1 package org.bouncycastle.crypto.digests; 2 3 4 import org.bouncycastle.crypto.digests.GeneralDigest; 5 import org.bouncycastle.crypto.util.Pack; 6 7 8 /** 9 * FIPS 180-2 implementation of SHA-256. 10 * 11 * <pre> 12 * block word digest 13 * SHA-1 512 32 160 14 * SHA-256 512 32 256 15 * SHA-384 1024 64 384 16 * SHA-512 1024 64 512 17 * </pre> 18 */ 19 public class SHA256Digest 20 extends GeneralDigest 21 { 22 private static final int DIGEST_LENGTH = 32; 23 24 private int H1, H2, H3, H4, H5, H6, H7, H8; 25 26 private int[] X = new int[64]; 27 private int xOff; 28 29 /** 30 * Standard constructor 31 */ 32 public SHA256Digest() 33 { 34 reset(); 35 } 36 37 /** 38 * Copy constructor. This will copy the state of the provided 39 * message digest. 40 */ 41 public SHA256Digest(SHA256Digest t) 42 { 43 super(t); 44 45 H1 = t.H1; 46 H2 = t.H2; 47 H3 = t.H3; 48 H4 = t.H4; 49 H5 = t.H5; 50 H6 = t.H6; 51 H7 = t.H7; 52 H8 = t.H8; 53 54 System.arraycopy(t.X, 0, X, 0, t.X.length); 55 xOff = t.xOff; 56 } 57 58 public String getAlgorithmName() 59 { 60 return "SHA-256"; 61 } 62 63 public int getDigestSize() 64 { 65 return DIGEST_LENGTH; 66 } 67 68 protected void processWord( 69 byte[] in, 70 int inOff) 71 { 72 // Note: Inlined for performance 73 // X[xOff] = Pack.bigEndianToInt(in, inOff); 74 int n = in[inOff] << 24; 75 n |= (in[++inOff] & 0xff) << 16; 76 n |= (in[++inOff] & 0xff) << 8; 77 n |= (in[++inOff] & 0xff); 78 X[xOff] = n; 79 80 if (++xOff == 16) 81 { 82 processBlock(); 83 } 84 } 85 86 protected void processLength( 87 long bitLength) 88 { 89 if (xOff > 14) 90 { 91 processBlock(); 92 } 93 94 X[14] = (int)(bitLength >>> 32); 95 X[15] = (int)(bitLength & 0xffffffff); 96 } 97 98 public int doFinal( 99 byte[] out, 100 int outOff) 101 { 102 finish(); 103 104 Pack.intToBigEndian(H1, out, outOff); 105 Pack.intToBigEndian(H2, out, outOff + 4); 106 Pack.intToBigEndian(H3, out, outOff + 8); 107 Pack.intToBigEndian(H4, out, outOff + 12); 108 Pack.intToBigEndian(H5, out, outOff + 16); 109 Pack.intToBigEndian(H6, out, outOff + 20); 110 Pack.intToBigEndian(H7, out, outOff + 24); 111 Pack.intToBigEndian(H8, out, outOff + 28); 112 113 reset(); 114 115 return DIGEST_LENGTH; 116 } 117 118 /** 119 * reset the chaining variables 120 */ 121 public void reset() 122 { 123 super.reset(); 124 125 /* SHA-256 initial hash value 126 * The first 32 bits of the fractional parts of the square roots 127 * of the first eight prime numbers 128 */ 129 130 H1 = 0x6a09e667; 131 H2 = 0xbb67ae85; 132 H3 = 0x3c6ef372; 133 H4 = 0xa54ff53a; 134 H5 = 0x510e527f; 135 H6 = 0x9b05688c; 136 H7 = 0x1f83d9ab; 137 H8 = 0x5be0cd19; 138 139 xOff = 0; 140 for (int i = 0; i != X.length; i++) 141 { 142 X[i] = 0; 143 } 144 } 145 146 protected void processBlock() 147 { 148 // 149 // expand 16 word block into 64 word blocks. 150 // 151 for (int t = 16; t <= 63; t++) 152 { 153 X[t] = Theta1(X[t - 2]) + X[t - 7] + Theta0(X[t - 15]) + X[t - 16]; 154 } 155 156 // 157 // set up working variables. 158 // 159 int a = H1; 160 int b = H2; 161 int c = H3; 162 int d = H4; 163 int e = H5; 164 int f = H6; 165 int g = H7; 166 int h = H8; 167 168 int t = 0; 169 for(int i = 0; i < 8; i ++) 170 { 171 // t = 8 * i 172 h += Sum1(e) + Ch(e, f, g) + K[t] + X[t]; 173 d += h; 174 h += Sum0(a) + Maj(a, b, c); 175 ++t; 176 177 // t = 8 * i + 1 178 g += Sum1(d) + Ch(d, e, f) + K[t] + X[t]; 179 c += g; 180 g += Sum0(h) + Maj(h, a, b); 181 ++t; 182 183 // t = 8 * i + 2 184 f += Sum1(c) + Ch(c, d, e) + K[t] + X[t]; 185 b += f; 186 f += Sum0(g) + Maj(g, h, a); 187 ++t; 188 189 // t = 8 * i + 3 190 e += Sum1(b) + Ch(b, c, d) + K[t] + X[t]; 191 a += e; 192 e += Sum0(f) + Maj(f, g, h); 193 ++t; 194 195 // t = 8 * i + 4 196 d += Sum1(a) + Ch(a, b, c) + K[t] + X[t]; 197 h += d; 198 d += Sum0(e) + Maj(e, f, g); 199 ++t; 200 201 // t = 8 * i + 5 202 c += Sum1(h) + Ch(h, a, b) + K[t] + X[t]; 203 g += c; 204 c += Sum0(d) + Maj(d, e, f); 205 ++t; 206 207 // t = 8 * i + 6 208 b += Sum1(g) + Ch(g, h, a) + K[t] + X[t]; 209 f += b; 210 b += Sum0(c) + Maj(c, d, e); 211 ++t; 212 213 // t = 8 * i + 7 214 a += Sum1(f) + Ch(f, g, h) + K[t] + X[t]; 215 e += a; 216 a += Sum0(b) + Maj(b, c, d); 217 ++t; 218 } 219 220 H1 += a; 221 H2 += b; 222 H3 += c; 223 H4 += d; 224 H5 += e; 225 H6 += f; 226 H7 += g; 227 H8 += h; 228 229 // 230 // reset the offset and clean out the word buffer. 231 // 232 xOff = 0; 233 for (int i = 0; i < 16; i++) 234 { 235 X[i] = 0; 236 } 237 } 238 239 /* SHA-256 functions */ 240 private int Ch( 241 int x, 242 int y, 243 int z) 244 { 245 return (x & y) ^ ((~x) & z); 246 } 247 248 private int Maj( 249 int x, 250 int y, 251 int z) 252 { 253 return (x & y) ^ (x & z) ^ (y & z); 254 } 255 256 private int Sum0( 257 int x) 258 { 259 return ((x >>> 2) | (x << 30)) ^ ((x >>> 13) | (x << 19)) ^ ((x >>> 22) | (x << 10)); 260 } 261 262 private int Sum1( 263 int x) 264 { 265 return ((x >>> 6) | (x << 26)) ^ ((x >>> 11) | (x << 21)) ^ ((x >>> 25) | (x << 7)); 266 } 267 268 private int Theta0( 269 int x) 270 { 271 return ((x >>> 7) | (x << 25)) ^ ((x >>> 18) | (x << 14)) ^ (x >>> 3); 272 } 273 274 private int Theta1( 275 int x) 276 { 277 return ((x >>> 17) | (x << 15)) ^ ((x >>> 19) | (x << 13)) ^ (x >>> 10); 278 } 279 280 /* SHA-256 Constants 281 * (represent the first 32 bits of the fractional parts of the 282 * cube roots of the first sixty-four prime numbers) 283 */ 284 static final int K[] = { 285 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, 286 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, 287 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 288 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, 289 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 290 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 291 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, 292 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2 293 }; 294 } 295 296
