apt-pkg/contrib/md5.cc

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: md5.cc,v 1.6 1999/10/31 06:32:28 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 #ifdef __GNUG__
  39 #pragma implementation "apt-pkg/md5.h"
  40 #endif
  41
  42 #include <apt-pkg/md5.h>
  43 #include <apt-pkg/strutl.h>
  44
  45 #include <string.h>
  46 #include <system.h>
  47 #include <unistd.h>
  48 #include <netinet/in.h>                          // For htonl
  49 #include <inttypes.h>
  50                                                                         /*}}}*/
  51
  52 // byteSwap - Swap bytes in a buffer                                    /*{{{*/
  53 // ---------------------------------------------------------------------
  54 /* Swap n 32 bit longs in given buffer */
  55 #ifdef WORDS_BIGENDIAN
  56 static void byteSwap(uint8_t *buf, unsigned words)
  57 {
  58    uint8_t *p = (uint8_t *)buf;
  59
  60    do
  61    {
  62       *buf++ = (UINT32)((unsigned)p[3] << 8 | p[2]) << 16 |
  63          ((unsigned)p[1] << 8 | p[0]);
  64       p += 4;
  65    } while (--words);
  66 }
  67 #else
  68 #define byteSwap(buf,words)
  69 #endif
  70                                                                         /*}}}*/
  71 // MD5Transform - Alters an existing MD5 hash                           /*{{{*/
  72 // ---------------------------------------------------------------------
  73 /* The core of the MD5 algorithm, this alters an existing MD5 hash to
  74    reflect the addition of 16 longwords of new data. Add blocks
  75    the data and converts bytes into longwords for this routine. */
  76
  77 // The four core functions - F1 is optimized somewhat
  78 // #define F1(x, y, z) (x & y | ~x & z)
  79 #define F1(x, y, z) (z ^ (x & (y ^ z)))
  80 #define F2(x, y, z) F1(z, x, y)
  81 #define F3(x, y, z) (x ^ y ^ z)
  82 #define F4(x, y, z) (y ^ (x | ~z))
  83
  84 // This is the central step in the MD5 algorithm.
  85 #define MD5STEP(f,w,x,y,z,in,s) \
  86          (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
  87
  88 static void MD5Transform(uint32_t buf[4], uint32_t const in[16])
  89 {
  90    register uint32_t a, b, c, d;
  91
  92    a = buf[0];
  93    b = buf[1];
  94    c = buf[2];
  95    d = buf[3];
  96
  97    MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
  98    MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
  99    MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
 100    MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
 101    MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
 102    MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
 103    MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
 104    MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
 105    MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
 106    MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
 107    MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
 108    MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
 109    MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
 110    MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
 111    MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
 112    MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
 113
 114    MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
 115    MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
 116    MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
 117    MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
 118    MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
 119    MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
 120    MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
 121    MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
 122    MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
 123    MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
 124    MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
 125    MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
 126    MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
 127    MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
 128    MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
 129    MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
 130
 131    MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
 132    MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
 133    MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 134    MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 135    MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
 136    MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
 137    MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
 138    MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 139    MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
 140    MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
 141    MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
 142    MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
 143    MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
 144    MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 145    MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 146    MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
 147
 148    MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
 149    MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
 150    MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 151    MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
 152    MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
 153    MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
 154    MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 155    MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
 156    MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
 157    MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 158    MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
 159    MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 160    MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
 161    MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 162    MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
 163    MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
 164
 165    buf[0] += a;
 166    buf[1] += b;
 167    buf[2] += c;
 168    buf[3] += d;
 169 }
 170                                                                         /*}}}*/
 171 // MD5SumValue::MD5SumValue - Constructs the summation from a string    /*{{{*/
 172 // ---------------------------------------------------------------------
 173 /* The string form of a MD5 is a 32 character hex number */
 174 MD5SumValue::MD5SumValue(string Str)
 175 {
 176    memset(Sum,0,sizeof(Sum));
 177    Set(Str);
 178 }
 179                                                                         /*}}}*/
 180 // MD5SumValue::MD5SumValue - Default constructor                       /*{{{*/
 181 // ---------------------------------------------------------------------
 182 /* Sets the value to 0 */
 183 MD5SumValue::MD5SumValue()
 184 {
 185    memset(Sum,0,sizeof(Sum));
 186 }
 187                                                                         /*}}}*/
 188 // MD5SumValue::Set - Set the sum from a string                         /*{{{*/
 189 // ---------------------------------------------------------------------
 190 /* Converts the hex string into a set of chars */
 191 bool MD5SumValue::Set(string Str)
 192 {
 193    return Hex2Num(Str.begin(),Str.end(),Sum,sizeof(Sum));
 194 }
 195                                                                         /*}}}*/
 196 // MD5SumValue::Value - Convert the number into a string                /*{{{*/
 197 // ---------------------------------------------------------------------
 198 /* Converts the set of chars into a hex string in lower case */
 199 string MD5SumValue::Value() const
 200 {
 201    char Conv[16] = {'0','1','2','3','4','5','6','7','8','9','a','b',
 202                     'c','d','e','f'};
 203    char Result[33];
 204    Result[32] = 0;
 205
 206    // Convert each char into two letters
 207    int J = 0;
 208    int I = 0;
 209    for (; I != 32; J++, I += 2)
 210    {
 211       Result[I] = Conv[Sum[J] >> 4];
 212       Result[I + 1] = Conv[Sum[J] & 0xF];
 213    }
 214
 215    return string(Result);
 216 }
 217                                                                         /*}}}*/
 218 // MD5SumValue::operator == - Comparitor                                /*{{{*/
 219 // ---------------------------------------------------------------------
 220 /* Call memcmp on the buffer */
 221 bool MD5SumValue::operator ==(const MD5SumValue &rhs) const
 222 {
 223    return memcmp(Sum,rhs.Sum,sizeof(Sum)) == 0;
 224 }
 225                                                                         /*}}}*/
 226 // MD5Summation::MD5Summation - Initialize the summer                   /*{{{*/
 227 // ---------------------------------------------------------------------
 228 /* This assigns the deep magic initial values */
 229 MD5Summation::MD5Summation()
 230 {
 231    uint32_t *buf = (uint32_t *)Buf;
 232    uint32_t *bytes = (uint32_t *)Bytes;
 233
 234    buf[0] = 0x67452301;
 235    buf[1] = 0xefcdab89;
 236    buf[2] = 0x98badcfe;
 237    buf[3] = 0x10325476;
 238
 239    bytes[0] = 0;
 240    bytes[1] = 0;
 241    Done = false;
 242 }
 243                                                                         /*}}}*/
 244 // MD5Summation::Add - 'Add' a data set to the hash                     /*{{{*/
 245 // ---------------------------------------------------------------------
 246 /* */
 247 bool MD5Summation::Add(const unsigned char *data,unsigned long len)
 248 {
 249    if (Done == true)
 250       return false;
 251
 252    uint32_t *buf = (uint32_t *)Buf;
 253    uint32_t *bytes = (uint32_t *)Bytes;
 254    uint32_t *in = (uint32_t *)In;
 255
 256    // Update byte count and carry (this could be done with a long long?)
 257    uint32_t t = bytes[0];
 258    if ((bytes[0] = t + len) < t)
 259       bytes[1]++;
 260
 261    // Space available (at least 1)
 262    t = 64 - (t & 0x3f);
 263    if (t > len)
 264    {
 265       memcpy((unsigned char *)in + 64 - t,data,len);
 266       return true;
 267    }
 268
 269    // First chunk is an odd size
 270    memcpy((unsigned char *)in + 64 - t,data,t);
 271    byteSwap(in, 16);
 272    MD5Transform(buf,in);
 273    data += t;
 274    len -= t;
 275
 276    // Process data in 64-byte chunks
 277    while (len >= 64)
 278    {
 279       memcpy(in,data,64);
 280       byteSwap(in,16);
 281       MD5Transform(buf,in);
 282       data += 64;
 283       len -= 64;
 284    }
 285
 286    // Handle any remaining bytes of data.
 287    memcpy(in,data,len);
 288
 289    return true;
 290 }
 291                                                                         /*}}}*/
 292 // MD5Summation::AddFD - Add the contents of a FD to the hash           /*{{{*/
 293 // ---------------------------------------------------------------------
 294 /* */
 295 bool MD5Summation::AddFD(int Fd,unsigned long Size)
 296 {
 297    unsigned char Buf[64*64];
 298    int Res = 0;
 299    while (Size != 0)
 300    {
 301       Res = read(Fd,Buf,MIN(Size,sizeof(Buf)));
 302       if (Res < 0 || (unsigned)Res != MIN(Size,sizeof(Buf)))
 303          return false;
 304       Size -= Res;
 305       Add(Buf,Res);
 306    }
 307    return true;
 308 }
 309                                                                         /*}}}*/
 310 // MD5Summation::Result - Returns the value of the sum                  /*{{{*/
 311 // ---------------------------------------------------------------------
 312 /* Because this must add in the last bytes of the series it prevents anyone
 313    from calling add after. */
 314 MD5SumValue MD5Summation::Result()
 315 {
 316    uint32_t *buf = (uint32_t *)Buf;
 317    uint32_t *bytes = (uint32_t *)Bytes;
 318    uint32_t *in = (uint32_t *)In;
 319
 320    if (Done == false)
 321    {
 322       // Number of bytes in In
 323       int count = bytes[0] & 0x3f;
 324       unsigned char *p = (unsigned char *)in + count;
 325
 326       // Set the first char of padding to 0x80.  There is always room.
 327       *p++ = 0x80;
 328
 329       // Bytes of padding needed to make 56 bytes (-8..55)
 330       count = 56 - 1 - count;
 331
 332       // Padding forces an extra block
 333       if (count < 0)
 334       {
 335          memset(p,0,count + 8);
 336          byteSwap(in, 16);
 337          MD5Transform(buf,in);
 338          p = (unsigned char *)in;
 339          count = 56;
 340       }
 341
 342       memset(p, 0, count);
 343       byteSwap(in, 14);
 344
 345       // Append length in bits and transform
 346       in[14] = bytes[0] << 3;
 347       in[15] = bytes[1] << 3 | bytes[0] >> 29;
 348       MD5Transform(buf,in);
 349       byteSwap(buf,4);
 350       Done = true;
 351    }
 352
 353    MD5SumValue V;
 354    memcpy(V.Sum,buf,16);
 355    return V;
 356 }
 357                                                                         /*}}}*/