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 static void Encode(unsigned char *, UINT4 *, unsigned int);
  50 static void Decode(UINT4 *, unsigned char *, unsigned int);
  51
  52 static unsigned char PADDING[64] = {
  53     0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  54     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
  55     0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
  56 };
  57
  58 /* F, G, H and I are basic MD5 functions. */
  59 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
  60 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
  61 #define H(x, y, z) ((x) ^ (y) ^ (z))
  62 #define I(x, y, z) ((y) ^ ((x) | (~z)))
  63
  64 /* ROTATE_LEFT rotates x left n bits. */
  65 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
  66
  67 /* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
  68    Rotation is separate from addition to prevent recomputation.
  69  */
  70 #define FF(a, b, c, d, x, s, ac) { \
  71      (a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
  72      (a) = ROTATE_LEFT ((a), (s)); \
  73      (a) += (b); \
  74     }
  75 #define GG(a, b, c, d, x, s, ac) { \
  76      (a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
  77      (a) = ROTATE_LEFT ((a), (s)); \
  78      (a) += (b); \
  79     }
  80 #define HH(a, b, c, d, x, s, ac) { \
  81      (a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
  82      (a) = ROTATE_LEFT ((a), (s)); \
  83      (a) += (b); \
  84     }
  85 #define II(a, b, c, d, x, s, ac) { \
  86      (a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
  87      (a) = ROTATE_LEFT ((a), (s)); \
  88      (a) += (b); \
  89     }
  90
  91
  92 /* MD5 initialization. Begins an MD5 operation, writing a new context. */
  93 void
  94 MD5Init(MD5_CTX *context)
  95 {
  96     context->count[0] = context->count[1] = 0;
  97     /* Load magic initialization constants. */
  98     context->state[0] = 0x67452301;
  99     context->state[1] = 0xefcdab89;
 100     context->state[2] = 0x98badcfe;
 101     context->state[3] = 0x10325476;
 102 }
 103
 104
 105 /* MD5 block update operation. Continues an MD5 message-digest
 106    operation, processing another message block, and updating the
 107    context.
 108  */
 109 void
 110 MD5Update(MD5_CTX *context, unsigned char *input, unsigned int inputLen)
 111 {
 112     unsigned int i, index, partLen;
 113
 114     /* Compute number of bytes mod 64 */
 115     index = (unsigned int)((context->count[0] >> 3) & 0x3F);
 116
 117     /* Update number of bits */
 118     if ((context->count[0] += ((UINT4)inputLen << 3))
 119         < ((UINT4)inputLen << 3))
 120         context->count[1]++;
 121     context->count[1] += ((UINT4)inputLen >> 29);
 122
 123     partLen = 64 - index;
 124
 125     /* Transform as many times as possible. */
 126     if (inputLen >= partLen) {
 127         memcpy((POINTER)&context->buffer[index], (POINTER)input, partLen);
 128         MD5Transform(context->state, context->buffer);
 129
 130         for (i = partLen; i + 63 < inputLen; i += 64)
 131             MD5Transform(context->state, &input[i]);
 132
 133         index = 0;
 134     }
 135     else
 136         i = 0;
 137
 138     /* Buffer remaining input */
 139     memcpy((POINTER)&context->buffer[index],
 140                (POINTER)&input[i], inputLen-i);
 141 }
 142
 143 /* MD5 finalization. Ends an MD5 message-digest operation, writing the
 144   the message digest and zeroing the context.
 145  */
 146 void
 147 MD5Final(unsigned char digest[16], MD5_CTX *context)
 148 {
 149     unsigned char bits[8];
 150     unsigned int index, padLen;
 151
 152     /* Save number of bits */
 153     Encode (bits, context->count, 8);
 154
 155     /* Pad out to 56 mod 64. */
 156     index = (unsigned int)((context->count[0] >> 3) & 0x3f);
 157     padLen = (index < 56) ? (56 - index) : (120 - index);
 158     MD5Update(context, PADDING, padLen);
 159
 160     /* Append length (before padding) */
 161     MD5Update(context, bits, 8);
 162
 163     /* Store state in digest */
 164     Encode(digest, context->state, 16);
 165
 166     /* Zeroize sensitive information. */
 167     memset((POINTER)context, 0, sizeof (*context));
 168 }
 169
 170
 171 /* MD5 basic transformation. Transforms state based on block. */
 172 static void
 173 MD5Transform(UINT4 state[4], unsigned char block[64])
 174 {
 175     UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
 176
 177     Decode (x, block, 64);
 178
 179     /* Round 1 */
 180     FF(a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
 181     FF(d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
 182     FF(c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
 183     FF(b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
 184     FF(a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
 185     FF(d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
 186     FF(c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
 187     FF(b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
 188     FF(a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
 189     FF(d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
 190     FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
 191     FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
 192     FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
 193     FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
 194     FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
 195     FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
 196
 197     /* Round 2 */
 198     GG(a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
 199     GG(d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
 200     GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
 201     GG(b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
 202     GG(a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
 203     GG(d, a, b, c, x[10], S22,  0x2441453); /* 22 */
 204     GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
 205     GG(b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
 206     GG(a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
 207     GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
 208     GG(c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
 209     GG(b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
 210     GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
 211     GG(d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
 212     GG(c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
 213     GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
 214
 215     /* Round 3 */
 216     HH(a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
 217     HH(d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
 218     HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
 219     HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
 220     HH(a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
 221     HH(d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
 222     HH(c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
 223     HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
 224     HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
 225     HH(d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
 226     HH(c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
 227     HH(b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
 228     HH(a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
 229     HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
 230     HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
 231     HH(b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
 232
 233     /* Round 4 */
 234     II(a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
 235     II(d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
 236     II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
 237     II(b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
 238     II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
 239     II(d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
 240     II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
 241     II(b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
 242     II(a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
 243     II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
 244     II(c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
 245     II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
 246     II(a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
 247     II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
 248     II(c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
 249     II(b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
 250
 251     state[0] += a;
 252     state[1] += b;
 253     state[2] += c;
 254     state[3] += d;
 255
 256     /* Zeroize sensitive information. */
 257     memset((POINTER)x, 0, sizeof (x));
 258 }
 259
 260
 261 /* Encodes input (UINT4) into output (unsigned char). Assumes len is
 262    a multiple of 4.
 263  */
 264 static void
 265 Encode(unsigned char *output, UINT4 *input, unsigned int len)
 266 {
 267     unsigned int i, j;
 268
 269     for (i = 0, j = 0; j < len; i++, j += 4) {
 270         output[j] = (unsigned char)(input[i] & 0xff);
 271         output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
 272         output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
 273         output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
 274     }
 275 }
 276
 277
 278 /* Decodes input (unsigned char) into output (UINT4). Assumes len is
 279    a multiple of 4.
 280  */
 281 static void
 282 Decode(UINT4 *output, unsigned char *input, unsigned int len)
 283 {
 284     unsigned int i, j;
 285
 286     for (i = 0, j = 0; j < len; i++, j += 4) {
 287         output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
 288             (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
 289     }
 290 }