diff options
| -rw-r--r-- | crypto/test/src/security/test/SecureRandomTest.cs | 277 |
1 files changed, 139 insertions, 138 deletions
diff --git a/crypto/test/src/security/test/SecureRandomTest.cs b/crypto/test/src/security/test/SecureRandomTest.cs index 12e4b9a47..eedcd0ebc 100644 --- a/crypto/test/src/security/test/SecureRandomTest.cs +++ b/crypto/test/src/security/test/SecureRandomTest.cs @@ -6,145 +6,146 @@ using Org.BouncyCastle.Crypto.Prng; namespace Org.BouncyCastle.Security.Tests { - [TestFixture] - public class SecureRandomTest - { + [TestFixture] + public class SecureRandomTest + { #if !NETCF_1_0 - [Test] - public void TestCryptoApi() - { - SecureRandom random = new SecureRandom( - new CryptoApiRandomGenerator()); - - checkSecureRandom(random); - } + [Test] + public void TestCryptoApi() + { + SecureRandom random = new SecureRandom( + new CryptoApiRandomGenerator()); + + CheckSecureRandom(random); + } #endif - [Test] - public void TestDefault() - { - SecureRandom random = new SecureRandom(); - - checkSecureRandom(random); - } - - [Test] - public void TestSha1Prng() - { - SecureRandom random = SecureRandom.GetInstance("SHA1PRNG"); - random.SetSeed(SecureRandom.GetSeed(20)); - - checkSecureRandom(random); - } - - [Test] - public void TestSha256Prng() - { - SecureRandom random = SecureRandom.GetInstance("SHA256PRNG"); - random.SetSeed(SecureRandom.GetSeed(32)); - - checkSecureRandom(random); - } - - [Test] - public void TestThreadedSeed() - { - SecureRandom random = new SecureRandom( - new ThreadedSeedGenerator().GenerateSeed(20, false)); - - checkSecureRandom(random); - } - - [Test] - public void TestVmpcPrng() - { - SecureRandom random = new SecureRandom(new VmpcRandomGenerator()); - random.SetSeed(SecureRandom.GetSeed(32)); - - checkSecureRandom(random); - } - - - private static void checkSecureRandom( - SecureRandom random) - { - // Note: This will periodically (< 1e-6 probability) give a false alarm. - // That's randomness for you! - Assert.IsTrue(runChiSquaredTests(random), "Chi2 test detected possible non-randomness"); - } - - private static bool runChiSquaredTests( - SecureRandom random) - { - int passes = 0; - - for (int tries = 0; tries < 100; ++tries) - { - double chi2 = measureChiSquared(random, 1000); - if (chi2 < 285.0) // 255 degrees of freedom in test => Q ~ 10.0% for 285 - ++passes; - } - - return passes > 75; - } - - private static double measureChiSquared( - SecureRandom random, - int rounds) - { - int[] counts = new int[256]; - - byte[] bs = new byte[256]; - for (int i = 0; i < rounds; ++i) - { - random.NextBytes(bs); - - for (int b = 0; b < 256; ++b) - { - ++counts[bs[b]]; - } - } - - byte mask = SecureRandom.GetSeed(1)[0]; - for (int i = 0; i < rounds; ++i) - { - random.NextBytes(bs); - - for (int b = 0; b < 256; ++b) - { - ++counts[bs[b] ^ mask]; - } - - ++mask; - } - - byte shift = SecureRandom.GetSeed(1)[0]; - for (int i = 0; i < rounds; ++i) - { - random.NextBytes(bs); - - for (int b = 0; b < 256; ++b) - { - ++counts[(byte)(bs[b] + shift)]; - } - - ++shift; - } - - int total = 3 * rounds; - - double chi2 = 0; - for (int k = 0; k < counts.Length; ++k) - { - double diff = ((double) counts[k]) - total; - double diff2 = diff * diff; - - chi2 += diff2; - } - - chi2 /= total; - - return chi2; - } - } + [Test] + public void TestDefault() + { + SecureRandom random = new SecureRandom(); + + CheckSecureRandom(random); + } + + [Test] + public void TestSha1Prng() + { + SecureRandom random = SecureRandom.GetInstance("SHA1PRNG"); + random.SetSeed(SecureRandom.GetSeed(20)); + + CheckSecureRandom(random); + } + + [Test] + public void TestSha256Prng() + { + SecureRandom random = SecureRandom.GetInstance("SHA256PRNG"); + random.SetSeed(SecureRandom.GetSeed(32)); + + CheckSecureRandom(random); + } + + [Test] + public void TestThreadedSeed() + { + SecureRandom random = new SecureRandom( + new ThreadedSeedGenerator().GenerateSeed(20, false)); + + CheckSecureRandom(random); + } + + [Test] + public void TestVmpcPrng() + { + SecureRandom random = new SecureRandom(new VmpcRandomGenerator()); + random.SetSeed(SecureRandom.GetSeed(32)); + + CheckSecureRandom(random); + } + + + private static void CheckSecureRandom(SecureRandom random) + { + // Note: This will periodically (< 1e-6 probability) give a false alarm. + // That's randomness for you! + Assert.IsTrue(RunChiSquaredTests(random), "Chi2 test detected possible non-randomness"); + } + + private static bool RunChiSquaredTests(SecureRandom random) + { + int passes = 0; + + for (int tries = 0; tries < 100; ++tries) + { + double chi2 = MeasureChiSquared(random, 1000); + + // 255 degrees of freedom in test => Q ~ 10.0% for 285 + if (chi2 < 285.0) + { + ++passes; + } + } + + return passes > 75; + } + + private static double MeasureChiSquared(SecureRandom random, int rounds) + { + byte[] opts = SecureRandom.GetSeed(2); + int[] counts = new int[256]; + + byte[] bs = new byte[256]; + for (int i = 0; i < rounds; ++i) + { + random.NextBytes(bs); + + for (int b = 0; b < 256; ++b) + { + ++counts[bs[b]]; + } + } + + byte mask = opts[0]; + for (int i = 0; i < rounds; ++i) + { + random.NextBytes(bs); + + for (int b = 0; b < 256; ++b) + { + ++counts[bs[b] ^ mask]; + } + + ++mask; + } + + byte shift = opts[1]; + for (int i = 0; i < rounds; ++i) + { + random.NextBytes(bs); + + for (int b = 0; b < 256; ++b) + { + ++counts[(byte)(bs[b] + shift)]; + } + + ++shift; + } + + int total = 3 * rounds; + + double chi2 = 0; + for (int k = 0; k < counts.Length; ++k) + { + double diff = ((double) counts[k]) - total; + double diff2 = diff * diff; + + chi2 += diff2; + } + + chi2 /= total; + + return chi2; + } + } } |