Annotation of sys/crypto/md5.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: md5.c,v 1.1 2004/05/07 14:42:26 millert Exp $ */
! 2:
! 3: /*
! 4: * This code implements the MD5 message-digest algorithm.
! 5: * The algorithm is due to Ron Rivest. This code was
! 6: * written by Colin Plumb in 1993, no copyright is claimed.
! 7: * This code is in the public domain; do with it what you wish.
! 8: *
! 9: * Equivalent code is available from RSA Data Security, Inc.
! 10: * This code has been tested against that, and is equivalent,
! 11: * except that you don't need to include two pages of legalese
! 12: * with every copy.
! 13: *
! 14: * To compute the message digest of a chunk of bytes, declare an
! 15: * MD5Context structure, pass it to MD5Init, call MD5Update as
! 16: * needed on buffers full of bytes, and then call MD5Final, which
! 17: * will fill a supplied 16-byte array with the digest.
! 18: */
! 19:
! 20: #include <sys/param.h>
! 21: #include <sys/systm.h>
! 22: #include <crypto/md5.h>
! 23:
! 24: #define PUT_64BIT_LE(cp, value) do { \
! 25: (cp)[7] = (value) >> 56; \
! 26: (cp)[6] = (value) >> 48; \
! 27: (cp)[5] = (value) >> 40; \
! 28: (cp)[4] = (value) >> 32; \
! 29: (cp)[3] = (value) >> 24; \
! 30: (cp)[2] = (value) >> 16; \
! 31: (cp)[1] = (value) >> 8; \
! 32: (cp)[0] = (value); } while (0)
! 33:
! 34: #define PUT_32BIT_LE(cp, value) do { \
! 35: (cp)[3] = (value) >> 24; \
! 36: (cp)[2] = (value) >> 16; \
! 37: (cp)[1] = (value) >> 8; \
! 38: (cp)[0] = (value); } while (0)
! 39:
! 40: static u_int8_t PADDING[MD5_BLOCK_LENGTH] = {
! 41: 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
! 42: 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
! 43: 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
! 44: };
! 45:
! 46: /*
! 47: * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
! 48: * initialization constants.
! 49: */
! 50: void
! 51: MD5Init(MD5_CTX *ctx)
! 52: {
! 53: ctx->count = 0;
! 54: ctx->state[0] = 0x67452301;
! 55: ctx->state[1] = 0xefcdab89;
! 56: ctx->state[2] = 0x98badcfe;
! 57: ctx->state[3] = 0x10325476;
! 58: }
! 59:
! 60: /*
! 61: * Update context to reflect the concatenation of another buffer full
! 62: * of bytes.
! 63: */
! 64: void
! 65: MD5Update(MD5_CTX *ctx, const unsigned char *input, size_t len)
! 66: {
! 67: size_t have, need;
! 68:
! 69: /* Check how many bytes we already have and how many more we need. */
! 70: have = (size_t)((ctx->count >> 3) & (MD5_BLOCK_LENGTH - 1));
! 71: need = MD5_BLOCK_LENGTH - have;
! 72:
! 73: /* Update bitcount */
! 74: ctx->count += (u_int64_t)len << 3;
! 75:
! 76: if (len >= need) {
! 77: if (have != 0) {
! 78: bcopy(input, ctx->buffer + have, need);
! 79: MD5Transform(ctx->state, ctx->buffer);
! 80: input += need;
! 81: len -= need;
! 82: have = 0;
! 83: }
! 84:
! 85: /* Process data in MD5_BLOCK_LENGTH-byte chunks. */
! 86: while (len >= MD5_BLOCK_LENGTH) {
! 87: MD5Transform(ctx->state, input);
! 88: input += MD5_BLOCK_LENGTH;
! 89: len -= MD5_BLOCK_LENGTH;
! 90: }
! 91: }
! 92:
! 93: /* Handle any remaining bytes of data. */
! 94: if (len != 0)
! 95: bcopy(input, ctx->buffer + have, len);
! 96: }
! 97:
! 98: /*
! 99: * Final wrapup - pad to 64-byte boundary with the bit pattern
! 100: * 1 0* (64-bit count of bits processed, MSB-first)
! 101: */
! 102: void
! 103: MD5Final(unsigned char digest[MD5_DIGEST_LENGTH], MD5_CTX *ctx)
! 104: {
! 105: u_int8_t count[8];
! 106: size_t padlen;
! 107: int i;
! 108:
! 109: /* Convert count to 8 bytes in little endian order. */
! 110: PUT_64BIT_LE(count, ctx->count);
! 111:
! 112: /* Pad out to 56 mod 64. */
! 113: padlen = MD5_BLOCK_LENGTH -
! 114: ((ctx->count >> 3) & (MD5_BLOCK_LENGTH - 1));
! 115: if (padlen < 1 + 8)
! 116: padlen += MD5_BLOCK_LENGTH;
! 117: MD5Update(ctx, PADDING, padlen - 8); /* padlen - 8 <= 64 */
! 118: MD5Update(ctx, count, 8);
! 119:
! 120: if (digest != NULL) {
! 121: for (i = 0; i < 4; i++)
! 122: PUT_32BIT_LE(digest + i * 4, ctx->state[i]);
! 123: }
! 124: bzero(ctx, sizeof(*ctx)); /* in case it's sensitive */
! 125: }
! 126:
! 127:
! 128: /* The four core functions - F1 is optimized somewhat */
! 129:
! 130: /* #define F1(x, y, z) (x & y | ~x & z) */
! 131: #define F1(x, y, z) (z ^ (x & (y ^ z)))
! 132: #define F2(x, y, z) F1(z, x, y)
! 133: #define F3(x, y, z) (x ^ y ^ z)
! 134: #define F4(x, y, z) (y ^ (x | ~z))
! 135:
! 136: /* This is the central step in the MD5 algorithm. */
! 137: #define MD5STEP(f, w, x, y, z, data, s) \
! 138: ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
! 139:
! 140: /*
! 141: * The core of the MD5 algorithm, this alters an existing MD5 hash to
! 142: * reflect the addition of 16 longwords of new data. MD5Update blocks
! 143: * the data and converts bytes into longwords for this routine.
! 144: */
! 145: void
! 146: MD5Transform(u_int32_t state[4], const u_int8_t block[MD5_BLOCK_LENGTH])
! 147: {
! 148: u_int32_t a, b, c, d, in[MD5_BLOCK_LENGTH / 4];
! 149:
! 150: #if BYTE_ORDER == LITTLE_ENDIAN
! 151: bcopy(block, in, sizeof(in));
! 152: #else
! 153: for (a = 0; a < MD5_BLOCK_LENGTH / 4; a++) {
! 154: in[a] = (u_int32_t)(
! 155: (u_int32_t)(block[a * 4 + 0]) |
! 156: (u_int32_t)(block[a * 4 + 1]) << 8 |
! 157: (u_int32_t)(block[a * 4 + 2]) << 16 |
! 158: (u_int32_t)(block[a * 4 + 3]) << 24);
! 159: }
! 160: #endif
! 161:
! 162: a = state[0];
! 163: b = state[1];
! 164: c = state[2];
! 165: d = state[3];
! 166:
! 167: MD5STEP(F1, a, b, c, d, in[ 0] + 0xd76aa478, 7);
! 168: MD5STEP(F1, d, a, b, c, in[ 1] + 0xe8c7b756, 12);
! 169: MD5STEP(F1, c, d, a, b, in[ 2] + 0x242070db, 17);
! 170: MD5STEP(F1, b, c, d, a, in[ 3] + 0xc1bdceee, 22);
! 171: MD5STEP(F1, a, b, c, d, in[ 4] + 0xf57c0faf, 7);
! 172: MD5STEP(F1, d, a, b, c, in[ 5] + 0x4787c62a, 12);
! 173: MD5STEP(F1, c, d, a, b, in[ 6] + 0xa8304613, 17);
! 174: MD5STEP(F1, b, c, d, a, in[ 7] + 0xfd469501, 22);
! 175: MD5STEP(F1, a, b, c, d, in[ 8] + 0x698098d8, 7);
! 176: MD5STEP(F1, d, a, b, c, in[ 9] + 0x8b44f7af, 12);
! 177: MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
! 178: MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
! 179: MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
! 180: MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
! 181: MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
! 182: MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
! 183:
! 184: MD5STEP(F2, a, b, c, d, in[ 1] + 0xf61e2562, 5);
! 185: MD5STEP(F2, d, a, b, c, in[ 6] + 0xc040b340, 9);
! 186: MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
! 187: MD5STEP(F2, b, c, d, a, in[ 0] + 0xe9b6c7aa, 20);
! 188: MD5STEP(F2, a, b, c, d, in[ 5] + 0xd62f105d, 5);
! 189: MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
! 190: MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
! 191: MD5STEP(F2, b, c, d, a, in[ 4] + 0xe7d3fbc8, 20);
! 192: MD5STEP(F2, a, b, c, d, in[ 9] + 0x21e1cde6, 5);
! 193: MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
! 194: MD5STEP(F2, c, d, a, b, in[ 3] + 0xf4d50d87, 14);
! 195: MD5STEP(F2, b, c, d, a, in[ 8] + 0x455a14ed, 20);
! 196: MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
! 197: MD5STEP(F2, d, a, b, c, in[ 2] + 0xfcefa3f8, 9);
! 198: MD5STEP(F2, c, d, a, b, in[ 7] + 0x676f02d9, 14);
! 199: MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
! 200:
! 201: MD5STEP(F3, a, b, c, d, in[ 5] + 0xfffa3942, 4);
! 202: MD5STEP(F3, d, a, b, c, in[ 8] + 0x8771f681, 11);
! 203: MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
! 204: MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
! 205: MD5STEP(F3, a, b, c, d, in[ 1] + 0xa4beea44, 4);
! 206: MD5STEP(F3, d, a, b, c, in[ 4] + 0x4bdecfa9, 11);
! 207: MD5STEP(F3, c, d, a, b, in[ 7] + 0xf6bb4b60, 16);
! 208: MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
! 209: MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
! 210: MD5STEP(F3, d, a, b, c, in[ 0] + 0xeaa127fa, 11);
! 211: MD5STEP(F3, c, d, a, b, in[ 3] + 0xd4ef3085, 16);
! 212: MD5STEP(F3, b, c, d, a, in[ 6] + 0x04881d05, 23);
! 213: MD5STEP(F3, a, b, c, d, in[ 9] + 0xd9d4d039, 4);
! 214: MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
! 215: MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
! 216: MD5STEP(F3, b, c, d, a, in[2 ] + 0xc4ac5665, 23);
! 217:
! 218: MD5STEP(F4, a, b, c, d, in[ 0] + 0xf4292244, 6);
! 219: MD5STEP(F4, d, a, b, c, in[7 ] + 0x432aff97, 10);
! 220: MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
! 221: MD5STEP(F4, b, c, d, a, in[5 ] + 0xfc93a039, 21);
! 222: MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
! 223: MD5STEP(F4, d, a, b, c, in[3 ] + 0x8f0ccc92, 10);
! 224: MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
! 225: MD5STEP(F4, b, c, d, a, in[1 ] + 0x85845dd1, 21);
! 226: MD5STEP(F4, a, b, c, d, in[8 ] + 0x6fa87e4f, 6);
! 227: MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
! 228: MD5STEP(F4, c, d, a, b, in[6 ] + 0xa3014314, 15);
! 229: MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
! 230: MD5STEP(F4, a, b, c, d, in[4 ] + 0xf7537e82, 6);
! 231: MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
! 232: MD5STEP(F4, c, d, a, b, in[2 ] + 0x2ad7d2bb, 15);
! 233: MD5STEP(F4, b, c, d, a, in[9 ] + 0xeb86d391, 21);
! 234:
! 235: state[0] += a;
! 236: state[1] += b;
! 237: state[2] += c;
! 238: state[3] += d;
! 239: }
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