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Diffstat (limited to 'core/src/main/java/org/spongycastle/crypto/digests/SHA256Digest.java')
| -rw-r--r-- | core/src/main/java/org/spongycastle/crypto/digests/SHA256Digest.java | 360 |
1 files changed, 360 insertions, 0 deletions
diff --git a/core/src/main/java/org/spongycastle/crypto/digests/SHA256Digest.java b/core/src/main/java/org/spongycastle/crypto/digests/SHA256Digest.java new file mode 100644 index 00000000..9fe18347 --- /dev/null +++ b/core/src/main/java/org/spongycastle/crypto/digests/SHA256Digest.java @@ -0,0 +1,360 @@ +package org.spongycastle.crypto.digests; + + +import org.spongycastle.util.Memoable; +import org.spongycastle.util.Pack; + + +/** + * FIPS 180-2 implementation of SHA-256. + * + * <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 + extends GeneralDigest + implements EncodableDigest +{ + private static final int DIGEST_LENGTH = 32; + + private int H1, H2, H3, H4, H5, H6, H7, H8; + + private int[] X = new int[64]; + private int xOff; + + /** + * Standard constructor + */ + public SHA256Digest() + { + reset(); + } + + /** + * Copy constructor. This will copy the state of the provided + * message digest. + */ + public SHA256Digest(SHA256Digest t) + { + super(t); + + copyIn(t); + } + + private void copyIn(SHA256Digest t) + { + super.copyIn(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; + + System.arraycopy(t.X, 0, X, 0, t.X.length); + xOff = t.xOff; + } + + public SHA256Digest(byte[] encodedState) + { + super(encodedState); + + H1 = Pack.bigEndianToInt(encodedState, 16); + H2 = Pack.bigEndianToInt(encodedState, 20); + H3 = Pack.bigEndianToInt(encodedState, 24); + H4 = Pack.bigEndianToInt(encodedState, 28); + H5 = Pack.bigEndianToInt(encodedState, 32); + H6 = Pack.bigEndianToInt(encodedState, 36); + H7 = Pack.bigEndianToInt(encodedState, 40); + H8 = Pack.bigEndianToInt(encodedState, 44); + + xOff = Pack.bigEndianToInt(encodedState, 48); + for (int i = 0; i != xOff; i++) + { + X[i] = Pack.bigEndianToInt(encodedState, 52 + (i * 4)); + } + } + + + public String getAlgorithmName() + { + return "SHA-256"; + } + + public int getDigestSize() + { + return DIGEST_LENGTH; + } + + protected void processWord( + byte[] in, + int inOff) + { + // Note: Inlined for performance +// X[xOff] = Pack.bigEndianToInt(in, inOff); + int n = in[inOff] << 24; + n |= (in[++inOff] & 0xff) << 16; + n |= (in[++inOff] & 0xff) << 8; + n |= (in[++inOff] & 0xff); + X[xOff] = n; + + if (++xOff == 16) + { + processBlock(); + } + } + + protected void processLength( + long bitLength) + { + if (xOff > 14) + { + processBlock(); + } + + X[14] = (int)(bitLength >>> 32); + X[15] = (int)(bitLength & 0xffffffff); + } + + public int doFinal( + byte[] out, + int outOff) + { + finish(); + + Pack.intToBigEndian(H1, out, outOff); + Pack.intToBigEndian(H2, out, outOff + 4); + Pack.intToBigEndian(H3, out, outOff + 8); + Pack.intToBigEndian(H4, out, outOff + 12); + Pack.intToBigEndian(H5, out, outOff + 16); + Pack.intToBigEndian(H6, out, outOff + 20); + Pack.intToBigEndian(H7, out, outOff + 24); + Pack.intToBigEndian(H8, out, outOff + 28); + + reset(); + + return DIGEST_LENGTH; + } + + /** + * reset the chaining variables + */ + public void reset() + { + super.reset(); + + /* 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; + + xOff = 0; + for (int i = 0; i != X.length; i++) + { + X[i] = 0; + } + } + + protected void processBlock() + { + // + // expand 16 word block into 64 word blocks. + // + for (int t = 16; t <= 63; t++) + { + X[t] = Theta1(X[t - 2]) + X[t - 7] + Theta0(X[t - 15]) + X[t - 16]; + } + + // + // set up working variables. + // + int a = H1; + int b = H2; + int c = H3; + int d = H4; + int e = H5; + int f = H6; + int g = H7; + int h = H8; + + int t = 0; + for(int i = 0; i < 8; i ++) + { + // t = 8 * i + h += Sum1(e) + Ch(e, f, g) + K[t] + X[t]; + d += h; + h += Sum0(a) + Maj(a, b, c); + ++t; + + // t = 8 * i + 1 + g += Sum1(d) + Ch(d, e, f) + K[t] + X[t]; + c += g; + g += Sum0(h) + Maj(h, a, b); + ++t; + + // t = 8 * i + 2 + f += Sum1(c) + Ch(c, d, e) + K[t] + X[t]; + b += f; + f += Sum0(g) + Maj(g, h, a); + ++t; + + // t = 8 * i + 3 + e += Sum1(b) + Ch(b, c, d) + K[t] + X[t]; + a += e; + e += Sum0(f) + Maj(f, g, h); + ++t; + + // t = 8 * i + 4 + d += Sum1(a) + Ch(a, b, c) + K[t] + X[t]; + h += d; + d += Sum0(e) + Maj(e, f, g); + ++t; + + // t = 8 * i + 5 + c += Sum1(h) + Ch(h, a, b) + K[t] + X[t]; + g += c; + c += Sum0(d) + Maj(d, e, f); + ++t; + + // t = 8 * i + 6 + b += Sum1(g) + Ch(g, h, a) + K[t] + X[t]; + f += b; + b += Sum0(c) + Maj(c, d, e); + ++t; + + // t = 8 * i + 7 + a += Sum1(f) + Ch(f, g, h) + K[t] + X[t]; + e += a; + a += Sum0(b) + Maj(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; + for (int i = 0; i < 16; i++) + { + X[i] = 0; + } + } + + /* SHA-256 functions */ + private int Ch( + int x, + int y, + int z) + { + return (x & y) ^ ((~x) & z); + } + + private int Maj( + int x, + int y, + int z) + { + return (x & y) ^ (x & z) ^ (y & z); + } + + private int Sum0( + int x) + { + return ((x >>> 2) | (x << 30)) ^ ((x >>> 13) | (x << 19)) ^ ((x >>> 22) | (x << 10)); + } + + private int Sum1( + int x) + { + return ((x >>> 6) | (x << 26)) ^ ((x >>> 11) | (x << 21)) ^ ((x >>> 25) | (x << 7)); + } + + private int Theta0( + int x) + { + return ((x >>> 7) | (x << 25)) ^ ((x >>> 18) | (x << 14)) ^ (x >>> 3); + } + + private int Theta1( + int 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) + */ + static final int 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 + }; + + public Memoable copy() + { + return new SHA256Digest(this); + } + + public void reset(Memoable other) + { + SHA256Digest d = (SHA256Digest)other; + + copyIn(d); + } + + public byte[] getEncodedState() + { + byte[] state = new byte[52 + xOff * 4]; + + super.populateState(state); + + Pack.intToBigEndian(H1, state, 16); + Pack.intToBigEndian(H2, state, 20); + Pack.intToBigEndian(H3, state, 24); + Pack.intToBigEndian(H4, state, 28); + Pack.intToBigEndian(H5, state, 32); + Pack.intToBigEndian(H6, state, 36); + Pack.intToBigEndian(H7, state, 40); + Pack.intToBigEndian(H8, state, 44); + Pack.intToBigEndian(xOff, state, 48); + + for (int i = 0; i != xOff; i++) + { + Pack.intToBigEndian(X[i], state, 52 + (i * 4)); + } + + return state; + } +} + |