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/*
* aes_calc.c
*
* A simple AES calculator for generating AES encryption values
*
* David A. McGrew
* Cisco Systems, Inc.
*/
/*
Example usage (with first NIST FIPS 197 test case):
[sh]$ test/aes_calc 000102030405060708090a0b0c0d0e0f 00112233445566778899aabbccddeeff -v
plaintext: 00112233445566778899aabbccddeeff
key: 000102030405060708090a0b0c0d0e0f
ciphertext: 69c4e0d86a7b0430d8cdb78070b4c55a
*/
#include "aes.h"
#include <stdio.h>
#include <string.h>
void
usage(char *prog_name) {
printf("usage: %s <key> <plaintext> [-v]\n", prog_name);
exit(255);
}
#define AES_KEY_LEN 16
int
main (int argc, char *argv[]) {
v128_t data, key;
aes_expanded_key_t exp_key;
int len;
int verbose;
if (argc == 3) {
/* we're not in verbose mode */
verbose = 0;
} else if (argc == 4) {
if (strncmp(argv[3], "-v", 2) == 0) {
/* we're in verbose mode */
verbose = 1;
} else {
/* unrecognized flag, complain and exit */
usage(argv[0]);
}
} else {
/* we've been fed the wrong number of arguments - compain and exit */
usage(argv[0]);
}
/* read in key, checking length */
if (strlen(argv[1]) > AES_KEY_LEN*2) {
fprintf(stderr,
"error: too many digits in key "
"(should be %d hexadecimal digits, found %u)\n",
AES_KEY_LEN*2, (unsigned)strlen(argv[1]));
exit(1);
}
len = hex_string_to_octet_string((char *)&key, argv[1], AES_KEY_LEN*2);
/* check that hex string is the right length */
if (len < AES_KEY_LEN*2) {
fprintf(stderr,
"error: too few digits in key "
"(should be %d hexadecimal digits, found %d)\n",
AES_KEY_LEN*2, len);
exit(1);
}
/* read in plaintext, checking length */
if (strlen(argv[2]) > 16*2) {
fprintf(stderr,
"error: too many digits in plaintext "
"(should be %d hexadecimal digits, found %u)\n",
16*2, (unsigned)strlen(argv[2]));
exit(1);
}
len = hex_string_to_octet_string((char *)(&data), argv[2], 16*2);
/* check that hex string is the right length */
if (len < 16*2) {
fprintf(stderr,
"error: too few digits in plaintext "
"(should be %d hexadecimal digits, found %d)\n",
16*2, len);
exit(1);
}
if (verbose) {
/* print out plaintext */
printf("plaintext:\t%s\n", octet_string_hex_string((uint8_t *)&data, 16));
}
/* encrypt plaintext */
aes_expand_encryption_key(&key, exp_key);
aes_encrypt(&data, exp_key);
/* write ciphertext to output */
if (verbose) {
printf("key:\t\t%s\n", v128_hex_string(&key));
printf("ciphertext:\t");
}
printf("%s\n", v128_hex_string(&data));
return 0;
}
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