diff options
Diffstat (limited to 'crypto')
| -rw-r--r-- | crypto/src/crypto/generators/NaccacheSternKeyPairGenerator.cs | 31 |
1 files changed, 15 insertions, 16 deletions
diff --git a/crypto/src/crypto/generators/NaccacheSternKeyPairGenerator.cs b/crypto/src/crypto/generators/NaccacheSternKeyPairGenerator.cs index 7a047cd26..09f4b3db9 100644 --- a/crypto/src/crypto/generators/NaccacheSternKeyPairGenerator.cs +++ b/crypto/src/crypto/generators/NaccacheSternKeyPairGenerator.cs @@ -1,18 +1,18 @@ -using System; using System.Collections.Generic; using Org.BouncyCastle.Crypto.Parameters; using Org.BouncyCastle.Math; using Org.BouncyCastle.Security; +using Org.BouncyCastle.Utilities; namespace Org.BouncyCastle.Crypto.Generators { - /** + /** * Key generation parameters for NaccacheStern cipher. For details on this cipher, please see * * http://www.gemplus.com/smart/rd/publications/pdf/NS98pkcs.pdf */ - public class NaccacheSternKeyPairGenerator + public class NaccacheSternKeyPairGenerator : IAsymmetricCipherKeyPairGenerator { private static readonly int[] smallPrimes = @@ -58,11 +58,11 @@ namespace Org.BouncyCastle.Crypto.Generators for (int i = 0; i < smallPrimes.Count / 2; i++) { - u = u.Multiply((BigInteger)smallPrimes[i]); + u = u.Multiply(smallPrimes[i]); } for (int i = smallPrimes.Count / 2; i < smallPrimes.Count; i++) { - v = v.Multiply((BigInteger)smallPrimes[i]); + v = v.Multiply(smallPrimes[i]); } BigInteger sigma = u.Multiply(v); @@ -87,6 +87,7 @@ namespace Org.BouncyCastle.Crypto.Generators BigInteger _2au = a.Multiply(u).ShiftLeft(1); BigInteger _2bv = b.Multiply(v).ShiftLeft(1); + BigInteger n; for (;;) { tries++; @@ -117,14 +118,12 @@ namespace Org.BouncyCastle.Crypto.Generators continue; } - if (p.Multiply(q).BitLength < strength) - { - continue; - } - break; + n = p.Multiply(q); + + if (n.BitLength >= strength) + break; } - BigInteger n = p.Multiply(q); BigInteger phi_n = p.Subtract(BigInteger.One).Multiply(q.Subtract(BigInteger.One)); BigInteger g; tries = 0; @@ -154,8 +153,8 @@ namespace Org.BouncyCastle.Crypto.Generators g = BigInteger.One; for (int i = 0; i < smallPrimes.Count; i++) { - BigInteger gPart = (BigInteger) gParts[i]; - BigInteger smallPrime = (BigInteger) smallPrimes[i]; + BigInteger gPart = gParts[i]; + BigInteger smallPrime = smallPrimes[i]; g = g.Multiply(gPart.ModPow(sigma.Divide(smallPrime), n)).Mod(n); } @@ -163,7 +162,7 @@ namespace Org.BouncyCastle.Crypto.Generators bool divisible = false; for (int i = 0; i < smallPrimes.Count; i++) { - if (g.ModPow(phi_n.Divide((BigInteger)smallPrimes[i]), n).Equals(BigInteger.One)) + if (g.ModPow(phi_n.Divide(smallPrimes[i]), n).Equals(BigInteger.One)) { divisible = true; break; @@ -202,7 +201,8 @@ namespace Org.BouncyCastle.Crypto.Generators break; } - return new AsymmetricCipherKeyPair(new NaccacheSternKeyParameters(false, g, n, sigma.BitLength), + return new AsymmetricCipherKeyPair( + new NaccacheSternKeyParameters(false, g, n, sigma.BitLength), new NaccacheSternPrivateKeyParameters(g, n, sigma.BitLength, smallPrimes, phi_n)); } @@ -254,6 +254,5 @@ namespace Org.BouncyCastle.Crypto.Generators return primes; } - } } |