common/hash_md5.c

   1 /*
   2  * This code implements the MD5 message-digest algorithm.
   3  * The algorithm is due to Ron Rivest.  This code was
   4  * written by Colin Plumb in 1993, no copyright is claimed.
   5  * This code is in the public domain; do with it what you wish.
   6  *
   7  * Equivalent code is available from RSA Data Security, Inc.
   8  * This code has been tested against that, and is equivalent,
   9  * except that you don't need to include two pages of legalese
  10  * with every copy.
  11  *
  12  * To compute the message digest of a chunk of bytes, declare an
  13  * MD5Context structure, pass it to MD5Init, call MD5Update as
  14  * needed on buffers full of bytes, and then call MD5Final, which
  15  * will fill a supplied 16-byte array with the digest.
  16  *
  17  * Changed so as no longer to depend on Colin Plumb's `usual.h' header
  18  * definitions; now uses stuff from dpkg's config.h.
  19  *  - Ian Jackson <ian@chiark.greenend.org.uk>.
  20  * Still in the public domain.
  21  */
  22
  23 #include "aiccu.h"
  24 #include "hash_md5.h"
  25
  26 #include <string.h>     /* for memcpy() */
  27 #include <sys/types.h>  /* for stupid systems */
  28
  29 #ifdef WORDS_BIGENDIAN
  30 void byteSwap(UWORD32 *buf, unsigned words);
  31 void byteSwap(UWORD32 *buf, unsigned words)
  32 {
  33         md5byte *p = (md5byte *)buf;
  34
  35         do {
  36                 *buf++ = (UWORD32)((unsigned)p[3] << 8 | p[2]) << 16 |
  37                         ((unsigned)p[1] << 8 | p[0]);
  38                 p += 4;
  39         } while (--words);
  40 }
  41 #else
  42 #define byteSwap(buf,words)
  43 #endif
  44
  45 /*
  46  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
  47  * initialization constants.
  48  */
  49 void
  50 MD5Init(struct MD5Context *ctx)
  51 {
  52         ctx->buf[0] = 0x67452301;
  53         ctx->buf[1] = 0xefcdab89;
  54         ctx->buf[2] = 0x98badcfe;
  55         ctx->buf[3] = 0x10325476;
  56
  57         ctx->bytes[0] = 0;
  58         ctx->bytes[1] = 0;
  59 }
  60
  61 /*
  62  * Update context to reflect the concatenation of another buffer full
  63  * of bytes.
  64  */
  65 void
  66 MD5Update(struct MD5Context *ctx, md5byte const *buf, unsigned len)
  67 {
  68         UWORD32 t;
  69
  70         /* Update byte count */
  71
  72         t = ctx->bytes[0];
  73         if ((ctx->bytes[0] = t + len) < t)
  74                 ctx->bytes[1]++;        /* Carry from low to high */
  75
  76         t = 64 - (t & 0x3f);    /* Space available in ctx->in (at least 1) */
  77         if (t > len) {
  78                 memcpy((md5byte *)ctx->in + 64 - t, buf, len);
  79                 return;
  80         }
  81         /* First chunk is an odd size */
  82         memcpy((md5byte *)ctx->in + 64 - t, buf, t);
  83         byteSwap(ctx->in, 16);
  84         MD5Transform(ctx->buf, ctx->in);
  85         buf += t;
  86         len -= t;
  87
  88         /* Process data in 64-byte chunks */
  89         while (len >= 64) {
  90                 memcpy(ctx->in, buf, 64);
  91                 byteSwap(ctx->in, 16);
  92                 MD5Transform(ctx->buf, ctx->in);
  93                 buf += 64;
  94                 len -= 64;
  95         }
  96
  97         /* Handle any remaining bytes of data. */
  98         memcpy(ctx->in, buf, len);
  99 }
 100
 101 /*
 102  * Final wrapup - pad to 64-byte boundary with the bit pattern
 103  * 1 0* (64-bit count of bits processed, MSB-first)
 104  */
 105 void
 106 MD5Final(md5byte digest[16], struct MD5Context *ctx)
 107 {
 108         int count = ctx->bytes[0] & 0x3f;       /* Number of bytes in ctx->in */
 109         md5byte *p = (md5byte *)ctx->in + count;
 110
 111         /* Set the first char of padding to 0x80.  There is always room. */
 112         *p++ = 0x80;
 113
 114         /* Bytes of padding needed to make 56 bytes (-8..55) */
 115         count = 56 - 1 - count;
 116
 117         if (count < 0) {        /* Padding forces an extra block */
 118                 memset(p, 0, count + 8);
 119                 byteSwap(ctx->in, 16);
 120                 MD5Transform(ctx->buf, ctx->in);
 121                 p = (md5byte *)ctx->in;
 122                 count = 56;
 123         }
 124         memset(p, 0, count);
 125         byteSwap(ctx->in, 14);
 126
 127         /* Append length in bits and transform */
 128         ctx->in[14] = ctx->bytes[0] << 3;
 129         ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
 130         MD5Transform(ctx->buf, ctx->in);
 131
 132         byteSwap(ctx->buf, 4);
 133         memcpy(digest, ctx->buf, 16);
 134         memset(ctx, 0, sizeof(ctx));    /* In case it's sensitive */
 135 }
 136
 137 #ifndef ASM_MD5
 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,in,s) \
 149          (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + 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(UWORD32 buf[4], UWORD32 const in[16])
 158 {
 159         register UWORD32 a, b, c, d;
 160
 161         a = buf[0];
 162         b = buf[1];
 163         c = buf[2];
 164         d = buf[3];
 165
 166         MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
 167         MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
 168         MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
 169         MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
 170         MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
 171         MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
 172         MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
 173         MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
 174         MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
 175         MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
 176         MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
 177         MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
 178         MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
 179         MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
 180         MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
 181         MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
 182
 183         MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
 184         MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
 185         MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
 186         MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
 187         MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
 188         MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
 189         MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
 190         MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
 191         MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
 192         MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
 193         MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
 194         MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
 195         MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
 196         MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
 197         MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
 198         MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
 199
 200         MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
 201         MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
 202         MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 203         MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 204         MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
 205         MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
 206         MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
 207         MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 208         MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
 209         MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
 210         MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
 211         MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
 212         MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
 213         MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 214         MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 215         MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
 216
 217         MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
 218         MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
 219         MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 220         MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
 221         MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
 222         MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
 223         MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 224         MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
 225         MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
 226         MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 227         MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
 228         MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 229         MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
 230         MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 231         MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
 232         MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
 233
 234         buf[0] += a;
 235         buf[1] += b;
 236         buf[2] += c;
 237         buf[3] += d;
 238 }
 239
 240 #endif