Tobias Frauenschläger
366000eec2
Server-side PKCS#7 encode improvements that let downstream EST/SCEP enrollment code (wolfCert) drive the existing encoder through the public API rather than hand-rolling DER. Everything is gated under the existing HAVE_PKCS7 — no new build options and no new public functions; the convenience wrappers live caller-side. Allow degenerate (certs-only) SignedData encode Relax the hashOID != 0 requirement in PKCS7_EncodeSigned() when sidType == DEGENERATE_SID, so a caller can produce a certs-only bundle (no signer, attributes, or eContent — the form used by EST /cacerts and SCEP GetCACert) by selecting DEGENERATE_SID via wc_PKCS7_SetSignerIdentifierType() and calling wc_PKCS7_EncodeSignedData(). The output round-trips through wc_PKCS7_VerifySignedData(). Size the signed-attribute array to the actual count The SignerInfo attribute working array is now sized to the real attribute count instead of a fixed [7] array. An inline buffer (sized MAX_SIGNED_ATTRIBS_SZ, the historical footprint) covers the common allocation-free case; a heap buffer is used only when the count exceeds it. The default-attribute count comes from a single helper (wc_PKCS7_GetDefaultSignedAttribCount) so the sizing matches the emission logic exactly, and the canned-attribute write is bound-checked against the array capacity. This also fixes a latent overflow where the backing array was hardcoded [7] while the bound check used MAX_SIGNED_ATTRIBS_SZ. The macro is retained for source compatibility but no longer caps the count. Document the decoded-attribute value shape Documented the stable shape of PKCS7DecodedAttrib.value (the contents of the SET OF AttributeValue, outer SET tag stripped) so callers can rely on it. No behavior change. Fix multi-certificate decode in non-streaming builds Bound the additional-certificate loop in wc_PKCS7_VerifySignedData against the absolute end of the certificate set (idx + length) rather than the relative length. In NO_PKCS7_STREAM builds the old bound dropped trailing certificates (all but the first when a large eContent preceded the set), failing verification when the signer cert was among those dropped. Streaming builds were unaffected. Tests Added coverage in pkcs7signed_test: degenerate certs-only encode via the public API, nine-attribute encode (beyond the inline capacity), decoded attribute value shape for PrintableString and OCTET STRING, and a multi-certificate decode regression with large content that triggers the bound bug under NO_PKCS7_STREAM. Added a signed-attribute selection round-trip covering a messageDigest-only subset and the no-attributes case via wc_PKCS7_SetDefaultSignedAttribs/wc_PKCS7_NoDefaultSignedAttribs, a WOLFSSL_NO_MALLOC over-capacity case that must return BUFFER_E instead of overrunning the inline buffer, and a malformed certificate-set length that exercises the certSetEnd clamp in the verifier. Config-sensitive cases are guarded.
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