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/* First example: Encrypts stdin to stdout using TWOFISH with 128 bit key and CFB */
#include <mcrypt.h>
#include <stdio.h>
#include <stdlib.h>
/* #include <mhash.h> */
main() {
MCRYPT td;
int i;
char *key;
char password[20];
char block_buffer;
char *IV;
int keysize=19; /* 128 bits */
key=calloc(1, keysize);
strcpy(password, "A_large_key");
/* Generate the key using the password */
/* mhash_keygen( KEYGEN_MCRYPT, MHASH_MD5, key, keysize, NULL, 0, password, strlen(password));
*/
memmove( key, password, strlen(password));
td = mcrypt_module_open("twofish", NULL, "cfb", NULL);
if (td==MCRYPT_FAILED) {
return 1;
}
IV = malloc(mcrypt_enc_get_iv_size(td));
/* Put random data in IV. Note these are not real random data,
* consider using /dev/random or /dev/urandom.
*/
/* srand(time(0)); */
for (i=0; i< mcrypt_enc_get_iv_size( td); i++) {
IV[i]=rand();
}
i=mcrypt_generic_init( td, key, keysize, IV);
if (i<0) {
mcrypt_perror(i);
return 1;
}
/* Encryption in CFB is performed in bytes */
while ( fread (&block_buffer, 1, 1, stdin) == 1 ) {
mcrypt_generic (td, &block_buffer, 1);
/* Comment above and uncomment this to decrypt */
/* mdecrypt_generic (td, &block_buffer, 1); */
fwrite ( &block_buffer, 1, 1, stdout);
}
mcrypt_generic_deinit(td);
mcrypt_module_close(td);
return 0;
}
#if 0
/* Second Example: encrypts using CBC and SAFER+ with 192 bits key */
#include <mcrypt.h>
#include <stdio.h>
#include <stdlib.h>
main() {
MCRYPT td;
int i;
char *key; /* created using mcrypt_gen_key */
char *block_buffer;
char *IV;
int blocksize;
int keysize = 24; /* 192 bits == 24 bytes */
key = calloc(1, keysize);
strcpy(key, "A_large_and_random_key");
td = mcrypt_module_open("saferplus", NULL, "cbc", NULL);
blocksize = mcrypt_enc_get_block_size(td);
block_buffer = malloc(blocksize);
/* but unfortunately this does not fill all the key so the rest bytes are
* padded with zeros. Try to use large keys or convert them with mcrypt_gen_key().
*/
IV=malloc(mcrypt_enc_get_iv_size(td));
/* Put random data in IV. Note these are not real random data,
* consider using /dev/random or /dev/urandom.
*/
/* srand(time(0)); */
for (i=0; i < mcrypt_enc_get_iv_size(td); i++) {
IV[i]=rand();
}
mcrypt_generic_init ( td key, keysize, IV);
/* Encryption in CBC is performed in blocks */
while ( fread (block_buffer, 1, blocksize, stdin) == blocksize ) {
mcrypt_generic (td, block_buffer, blocksize);
/* mdecrypt_generic (td, block_buffer, blocksize); */
fwrite ( block_buffer, 1, blocksize, stdout);
}
mcrypt_generic_end (td);
return 0;
}
#endif
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