diff options
| -rw-r--r-- | src/rng/hmac_rng/hmac_rng.cpp | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/src/rng/hmac_rng/hmac_rng.cpp b/src/rng/hmac_rng/hmac_rng.cpp index 4944a61b3..c60a732b5 100644 --- a/src/rng/hmac_rng/hmac_rng.cpp +++ b/src/rng/hmac_rng/hmac_rng.cpp @@ -89,14 +89,14 @@ void HMAC_RNG::randomize(byte out[], u32bit length) prf->update(get_byte(i, counter)); prf->final(K); + ++counter; + u32bit copied = std::min(K.size(), length); copy_mem(out, K.begin(), copied); out += copied; length -= copied; - - ++counter; } } @@ -207,7 +207,9 @@ void HMAC_RNG::reseed_with_input(const byte input[], u32bit input_length) } // Generate a new output using the HMAC PRF construction, - // using a CTXinfo of "reseed" and the last K value + counter + // using a CTXinfo of "reseed" + // the last K value used (possibly entirely output to user) + // the next counter value for(u32bit i = 0; i != prf->OUTPUT_LENGTH; ++i) prf->update(K); @@ -215,13 +217,14 @@ void HMAC_RNG::reseed_with_input(const byte input[], u32bit input_length) for(u32bit i = 0; i != 4; ++i) prf->update(get_byte(i, counter)); - // Add PRF output K(1) with CTXinfo "reseed" to the new SKM + // Add PRF output with CTXinfo "reseed" to the new SKM extractor->update(prf->final()); // Now derive the new PRK and set the PRF key to that SecureVector<byte> prk = extractor->final(); prf->set_key(prk, prk.size()); + K.clear(); counter = 0; // Increase entropy estimate (for is_seeded) |