csu_util/MD5Sum.cc

   1 /*
   2  * Copyright (c) 2004 Max Bowsher
   3  *
   4  *     This program 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  *     A copy of the GNU General Public License can be found at
  10  *     http://www.gnu.org/
  11  *
  12  * Written by Max Bowsher
  13  */
  14
  15 #include "MD5Sum.h"
  16 #include <string>
  17 #include <sstream>
  18 #include <iostream>
  19 #include <iomanip>
  20 #include <stdexcept>
  21
  22 MD5Sum::MD5Sum(const MD5Sum& source)
  23 {
  24   *this = source;
  25 }
  26
  27 MD5Sum&
  28 MD5Sum::operator= (const MD5Sum& source)
  29 {
  30   state = source.state;
  31   memcpy(digest, source.digest, sizeof(digest));
  32   internalData = 0;
  33   if (source.internalData)
  34   {
  35     internalData = new gcry_md_hd_t;
  36     *internalData = *(source.internalData);
  37   }
  38   return *this;
  39 }
  40
  41 MD5Sum::~MD5Sum()
  42 {
  43   if (internalData) delete internalData;
  44 }
  45
  46 void
  47 MD5Sum::set(const unsigned char digest[16])
  48 {
  49   memcpy(this->digest, digest, sizeof(this->digest));
  50   state = Set;
  51   if (internalData) delete internalData;
  52 }
  53
  54 void
  55 MD5Sum::begin()
  56 {
  57   if (internalData) delete internalData;
  58   internalData = new gcry_md_hd_t;
  59   state = Accumulating;
  60   gcry_md_open(internalData, GCRY_MD_MD5, 0);
  61 }
  62
  63 void
  64 MD5Sum::append(const unsigned char* data, int nbytes)
  65 {
  66   if (!internalData)
  67     throw new std::logic_error("MD5Sum::append() called on an object not "
  68                                "in the 'Accumulating' state");
  69   gcry_md_write(*internalData, data, nbytes);
  70 }
  71
  72 void
  73 MD5Sum::finish()
  74 {
  75   if (!internalData)
  76     throw new std::logic_error("MD5Sum::finish() called on an object not "
  77                                "in the 'Accumulating' state");
  78   memcpy(digest, gcry_md_read(*internalData, GCRY_MD_MD5), 16);
  79   state = Set;
  80   delete internalData; internalData = 0;
  81 }
  82
  83 std::string
  84 MD5Sum::str() const
  85 {
  86   std::ostringstream hexdigest;
  87
  88   for (int i=0; i<16; ++i )
  89     hexdigest << std::hex << std::setfill('0') << std::setw(2)
  90               << static_cast<unsigned int>(digest[i]);
  91   return hexdigest.str();
  92 }
  93
  94 bool
  95 MD5Sum::operator == (const MD5Sum& other) const
  96 {
  97   if (state != Set || other.state != Set)
  98     throw new std::logic_error("MD5Sum comparison attempted on operands not "
  99                                "in the 'Set' state");
 100   return (memcmp(digest, other.digest, sizeof(digest)) == 0);
 101 }