diff --git a/crypto/src/security/SecureRandom.cs b/crypto/src/security/SecureRandom.cs
index ac9d98158..c91b5ee91 100644
--- a/crypto/src/security/SecureRandom.cs
+++ b/crypto/src/security/SecureRandom.cs
@@ -22,13 +22,19 @@ namespace Org.BouncyCastle.Security
{
if (master[0] == null)
{
- IRandomGenerator gen = sha256Generator;
- gen = new ReversedWindowGenerator(gen, 32);
- SecureRandom sr = master[0] = new SecureRandom(gen);
+ SecureRandom sr = master[0] = new SecureRandom(sha256Generator);
+ // Even though Ticks has at most 8 or 14 bits of entropy, there's no harm in adding it.
sr.SetSeed(DateTime.Now.Ticks);
- sr.SetSeed(new ThreadedSeedGenerator().GenerateSeed(24, true));
- sr.GenerateSeed(1 + sr.Next(32));
+ // In addition to Ticks and ThreadedSeedGenerator, also seed from CryptoApiRandomGenerator
+ CryptoApiRandomGenerator systemRNG = new CryptoApiRandomGenerator();
+ byte[] systemSeed = new byte[32];
+ systemRNG.NextBytes(systemSeed);
+ sr.SetSeed(systemSeed);
+ Array.Clear(systemSeed,0,systemSeed.Length);
+ // 32 will be enough when ThreadedSeedGenerator is fixed. Until then, ThreadedSeedGenerator returns low
+ // entropy, and this is not sufficient to be secure. http://www.bouncycastle.org/csharpdevmailarchive/msg00814.html
+ sr.SetSeed(new ThreadedSeedGenerator().GenerateSeed(32, true));
}
return master[0];
@@ -38,24 +44,20 @@ namespace Org.BouncyCastle.Security
public static SecureRandom GetInstance(
string algorithm)
{
- // TODO Compared to JDK, we don't auto-seed if the client forgets - problem?
-
// TODO Support all digests more generally, by stripping PRNG and calling DigestUtilities?
string drgName = Platform.ToUpperInvariant(algorithm);
- IRandomGenerator drg = null;
if (drgName == "SHA1PRNG")
{
- drg = sha1Generator;
+ SecureRandom newPrng = new SecureRandom(sha1Generator);
+ newPrng.SetSeed(GetSeed(20));
+ return newPrng;
}
else if (drgName == "SHA256PRNG")
{
- drg = sha256Generator;
- }
-
- if (drg != null)
- {
- return new SecureRandom(drg);
+ SecureRandom newPrng = new SecureRandom(sha256Generator);
+ newPrng.SetSeed(GetSeed(32));
+ return newPrng;
}
throw new ArgumentException("Unrecognised PRNG algorithm: " + algorithm, "algorithm");
@@ -72,7 +74,7 @@ namespace Org.BouncyCastle.Security
public SecureRandom()
: this(sha1Generator)
{
- SetSeed(GetSeed(8));
+ SetSeed(GetSeed(20)); // 20 bytes because this is sha1Generator
}
public SecureRandom(
|
