md5wrapper.cpp

/*
 * This is part of my wrapper-class to create
 * a MD5 Hash from a string and a file.
 *
 * This code is completly free, you
 * can copy it, modify it, or do
 * what ever you want with it.
 *
 * Feb. 2005
 * Benjamin Grüdelbach
 */

//----------------------------------------------------------------------
//basic includes
#include <fstream>
#include <iostream>

//my includes
#include "md5wrapper.h"
#include "md5.h"

//---------privates--------------------------

/*
 * internal hash function, calling
 * the basic methods from md5.h
 */
QString md5wrapper::hashit(QString text) {
  MD5_CTX ctx;

  //init md5
  md5->MD5Init(&ctx);
  //update with our string
  md5->MD5Update(&ctx,
                 (unsigned char *)text.toLatin1().data(),
                 text.length());

  //create the hash
  unsigned char buff[16] = "";
  md5->MD5Final((unsigned char *)buff, &ctx);

  //converte the hash to a string and return it
  return convToString(buff);
}

/*
 * converts the numeric hash to
 * a valid QString.
 * (based on Jim Howard's code;
 * http://www.codeproject.com/cpp/cmd5.asp)
 */
QString md5wrapper::convToString(unsigned char *bytes) {
  char asciihash[33];

  int p = 0;
  for(int i = 0; i < 16; i++) {
    ::sprintf(&asciihash[p], "%02x", bytes[i]);
    p += 2;
  }
  asciihash[32] = '\0';
  return QString(asciihash);
}

//---------publics--------------------------

//constructor
md5wrapper::md5wrapper() {
  md5 = new MD5();
}


//destructor
md5wrapper::~md5wrapper() {
  delete md5;
}

/*
 * creates a MD5 hash from
 * "text" and returns it as
 * string
 */
QString md5wrapper::getHashFromString(QString text) {
  return this->hashit(text);
}


/*
 * creates a MD5 hash from
 * a file specified in "filename" and
 * returns it as string
 * (based on Ronald L. Rivest's code
 * from RFC1321 "The MD5 Message-Digest Algorithm")
 */
QString md5wrapper::getHashFromFile(QString filename) {
  FILE *file;
  MD5_CTX context;

  int len;
  unsigned char buffer[1024], digest[16];

  //open file
  if((file = fopen(filename.toLatin1().data(), "rb")) == NULL) {
    return "-1";
  }

  //init md5
  md5->MD5Init(&context);

  //read the filecontent
  while((len = fread(buffer, 1, 1024, file))) {
    md5->MD5Update(&context, buffer, len);
  }

  /*
  generate hash, close the file and return the
  hash as QString
  */
  md5->MD5Final(digest, &context);
  fclose(file);
  return convToString(digest);
}

/*
 * EOF
 */