Annotation of src/usr.bin/ssh/ssh_md5.c, Revision 1.1
1.1 ! deraadt 1: /* This code has been heavily hacked by Tatu Ylonen <ylo@cs.hut.fi> to
! 2: make it compile on machines like Cray that don't have a 32 bit integer
! 3: type. */
! 4: /*
! 5: * This code implements the MD5 message-digest algorithm.
! 6: * The algorithm is due to Ron Rivest. This code was
! 7: * written by Colin Plumb in 1993, no copyright is claimed.
! 8: * This code is in the public domain; do with it what you wish.
! 9: *
! 10: * Equivalent code is available from RSA Data Security, Inc.
! 11: * This code has been tested against that, and is equivalent,
! 12: * except that you don't need to include two pages of legalese
! 13: * with every copy.
! 14: *
! 15: * To compute the message digest of a chunk of bytes, declare an
! 16: * MD5Context structure, pass it to MD5Init, call MD5Update as
! 17: * needed on buffers full of bytes, and then call MD5Final, which
! 18: * will fill a supplied 16-byte array with the digest.
! 19: */
! 20:
! 21: #include "includes.h"
! 22: #include "ssh_md5.h"
! 23: #include "getput.h"
! 24:
! 25: /*
! 26: * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
! 27: * initialization constants.
! 28: */
! 29: void MD5Init(struct MD5Context *ctx)
! 30: {
! 31: ctx->buf[0] = 0x67452301;
! 32: ctx->buf[1] = 0xefcdab89;
! 33: ctx->buf[2] = 0x98badcfe;
! 34: ctx->buf[3] = 0x10325476;
! 35:
! 36: ctx->bits[0] = 0;
! 37: ctx->bits[1] = 0;
! 38: }
! 39:
! 40: /*
! 41: * Update context to reflect the concatenation of another buffer full
! 42: * of bytes.
! 43: */
! 44: void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
! 45: {
! 46: uint32 t;
! 47:
! 48: /* Update bitcount */
! 49:
! 50: t = ctx->bits[0];
! 51: if ((ctx->bits[0] = (t + ((uint32)len << 3)) & 0xffffffff) < t)
! 52: ctx->bits[1]++; /* Carry from low to high */
! 53: ctx->bits[1] += len >> 29;
! 54:
! 55: t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
! 56:
! 57: /* Handle any leading odd-sized chunks */
! 58:
! 59: if (t) {
! 60: unsigned char *p = ctx->in + t;
! 61:
! 62: t = 64 - t;
! 63: if (len < t) {
! 64: memcpy(p, buf, len);
! 65: return;
! 66: }
! 67: memcpy(p, buf, t);
! 68: MD5Transform(ctx->buf, ctx->in);
! 69: buf += t;
! 70: len -= t;
! 71: }
! 72: /* Process data in 64-byte chunks */
! 73:
! 74: while (len >= 64) {
! 75: memcpy(ctx->in, buf, 64);
! 76: MD5Transform(ctx->buf, ctx->in);
! 77: buf += 64;
! 78: len -= 64;
! 79: }
! 80:
! 81: /* Handle any remaining bytes of data. */
! 82:
! 83: memcpy(ctx->in, buf, len);
! 84: }
! 85:
! 86: /*
! 87: * Final wrapup - pad to 64-byte boundary with the bit pattern
! 88: * 1 0* (64-bit count of bits processed, MSB-first)
! 89: */
! 90: void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
! 91: {
! 92: unsigned count;
! 93: unsigned char *p;
! 94:
! 95: /* Compute number of bytes mod 64 */
! 96: count = (ctx->bits[0] >> 3) & 0x3F;
! 97:
! 98: /* Set the first char of padding to 0x80. This is safe since there is
! 99: always at least one byte free */
! 100: p = ctx->in + count;
! 101: *p++ = 0x80;
! 102:
! 103: /* Bytes of padding needed to make 64 bytes */
! 104: count = 64 - 1 - count;
! 105:
! 106: /* Pad out to 56 mod 64 */
! 107: if (count < 8) {
! 108: /* Two lots of padding: Pad the first block to 64 bytes */
! 109: memset(p, 0, count);
! 110: MD5Transform(ctx->buf, ctx->in);
! 111:
! 112: /* Now fill the next block with 56 bytes */
! 113: memset(ctx->in, 0, 56);
! 114: } else {
! 115: /* Pad block to 56 bytes */
! 116: memset(p, 0, count - 8);
! 117: }
! 118:
! 119: /* Append length in bits and transform */
! 120: PUT_32BIT_LSB_FIRST(ctx->in + 56, ctx->bits[0]);
! 121: PUT_32BIT_LSB_FIRST(ctx->in + 60, ctx->bits[1]);
! 122:
! 123: MD5Transform(ctx->buf, ctx->in);
! 124: PUT_32BIT_LSB_FIRST(digest, ctx->buf[0]);
! 125: PUT_32BIT_LSB_FIRST(digest + 4, ctx->buf[1]);
! 126: PUT_32BIT_LSB_FIRST(digest + 8, ctx->buf[2]);
! 127: PUT_32BIT_LSB_FIRST(digest + 12, ctx->buf[3]);
! 128: memset(ctx, 0, sizeof(ctx)); /* In case it's sensitive */
! 129: }
! 130:
! 131: #ifndef ASM_MD5
! 132:
! 133: /* The four core functions - F1 is optimized somewhat */
! 134:
! 135: /* #define F1(x, y, z) (x & y | ~x & z) */
! 136: #define F1(x, y, z) (z ^ (x & (y ^ z)))
! 137: #define F2(x, y, z) F1(z, x, y)
! 138: #define F3(x, y, z) (x ^ y ^ z)
! 139: #define F4(x, y, z) (y ^ (x | ~z))
! 140:
! 141: /* This is the central step in the MD5 algorithm. */
! 142: #define MD5STEP(f, w, x, y, z, data, s) \
! 143: ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
! 144:
! 145: /*
! 146: * The core of the MD5 algorithm, this alters an existing MD5 hash to
! 147: * reflect the addition of 16 longwords of new data. MD5Update blocks
! 148: * the data and converts bytes into longwords for this routine.
! 149: */
! 150: void MD5Transform(uint32 buf[4], const unsigned char inext[64])
! 151: {
! 152: register word32 a, b, c, d, i;
! 153: word32 in[16];
! 154:
! 155: for (i = 0; i < 16; i++)
! 156: in[i] = GET_32BIT_LSB_FIRST(inext + 4 * i);
! 157:
! 158: a = buf[0];
! 159: b = buf[1];
! 160: c = buf[2];
! 161: d = buf[3];
! 162:
! 163: MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
! 164: MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
! 165: MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
! 166: MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
! 167: MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
! 168: MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
! 169: MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
! 170: MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
! 171: MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
! 172: MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
! 173: MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
! 174: MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
! 175: MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
! 176: MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
! 177: MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
! 178: MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
! 179:
! 180: MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
! 181: MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
! 182: MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
! 183: MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
! 184: MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
! 185: MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
! 186: MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
! 187: MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
! 188: MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
! 189: MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
! 190: MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
! 191: MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
! 192: MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
! 193: MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
! 194: MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
! 195: MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
! 196:
! 197: MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
! 198: MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
! 199: MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
! 200: MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
! 201: MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
! 202: MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
! 203: MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
! 204: MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
! 205: MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
! 206: MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
! 207: MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
! 208: MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
! 209: MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
! 210: MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
! 211: MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
! 212: MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
! 213:
! 214: MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
! 215: MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
! 216: MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
! 217: MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
! 218: MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
! 219: MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
! 220: MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
! 221: MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
! 222: MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
! 223: MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
! 224: MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
! 225: MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
! 226: MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
! 227: MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
! 228: MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
! 229: MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
! 230:
! 231: buf[0] += a;
! 232: buf[1] += b;
! 233: buf[2] += c;
! 234: buf[3] += d;
! 235: }
! 236:
! 237: #endif
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