# wolfCrypt Test
Tool for performing cryptographic algorithm testing.
## Example Output
Run on Intel(R) Core(TM) i7-7920HQ CPU @ 3.10GHz.
```sh
./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