#include <stdio.h>
#include <QuickCrypt.h>
#define BUFF_SIZE 1024
/* performs Blowfish file encryption/decryption in Counter mode */
int EncryptDecryptFile( const char* filenamefrom, const char* filenameto, const unsigned char* iv, const unsigned char* key )
{
FILE *filefrom, *fileto;
unsigned char buff[ BUFF_SIZE ];
unsigned char context[ SLC_BLOWFISH_CONTEXTSIZE ];
/***** Open files ***********************/
filefrom = fopen( filenamefrom, "rb" );
if( filefrom == NULL )
{
printf( "\nCould not open file: %s", filenamefrom );
return 0;
}
fileto = fopen( filenameto, "wb" );
if( fileto == NULL )
{
printf( "\nCould not open file: %s", filenameto );
fclose( filefrom );
return 0;
}
/***** Initialize context ****************/
SL_BLOWFISH_Init( context, SLC_ENCRYPT, key, SLC_BLOWFISH_DEFAULTKEYSIZE );
SL_CTR_Init( context, iv );
/***** Encrypt/Decrypt file **************/
while( !feof( filefrom ) )
{
unsigned int buffsize = fread( buff, sizeof( char ), BUFF_SIZE, filefrom );
if( ferror( filefrom ) )
{
printf( "\nAn error occurred when accessing the file: %s", filenamefrom );
fclose( filefrom );
fclose( fileto );
return 0;
}
SL_CTR_Process( context, buff, buff, buffsize ); /* in-place encryption/decryption */
fwrite( buff, sizeof( char ), buffsize, fileto );
}
/***** Close files ***********************/
fclose( filefrom );
fclose( fileto );
return 1;
}
int main()
{
char buff[10];
char filename[256]; /* Initial file */
char filenameencr[256]; /* Encrypted file */
char filenamedecr[256]; /* Decrypted file */
/***** Define key & iv ********************************************************/
char key[SLC_BLOWFISH_DEFAULTKEYSIZE] =
{
's', 'e', 'c', 'r', 'e', 't', 'l', 'y',
'9', '6', '7', '1', '2', '9', '2', '7',
'0', '1', '2', '2', '0', '0', '5', '7',
'*', '-', '*', '-', '*', '-', '*', '-',
'9', '6', '7', '1', '2', '9', '2', '7',
'0', '1', '2', '2', '0', '0', '5', '7',
'*', '-', '*', '-', '*', '-', '*', '-'
};
unsigned char iv[SLC_BLOWFISH_BLOCKSIZE] =
{
0x41, 0x3E, 0xF0, 0xA1, 0xC6, 0x11, 0xE5, 0x50
};
do
{
/***** Get file to encrypt (Initial file) *********************************/
printf( "Enter the full name of the file to encrypt:\n" );
gets( filename );
/***** Get file to store the result of encryption (Encrypted file) ********/
printf( "Enter the full name of the file to store the result of encryption:\n" );
gets( filenameencr );
/***** Encrypt file *******************************************************/
if( EncryptDecryptFile( filename, filenameencr, iv, (const unsigned char*)key ) )
{
/***** Get file to store the result of decryption (Decrypted file) ****/
printf( "Enter the full name of the file to store the result of decryption:\n" );
gets( filenamedecr );
/***** Decrypt file ***************************************************/
EncryptDecryptFile( filenameencr, filenamedecr, iv, (const unsigned char*)key );
/* At this point compare Initial file with Decrypted file. They must be identical. */
}
/***** Continue? **********************************************************/
printf( "\nContinue (Y/N)?" );
gets( buff );
} while( *buff == 'Y' || *buff == 'y' );
return 0;
} |