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
  42 #include <stdint.h>
  43 #include <string.h>
  44                                                                         /*}}}*/
  45
  46 // byteSwap - Swap bytes in a buffer                                    /*{{{*/
  47 // ---------------------------------------------------------------------
  48 /* Swap n 32 bit longs in given buffer */
  49 #ifdef WORDS_BIGENDIAN
  50 static void byteSwap(uint32_t *buf, unsigned words)
  51 {
  52    uint8_t *p = (uint8_t *)buf;
  53
  54    do
  55    {
  56       *buf++ = (uint32_t)((unsigned)p[3] << 8 | p[2]) << 16 |
  57          ((unsigned)p[1] << 8 | p[0]);
  58       p += 4;
  59    } while (--words);
  60 }
  61 #else
  62 #define byteSwap(buf,words)
  63 #endif
  64                                                                         /*}}}*/
  65 // MD5Transform - Alters an existing MD5 hash                           /*{{{*/
  66 // ---------------------------------------------------------------------
  67 /* The core of the MD5 algorithm, this alters an existing MD5 hash to
  68    reflect the addition of 16 longwords of new data. Add blocks
  69    the data and converts bytes into longwords for this routine. */
  70
  71 // The four core functions - F1 is optimized somewhat
  72 // #define F1(x, y, z) (x & y | ~x & z)
  73 #define F1(x, y, z) (z ^ (x & (y ^ z)))
  74 #define F2(x, y, z) F1(z, x, y)
  75 #define F3(x, y, z) (x ^ y ^ z)
  76 #define F4(x, y, z) (y ^ (x | ~z))
  77
  78 // This is the central step in the MD5 algorithm.
  79 #define MD5STEP(f,w,x,y,z,in,s) \
  80          (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
  81
  82 static void MD5Transform(uint32_t buf[4], uint32_t const in[16])
  83 {
  84    register uint32_t a, b, c, d;
  85
  86    a = buf[0];
  87    b = buf[1];
  88    c = buf[2];
  89    d = buf[3];
  90
  91    MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
  92    MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
  93    MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
  94    MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
  95    MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
  96    MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
  97    MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
  98    MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
  99    MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
 100    MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
 101    MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
 102    MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
 103    MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
 104    MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
 105    MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
 106    MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
 107
 108    MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
 109    MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
 110    MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
 111    MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
 112    MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
 113    MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
 114    MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
 115    MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
 116    MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
 117    MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
 118    MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
 119    MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
 120    MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
 121    MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
 122    MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
 123    MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
 124
 125    MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
 126    MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
 127    MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 128    MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 129    MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
 130    MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
 131    MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
 132    MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 133    MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
 134    MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
 135    MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
 136    MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
 137    MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
 138    MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 139    MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 140    MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
 141
 142    MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
 143    MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
 144    MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 145    MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
 146    MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
 147    MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
 148    MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 149    MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
 150    MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
 151    MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 152    MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
 153    MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 154    MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
 155    MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 156    MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
 157    MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
 158
 159    buf[0] += a;
 160    buf[1] += b;
 161    buf[2] += c;
 162    buf[3] += d;
 163 }
 164                                                                         /*}}}*/
 165 // MD5Summation::MD5Summation - Initialize the summer                   /*{{{*/
 166 // ---------------------------------------------------------------------
 167 /* This assigns the deep magic initial values */
 168 MD5Summation::MD5Summation()
 169 {
 170    uint32_t *buf = (uint32_t *)Buf;
 171    uint32_t *bytes = (uint32_t *)Bytes;
 172
 173    buf[0] = 0x67452301;
 174    buf[1] = 0xefcdab89;
 175    buf[2] = 0x98badcfe;
 176    buf[3] = 0x10325476;
 177
 178    bytes[0] = 0;
 179    bytes[1] = 0;
 180    Done = false;
 181 }
 182                                                                         /*}}}*/
 183 // MD5Summation::Add - 'Add' a data set to the hash                     /*{{{*/
 184 // ---------------------------------------------------------------------
 185 /* */
 186 bool MD5Summation::Add(const unsigned char *data,unsigned long long len)
 187 {
 188    if (Done == true)
 189       return false;
 190
 191    uint32_t *buf = (uint32_t *)Buf;
 192    uint32_t *bytes = (uint32_t *)Bytes;
 193    uint32_t *in = (uint32_t *)In;
 194
 195    // Update byte count and carry (this could be done with a long long?)
 196    uint32_t t = bytes[0];
 197    if ((bytes[0] = t + len) < t)
 198       bytes[1]++;
 199
 200    // Space available (at least 1)
 201    t = 64 - (t & 0x3f);
 202    if (t > len)
 203    {
 204       memcpy((unsigned char *)in + 64 - t,data,len);
 205       return true;
 206    }
 207
 208    // First chunk is an odd size
 209    memcpy((unsigned char *)in + 64 - t,data,t);
 210    byteSwap(in, 16);
 211    MD5Transform(buf,in);
 212    data += t;
 213    len -= t;
 214
 215    // Process data in 64-byte chunks
 216    while (len >= 64)
 217    {
 218       memcpy(in,data,64);
 219       byteSwap(in,16);
 220       MD5Transform(buf,in);
 221       data += 64;
 222       len -= 64;
 223    }
 224
 225    // Handle any remaining bytes of data.
 226    memcpy(in,data,len);
 227
 228    return true;
 229 }
 230                                                                         /*}}}*/
 231 // MD5Summation::Result - Returns the value of the sum                  /*{{{*/
 232 // ---------------------------------------------------------------------
 233 /* Because this must add in the last bytes of the series it prevents anyone
 234    from calling add after. */
 235 MD5SumValue MD5Summation::Result()
 236 {
 237    uint32_t *buf = (uint32_t *)Buf;
 238    uint32_t *bytes = (uint32_t *)Bytes;
 239    uint32_t *in = (uint32_t *)In;
 240
 241    if (Done == false)
 242    {
 243       // Number of bytes in In
 244       int count = bytes[0] & 0x3f;
 245       unsigned char *p = (unsigned char *)in + count;
 246
 247       // Set the first char of padding to 0x80.  There is always room.
 248       *p++ = 0x80;
 249
 250       // Bytes of padding needed to make 56 bytes (-8..55)
 251       count = 56 - 1 - count;
 252
 253       // Padding forces an extra block
 254       if (count < 0)
 255       {
 256          memset(p,0,count + 8);
 257          byteSwap(in, 16);
 258          MD5Transform(buf,in);
 259          p = (unsigned char *)in;
 260          count = 56;
 261       }
 262
 263       memset(p, 0, count);
 264       byteSwap(in, 14);
 265
 266       // Append length in bits and transform
 267       in[14] = bytes[0] << 3;
 268       in[15] = bytes[1] << 3 | bytes[0] >> 29;
 269       MD5Transform(buf,in);
 270       byteSwap(buf,4);
 271       Done = true;
 272    }
 273
 274    MD5SumValue V;
 275    V.Set((unsigned char *)buf);
 276    return V;
 277 }
 278                                                                         /*}}}*/