Modules/md5c.c

   1 /* MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
   2  */
   3
   4 /* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
   5 rights reserved.
   6
   7 License to copy and use this software is granted provided that it
   8 is identified as the "RSA Data Security, Inc. MD5 Message-Digest
   9 Algorithm" in all material mentioning or referencing this software
  10 or this function.
  11
  12 License is also granted to make and use derivative works provided
  13 that such works are identified as "derived from the RSA Data
  14 Security, Inc. MD5 Message-Digest Algorithm" in all material
  15 mentioning or referencing the derived work.
  16
  17 RSA Data Security, Inc. makes no representations concerning either
  18 the merchantability of this software or the suitability of this
  19 software for any particular purpose. It is provided "as is"
  20 without express or implied warranty of any kind.
  21
  22 These notices must be retained in any copies of any part of this
  23 documentation and/or software.
  24  */
  25
  26 #include "Python.h"
  27 #include "md5.h"
  28
  29 /* Constants for MD5Transform routine. */
  30
  31 #define S11 7
  32 #define S12 12
  33 #define S13 17
  34 #define S14 22
  35 #define S21 5
  36 #define S22 9
  37 #define S23 14
  38 #define S24 20
  39 #define S31 4
  40 #define S32 11
  41 #define S33 16
  42 #define S34 23
  43 #define S41 6
  44 #define S42 10
  45 #define S43 15
  46 #define S44 21
  47
  48 static void MD5Transform(UINT4[4], unsigned char[64]);
  49
  50
  51 /* Encodes input (UINT4) into output (unsigned char). Assumes len is
  52    a multiple of 4.
  53  */
  54 static void
  55 Encode(unsigned char *output, UINT4 *input, unsigned int len)
  56 {
  57     unsigned int i, j;
  58
  59     for (i = 0, j = 0; j < len; i++, j += 4) {
  60         output[j] = (unsigned char)(input[i] & 0xff);
  61         output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
  62         output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
  63         output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
  64     }
  65 }
  66
  67
  68 /* Decodes input (unsigned char) into output (UINT4). Assumes len is
  69    a multiple of 4.
  70  */
  71 static void
  72 Decode(UINT4 *output, unsigned char *input, unsigned int len)
  73 {
  74     unsigned int i, j;
  75
  76     for (i = 0, j = 0; j < len; i++, j += 4) {
  77         output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
  78             (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
  79     }
  80 }
  81
  82
  83 static unsigned char PADDING[64] = {
  84     0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  85     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  86     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  87 };
  88
  89 /* F, G, H and I are basic MD5 functions. */
  90 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
  91 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
  92 #define H(x, y, z) ((x) ^ (y) ^ (z))
  93 #define I(x, y, z) ((y) ^ ((x) | (~z)))
  94
  95 /* ROTATE_LEFT rotates x left n bits. */
  96 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
  97
  98 /* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
  99    Rotation is separate from addition to prevent recomputation.
 100  */
 101 #define FF(a, b, c, d, x, s, ac) { \
 102      (a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
 103      (a) = ROTATE_LEFT ((a), (s)); \
 104      (a) += (b); \
 105     }
 106 #define GG(a, b, c, d, x, s, ac) { \
 107      (a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
 108      (a) = ROTATE_LEFT ((a), (s)); \
 109      (a) += (b); \
 110     }
 111 #define HH(a, b, c, d, x, s, ac) { \
 112      (a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
 113      (a) = ROTATE_LEFT ((a), (s)); \
 114      (a) += (b); \
 115     }
 116 #define II(a, b, c, d, x, s, ac) { \
 117      (a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
 118      (a) = ROTATE_LEFT ((a), (s)); \
 119      (a) += (b); \
 120     }
 121
 122
 123 /* MD5 initialization. Begins an MD5 operation, writing a new context. */
 124 void
 125 MD5Init(MD5_CTX *context)
 126 {
 127     context->count[0] = context->count[1] = 0;
 128     /* Load magic initialization constants. */
 129     context->state[0] = 0x67452301;
 130     context->state[1] = 0xefcdab89;
 131     context->state[2] = 0x98badcfe;
 132     context->state[3] = 0x10325476;
 133 }
 134
 135
 136 /* MD5 block update operation. Continues an MD5 message-digest
 137    operation, processing another message block, and updating the
 138    context.
 139  */
 140 void
 141 MD5Update(MD5_CTX *context, unsigned char *input, unsigned int inputLen)
 142 {
 143     unsigned int i, index, partLen;
 144
 145     /* Compute number of bytes mod 64 */
 146     index = (unsigned int)((context->count[0] >> 3) & 0x3F);
 147
 148     /* Update number of bits */
 149     if ((context->count[0] += ((UINT4)inputLen << 3))
 150         < ((UINT4)inputLen << 3))
 151         context->count[1]++;
 152     context->count[1] += ((UINT4)inputLen >> 29);
 153
 154     partLen = 64 - index;
 155
 156     /* Transform as many times as possible. */
 157     if (inputLen >= partLen) {
 158         memcpy((POINTER)&context->buffer[index], (POINTER)input, partLen);
 159         MD5Transform(context->state, context->buffer);
 160
 161         for (i = partLen; i + 63 < inputLen; i += 64)
 162             MD5Transform(context->state, &input[i]);
 163
 164         index = 0;
 165     }
 166     else
 167         i = 0;
 168
 169     /* Buffer remaining input */
 170     memcpy((POINTER)&context->buffer[index],
 171                (POINTER)&input[i], inputLen-i);
 172 }
 173
 174 /* MD5 finalization. Ends an MD5 message-digest operation, writing the
 175   message digest and zeroing the context.
 176  */
 177 void
 178 MD5Final(unsigned char digest[16], MD5_CTX *context)
 179 {
 180     unsigned char bits[8];
 181     unsigned int index, padLen;
 182
 183     /* Save number of bits */
 184     Encode (bits, context->count, 8);
 185
 186     /* Pad out to 56 mod 64. */
 187     index = (unsigned int)((context->count[0] >> 3) & 0x3f);
 188     padLen = (index < 56) ? (56 - index) : (120 - index);
 189     MD5Update(context, PADDING, padLen);
 190
 191     /* Append length (before padding) */
 192     MD5Update(context, bits, 8);
 193
 194     /* Store state in digest */
 195     Encode(digest, context->state, 16);
 196
 197     /* Zeroize sensitive information. */
 198     memset((POINTER)context, 0, sizeof (*context));
 199 }
 200
 201
 202 /* MD5 basic transformation. Transforms state based on block. */
 203 static void
 204 MD5Transform(UINT4 state[4], unsigned char block[64])
 205 {
 206     UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
 207
 208     Decode (x, block, 64);
 209
 210     /* Round 1 */
 211     FF(a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
 212     FF(d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
 213     FF(c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
 214     FF(b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
 215     FF(a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
 216     FF(d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
 217     FF(c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
 218     FF(b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
 219     FF(a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
 220     FF(d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
 221     FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
 222     FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
 223     FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
 224     FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
 225     FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
 226     FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
 227
 228     /* Round 2 */
 229     GG(a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
 230     GG(d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
 231     GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
 232     GG(b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
 233     GG(a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
 234     GG(d, a, b, c, x[10], S22,  0x2441453); /* 22 */
 235     GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
 236     GG(b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
 237     GG(a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
 238     GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
 239     GG(c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
 240     GG(b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
 241     GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
 242     GG(d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
 243     GG(c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
 244     GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
 245
 246     /* Round 3 */
 247     HH(a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
 248     HH(d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
 249     HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
 250     HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
 251     HH(a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
 252     HH(d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
 253     HH(c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
 254     HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
 255     HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
 256     HH(d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
 257     HH(c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
 258     HH(b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
 259     HH(a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
 260     HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
 261     HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
 262     HH(b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
 263
 264     /* Round 4 */
 265     II(a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
 266     II(d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
 267     II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
 268     II(b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
 269     II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
 270     II(d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
 271     II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
 272     II(b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
 273     II(a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
 274     II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
 275     II(c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
 276     II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
 277     II(a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
 278     II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
 279     II(c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
 280     II(b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
 281
 282     state[0] += a;
 283     state[1] += b;
 284     state[2] += c;
 285     state[3] += d;
 286
 287     /* Zeroize sensitive information. */
 288     memset((POINTER)x, 0, sizeof (x));
 289 }