source/maths/MD5.h

   1 /* Copyright (C) 2010 Wildfire Games.
   2  * This file is part of 0 A.D.
   3  *
   4  * 0 A.D. is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * 0 A.D. is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with 0 A.D.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #ifndef INCLUDED_MD5
  19 #define INCLUDED_MD5
  20
  21 #include <cstring>
  22
  23 /**
  24  * MD5 hashing algorithm. Note that MD5 is broken and must not be used for
  25  * anything that requires security.
  26  */
  27 class MD5
  28 {
  29 public:
  30         static const size_t DIGESTSIZE = 16;
  31
  32         MD5();
  33
  34         void Update(const u8* data, size_t len)
  35         {
  36                 // (Defined inline for efficiency in the common fixed-length fits-in-buffer case)
  37
  38                 const size_t CHUNK_SIZE = sizeof(m_Buf);
  39
  40                 m_InputLen += len;
  41
  42                 // If we have enough space in m_Buf and won't flush, simply append the input
  43                 if (m_BufLen + len < CHUNK_SIZE)
  44                 {
  45                         memcpy(m_Buf + m_BufLen, data, len);
  46                         m_BufLen += len;
  47                         return;
  48                 }
  49
  50                 // Fall back to non-inline function if we have to do more work
  51                 UpdateRest(data, len);
  52         }
  53
  54         void Final(u8* digest);
  55
  56 private:
  57         void InitState();
  58         void UpdateRest(const u8* data, size_t len);
  59         void Transform(const u32* in);
  60         u32 m_Digest[4]; // internal state
  61         u8 m_Buf[64]; // buffered input bytes
  62         size_t m_BufLen; // bytes in m_Buf that are valid
  63         u64 m_InputLen; // bytes
  64 };
  65
  66 #endif // INCLUDED_MD5