apt-pkg/contrib/md5.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: md5.cc,v 1.12 2001/05/13 05:15:03 jgg Exp $
   4 /* ######################################################################
   5
   6    MD5Sum - MD5 Message Digest Algorithm.
   7
   8    This code implements the MD5 message-digest algorithm. The algorithm is
   9    due to Ron Rivest.  This code was written by Colin Plumb in 1993, no
  10    copyright is claimed. This code is in the public domain; do with it what
  11    you wish.
  12
  13    Equivalent code is available from RSA Data Security, Inc. This code has
  14    been tested against that, and is equivalent, except that you don't need to
  15    include two pages of legalese with every copy.
  16
  17    To compute the message digest of a chunk of bytes, instantiate the class,
  18    and repeatedly call one of the Add() members. When finished the Result
  19    method will return the Hash and finalize the value.
  20
  21    Changed so as no longer to depend on Colin Plumb's `usual.h' header
  22    definitions; now uses stuff from dpkg's config.h.
  23     - Ian Jackson <ijackson@nyx.cs.du.edu>.
  24
  25    Changed into a C++ interface and made work with APT's config.h.
  26     - Jason Gunthorpe <jgg@gpu.srv.ualberta.ca>
  27
  28    Still in the public domain.
  29
  30    The classes use arrays of char that are a specific size. We cast those
  31    arrays to uint8_t's and go from there. This allows us to advoid using
  32    the uncommon inttypes.h in a public header or internally newing memory.
  33    In theory if C9x becomes nicely accepted
  34
  35    ##################################################################### */
  36                                                                         /*}}}*/
  37 // Include Files                                                        /*{{{*/
  38 #include <config.h>
  39
  40 #include <apt-pkg/md5.h>
  41 #include <apt-pkg/strutl.h>
  42 #include <apt-pkg/macros.h>
  43
  44 #include <string.h>
  45 #include <unistd.h>
  46 #include <netinet/in.h>                          // For htonl
  47 #include <inttypes.h>
  48                                                                         /*}}}*/
  49
  50 // byteSwap - Swap bytes in a buffer                                    /*{{{*/
  51 // ---------------------------------------------------------------------
  52 /* Swap n 32 bit longs in given buffer */
  53 #ifdef WORDS_BIGENDIAN
  54 static void byteSwap(uint32_t *buf, unsigned words)
  55 {
  56    uint8_t *p = (uint8_t *)buf;
  57
  58    do
  59    {
  60       *buf++ = (uint32_t)((unsigned)p[3] << 8 | p[2]) << 16 |
  61          ((unsigned)p[1] << 8 | p[0]);
  62       p += 4;
  63    } while (--words);
  64 }
  65 #else
  66 #define byteSwap(buf,words)
  67 #endif
  68                                                                         /*}}}*/
  69 // MD5Transform - Alters an existing MD5 hash                           /*{{{*/
  70 // ---------------------------------------------------------------------
  71 /* The core of the MD5 algorithm, this alters an existing MD5 hash to
  72    reflect the addition of 16 longwords of new data. Add blocks
  73    the data and converts bytes into longwords for this routine. */
  74
  75 // The four core functions - F1 is optimized somewhat
  76 // #define F1(x, y, z) (x & y | ~x & z)
  77 #define F1(x, y, z) (z ^ (x & (y ^ z)))
  78 #define F2(x, y, z) F1(z, x, y)
  79 #define F3(x, y, z) (x ^ y ^ z)
  80 #define F4(x, y, z) (y ^ (x | ~z))
  81
  82 // This is the central step in the MD5 algorithm.
  83 #define MD5STEP(f,w,x,y,z,in,s) \
  84          (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
  85
  86 static void MD5Transform(uint32_t buf[4], uint32_t const in[16])
  87 {
  88    register uint32_t a, b, c, d;
  89
  90    a = buf[0];
  91    b = buf[1];
  92    c = buf[2];
  93    d = buf[3];
  94
  95    MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
  96    MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
  97    MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
  98    MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
  99    MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
 100    MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
 101    MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
 102    MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
 103    MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
 104    MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
 105    MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
 106    MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
 107    MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
 108    MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
 109    MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
 110    MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
 111
 112    MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
 113    MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
 114    MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
 115    MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
 116    MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
 117    MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
 118    MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
 119    MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
 120    MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
 121    MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
 122    MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
 123    MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
 124    MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
 125    MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
 126    MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
 127    MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
 128
 129    MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
 130    MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
 131    MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 132    MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 133    MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
 134    MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
 135    MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
 136    MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 137    MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
 138    MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
 139    MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
 140    MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
 141    MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
 142    MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 143    MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 144    MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
 145
 146    MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
 147    MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
 148    MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 149    MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
 150    MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
 151    MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
 152    MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 153    MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
 154    MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
 155    MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 156    MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
 157    MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 158    MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
 159    MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 160    MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
 161    MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
 162
 163    buf[0] += a;
 164    buf[1] += b;
 165    buf[2] += c;
 166    buf[3] += d;
 167 }
 168                                                                         /*}}}*/
 169 // MD5Summation::MD5Summation - Initialize the summer                   /*{{{*/
 170 // ---------------------------------------------------------------------
 171 /* This assigns the deep magic initial values */
 172 MD5Summation::MD5Summation()
 173 {
 174    uint32_t *buf = (uint32_t *)Buf;
 175    uint32_t *bytes = (uint32_t *)Bytes;
 176
 177    buf[0] = 0x67452301;
 178    buf[1] = 0xefcdab89;
 179    buf[2] = 0x98badcfe;
 180    buf[3] = 0x10325476;
 181
 182    bytes[0] = 0;
 183    bytes[1] = 0;
 184    Done = false;
 185 }
 186                                                                         /*}}}*/
 187 // MD5Summation::Add - 'Add' a data set to the hash                     /*{{{*/
 188 // ---------------------------------------------------------------------
 189 /* */
 190 bool MD5Summation::Add(const unsigned char *data,unsigned long len)
 191 {
 192    if (Done == true)
 193       return false;
 194
 195    uint32_t *buf = (uint32_t *)Buf;
 196    uint32_t *bytes = (uint32_t *)Bytes;
 197    uint32_t *in = (uint32_t *)In;
 198
 199    // Update byte count and carry (this could be done with a long long?)
 200    uint32_t t = bytes[0];
 201    if ((bytes[0] = t + len) < t)
 202       bytes[1]++;
 203
 204    // Space available (at least 1)
 205    t = 64 - (t & 0x3f);
 206    if (t > len)
 207    {
 208       memcpy((unsigned char *)in + 64 - t,data,len);
 209       return true;
 210    }
 211
 212    // First chunk is an odd size
 213    memcpy((unsigned char *)in + 64 - t,data,t);
 214    byteSwap(in, 16);
 215    MD5Transform(buf,in);
 216    data += t;
 217    len -= t;
 218
 219    // Process data in 64-byte chunks
 220    while (len >= 64)
 221    {
 222       memcpy(in,data,64);
 223       byteSwap(in,16);
 224       MD5Transform(buf,in);
 225       data += 64;
 226       len -= 64;
 227    }
 228
 229    // Handle any remaining bytes of data.
 230    memcpy(in,data,len);
 231
 232    return true;
 233 }
 234                                                                         /*}}}*/
 235 // MD5Summation::Result - Returns the value of the sum                  /*{{{*/
 236 // ---------------------------------------------------------------------
 237 /* Because this must add in the last bytes of the series it prevents anyone
 238    from calling add after. */
 239 MD5SumValue MD5Summation::Result()
 240 {
 241    uint32_t *buf = (uint32_t *)Buf;
 242    uint32_t *bytes = (uint32_t *)Bytes;
 243    uint32_t *in = (uint32_t *)In;
 244
 245    if (Done == false)
 246    {
 247       // Number of bytes in In
 248       int count = bytes[0] & 0x3f;
 249       unsigned char *p = (unsigned char *)in + count;
 250
 251       // Set the first char of padding to 0x80.  There is always room.
 252       *p++ = 0x80;
 253
 254       // Bytes of padding needed to make 56 bytes (-8..55)
 255       count = 56 - 1 - count;
 256
 257       // Padding forces an extra block
 258       if (count < 0)
 259       {
 260          memset(p,0,count + 8);
 261          byteSwap(in, 16);
 262          MD5Transform(buf,in);
 263          p = (unsigned char *)in;
 264          count = 56;
 265       }
 266
 267       memset(p, 0, count);
 268       byteSwap(in, 14);
 269
 270       // Append length in bits and transform
 271       in[14] = bytes[0] << 3;
 272       in[15] = bytes[1] << 3 | bytes[0] >> 29;
 273       MD5Transform(buf,in);
 274       byteSwap(buf,4);
 275       Done = true;
 276    }
 277
 278    MD5SumValue V;
 279    V.Set((unsigned char *)buf);
 280    return V;
 281 }
 282                                                                         /*}}}*/