int main(void)
{
int i;
AES_KEY key;
BIO* bio_out;
unsigned char key_data[KEY_SIZE] = {
0xfe, 0xec, 0x82, 0x17, 0xb5, 0x1, 0x98, 0x6b,
0x5e, 0xf1, 0xb8, 0x6, 0x52, 0x74, 0x2e, 0x52
};
unsigned char iv[AES_BLOCK_SIZE];
unsigned char const iv_data[AES_BLOCK_SIZE] = {
0x10, 0x8a, 0xc9, 0x30, 0xb7, 0xf2, 0x35, 0x21,
0xfb, 0xac, 0x6b, 0xdf, 0x80, 0x95, 0xeb, 0x1e
};
char* data = "The worthwhile problems are the ones you can "
"really solve or help solve, the ones you can "
"really contribute something to. No "
"problem is too small or too trivial if we "
"can really do something about it."
"- Richard Feynman";
int length = (int) strlen(data);
/* Initialize how far we've gone through the IV */
int num = 0;
/* Allocate some space for the ciphertext and plaintext */
char* ciphertext = (char*) malloc(sizeof(char) * length);
char* plaintext = (char*) malloc(sizeof(char) * length);
/* Copy the IV data to the IV array */
memcpy(iv, iv_data, AES_BLOCK_SIZE);
/* Set the encrypt key structure using the predefined key */
AES_set_encrypt_key(key_data, KEY_SIZE * 8, &key);
/* Carry out the encryption */
/* Note: For CFB-1, the length of the data needs to be specified in bits. */
/* Hence, the length is multiplied by 8 before being passed to the call */
AES_cfb1_encrypt(data, ciphertext, length * 8, &key, iv, &num, AES_ENCRYPT);
/* Setup output */
bio_out = BIO_new_fp(stdout, BIO_NOCLOSE);
BIO_printf(bio_out, "Original plaintext: %s\n\n", data);
BIO_printf(bio_out, "Ciphertext: ");
/* Print out the ciphertext */
for (i = 0; i < length; i++)
BIO_printf(bio_out, "%02x", ((unsigned char*)ciphertext)[i]);
BIO_printf(bio_out, "\n\n");
/* Start the decryption process */
/* First, copy the original IV data back to the IV array - as it was overwritten
* during the encryption process
*/
memcpy(iv, iv_data, AES_BLOCK_SIZE);
/* Reset how far we've gone through the IV */
num = 0;
/* Note: we don't need to set the decrypt key (as in other samples) */
/* because encryption and decryption processes are the same for CFB. */
/* Carry out the decryption */
/* Note: For CFB-1, the length of the data needs to be specified in bits */
/* Hence, the length is multiplied by 8 before being passed to the call */
AES_cfb1_encrypt(ciphertext, plaintext, length * 8, &key, iv, &num, AES_DECRYPT);
BIO_printf(bio_out, "Recovered plaintext: ");
/* print out the plaintext */
for (i = 0; i < length; i++)
BIO_printf(bio_out, "%c", ((unsigned char*)plaintext)[i]);
BIO_printf(bio_out, "\n\n");
BIO_free(bio_out);
free(ciphertext);
free(plaintext);
return 0;
}
virtual void decrypt(const unsigned char* in, unsigned char* out, std::size_t length) {
assert(in && out);
AES_cfb1_encrypt(in, out, length * 8, &this->aes_ctx, this->ivec, &this->num, AES_DECRYPT);
}
