diff options
| author | Peter Dettman <peter.dettman@bouncycastle.org> | 2014-04-03 07:06:00 +0400 |
|---|---|---|
| committer | Peter Dettman <peter.dettman@bouncycastle.org> | 2014-04-03 07:06:00 +0400 |
| commit | 9c9a768735900610a339318bf38267c908fe8dd5 (patch) | |
| tree | 926820232a0534e25f269b7e7b6e8d6fbb5be315 /core/src/main/java/org/bouncycastle | |
| parent | af45f893c4c7d389237c0bf5946e10cc807adb16 (diff) | |
Avoid revealing raw RNG output in the random block
Diffstat (limited to 'core/src/main/java/org/bouncycastle')
| -rw-r--r-- | core/src/main/java/org/bouncycastle/crypto/tls/TlsProtocol.java | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/core/src/main/java/org/bouncycastle/crypto/tls/TlsProtocol.java b/core/src/main/java/org/bouncycastle/crypto/tls/TlsProtocol.java index 22a242a6..6f09a0ff 100644 --- a/core/src/main/java/org/bouncycastle/crypto/tls/TlsProtocol.java +++ b/core/src/main/java/org/bouncycastle/crypto/tls/TlsProtocol.java @@ -14,6 +14,7 @@ import java.util.Vector; import org.bouncycastle.crypto.Digest; import org.bouncycastle.util.Arrays; import org.bouncycastle.util.Integers; +import org.bouncycastle.util.Strings; import org.bouncycastle.util.Times; /** @@ -825,10 +826,21 @@ public abstract class TlsProtocol protected static byte[] createRandomBlock(boolean useGMTUnixTime, SecureRandom random) { - random.setSeed(Times.nanoTime()); - + /* + * We hash the SecureRandom output here to guard against RNGs where the raw output could be + * used to recover the internal state. + */ byte[] result = new byte[32]; + Digest d = TlsUtils.createHash(HashAlgorithm.sha256); + + TlsUtils.writeUint64(Times.nanoTime(), result, 0); + Strings.toByteArray("BouncyCastle TlsProtocol", result, 8); + d.update(result, 0, 32); + random.nextBytes(result); + d.update(result, 0, 32); + + d.doFinal(result, 0); if (useGMTUnixTime) { |