src/backend/libpq/md5.c

   1 /*
   2  *      md5.c
   3  *
   4  *      Implements      the  MD5 Message-Digest Algorithm as specified in
   5  *      RFC  1321.      This  implementation  is a simple one, in that it
   6  *      needs  every  input  byte  to  be  buffered  before doing any
   7  *      calculations.  I  do  not  expect  this  file  to be used for
   8  *      general  purpose  MD5'ing  of large amounts of data, only for
   9  *      generating hashed passwords from limited input.
  10  *
  11  *      Sverre H. Huseby <sverrehu@online.no>
  12  *
  13  *      Portions Copyright (c) 1996-2009, PostgreSQL Global Development Group
  14  *      Portions Copyright (c) 1994, Regents of the University of California
  15  *
  16  * IDENTIFICATION
  17  *        $PostgreSQL$
  18  */
  19
  20 /* This is intended to be used in both frontend and backend, so use c.h */
  21 #include "c.h"
  22
  23 #include "libpq/md5.h"
  24
  25
  26 /*
  27  *      PRIVATE FUNCTIONS
  28  */
  29
  30
  31 /*
  32  *      The returned array is allocated using malloc.  the caller should free it
  33  *      when it is no longer needed.
  34  */
  35 static uint8 *
  36 createPaddedCopyWithLength(uint8 *b, uint32 *l)
  37 {
  38         uint8      *ret;
  39         uint32          q;
  40         uint32          len,
  41                                 newLen448;
  42         uint32          len_high,
  43                                 len_low;                /* 64-bit value split into 32-bit sections */
  44
  45         len = ((b == NULL) ? 0 : *l);
  46         newLen448 = len + 64 - (len % 64) - 8;
  47         if (newLen448 <= len)
  48                 newLen448 += 64;
  49
  50         *l = newLen448 + 8;
  51         if ((ret = (uint8 *) malloc(sizeof(uint8) * *l)) == NULL)
  52                 return NULL;
  53
  54         if (b != NULL)
  55                 memcpy(ret, b, sizeof(uint8) * len);
  56
  57         /* pad */
  58         ret[len] = 0x80;
  59         for (q = len + 1; q < newLen448; q++)
  60                 ret[q] = 0x00;
  61
  62         /* append length as a 64 bit bitcount */
  63         len_low = len;
  64         /* split into two 32-bit values */
  65         /* we only look at the bottom 32-bits */
  66         len_high = len >> 29;
  67         len_low <<= 3;
  68         q = newLen448;
  69         ret[q++] = (len_low & 0xff);
  70         len_low >>= 8;
  71         ret[q++] = (len_low & 0xff);
  72         len_low >>= 8;
  73         ret[q++] = (len_low & 0xff);
  74         len_low >>= 8;
  75         ret[q++] = (len_low & 0xff);
  76         ret[q++] = (len_high & 0xff);
  77         len_high >>= 8;
  78         ret[q++] = (len_high & 0xff);
  79         len_high >>= 8;
  80         ret[q++] = (len_high & 0xff);
  81         len_high >>= 8;
  82         ret[q] = (len_high & 0xff);
  83
  84         return ret;
  85 }
  86
  87 #define F(x, y, z) (((x) & (y)) | (~(x) & (z)))
  88 #define G(x, y, z) (((x) & (z)) | ((y) & ~(z)))
  89 #define H(x, y, z) ((x) ^ (y) ^ (z))
  90 #define I(x, y, z) ((y) ^ ((x) | ~(z)))
  91 #define ROT_LEFT(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
  92
  93 static void
  94 doTheRounds(uint32 X[16], uint32 state[4])
  95 {
  96         uint32          a,
  97                                 b,
  98                                 c,
  99                                 d;
 100
 101         a = state[0];
 102         b = state[1];
 103         c = state[2];
 104         d = state[3];
 105
 106         /* round 1 */
 107         a = b + ROT_LEFT((a + F(b, c, d) + X[0] + 0xd76aa478), 7);      /* 1 */
 108         d = a + ROT_LEFT((d + F(a, b, c) + X[1] + 0xe8c7b756), 12); /* 2 */
 109         c = d + ROT_LEFT((c + F(d, a, b) + X[2] + 0x242070db), 17); /* 3 */
 110         b = c + ROT_LEFT((b + F(c, d, a) + X[3] + 0xc1bdceee), 22); /* 4 */
 111         a = b + ROT_LEFT((a + F(b, c, d) + X[4] + 0xf57c0faf), 7);      /* 5 */
 112         d = a + ROT_LEFT((d + F(a, b, c) + X[5] + 0x4787c62a), 12); /* 6 */
 113         c = d + ROT_LEFT((c + F(d, a, b) + X[6] + 0xa8304613), 17); /* 7 */
 114         b = c + ROT_LEFT((b + F(c, d, a) + X[7] + 0xfd469501), 22); /* 8 */
 115         a = b + ROT_LEFT((a + F(b, c, d) + X[8] + 0x698098d8), 7);      /* 9 */
 116         d = a + ROT_LEFT((d + F(a, b, c) + X[9] + 0x8b44f7af), 12); /* 10 */
 117         c = d + ROT_LEFT((c + F(d, a, b) + X[10] + 0xffff5bb1), 17);            /* 11 */
 118         b = c + ROT_LEFT((b + F(c, d, a) + X[11] + 0x895cd7be), 22);            /* 12 */
 119         a = b + ROT_LEFT((a + F(b, c, d) + X[12] + 0x6b901122), 7); /* 13 */
 120         d = a + ROT_LEFT((d + F(a, b, c) + X[13] + 0xfd987193), 12);            /* 14 */
 121         c = d + ROT_LEFT((c + F(d, a, b) + X[14] + 0xa679438e), 17);            /* 15 */
 122         b = c + ROT_LEFT((b + F(c, d, a) + X[15] + 0x49b40821), 22);            /* 16 */
 123
 124         /* round 2 */
 125         a = b + ROT_LEFT((a + G(b, c, d) + X[1] + 0xf61e2562), 5);      /* 17 */
 126         d = a + ROT_LEFT((d + G(a, b, c) + X[6] + 0xc040b340), 9);      /* 18 */
 127         c = d + ROT_LEFT((c + G(d, a, b) + X[11] + 0x265e5a51), 14);            /* 19 */
 128         b = c + ROT_LEFT((b + G(c, d, a) + X[0] + 0xe9b6c7aa), 20); /* 20 */
 129         a = b + ROT_LEFT((a + G(b, c, d) + X[5] + 0xd62f105d), 5);      /* 21 */
 130         d = a + ROT_LEFT((d + G(a, b, c) + X[10] + 0x02441453), 9); /* 22 */
 131         c = d + ROT_LEFT((c + G(d, a, b) + X[15] + 0xd8a1e681), 14);            /* 23 */
 132         b = c + ROT_LEFT((b + G(c, d, a) + X[4] + 0xe7d3fbc8), 20); /* 24 */
 133         a = b + ROT_LEFT((a + G(b, c, d) + X[9] + 0x21e1cde6), 5);      /* 25 */
 134         d = a + ROT_LEFT((d + G(a, b, c) + X[14] + 0xc33707d6), 9); /* 26 */
 135         c = d + ROT_LEFT((c + G(d, a, b) + X[3] + 0xf4d50d87), 14); /* 27 */
 136         b = c + ROT_LEFT((b + G(c, d, a) + X[8] + 0x455a14ed), 20); /* 28 */
 137         a = b + ROT_LEFT((a + G(b, c, d) + X[13] + 0xa9e3e905), 5); /* 29 */
 138         d = a + ROT_LEFT((d + G(a, b, c) + X[2] + 0xfcefa3f8), 9);      /* 30 */
 139         c = d + ROT_LEFT((c + G(d, a, b) + X[7] + 0x676f02d9), 14); /* 31 */
 140         b = c + ROT_LEFT((b + G(c, d, a) + X[12] + 0x8d2a4c8a), 20);            /* 32 */
 141
 142         /* round 3 */
 143         a = b + ROT_LEFT((a + H(b, c, d) + X[5] + 0xfffa3942), 4);      /* 33 */
 144         d = a + ROT_LEFT((d + H(a, b, c) + X[8] + 0x8771f681), 11); /* 34 */
 145         c = d + ROT_LEFT((c + H(d, a, b) + X[11] + 0x6d9d6122), 16);            /* 35 */
 146         b = c + ROT_LEFT((b + H(c, d, a) + X[14] + 0xfde5380c), 23);            /* 36 */
 147         a = b + ROT_LEFT((a + H(b, c, d) + X[1] + 0xa4beea44), 4);      /* 37 */
 148         d = a + ROT_LEFT((d + H(a, b, c) + X[4] + 0x4bdecfa9), 11); /* 38 */
 149         c = d + ROT_LEFT((c + H(d, a, b) + X[7] + 0xf6bb4b60), 16); /* 39 */
 150         b = c + ROT_LEFT((b + H(c, d, a) + X[10] + 0xbebfbc70), 23);            /* 40 */
 151         a = b + ROT_LEFT((a + H(b, c, d) + X[13] + 0x289b7ec6), 4); /* 41 */
 152         d = a + ROT_LEFT((d + H(a, b, c) + X[0] + 0xeaa127fa), 11); /* 42 */
 153         c = d + ROT_LEFT((c + H(d, a, b) + X[3] + 0xd4ef3085), 16); /* 43 */
 154         b = c + ROT_LEFT((b + H(c, d, a) + X[6] + 0x04881d05), 23); /* 44 */
 155         a = b + ROT_LEFT((a + H(b, c, d) + X[9] + 0xd9d4d039), 4);      /* 45 */
 156         d = a + ROT_LEFT((d + H(a, b, c) + X[12] + 0xe6db99e5), 11);            /* 46 */
 157         c = d + ROT_LEFT((c + H(d, a, b) + X[15] + 0x1fa27cf8), 16);            /* 47 */
 158         b = c + ROT_LEFT((b + H(c, d, a) + X[2] + 0xc4ac5665), 23); /* 48 */
 159
 160         /* round 4 */
 161         a = b + ROT_LEFT((a + I(b, c, d) + X[0] + 0xf4292244), 6);      /* 49 */
 162         d = a + ROT_LEFT((d + I(a, b, c) + X[7] + 0x432aff97), 10); /* 50 */
 163         c = d + ROT_LEFT((c + I(d, a, b) + X[14] + 0xab9423a7), 15);            /* 51 */
 164         b = c + ROT_LEFT((b + I(c, d, a) + X[5] + 0xfc93a039), 21); /* 52 */
 165         a = b + ROT_LEFT((a + I(b, c, d) + X[12] + 0x655b59c3), 6); /* 53 */
 166         d = a + ROT_LEFT((d + I(a, b, c) + X[3] + 0x8f0ccc92), 10); /* 54 */
 167         c = d + ROT_LEFT((c + I(d, a, b) + X[10] + 0xffeff47d), 15);            /* 55 */
 168         b = c + ROT_LEFT((b + I(c, d, a) + X[1] + 0x85845dd1), 21); /* 56 */
 169         a = b + ROT_LEFT((a + I(b, c, d) + X[8] + 0x6fa87e4f), 6);      /* 57 */
 170         d = a + ROT_LEFT((d + I(a, b, c) + X[15] + 0xfe2ce6e0), 10);            /* 58 */
 171         c = d + ROT_LEFT((c + I(d, a, b) + X[6] + 0xa3014314), 15); /* 59 */
 172         b = c + ROT_LEFT((b + I(c, d, a) + X[13] + 0x4e0811a1), 21);            /* 60 */
 173         a = b + ROT_LEFT((a + I(b, c, d) + X[4] + 0xf7537e82), 6);      /* 61 */
 174         d = a + ROT_LEFT((d + I(a, b, c) + X[11] + 0xbd3af235), 10);            /* 62 */
 175         c = d + ROT_LEFT((c + I(d, a, b) + X[2] + 0x2ad7d2bb), 15); /* 63 */
 176         b = c + ROT_LEFT((b + I(c, d, a) + X[9] + 0xeb86d391), 21); /* 64 */
 177
 178         state[0] += a;
 179         state[1] += b;
 180         state[2] += c;
 181         state[3] += d;
 182 }
 183
 184 static int
 185 calculateDigestFromBuffer(uint8 *b, uint32 len, uint8 sum[16])
 186 {
 187         register uint32 i,
 188                                 j,
 189                                 k,
 190                                 newI;
 191         uint32          l;
 192         uint8      *input;
 193         register uint32 *wbp;
 194         uint32          workBuff[16],
 195                                 state[4];
 196
 197         l = len;
 198
 199         state[0] = 0x67452301;
 200         state[1] = 0xEFCDAB89;
 201         state[2] = 0x98BADCFE;
 202         state[3] = 0x10325476;
 203
 204         if ((input = createPaddedCopyWithLength(b, &l)) == NULL)
 205                 return 0;
 206
 207         for (i = 0;;)
 208         {
 209                 if ((newI = i + 16 * 4) > l)
 210                         break;
 211                 k = i + 3;
 212                 for (j = 0; j < 16; j++)
 213                 {
 214                         wbp = (workBuff + j);
 215                         *wbp = input[k--];
 216                         *wbp <<= 8;
 217                         *wbp |= input[k--];
 218                         *wbp <<= 8;
 219                         *wbp |= input[k--];
 220                         *wbp <<= 8;
 221                         *wbp |= input[k];
 222                         k += 7;
 223                 }
 224                 doTheRounds(workBuff, state);
 225                 i = newI;
 226         }
 227         free(input);
 228
 229         j = 0;
 230         for (i = 0; i < 4; i++)
 231         {
 232                 k = state[i];
 233                 sum[j++] = (k & 0xff);
 234                 k >>= 8;
 235                 sum[j++] = (k & 0xff);
 236                 k >>= 8;
 237                 sum[j++] = (k & 0xff);
 238                 k >>= 8;
 239                 sum[j++] = (k & 0xff);
 240         }
 241         return 1;
 242 }
 243
 244 static void
 245 bytesToHex(uint8 b[16], char *s)
 246 {
 247         static const char *hex = "0123456789abcdef";
 248         int                     q,
 249                                 w;
 250
 251         for (q = 0, w = 0; q < 16; q++)
 252         {
 253                 s[w++] = hex[(b[q] >> 4) & 0x0F];
 254                 s[w++] = hex[b[q] & 0x0F];
 255         }
 256         s[w] = '\0';
 257 }
 258
 259 /*
 260  *      PUBLIC FUNCTIONS
 261  */
 262
 263 /*
 264  *      pg_md5_hash
 265  *
 266  *      Calculates the MD5 sum of the bytes in a buffer.
 267  *
 268  *      SYNOPSIS          #include "md5.h"
 269  *                                int pg_md5_hash(const void *buff, size_t len, char *hexsum)
 270  *
 271  *      INPUT             buff    the buffer containing the bytes that you want
 272  *                                                the MD5 sum of.
 273  *                                len     number of bytes in the buffer.
 274  *
 275  *      OUTPUT            hexsum  the MD5 sum as a '\0'-terminated string of
 276  *                                                hexadecimal digits.  an MD5 sum is 16 bytes long.
 277  *                                                each byte is represented by two heaxadecimal
 278  *                                                characters.  you thus need to provide an array
 279  *                                                of 33 characters, including the trailing '\0'.
 280  *
 281  *      RETURNS           false on failure (out of memory for internal buffers) or
 282  *                                true on success.
 283  *
 284  *      STANDARDS         MD5 is described in RFC 1321.
 285  *
 286  *      AUTHOR            Sverre H. Huseby <sverrehu@online.no>
 287  *
 288  */
 289 bool
 290 pg_md5_hash(const void *buff, size_t len, char *hexsum)
 291 {
 292         uint8           sum[16];
 293
 294         if (!calculateDigestFromBuffer((uint8 *) buff, len, sum))
 295                 return false;
 296
 297         bytesToHex(sum, hexsum);
 298         return true;
 299 }
 300
 301
 302
 303 /*
 304  * Computes MD5 checksum of "passwd" (a null-terminated string) followed
 305  * by "salt" (which need not be null-terminated).
 306  *
 307  * Output format is "md5" followed by a 32-hex-digit MD5 checksum.
 308  * Hence, the output buffer "buf" must be at least 36 bytes long.
 309  *
 310  * Returns TRUE if okay, FALSE on error (out of memory).
 311  */
 312 bool
 313 pg_md5_encrypt(const char *passwd, const char *salt, size_t salt_len,
 314                            char *buf)
 315 {
 316         size_t          passwd_len = strlen(passwd);
 317         char       *crypt_buf = malloc(passwd_len + salt_len);
 318         bool            ret;
 319
 320         if (!crypt_buf)
 321                 return false;
 322
 323         /*
 324          * Place salt at the end because it may be known by users trying to crack
 325          * the MD5 output.
 326          */
 327         strcpy(crypt_buf, passwd);
 328         memcpy(crypt_buf + passwd_len, salt, salt_len);
 329
 330         strcpy(buf, "md5");
 331         ret = pg_md5_hash(crypt_buf, passwd_len + salt_len, buf + 3);
 332
 333         free(crypt_buf);
 334
 335         return ret;
 336 }