diff options
Diffstat (limited to 'Crypto/src/crypto/digests/Sha256Digest.cs')
| -rw-r--r-- | Crypto/src/crypto/digests/Sha256Digest.cs | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/Crypto/src/crypto/digests/Sha256Digest.cs b/Crypto/src/crypto/digests/Sha256Digest.cs new file mode 100644 index 000000000..1c00ab71f --- /dev/null +++ b/Crypto/src/crypto/digests/Sha256Digest.cs @@ -0,0 +1,309 @@ +using System; + +using Org.BouncyCastle.Crypto.Utilities; + +namespace Org.BouncyCastle.Crypto.Digests +{ + /** + * Draft FIPS 180-2 implementation of SHA-256. <b>Note:</b> As this is + * based on a draft this implementation is subject to change. + * + * <pre> + * block word digest + * SHA-1 512 32 160 + * SHA-256 512 32 256 + * SHA-384 1024 64 384 + * SHA-512 1024 64 512 + * </pre> + */ + public class Sha256Digest + : GeneralDigest + { + private const int DigestLength = 32; + + private uint H1, H2, H3, H4, H5, H6, H7, H8; + private uint[] X = new uint[64]; + private int xOff; + + public Sha256Digest() + { + initHs(); + } + + /** + * Copy constructor. This will copy the state of the provided + * message digest. + */ + public Sha256Digest(Sha256Digest t) : base(t) + { + H1 = t.H1; + H2 = t.H2; + H3 = t.H3; + H4 = t.H4; + H5 = t.H5; + H6 = t.H6; + H7 = t.H7; + H8 = t.H8; + + Array.Copy(t.X, 0, X, 0, t.X.Length); + xOff = t.xOff; + } + + public override string AlgorithmName + { + get { return "SHA-256"; } + } + + public override int GetDigestSize() + { + return DigestLength; + } + + internal override void ProcessWord( + byte[] input, + int inOff) + { + X[xOff] = Pack.BE_To_UInt32(input, inOff); + + if (++xOff == 16) + { + ProcessBlock(); + } + } + + internal override void ProcessLength( + long bitLength) + { + if (xOff > 14) + { + ProcessBlock(); + } + + X[14] = (uint)((ulong)bitLength >> 32); + X[15] = (uint)((ulong)bitLength); + } + + public override int DoFinal( + byte[] output, + int outOff) + { + Finish(); + + Pack.UInt32_To_BE((uint)H1, output, outOff); + Pack.UInt32_To_BE((uint)H2, output, outOff + 4); + Pack.UInt32_To_BE((uint)H3, output, outOff + 8); + Pack.UInt32_To_BE((uint)H4, output, outOff + 12); + Pack.UInt32_To_BE((uint)H5, output, outOff + 16); + Pack.UInt32_To_BE((uint)H6, output, outOff + 20); + Pack.UInt32_To_BE((uint)H7, output, outOff + 24); + Pack.UInt32_To_BE((uint)H8, output, outOff + 28); + + Reset(); + + return DigestLength; + } + + /** + * reset the chaining variables + */ + public override void Reset() + { + base.Reset(); + + initHs(); + + xOff = 0; + Array.Clear(X, 0, X.Length); + } + + private void initHs() + { + /* SHA-256 initial hash value + * The first 32 bits of the fractional parts of the square roots + * of the first eight prime numbers + */ + H1 = 0x6a09e667; + H2 = 0xbb67ae85; + H3 = 0x3c6ef372; + H4 = 0xa54ff53a; + H5 = 0x510e527f; + H6 = 0x9b05688c; + H7 = 0x1f83d9ab; + H8 = 0x5be0cd19; + } + + internal override void ProcessBlock() + { + // + // expand 16 word block into 64 word blocks. + // + for (int ti = 16; ti <= 63; ti++) + { + X[ti] = Theta1(X[ti - 2]) + X[ti - 7] + Theta0(X[ti - 15]) + X[ti - 16]; + } + + // + // set up working variables. + // + uint a = H1; + uint b = H2; + uint c = H3; + uint d = H4; + uint e = H5; + uint f = H6; + uint g = H7; + uint h = H8; + + int t = 0; + for(int i = 0; i < 8; ++i) + { + // t = 8 * i + h += Sum1Ch(e, f, g) + K[t] + X[t]; + d += h; + h += Sum0Maj(a, b, c); + ++t; + + // t = 8 * i + 1 + g += Sum1Ch(d, e, f) + K[t] + X[t]; + c += g; + g += Sum0Maj(h, a, b); + ++t; + + // t = 8 * i + 2 + f += Sum1Ch(c, d, e) + K[t] + X[t]; + b += f; + f += Sum0Maj(g, h, a); + ++t; + + // t = 8 * i + 3 + e += Sum1Ch(b, c, d) + K[t] + X[t]; + a += e; + e += Sum0Maj(f, g, h); + ++t; + + // t = 8 * i + 4 + d += Sum1Ch(a, b, c) + K[t] + X[t]; + h += d; + d += Sum0Maj(e, f, g); + ++t; + + // t = 8 * i + 5 + c += Sum1Ch(h, a, b) + K[t] + X[t]; + g += c; + c += Sum0Maj(d, e, f); + ++t; + + // t = 8 * i + 6 + b += Sum1Ch(g, h, a) + K[t] + X[t]; + f += b; + b += Sum0Maj(c, d, e); + ++t; + + // t = 8 * i + 7 + a += Sum1Ch(f, g, h) + K[t] + X[t]; + e += a; + a += Sum0Maj(b, c, d); + ++t; + } + + H1 += a; + H2 += b; + H3 += c; + H4 += d; + H5 += e; + H6 += f; + H7 += g; + H8 += h; + + // + // reset the offset and clean out the word buffer. + // + xOff = 0; + Array.Clear(X, 0, 16); + } + + private static uint Sum1Ch( + uint x, + uint y, + uint z) + { +// return Sum1(x) + Ch(x, y, z); + return (((x >> 6) | (x << 26)) ^ ((x >> 11) | (x << 21)) ^ ((x >> 25) | (x << 7))) + + ((x & y) ^ ((~x) & z)); + } + + private static uint Sum0Maj( + uint x, + uint y, + uint z) + { +// return Sum0(x) + Maj(x, y, z); + return (((x >> 2) | (x << 30)) ^ ((x >> 13) | (x << 19)) ^ ((x >> 22) | (x << 10))) + + ((x & y) ^ (x & z) ^ (y & z)); + } + +// /* SHA-256 functions */ +// private static uint Ch( +// uint x, +// uint y, +// uint z) +// { +// return ((x & y) ^ ((~x) & z)); +// } +// +// private static uint Maj( +// uint x, +// uint y, +// uint z) +// { +// return ((x & y) ^ (x & z) ^ (y & z)); +// } +// +// private static uint Sum0( +// uint x) +// { +// return ((x >> 2) | (x << 30)) ^ ((x >> 13) | (x << 19)) ^ ((x >> 22) | (x << 10)); +// } +// +// private static uint Sum1( +// uint x) +// { +// return ((x >> 6) | (x << 26)) ^ ((x >> 11) | (x << 21)) ^ ((x >> 25) | (x << 7)); +// } + + private static uint Theta0( + uint x) + { + return ((x >> 7) | (x << 25)) ^ ((x >> 18) | (x << 14)) ^ (x >> 3); + } + + private static uint Theta1( + uint x) + { + return ((x >> 17) | (x << 15)) ^ ((x >> 19) | (x << 13)) ^ (x >> 10); + } + + /* SHA-256 Constants + * (represent the first 32 bits of the fractional parts of the + * cube roots of the first sixty-four prime numbers) + */ + private static readonly uint[] K = { + 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, + 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, + 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, + 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, + 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, + 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, + 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, + 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, + 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, + 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, + 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, + 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, + 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, + 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, + 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, + 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2 + }; + } +} |