not replace them).
• Adopting or migrating? Validate a module before you deploy, and confirm parity when you switch providers, versions, or loaders (pkcs11-check compare-results / pkcs11-check compare-coverage).
• Maintaining or comparing providers? Produce reproducible behavioral evidence to compare and discuss.

Quick start

# Install
git clone https://github.com/mingulov/pkcs11-check
cd pkcs11-check
uv sync

# Run against any PKCS#11 module you provide
uv run pkcs11-check test --module /path/to/module.so --pin 1234

(See "First run in 60 seconds" below for a complete SoftHSM2 example. For container-based walkthroughs see docs/docker-examples.md.)

First run in 60 seconds (from PyPI)

pip install pkcs11-check

# 1. Make a token (one-time; SoftHSM2 is the easiest provider)
export SOFTHSM2_CONF="$HOME/softhsm2.conf"
mkdir -p "$HOME/softhsm2-tokens"
echo "directories.tokendir = $HOME/softhsm2-tokens" > "$SOFTHSM2_CONF"
softhsm2-util --init-token --slot 0 --label demo --pin 1234 --so-pin 5678

# 2. Diagnose the setup (module loads? slot / PIN / token OK?)
pkcs11-check doctor --module /usr/lib/softhsm/libsofthsm2.so --slot 0 --pin 1234

# 3. Fast first run (~2s)
pkcs11-check test --module /usr/lib/softhsm/libsofthsm2.so --pin 1234 --slot 0 --marker smoke

# 4. Optional: full coverage (downloads ~800 MB of vectors, then runs the suite)
pkcs11-check fetch-data all
pkcs11-check test --module /usr/lib/softhsm/libsofthsm2.so --pin 1234 --slot 0

Two non-obvious rules:

• --slot is a 0-based index into the token-present slots, not the provider's slot ID. Run pkcs11-check info --module <lib> (or pkcs11-check doctor) to list them. (NSS, for example, uses index 1.)
• fetch-data is optional - only the KAT / Wycheproof / ACVP suites need it; without it those are skipped and the rest still runs.

If anything fails, run pkcs11-check doctor first - it checks the module, slot, PIN, token, and data, and prints the exact next step for each problem.

New to this? docs/getting-started-softhsm2.md is a complete copy-pasteable walkthrough - install, create a SoftHSM2 config and token from scratch, run the suite, and read the results.

Saving a report

By default pkcs11-check test prints a human-readable summary and keeps no report file. The generated report log file: /tmp/pkcs11-check-...jsonl lines you may notice are internal per-process logs that the isolated runner aggregates and then deletes - they are not meant to be read directly.

To save a machine-readable report, add --output json and --output-file. The files are written next to the path you give:

pkcs11-check test --module /usr/lib/softhsm/libsofthsm2.so --pin 1234 --slot 0 \
    --output json --output-file ./reports/results.json

That writes into ./reports/:

• report.jsonl - one JSON record per test (outcome, return code, notes)
• results.json - the consolidated run summary (counts, crashes, environment)
• coverage.json, quality.json - mechanism coverage and the per-outcome classification report

Use --output junit --output-file ./reports/results.xml for JUnit XML instead (for CI). The output directory is taken from the --output-file path, so point it wherever you want the files created.

Test suite

Test categories:

Implementations exercised

pkcs11-check runs against any PKCS#11 module. It is regularly exercised against a broad set of open-source implementations - software HSMs, a TPM stack, cloud KMS bridges, smart-card simulators, and a TEE - listed with upstream links in docs/providers.md. Several C/C++ implementations are additionally run under a separate AddressSanitizer + UBSan build. Exact versions move over time and are intentionally not pinned here.

Known limitations

• SO login is not implemented yet, so trusted-certificate import with CKA_TRUSTED=True is not fully covered through CKU_SO workflows.
• Provider-generated in-band IV profiles, proxy/loader mutable-parameter preservation checks, and broader mutable-output simulator targets are tracked as future interop work.

Planned and considered work is listed in docs/roadmap.md.

Architecture

src/pkcs11_check/
  raw/          - pure ctypes PKCS#11 binding (v2.40-v3.2, PQC)
  cli/          - typer CLI (test, doctor, info, version, ... commands)
  core/         - module loader, isolation runner, preflight
  testcases/    - test files (the product)
    ckr/        - CKR return code compliance tests
  plugin.py     - pytest plugin (markers, fixtures, collection)
  fixtures.py   - p11_session, p11_module, p11_config
  config.py     - four-layer config (CLI > env > TOML > defaults)

Key features

• pkcs11_check.raw - pure Python ctypes binding with v2.40/v3.0/v3.1/v3.2 interface negotiation, 50+ PQC mechanisms, all 68 standard functions
• --isolation file mode runs each test file in its own subprocess - crashes don't kill the suite
• --ckr-strict mode enforces exact OASIS spec CKR codes (not just "any error")
• Wycheproof + ACVP vectors - cross-verification against C2SP and NIST test vectors

Documentation

• docs/interpreting-results.md - what the pass/xfail/fail/skip counts mean (read this first)
• docs/architecture.md - codebase structure and test writing guide
• docs/commands.md - build, test, and Docker commands
• docs/test-universe.md - collected product-test counts by group
• docs/mechanism-output-parameters.md - generated IV/nonce/tag output-parameter coverage
• docs/file-isolation.md - isolation runner design
• docs/providers.md - PKCS#11 implementations pkcs11-check is exercised against
• docs/roadmap.md - planned and considered work

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Third-party attributions

pkcs11-check ships ctypes bindings generated from the public-domain PKCS#11 v3.2 header from latchset/pkcs11-headers (the header itself is a dev-time codegen input kept in the source repository, not shipped in the package), and its fetch-data command downloads test vectors from C2SP and NIST. See THIRD_PARTY_LICENSES.md for the full list and per-source license terms.