drivers/filter/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
  18 /* This code was modified in 1997 by Jim Kingdon of Cyclic Software to
  19    not require an integer type which is exactly 32 bits.  This work
  20    draws on the changes for the same purpose by Tatu Ylonen
  21    <ylo@cs.hut.fi> as part of SSH, but since I didn't actually use
  22    that code, there is no copyright issue.  I hereby disclaim
  23    copyright in any changes I have made; this code remains in the
  24    public domain.  */
  25
  26 #ifdef TEST
  27 #include <stdlib.h>
  28 #endif
  29
  30 #include <string.h>     /* for memcpy() and memset() */
  31
  32 #include "md5.h"
  33
  34 /* Little-endian byte-swapping routines.  Note that these do not
  35    depend on the size of datatypes such as uint32, nor do they require
  36    us to detect the endianness of the machine we are running on.  It
  37    is possible they should be macros for speed, but I would be
  38    surprised if they were a performance bottleneck for MD5.  */
  39
  40 static uint32
  41 getu32 (const unsigned char *addr)
  42 {
  43         return (((((unsigned long)addr[3] << 8) | addr[2]) << 8)
  44                 | addr[1]) << 8 | addr[0];
  45 }
  46
  47 static void
  48 putu32 (uint32 data, unsigned char *addr)
  49 {
  50         addr[0] = (unsigned char)data;
  51         addr[1] = (unsigned char)(data >> 8);
  52         addr[2] = (unsigned char)(data >> 16);
  53         addr[3] = (unsigned char)(data >> 24);
  54 }
  55
  56 /*
  57  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
  58  * initialization constants.
  59  */
  60 void
  61 MD5Init (ctx)
  62      struct MD5Context *ctx;
  63 {
  64         ctx->buf[0] = 0x67452301;
  65         ctx->buf[1] = 0xefcdab89;
  66         ctx->buf[2] = 0x98badcfe;
  67         ctx->buf[3] = 0x10325476;
  68
  69         ctx->bits[0] = 0;
  70         ctx->bits[1] = 0;
  71 }
  72
  73 /*
  74  * Update context to reflect the concatenation of another buffer full
  75  * of bytes.
  76  */
  77 void
  78 MD5Update (ctx, buf, len)
  79      struct MD5Context *ctx;
  80      unsigned char const *buf;
  81      unsigned len;
  82 {
  83         uint32 t;
  84
  85         /* Update bitcount */
  86
  87         t = ctx->bits[0];
  88         if ((ctx->bits[0] = (t + ((uint32)len << 3)) & 0xffffffff) < t)
  89                 ctx->bits[1]++; /* Carry from low to high */
  90         ctx->bits[1] += len >> 29;
  91
  92         t = (t >> 3) & 0x3f;    /* Bytes already in shsInfo->data */
  93
  94         /* Handle any leading odd-sized chunks */
  95
  96         if ( t ) {
  97                 unsigned char *p = ctx->in + t;
  98
  99                 t = 64-t;
 100                 if (len < t) {
 101                         memcpy(p, buf, len);
 102                         return;
 103                 }
 104                 memcpy(p, buf, t);
 105                 MD5Transform (ctx->buf, ctx->in);
 106                 buf += t;
 107                 len -= t;
 108         }
 109
 110         /* Process data in 64-byte chunks */
 111
 112         while (len >= 64) {
 113                 memcpy(ctx->in, buf, 64);
 114                 MD5Transform (ctx->buf, ctx->in);
 115                 buf += 64;
 116                 len -= 64;
 117         }
 118
 119         /* Handle any remaining bytes of data. */
 120
 121         memcpy(ctx->in, buf, len);
 122 }
 123
 124 /*
 125  * Final wrapup - pad to 64-byte boundary with the bit pattern
 126  * 1 0* (64-bit count of bits processed, MSB-first)
 127  */
 128 void
 129 MD5Final (digest, ctx)
 130      unsigned char digest[16];
 131      struct MD5Context *ctx;
 132 {
 133         unsigned count;
 134         unsigned char *p;
 135
 136         /* Compute number of bytes mod 64 */
 137         count = (ctx->bits[0] >> 3) & 0x3F;
 138
 139         /* Set the first char of padding to 0x80.  This is safe since there is
 140            always at least one byte free */
 141         p = ctx->in + count;
 142         *p++ = 0x80;
 143
 144         /* Bytes of padding needed to make 64 bytes */
 145         count = 64 - 1 - count;
 146
 147         /* Pad out to 56 mod 64 */
 148         if (count < 8) {
 149                 /* Two lots of padding:  Pad the first block to 64 bytes */
 150                 memset(p, 0, count);
 151                 MD5Transform (ctx->buf, ctx->in);
 152
 153                 /* Now fill the next block with 56 bytes */
 154                 memset(ctx->in, 0, 56);
 155         } else {
 156                 /* Pad block to 56 bytes */
 157                 memset(p, 0, count-8);
 158         }
 159
 160         /* Append length in bits and transform */
 161         putu32(ctx->bits[0], ctx->in + 56);
 162         putu32(ctx->bits[1], ctx->in + 60);
 163
 164         MD5Transform (ctx->buf, ctx->in);
 165         putu32(ctx->buf[0], digest);
 166         putu32(ctx->buf[1], digest + 4);
 167         putu32(ctx->buf[2], digest + 8);
 168         putu32(ctx->buf[3], digest + 12);
 169         memset(ctx, 0, sizeof(*ctx));   /* In case it's sensitive */
 170 }
 171
 172 #ifndef ASM_MD5
 173
 174 /* The four core functions - F1 is optimized somewhat */
 175
 176 /* #define F1(x, y, z) (x & y | ~x & z) */
 177 #define F1(x, y, z) (z ^ (x & (y ^ z)))
 178 #define F2(x, y, z) F1(z, x, y)
 179 #define F3(x, y, z) (x ^ y ^ z)
 180 #define F4(x, y, z) (y ^ (x | ~z))
 181
 182 /* This is the central step in the MD5 algorithm. */
 183 #define MD5STEP(f, w, x, y, z, data, s) \
 184         ( w += f(x, y, z) + data, w &= 0xffffffff, w = w<<s | w>>(32-s), w += x )
 185
 186 /*
 187  * The core of the MD5 algorithm, this alters an existing MD5 hash to
 188  * reflect the addition of 16 longwords of new data.  MD5Update blocks
 189  * the data and converts bytes into longwords for this routine.
 190  */
 191 void
 192 MD5Transform (buf, inraw)
 193      uint32 buf[4];
 194      const unsigned char inraw[64];
 195 {
 196         register uint32 a, b, c, d;
 197         uint32 in[16];
 198         int i;
 199
 200         for (i = 0; i < 16; ++i)
 201                 in[i] = getu32 (inraw + 4 * i);
 202
 203         a = buf[0];
 204         b = buf[1];
 205         c = buf[2];
 206         d = buf[3];
 207
 208         MD5STEP(F1, a, b, c, d, in[ 0]+0xd76aa478,  7);
 209         MD5STEP(F1, d, a, b, c, in[ 1]+0xe8c7b756, 12);
 210         MD5STEP(F1, c, d, a, b, in[ 2]+0x242070db, 17);
 211         MD5STEP(F1, b, c, d, a, in[ 3]+0xc1bdceee, 22);
 212         MD5STEP(F1, a, b, c, d, in[ 4]+0xf57c0faf,  7);
 213         MD5STEP(F1, d, a, b, c, in[ 5]+0x4787c62a, 12);
 214         MD5STEP(F1, c, d, a, b, in[ 6]+0xa8304613, 17);
 215         MD5STEP(F1, b, c, d, a, in[ 7]+0xfd469501, 22);
 216         MD5STEP(F1, a, b, c, d, in[ 8]+0x698098d8,  7);
 217         MD5STEP(F1, d, a, b, c, in[ 9]+0x8b44f7af, 12);
 218         MD5STEP(F1, c, d, a, b, in[10]+0xffff5bb1, 17);
 219         MD5STEP(F1, b, c, d, a, in[11]+0x895cd7be, 22);
 220         MD5STEP(F1, a, b, c, d, in[12]+0x6b901122,  7);
 221         MD5STEP(F1, d, a, b, c, in[13]+0xfd987193, 12);
 222         MD5STEP(F1, c, d, a, b, in[14]+0xa679438e, 17);
 223         MD5STEP(F1, b, c, d, a, in[15]+0x49b40821, 22);
 224
 225         MD5STEP(F2, a, b, c, d, in[ 1]+0xf61e2562,  5);
 226         MD5STEP(F2, d, a, b, c, in[ 6]+0xc040b340,  9);
 227         MD5STEP(F2, c, d, a, b, in[11]+0x265e5a51, 14);
 228         MD5STEP(F2, b, c, d, a, in[ 0]+0xe9b6c7aa, 20);
 229         MD5STEP(F2, a, b, c, d, in[ 5]+0xd62f105d,  5);
 230         MD5STEP(F2, d, a, b, c, in[10]+0x02441453,  9);
 231         MD5STEP(F2, c, d, a, b, in[15]+0xd8a1e681, 14);
 232         MD5STEP(F2, b, c, d, a, in[ 4]+0xe7d3fbc8, 20);
 233         MD5STEP(F2, a, b, c, d, in[ 9]+0x21e1cde6,  5);
 234         MD5STEP(F2, d, a, b, c, in[14]+0xc33707d6,  9);
 235         MD5STEP(F2, c, d, a, b, in[ 3]+0xf4d50d87, 14);
 236         MD5STEP(F2, b, c, d, a, in[ 8]+0x455a14ed, 20);
 237         MD5STEP(F2, a, b, c, d, in[13]+0xa9e3e905,  5);
 238         MD5STEP(F2, d, a, b, c, in[ 2]+0xfcefa3f8,  9);
 239         MD5STEP(F2, c, d, a, b, in[ 7]+0x676f02d9, 14);
 240         MD5STEP(F2, b, c, d, a, in[12]+0x8d2a4c8a, 20);
 241
 242         MD5STEP(F3, a, b, c, d, in[ 5]+0xfffa3942,  4);
 243         MD5STEP(F3, d, a, b, c, in[ 8]+0x8771f681, 11);
 244         MD5STEP(F3, c, d, a, b, in[11]+0x6d9d6122, 16);
 245         MD5STEP(F3, b, c, d, a, in[14]+0xfde5380c, 23);
 246         MD5STEP(F3, a, b, c, d, in[ 1]+0xa4beea44,  4);
 247         MD5STEP(F3, d, a, b, c, in[ 4]+0x4bdecfa9, 11);
 248         MD5STEP(F3, c, d, a, b, in[ 7]+0xf6bb4b60, 16);
 249         MD5STEP(F3, b, c, d, a, in[10]+0xbebfbc70, 23);
 250         MD5STEP(F3, a, b, c, d, in[13]+0x289b7ec6,  4);
 251         MD5STEP(F3, d, a, b, c, in[ 0]+0xeaa127fa, 11);
 252         MD5STEP(F3, c, d, a, b, in[ 3]+0xd4ef3085, 16);
 253         MD5STEP(F3, b, c, d, a, in[ 6]+0x04881d05, 23);
 254         MD5STEP(F3, a, b, c, d, in[ 9]+0xd9d4d039,  4);
 255         MD5STEP(F3, d, a, b, c, in[12]+0xe6db99e5, 11);
 256         MD5STEP(F3, c, d, a, b, in[15]+0x1fa27cf8, 16);
 257         MD5STEP(F3, b, c, d, a, in[ 2]+0xc4ac5665, 23);
 258
 259         MD5STEP(F4, a, b, c, d, in[ 0]+0xf4292244,  6);
 260         MD5STEP(F4, d, a, b, c, in[ 7]+0x432aff97, 10);
 261         MD5STEP(F4, c, d, a, b, in[14]+0xab9423a7, 15);
 262         MD5STEP(F4, b, c, d, a, in[ 5]+0xfc93a039, 21);
 263         MD5STEP(F4, a, b, c, d, in[12]+0x655b59c3,  6);
 264         MD5STEP(F4, d, a, b, c, in[ 3]+0x8f0ccc92, 10);
 265         MD5STEP(F4, c, d, a, b, in[10]+0xffeff47d, 15);
 266         MD5STEP(F4, b, c, d, a, in[ 1]+0x85845dd1, 21);
 267         MD5STEP(F4, a, b, c, d, in[ 8]+0x6fa87e4f,  6);
 268         MD5STEP(F4, d, a, b, c, in[15]+0xfe2ce6e0, 10);
 269         MD5STEP(F4, c, d, a, b, in[ 6]+0xa3014314, 15);
 270         MD5STEP(F4, b, c, d, a, in[13]+0x4e0811a1, 21);
 271         MD5STEP(F4, a, b, c, d, in[ 4]+0xf7537e82,  6);
 272         MD5STEP(F4, d, a, b, c, in[11]+0xbd3af235, 10);
 273         MD5STEP(F4, c, d, a, b, in[ 2]+0x2ad7d2bb, 15);
 274         MD5STEP(F4, b, c, d, a, in[ 9]+0xeb86d391, 21);
 275
 276         buf[0] += a;
 277         buf[1] += b;
 278         buf[2] += c;
 279         buf[3] += d;
 280 }
 281 #endif
 282
 283 #ifdef TEST
 284 /* Simple test program.  Can use it to manually run the tests from
 285    RFC1321 for example.  */
 286 #include <stdio.h>
 287
 288 int
 289 main (int argc, char **argv)
 290 {
 291         struct MD5Context context;
 292         unsigned char checksum[16];
 293         int i;
 294         int j;
 295
 296         if (argc < 2)
 297         {
 298                 fprintf (stderr, "usage: %s string-to-hash\n", argv[0]);
 299                 exit (1);
 300         }
 301         for (j = 1; j < argc; ++j)
 302         {
 303                 printf ("MD5 (\"%s\") = ", argv[j]);
 304                 MD5Init (&context);
 305                 MD5Update (&context, (unsigned char *)argv[j], strlen (argv[j]));
 306                 MD5Final (checksum, &context);
 307                 for (i = 0; i < 16; i++)
 308                 {
 309                         printf ("%02x", (unsigned int) checksum[i]);
 310                 }
 311                 printf ("\n");
 312         }
 313         return 0;
 314 }
 315 #endif /* TEST */