wolfssl/wolfcrypt/test

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:

1. Statistical false positives (expected behavior)
2. Entropy source depletion (under heavy concurrent load)
3. 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