crypto/openssh/openbsd-compat/md5.c

   1 /*      $OpenBSD: md5.c,v 1.9 2014/01/08 06:14:57 tedu 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 "includes.h"
  21
  22 #ifndef WITH_OPENSSL
  23
  24 #include <sys/types.h>
  25 #include <string.h>
  26 #include "md5.h"
  27
  28 #define PUT_64BIT_LE(cp, value) do {                                    \
  29         (cp)[7] = (value) >> 56;                                        \
  30         (cp)[6] = (value) >> 48;                                        \
  31         (cp)[5] = (value) >> 40;                                        \
  32         (cp)[4] = (value) >> 32;                                        \
  33         (cp)[3] = (value) >> 24;                                        \
  34         (cp)[2] = (value) >> 16;                                        \
  35         (cp)[1] = (value) >> 8;                                         \
  36         (cp)[0] = (value); } while (0)
  37
  38 #define PUT_32BIT_LE(cp, value) do {                                    \
  39         (cp)[3] = (value) >> 24;                                        \
  40         (cp)[2] = (value) >> 16;                                        \
  41         (cp)[1] = (value) >> 8;                                         \
  42         (cp)[0] = (value); } while (0)
  43
  44 static u_int8_t PADDING[MD5_BLOCK_LENGTH] = {
  45         0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  46         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  47         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  48 };
  49
  50 /*
  51  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
  52  * initialization constants.
  53  */
  54 void
  55 MD5Init(MD5_CTX *ctx)
  56 {
  57         ctx->count = 0;
  58         ctx->state[0] = 0x67452301;
  59         ctx->state[1] = 0xefcdab89;
  60         ctx->state[2] = 0x98badcfe;
  61         ctx->state[3] = 0x10325476;
  62 }
  63
  64 /*
  65  * Update context to reflect the concatenation of another buffer full
  66  * of bytes.
  67  */
  68 void
  69 MD5Update(MD5_CTX *ctx, const unsigned char *input, size_t len)
  70 {
  71         size_t have, need;
  72
  73         /* Check how many bytes we already have and how many more we need. */
  74         have = (size_t)((ctx->count >> 3) & (MD5_BLOCK_LENGTH - 1));
  75         need = MD5_BLOCK_LENGTH - have;
  76
  77         /* Update bitcount */
  78         ctx->count += (u_int64_t)len << 3;
  79
  80         if (len >= need) {
  81                 if (have != 0) {
  82                         memcpy(ctx->buffer + have, input, need);
  83                         MD5Transform(ctx->state, ctx->buffer);
  84                         input += need;
  85                         len -= need;
  86                         have = 0;
  87                 }
  88
  89                 /* Process data in MD5_BLOCK_LENGTH-byte chunks. */
  90                 while (len >= MD5_BLOCK_LENGTH) {
  91                         MD5Transform(ctx->state, input);
  92                         input += MD5_BLOCK_LENGTH;
  93                         len -= MD5_BLOCK_LENGTH;
  94                 }
  95         }
  96
  97         /* Handle any remaining bytes of data. */
  98         if (len != 0)
  99                 memcpy(ctx->buffer + have, input, len);
 100 }
 101
 102 /*
 103  * Pad pad to 64-byte boundary with the bit pattern
 104  * 1 0* (64-bit count of bits processed, MSB-first)
 105  */
 106 void
 107 MD5Pad(MD5_CTX *ctx)
 108 {
 109         u_int8_t count[8];
 110         size_t padlen;
 111
 112         /* Convert count to 8 bytes in little endian order. */
 113         PUT_64BIT_LE(count, ctx->count);
 114
 115         /* Pad out to 56 mod 64. */
 116         padlen = MD5_BLOCK_LENGTH -
 117             ((ctx->count >> 3) & (MD5_BLOCK_LENGTH - 1));
 118         if (padlen < 1 + 8)
 119                 padlen += MD5_BLOCK_LENGTH;
 120         MD5Update(ctx, PADDING, padlen - 8);            /* padlen - 8 <= 64 */
 121         MD5Update(ctx, count, 8);
 122 }
 123
 124 /*
 125  * Final wrapup--call MD5Pad, fill in digest and zero out ctx.
 126  */
 127 void
 128 MD5Final(unsigned char digest[MD5_DIGEST_LENGTH], MD5_CTX *ctx)
 129 {
 130         int i;
 131
 132         MD5Pad(ctx);
 133         for (i = 0; i < 4; i++)
 134                 PUT_32BIT_LE(digest + i * 4, ctx->state[i]);
 135         memset(ctx, 0, sizeof(*ctx));
 136 }
 137
 138
 139 /* The four core functions - F1 is optimized somewhat */
 140
 141 /* #define F1(x, y, z) (x & y | ~x & z) */
 142 #define F1(x, y, z) (z ^ (x & (y ^ z)))
 143 #define F2(x, y, z) F1(z, x, y)
 144 #define F3(x, y, z) (x ^ y ^ z)
 145 #define F4(x, y, z) (y ^ (x | ~z))
 146
 147 /* This is the central step in the MD5 algorithm. */
 148 #define MD5STEP(f, w, x, y, z, data, s) \
 149         ( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
 150
 151 /*
 152  * The core of the MD5 algorithm, this alters an existing MD5 hash to
 153  * reflect the addition of 16 longwords of new data.  MD5Update blocks
 154  * the data and converts bytes into longwords for this routine.
 155  */
 156 void
 157 MD5Transform(u_int32_t state[4], const u_int8_t block[MD5_BLOCK_LENGTH])
 158 {
 159         u_int32_t a, b, c, d, in[MD5_BLOCK_LENGTH / 4];
 160
 161 #if BYTE_ORDER == LITTLE_ENDIAN
 162         memcpy(in, block, sizeof(in));
 163 #else
 164         for (a = 0; a < MD5_BLOCK_LENGTH / 4; a++) {
 165                 in[a] = (u_int32_t)(
 166                     (u_int32_t)(block[a * 4 + 0]) |
 167                     (u_int32_t)(block[a * 4 + 1]) <<  8 |
 168                     (u_int32_t)(block[a * 4 + 2]) << 16 |
 169                     (u_int32_t)(block[a * 4 + 3]) << 24);
 170         }
 171 #endif
 172
 173         a = state[0];
 174         b = state[1];
 175         c = state[2];
 176         d = state[3];
 177
 178         MD5STEP(F1, a, b, c, d, in[ 0] + 0xd76aa478,  7);
 179         MD5STEP(F1, d, a, b, c, in[ 1] + 0xe8c7b756, 12);
 180         MD5STEP(F1, c, d, a, b, in[ 2] + 0x242070db, 17);
 181         MD5STEP(F1, b, c, d, a, in[ 3] + 0xc1bdceee, 22);
 182         MD5STEP(F1, a, b, c, d, in[ 4] + 0xf57c0faf,  7);
 183         MD5STEP(F1, d, a, b, c, in[ 5] + 0x4787c62a, 12);
 184         MD5STEP(F1, c, d, a, b, in[ 6] + 0xa8304613, 17);
 185         MD5STEP(F1, b, c, d, a, in[ 7] + 0xfd469501, 22);
 186         MD5STEP(F1, a, b, c, d, in[ 8] + 0x698098d8,  7);
 187         MD5STEP(F1, d, a, b, c, in[ 9] + 0x8b44f7af, 12);
 188         MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
 189         MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
 190         MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122,  7);
 191         MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
 192         MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
 193         MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
 194
 195         MD5STEP(F2, a, b, c, d, in[ 1] + 0xf61e2562,  5);
 196         MD5STEP(F2, d, a, b, c, in[ 6] + 0xc040b340,  9);
 197         MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
 198         MD5STEP(F2, b, c, d, a, in[ 0] + 0xe9b6c7aa, 20);
 199         MD5STEP(F2, a, b, c, d, in[ 5] + 0xd62f105d,  5);
 200         MD5STEP(F2, d, a, b, c, in[10] + 0x02441453,  9);
 201         MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
 202         MD5STEP(F2, b, c, d, a, in[ 4] + 0xe7d3fbc8, 20);
 203         MD5STEP(F2, a, b, c, d, in[ 9] + 0x21e1cde6,  5);
 204         MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6,  9);
 205         MD5STEP(F2, c, d, a, b, in[ 3] + 0xf4d50d87, 14);
 206         MD5STEP(F2, b, c, d, a, in[ 8] + 0x455a14ed, 20);
 207         MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905,  5);
 208         MD5STEP(F2, d, a, b, c, in[ 2] + 0xfcefa3f8,  9);
 209         MD5STEP(F2, c, d, a, b, in[ 7] + 0x676f02d9, 14);
 210         MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
 211
 212         MD5STEP(F3, a, b, c, d, in[ 5] + 0xfffa3942,  4);
 213         MD5STEP(F3, d, a, b, c, in[ 8] + 0x8771f681, 11);
 214         MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 215         MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 216         MD5STEP(F3, a, b, c, d, in[ 1] + 0xa4beea44,  4);
 217         MD5STEP(F3, d, a, b, c, in[ 4] + 0x4bdecfa9, 11);
 218         MD5STEP(F3, c, d, a, b, in[ 7] + 0xf6bb4b60, 16);
 219         MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 220         MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6,  4);
 221         MD5STEP(F3, d, a, b, c, in[ 0] + 0xeaa127fa, 11);
 222         MD5STEP(F3, c, d, a, b, in[ 3] + 0xd4ef3085, 16);
 223         MD5STEP(F3, b, c, d, a, in[ 6] + 0x04881d05, 23);
 224         MD5STEP(F3, a, b, c, d, in[ 9] + 0xd9d4d039,  4);
 225         MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 226         MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 227         MD5STEP(F3, b, c, d, a, in[2 ] + 0xc4ac5665, 23);
 228
 229         MD5STEP(F4, a, b, c, d, in[ 0] + 0xf4292244,  6);
 230         MD5STEP(F4, d, a, b, c, in[7 ] + 0x432aff97, 10);
 231         MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 232         MD5STEP(F4, b, c, d, a, in[5 ] + 0xfc93a039, 21);
 233         MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3,  6);
 234         MD5STEP(F4, d, a, b, c, in[3 ] + 0x8f0ccc92, 10);
 235         MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 236         MD5STEP(F4, b, c, d, a, in[1 ] + 0x85845dd1, 21);
 237         MD5STEP(F4, a, b, c, d, in[8 ] + 0x6fa87e4f,  6);
 238         MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 239         MD5STEP(F4, c, d, a, b, in[6 ] + 0xa3014314, 15);
 240         MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 241         MD5STEP(F4, a, b, c, d, in[4 ] + 0xf7537e82,  6);
 242         MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 243         MD5STEP(F4, c, d, a, b, in[2 ] + 0x2ad7d2bb, 15);
 244         MD5STEP(F4, b, c, d, a, in[9 ] + 0xeb86d391, 21);
 245
 246         state[0] += a;
 247         state[1] += b;
 248         state[2] += c;
 249         state[3] += d;
 250 }
 251 #endif /* !WITH_OPENSSL */