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 <apt-pkg/md5.h>
  39 #include <apt-pkg/strutl.h>
  40
  41 #include <string.h>
  42 #include <unistd.h>
  43 #include <netinet/in.h>                          // For htonl
  44 #include <inttypes.h>
  45 #include <config.h>
  46 #include <system.h>
  47
  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 // MD5SumValue::MD5SumValue - Constructs the summation from a string    /*{{{*/
 170 // ---------------------------------------------------------------------
 171 /* The string form of a MD5 is a 32 character hex number */
 172 MD5SumValue::MD5SumValue(string Str)
 173 {
 174    memset(Sum,0,sizeof(Sum));
 175    Set(Str);
 176 }
 177                                                                         /*}}}*/
 178 // MD5SumValue::MD5SumValue - Default constructor                       /*{{{*/
 179 // ---------------------------------------------------------------------
 180 /* Sets the value to 0 */
 181 MD5SumValue::MD5SumValue()
 182 {
 183    memset(Sum,0,sizeof(Sum));
 184 }
 185                                                                         /*}}}*/
 186 // MD5SumValue::Set - Set the sum from a string                         /*{{{*/
 187 // ---------------------------------------------------------------------
 188 /* Converts the hex string into a set of chars */
 189 bool MD5SumValue::Set(string Str)
 190 {
 191    return Hex2Num(Str,Sum,sizeof(Sum));
 192 }
 193                                                                         /*}}}*/
 194 // MD5SumValue::Value - Convert the number into a string                /*{{{*/
 195 // ---------------------------------------------------------------------
 196 /* Converts the set of chars into a hex string in lower case */
 197 string MD5SumValue::Value() const
 198 {
 199    char Conv[16] = {'0','1','2','3','4','5','6','7','8','9','a','b',
 200                     'c','d','e','f'};
 201    char Result[33];
 202    Result[32] = 0;
 203
 204    // Convert each char into two letters
 205    int J = 0;
 206    int I = 0;
 207    for (; I != 32; J++, I += 2)
 208    {
 209       Result[I] = Conv[Sum[J] >> 4];
 210       Result[I + 1] = Conv[Sum[J] & 0xF];
 211    }
 212
 213    return string(Result);
 214 }
 215                                                                         /*}}}*/
 216 // MD5SumValue::operator == - Comparitor                                /*{{{*/
 217 // ---------------------------------------------------------------------
 218 /* Call memcmp on the buffer */
 219 bool MD5SumValue::operator ==(const MD5SumValue &rhs) const
 220 {
 221    return memcmp(Sum,rhs.Sum,sizeof(Sum)) == 0;
 222 }
 223                                                                         /*}}}*/
 224 // MD5Summation::MD5Summation - Initialize the summer                   /*{{{*/
 225 // ---------------------------------------------------------------------
 226 /* This assigns the deep magic initial values */
 227 MD5Summation::MD5Summation()
 228 {
 229    uint32_t *buf = (uint32_t *)Buf;
 230    uint32_t *bytes = (uint32_t *)Bytes;
 231
 232    buf[0] = 0x67452301;
 233    buf[1] = 0xefcdab89;
 234    buf[2] = 0x98badcfe;
 235    buf[3] = 0x10325476;
 236
 237    bytes[0] = 0;
 238    bytes[1] = 0;
 239    Done = false;
 240 }
 241                                                                         /*}}}*/
 242 // MD5Summation::Add - 'Add' a data set to the hash                     /*{{{*/
 243 // ---------------------------------------------------------------------
 244 /* */
 245 bool MD5Summation::Add(const unsigned char *data,unsigned long len)
 246 {
 247    if (Done == true)
 248       return false;
 249
 250    uint32_t *buf = (uint32_t *)Buf;
 251    uint32_t *bytes = (uint32_t *)Bytes;
 252    uint32_t *in = (uint32_t *)In;
 253
 254    // Update byte count and carry (this could be done with a long long?)
 255    uint32_t t = bytes[0];
 256    if ((bytes[0] = t + len) < t)
 257       bytes[1]++;
 258
 259    // Space available (at least 1)
 260    t = 64 - (t & 0x3f);
 261    if (t > len)
 262    {
 263       memcpy((unsigned char *)in + 64 - t,data,len);
 264       return true;
 265    }
 266
 267    // First chunk is an odd size
 268    memcpy((unsigned char *)in + 64 - t,data,t);
 269    byteSwap(in, 16);
 270    MD5Transform(buf,in);
 271    data += t;
 272    len -= t;
 273
 274    // Process data in 64-byte chunks
 275    while (len >= 64)
 276    {
 277       memcpy(in,data,64);
 278       byteSwap(in,16);
 279       MD5Transform(buf,in);
 280       data += 64;
 281       len -= 64;
 282    }
 283
 284    // Handle any remaining bytes of data.
 285    memcpy(in,data,len);
 286
 287    return true;
 288 }
 289                                                                         /*}}}*/
 290 // MD5Summation::AddFD - Add the contents of a FD to the hash           /*{{{*/
 291 // ---------------------------------------------------------------------
 292 /* */
 293 bool MD5Summation::AddFD(int Fd,unsigned long Size)
 294 {
 295    unsigned char Buf[64*64];
 296    int Res = 0;
 297    while (Size != 0)
 298    {
 299       Res = read(Fd,Buf,min(Size,(unsigned long)sizeof(Buf)));
 300       if (Res < 0 || (unsigned)Res != min(Size,(unsigned long)sizeof(Buf)))
 301          return false;
 302       Size -= Res;
 303       Add(Buf,Res);
 304    }
 305    return true;
 306 }
 307                                                                         /*}}}*/
 308 // MD5Summation::Result - Returns the value of the sum                  /*{{{*/
 309 // ---------------------------------------------------------------------
 310 /* Because this must add in the last bytes of the series it prevents anyone
 311    from calling add after. */
 312 MD5SumValue MD5Summation::Result()
 313 {
 314    uint32_t *buf = (uint32_t *)Buf;
 315    uint32_t *bytes = (uint32_t *)Bytes;
 316    uint32_t *in = (uint32_t *)In;
 317
 318    if (Done == false)
 319    {
 320       // Number of bytes in In
 321       int count = bytes[0] & 0x3f;
 322       unsigned char *p = (unsigned char *)in + count;
 323
 324       // Set the first char of padding to 0x80.  There is always room.
 325       *p++ = 0x80;
 326
 327       // Bytes of padding needed to make 56 bytes (-8..55)
 328       count = 56 - 1 - count;
 329
 330       // Padding forces an extra block
 331       if (count < 0)
 332       {
 333          memset(p,0,count + 8);
 334          byteSwap(in, 16);
 335          MD5Transform(buf,in);
 336          p = (unsigned char *)in;
 337          count = 56;
 338       }
 339
 340       memset(p, 0, count);
 341       byteSwap(in, 14);
 342
 343       // Append length in bits and transform
 344       in[14] = bytes[0] << 3;
 345       in[15] = bytes[1] << 3 | bytes[0] >> 29;
 346       MD5Transform(buf,in);
 347       byteSwap(buf,4);
 348       Done = true;
 349    }
 350
 351    MD5SumValue V;
 352    memcpy(V.Sum,buf,16);
 353    return V;
 354 }
 355                                                                         /*}}}*/