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 #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 <unistd.h>
  47 #include <netinet/in.h>                          // For htonl
  48 #include <inttypes.h>
  49 #include <config.h>
  50 #include <system.h>
  51                                                                         /*}}}*/
  52
  53 // byteSwap - Swap bytes in a buffer                                    /*{{{*/
  54 // ---------------------------------------------------------------------
  55 /* Swap n 32 bit longs in given buffer */
  56 #ifdef WORDS_BIGENDIAN
  57 static void byteSwap(uint32_t *buf, unsigned words)
  58 {
  59    uint8_t *p = (uint8_t *)buf;
  60
  61    do
  62    {
  63       *buf++ = (uint32_t)((unsigned)p[3] << 8 | p[2]) << 16 |
  64          ((unsigned)p[1] << 8 | p[0]);
  65       p += 4;
  66    } while (--words);
  67 }
  68 #else
  69 #define byteSwap(buf,words)
  70 #endif
  71                                                                         /*}}}*/
  72 // MD5Transform - Alters an existing MD5 hash                           /*{{{*/
  73 // ---------------------------------------------------------------------
  74 /* The core of the MD5 algorithm, this alters an existing MD5 hash to
  75    reflect the addition of 16 longwords of new data. Add blocks
  76    the data and converts bytes into longwords for this routine. */
  77
  78 // The four core functions - F1 is optimized somewhat
  79 // #define F1(x, y, z) (x & y | ~x & z)
  80 #define F1(x, y, z) (z ^ (x & (y ^ z)))
  81 #define F2(x, y, z) F1(z, x, y)
  82 #define F3(x, y, z) (x ^ y ^ z)
  83 #define F4(x, y, z) (y ^ (x | ~z))
  84
  85 // This is the central step in the MD5 algorithm.
  86 #define MD5STEP(f,w,x,y,z,in,s) \
  87          (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
  88
  89 static void MD5Transform(uint32_t buf[4], uint32_t const in[16])
  90 {
  91    register uint32_t a, b, c, d;
  92
  93    a = buf[0];
  94    b = buf[1];
  95    c = buf[2];
  96    d = buf[3];
  97
  98    MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
  99    MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
 100    MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
 101    MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
 102    MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
 103    MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
 104    MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
 105    MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
 106    MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
 107    MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
 108    MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
 109    MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
 110    MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
 111    MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
 112    MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
 113    MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
 114
 115    MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
 116    MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
 117    MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
 118    MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
 119    MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
 120    MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
 121    MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
 122    MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
 123    MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
 124    MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
 125    MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
 126    MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
 127    MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
 128    MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
 129    MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
 130    MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
 131
 132    MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
 133    MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
 134    MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
 135    MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
 136    MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
 137    MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
 138    MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
 139    MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
 140    MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
 141    MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
 142    MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
 143    MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
 144    MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
 145    MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
 146    MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
 147    MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
 148
 149    MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
 150    MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
 151    MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
 152    MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
 153    MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
 154    MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
 155    MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
 156    MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
 157    MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
 158    MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
 159    MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
 160    MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
 161    MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
 162    MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
 163    MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
 164    MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
 165
 166    buf[0] += a;
 167    buf[1] += b;
 168    buf[2] += c;
 169    buf[3] += d;
 170 }
 171                                                                         /*}}}*/
 172 // MD5SumValue::MD5SumValue - Constructs the summation from a string    /*{{{*/
 173 // ---------------------------------------------------------------------
 174 /* The string form of a MD5 is a 32 character hex number */
 175 MD5SumValue::MD5SumValue(string Str)
 176 {
 177    memset(Sum,0,sizeof(Sum));
 178    Set(Str);
 179 }
 180                                                                         /*}}}*/
 181 // MD5SumValue::MD5SumValue - Default constructor                       /*{{{*/
 182 // ---------------------------------------------------------------------
 183 /* Sets the value to 0 */
 184 MD5SumValue::MD5SumValue()
 185 {
 186    memset(Sum,0,sizeof(Sum));
 187 }
 188                                                                         /*}}}*/
 189 // MD5SumValue::Set - Set the sum from a string                         /*{{{*/
 190 // ---------------------------------------------------------------------
 191 /* Converts the hex string into a set of chars */
 192 bool MD5SumValue::Set(string Str)
 193 {
 194    return Hex2Num(Str,Sum,sizeof(Sum));
 195 }
 196                                                                         /*}}}*/
 197 // MD5SumValue::Value - Convert the number into a string                /*{{{*/
 198 // ---------------------------------------------------------------------
 199 /* Converts the set of chars into a hex string in lower case */
 200 string MD5SumValue::Value() const
 201 {
 202    char Conv[16] = {'0','1','2','3','4','5','6','7','8','9','a','b',
 203                     'c','d','e','f'};
 204    char Result[33];
 205    Result[32] = 0;
 206
 207    // Convert each char into two letters
 208    int J = 0;
 209    int I = 0;
 210    for (; I != 32; J++, I += 2)
 211    {
 212       Result[I] = Conv[Sum[J] >> 4];
 213       Result[I + 1] = Conv[Sum[J] & 0xF];
 214    }
 215
 216    return string(Result);
 217 }
 218                                                                         /*}}}*/
 219 // MD5SumValue::operator == - Comparitor                                /*{{{*/
 220 // ---------------------------------------------------------------------
 221 /* Call memcmp on the buffer */
 222 bool MD5SumValue::operator ==(const MD5SumValue &rhs) const
 223 {
 224    return memcmp(Sum,rhs.Sum,sizeof(Sum)) == 0;
 225 }
 226                                                                         /*}}}*/
 227 // MD5Summation::MD5Summation - Initialize the summer                   /*{{{*/
 228 // ---------------------------------------------------------------------
 229 /* This assigns the deep magic initial values */
 230 MD5Summation::MD5Summation()
 231 {
 232    uint32_t *buf = (uint32_t *)Buf;
 233    uint32_t *bytes = (uint32_t *)Bytes;
 234
 235    buf[0] = 0x67452301;
 236    buf[1] = 0xefcdab89;
 237    buf[2] = 0x98badcfe;
 238    buf[3] = 0x10325476;
 239
 240    bytes[0] = 0;
 241    bytes[1] = 0;
 242    Done = false;
 243 }
 244                                                                         /*}}}*/
 245 // MD5Summation::Add - 'Add' a data set to the hash                     /*{{{*/
 246 // ---------------------------------------------------------------------
 247 /* */
 248 bool MD5Summation::Add(const unsigned char *data,unsigned long len)
 249 {
 250    if (Done == true)
 251       return false;
 252
 253    uint32_t *buf = (uint32_t *)Buf;
 254    uint32_t *bytes = (uint32_t *)Bytes;
 255    uint32_t *in = (uint32_t *)In;
 256
 257    // Update byte count and carry (this could be done with a long long?)
 258    uint32_t t = bytes[0];
 259    if ((bytes[0] = t + len) < t)
 260       bytes[1]++;
 261
 262    // Space available (at least 1)
 263    t = 64 - (t & 0x3f);
 264    if (t > len)
 265    {
 266       memcpy((unsigned char *)in + 64 - t,data,len);
 267       return true;
 268    }
 269
 270    // First chunk is an odd size
 271    memcpy((unsigned char *)in + 64 - t,data,t);
 272    byteSwap(in, 16);
 273    MD5Transform(buf,in);
 274    data += t;
 275    len -= t;
 276
 277    // Process data in 64-byte chunks
 278    while (len >= 64)
 279    {
 280       memcpy(in,data,64);
 281       byteSwap(in,16);
 282       MD5Transform(buf,in);
 283       data += 64;
 284       len -= 64;
 285    }
 286
 287    // Handle any remaining bytes of data.
 288    memcpy(in,data,len);
 289
 290    return true;
 291 }
 292                                                                         /*}}}*/
 293 // MD5Summation::AddFD - Add the contents of a FD to the hash           /*{{{*/
 294 // ---------------------------------------------------------------------
 295 /* */
 296 bool MD5Summation::AddFD(int Fd,unsigned long Size)
 297 {
 298    unsigned char Buf[64*64];
 299    int Res = 0;
 300    while (Size != 0)
 301    {
 302       Res = read(Fd,Buf,min(Size,(unsigned long)sizeof(Buf)));
 303       if (Res < 0 || (unsigned)Res != min(Size,(unsigned long)sizeof(Buf)))
 304          return false;
 305       Size -= Res;
 306       Add(Buf,Res);
 307    }
 308    return true;
 309 }
 310                                                                         /*}}}*/
 311 // MD5Summation::Result - Returns the value of the sum                  /*{{{*/
 312 // ---------------------------------------------------------------------
 313 /* Because this must add in the last bytes of the series it prevents anyone
 314    from calling add after. */
 315 MD5SumValue MD5Summation::Result()
 316 {
 317    uint32_t *buf = (uint32_t *)Buf;
 318    uint32_t *bytes = (uint32_t *)Bytes;
 319    uint32_t *in = (uint32_t *)In;
 320
 321    if (Done == false)
 322    {
 323       // Number of bytes in In
 324       int count = bytes[0] & 0x3f;
 325       unsigned char *p = (unsigned char *)in + count;
 326
 327       // Set the first char of padding to 0x80.  There is always room.
 328       *p++ = 0x80;
 329
 330       // Bytes of padding needed to make 56 bytes (-8..55)
 331       count = 56 - 1 - count;
 332
 333       // Padding forces an extra block
 334       if (count < 0)
 335       {
 336          memset(p,0,count + 8);
 337          byteSwap(in, 16);
 338          MD5Transform(buf,in);
 339          p = (unsigned char *)in;
 340          count = 56;
 341       }
 342
 343       memset(p, 0, count);
 344       byteSwap(in, 14);
 345
 346       // Append length in bits and transform
 347       in[14] = bytes[0] << 3;
 348       in[15] = bytes[1] << 3 | bytes[0] >> 29;
 349       MD5Transform(buf,in);
 350       byteSwap(buf,4);
 351       Done = true;
 352    }
 353
 354    MD5SumValue V;
 355    memcpy(V.Sum,buf,16);
 356    return V;
 357 }
 358                                                                         /*}}}*/