Tobias Frauenschläger
bc3288204e
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.
wolfCrypt Test
Tool for performing cryptographic algorithm testing.
Example Output
Run on Intel(R) Core(TM) i7-7920HQ CPU @ 3.10GHz.
./configure --enable-intelasm --enable-aesni --enable-sp --enable-sp-asm && make
./wolfcrypt/test/testwolfcrypt
------------------------------------------------------------------------------
wolfSSL version 4.0.0
------------------------------------------------------------------------------
error test passed!
MEMORY test passed!
base64 test passed!
asn test passed!
MD5 test passed!
SHA test passed!
SHA-224 test passed!
SHA-256 test passed!
SHA-384 test passed!
SHA-512 test passed!
SHA-3 test passed!
Hash test passed!
HMAC-MD5 test passed!
HMAC-SHA test passed!
HMAC-SHA224 test passed!
HMAC-SHA256 test passed!
HMAC-SHA384 test passed!
HMAC-SHA512 test passed!
HMAC-SHA3 test passed!
GMAC test passed!
Chacha test passed!
POLY1305 test passed!
ChaCha20-Poly1305 AEAD test passed!
AES test passed!
AES192 test passed!
AES256 test passed!
AES-GCM test passed!
RANDOM test passed!
RSA test passed!
DH test passed!
ECC test passed!
logging test passed!
mutex test passed!
memcb test passed!
Test complete
Windows Visual Studio
For building wolfCrypt test project in Visual Studio open the test.sln. For newer Visual Studio version it may prompt for a one-way upgrade. Then you may have to right-click on the solution and choose Retarget solution to update the project files for your Visual Studio version.
If you see an error about rc.exe then you'll need to update the "Target Platform Version". You can do this by right-clicking on the test project -> General -> "Target Platform Version" and changing to 8.1 (needs to match the wolfssl library project).
This solution includes the wolfSSL library project at <wolfssl-root>wolfssl.vcxproj and will compile the library, then the test project.
Jan 2026 - Reviewing the older FIPS compliant CRNGT test specified in FIPS 140-2 ss 4.9.2 vs the newer replacement tests RCT/ADP that are allowed to replace the CRNGT under the new FIPS 140-3 / ISO 19790 standard.
================================================================================ DRBG Continuous Health Test Statistical Analysis & Diagnostic Report
OVERVIEW
This document describes the statistical false positive behavior of the DRBG continuous health test in wc_RNG_TestSeed() and provides diagnostic tools to distinguish between:
- Statistical false positives (expected behavior)
- Entropy source depletion (under heavy concurrent load)
- Actual stuck entropy source (hardware failure)
BACKGROUND: THE ISSUE
The DRBG was experiencing high volumes of (DRBG_CONT_FIPS_E) on wc_InitRng() calls.
Example error: ERROR: wc_InitRng failed at iteration 330788 with code -209
This raises the question: Is this a bug in wc_RNG_TestSeed() or expected statistical behavior?
STATISTICAL ANALYSIS
The wc_RNG_TestSeed() Function Behavior:
- Compares ALL consecutive SEED_BLOCK_SZ chunks in the seed buffer
- With FIPS mode (typical configuration): SEED_SZ = 256 * 4 / 8 = 128 bytes (1024-bits) SEED_BLOCK_SZ = 4 bytes (default) (32-bits) seedSz passed to test = 132 bytes (SEED_SZ + SEED_BLOCK_SZ) Number of comparisons = ~32 consecutive block pairs
False Positive Probability Calculation:
- Probability one 4-byte block equals another random 4-byte block: 1/2^32
- With 32 comparisons per seed: 32/2^32 ≈ 1 in 134 million per wc_InitRng()
Test Configuration (Default):
- 40 threads × 100M iterations = 4 BILLION total wc_InitRng() calls
- Expected false positives: 4,000,000,000 × (32/2^32) ≈ 30 failures
Conclusion: Seeing failures around 1 in 30-140 million is EXPECTED STATISTICAL BEHAVIOR. Under heavy concurrent load (40 threads), entropy source depletion can also cause legitimate failures.
TESTING IT
Non-FIPS:
./configure CFLAGS="-DWC_RNG_SEED_DEBUG -DREALLY_LONG_DRBG_CONTINUOUS_TEST"
make
./wolfcrypt/test/testwolfcrypt
FIPS:
./configure --enable-fips=<flavor> CFLAGS="-DWC_RNG_SEED_DEBUG -DREALLY_LONG_DRBG_CONTINUOUS_TEST"
make
./fips-hash.sh
make
./wolfcrypt/test/testwolfcrypt
OUTPUTS EXPECTED
Non-FIPS:
Math: Multi-Precision: Wolf(SP) word-size=64 bits=4096 sp_int.c
------------------------------------------------------------------------------
wolfSSL version 5.8.4
------------------------------------------------------------------------------
macro test passed!
error test passed!
MEMORY test passed!
base64 test passed!
asn test passed!
MD5 test passed!
SHA test passed!
SHA-224 test passed!
SHA-256 test passed!
SHA-384 test passed!
SHA-512 test passed!
SHA-512/224 test passed!
SHA-512/256 test passed!
SHA-3 test passed!
RNG Entropy Source: getrandom() syscall
===============================================
DRBG Continuous Test Validation Suite
===============================================
FIPS Build: NO
--- Test 1: Basic RNG Functionality ---
Generated 32 random bytes successfully
[PASS] Basic RNG Functionality
--- Test 2: Multiple RNG Instances ---
Successfully operated 100 RNG instances concurrently
[PASS] Multiple RNG Instances
--- Test 3: FIPS Status Check ---
SKIPPED: FIPS not enabled
[PASS] FIPS Status Check
--- Test 4: RNG ReInit Test (multi-threaded) ---
Configuration: 40 threads × 100000000 iterations = 4000000000 total
Test Profile: Default (Aggressive multi-threaded)
Expected statistical false positive rate: ~29.80 failures
Duplicate block at offset 4:
Block 1: E6 E9 D1 7B
Block 2: E6 E9 D1 7B
Full seed buffer (52 bytes):
DA 93 B7 88 E6 E9 D1 7B E6 E9 D1 7B A5 4C C9 E9
13 EE D8 4C B3 C1 71 DE 32 37 17 F2 E7 A4 29 7D
9B 02 B0 0C EC 8D AC F5 DA B1 71 05 84 C0 61 75
59 6D 87 B5
ERROR: wc_InitRng failed at iteration 778551 with code -209
ERROR: wc_RNG_GenerateBlock failed at iteration 778551 with code -199
... (18 other failures truncated here for brevity) ... Duplicate block at offset 16: Block 1: C1 19 37 B1 Block 2: C1 19 37 B1 Full seed buffer (52 bytes): 62 66 5B D2 F5 54 47 9B 59 DD 0A 55 4B 52 8C 39 C1 19 37 B1 C1 19 37 B1 3F 62 CB 2E FE 56 65 4D 4F 0C A7 7D 1C 09 48 51 30 1B CA 00 56 9F 29 A7 E3 93 EF 8E ERROR: wc_InitRng failed at iteration 90467867 with code -209 ERROR: wc_RNG_GenerateBlock failed at iteration 90467867 with code -199 Thread 0 Succeeded ... 38 other thread results truncated here for brevity (all threads succeeded even though they experienced 1 or 2 failures in several of the threads) ... Thread 39 Succeeded Reinitialized RNG 4000000000 times across 40 threads Experienced 0 thread failures and 40 thread successes 20/4000000000 API calls failed <--- This is the bread and the butter of the test, we unfortunately expect to see ~29.80 failures, prior to the newer FIPS 140-3 RCT and ADP tests the CRNGT was required. Now the CRNGT is replaceable by the more mathematically robust RCT/ADP. [PASS] RNG Reinitialization
TESTING RESULTS with the CRNGT test:
Old implementation non-FIPS: Run 1 - 6 failures in 4 billion runs (100M per thread, 40 threads) Run 2 - 11 failures in 4 billion (100M per thread, 40 threads) Run 3 - 13 failures in 4 billion (100M per thread, 40 threads)
Old implementation with FIPS: (keeping in mind just a single failure means catastrophic failure for the entire module until power cycled): Run 1 - 3990118689 failures in 4 billion API calls (yikes)
TESTING RESULTS with the RCT/ADP tests in place of the CRNGT test:
New implementation non-FIPS: 4 billion successes New implementation FIPS: 4 billion successes