Add ML-DSA signing and verification for CMS/PKCS#7 SignedData, following
RFC 9882. ML-DSA is used in CMS "pure" mode: the signature is computed
over the complete message (the DER SET OF signed attributes, or the
eContent when none are present) with an empty context string and absent
signatureAlgorithm parameters, rather than over a pre-computed DigestInfo
as with RSA/ECDSA.
wolfcrypt/src/pkcs7.c:
- New ML-DSA helpers: wc_PKCS7_MlDsaLevelFromOID, wc_PKCS7_BuildPureSigMessage,
wc_PKCS7_MlDsaSign and wc_PKCS7_MlDsaVerify, wired into the per-algorithm
switch sites (GetSignSize, SignedDataGetEncAlgoId, SetPublicKeyOID,
CheckPublicKeyDer) and the sign/verify dispatchers. Only the final FIPS 204
ML-DSA OIDs are accepted; pre-standard draft Dilithium OIDs are not.
- GetSignSize derives the ML-DSA signature length from the parameter set.
- InitWithCert copies the signer public key into the RSA-sized publicKey buffer
only for RSA/ECC certs (the raw-sign callback consumers); large PQC keys such
as ML-DSA would overflow it and are never read back, so publicKeySz stays 0.
- wc_MlDsaKey is always heap allocated (it embeds multi-KB key buffers); the
accompanying DecodedCert uses the WC_DECLARE_VAR/WC_ALLOC_VAR_EX macros for
stack-vs-heap handling under WOLFSSL_SMALL_STACK.
- wc_PKCS7_SignedDataBuildSignature skips building the DigestInfo for ML-DSA,
which signs the full message in pure mode and never consumes it.
- wc_PKCS7_MlDsaSign wraps the ML-DSA private-key decode in
PRIVATE_KEY_UNLOCK/PRIVATE_KEY_LOCK. Unlike RSA/ECC, the FIPS module gates
wc_MlDsaKey_PrivateKeyDecode behind the private-key read lock, so signing
would otherwise fail with FIPS_PRIVATE_KEY_LOCKED_E under --enable-fips. The
macros are no-ops in non-FIPS builds.
wolfssl/wolfcrypt/pkcs7.h:
- Document that the fixed-size signer public key buffer (publicKey/publicKeySz)
holds only RSA/ECC keys; it stays RSA-sized.
wolfcrypt/src/hash.c:
- Map the SHAKE128/SHAKE256 OIDs to their hash types in wc_OidGetHash().
certs/mldsa:
- Add expanded-only PKCS#8 DER private keys (mldsa44/65/87-key.der) matching
the self-signed ML-DSA certificates, with README and include.am updates.
The expanded-only shape (no seed) decodes via wc_MlDsaKey_ImportPrivRaw
without keygen-from-seed or the ASN template, so pkcs7signed_mldsa_test also
passes in WOLFSSL_MLDSA_NO_MAKE_KEY and non-WOLFSSL_ASN_TEMPLATE builds.
certs/renewcerts.sh:
- Generate the mldsa<N>-key.der files from the matching mldsa<N>-key.pem in the
expanded-only shape (openssl pkey -provparam ml-dsa.output_formats=priv), so
a regeneration keeps the DER key in step with the cert. The OpenSSL detection
probe now requires both ML-DSA keygen and that conversion across all three
levels, so the block runs fully (matched cert+key) or is skipped entirely
rather than aborting mid-way.
wolfcrypt/test/test.c:
- Add pkcs7signed_mldsa_test(): round-trip encode/verify of SignedData across
ML-DSA-44/65/87, with and without signed attributes, including a check that
the digest algorithm parameters are encoded as expected. The message-digest
OID is selected from the enabled hash set (SHA-512, else SHA-256, else SHA-1)
so the test builds when SHA-512 is disabled. A negative case confirms ML-DSA
rejects a caller-supplied pre-computed content hash with BAD_FUNC_ARG.
Tobias Frauenschläger
bc3288204e