1/*
2 * aes_calc.c
3 *
4 * A simple AES calculator for generating AES encryption values
5 *
6 * David A. McGrew
7 * Cisco Systems, Inc.
8 */
9/*
10 *
11 * Copyright (c) 2001-2006, Cisco Systems, Inc.
12 * All rights reserved.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 *
18 *   Redistributions of source code must retain the above copyright
19 *   notice, this list of conditions and the following disclaimer.
20 *
21 *   Redistributions in binary form must reproduce the above
22 *   copyright notice, this list of conditions and the following
23 *   disclaimer in the documentation and/or other materials provided
24 *   with the distribution.
25 *
26 *   Neither the name of the Cisco Systems, Inc. nor the names of its
27 *   contributors may be used to endorse or promote products derived
28 *   from this software without specific prior written permission.
29 *
30 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
31 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
32 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
33 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
34 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
35 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
36 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
37 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
38 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
41 * OF THE POSSIBILITY OF SUCH DAMAGE.
42 *
43 */
44
45/*
46
47 Example usage (with first NIST FIPS 197 test case):
48
49[sh]$ test/aes_calc 000102030405060708090a0b0c0d0e0f 00112233445566778899aabbccddeeff -v
50 plaintext:      00112233445566778899aabbccddeeff
51 key:            000102030405060708090a0b0c0d0e0f
52 ciphertext:     69c4e0d86a7b0430d8cdb78070b4c55a
53
54 */
55
56#include "aes.h"
57#include <stdio.h>
58#include <string.h>
59
60void
61usage(char *prog_name) {
62  printf("usage: %s <key> <plaintext> [-v]\n", prog_name);
63  exit(255);
64}
65
66#define AES_MAX_KEY_LEN 32
67
68int
69main (int argc, char *argv[]) {
70  v128_t data;
71  uint8_t key[AES_MAX_KEY_LEN];
72  aes_expanded_key_t exp_key;
73  int key_len, len;
74  int verbose;
75  err_status_t status;
76
77  if (argc == 3) {
78    /* we're not in verbose mode */
79    verbose = 0;
80  } else if (argc == 4) {
81    if (strncmp(argv[3], "-v", 2) == 0) {
82      /* we're in verbose mode */
83      verbose = 1;
84    } else {
85      /* unrecognized flag, complain and exit */
86      usage(argv[0]);
87    }
88  } else {
89    /* we've been fed the wrong number of arguments - compain and exit */
90    usage(argv[0]);
91  }
92
93  /* read in key, checking length */
94  if (strlen(argv[1]) > AES_MAX_KEY_LEN*2) {
95    fprintf(stderr,
96	    "error: too many digits in key "
97	    "(should be at most %d hexadecimal digits, found %u)\n",
98	    AES_MAX_KEY_LEN*2, (unsigned)strlen(argv[1]));
99    exit(1);
100  }
101  len = hex_string_to_octet_string((char*)key, argv[1], AES_MAX_KEY_LEN*2);
102  /* check that hex string is the right length */
103  if (len != 32 && len != 48 && len != 64) {
104    fprintf(stderr,
105	    "error: bad number of digits in key "
106	    "(should be 32/48/64 hexadecimal digits, found %d)\n",
107	    len);
108    exit(1);
109  }
110  key_len = len/2;
111
112  /* read in plaintext, checking length */
113  if (strlen(argv[2]) > 16*2) {
114    fprintf(stderr,
115	    "error: too many digits in plaintext "
116	    "(should be %d hexadecimal digits, found %u)\n",
117	    16*2, (unsigned)strlen(argv[2]));
118    exit(1);
119  }
120  len = hex_string_to_octet_string((char *)(&data), argv[2], 16*2);
121  /* check that hex string is the right length */
122  if (len < 16*2) {
123    fprintf(stderr,
124	    "error: too few digits in plaintext "
125	    "(should be %d hexadecimal digits, found %d)\n",
126	    16*2, len);
127    exit(1);
128  }
129
130  if (verbose) {
131    /* print out plaintext */
132    printf("plaintext:\t%s\n", octet_string_hex_string((uint8_t *)&data, 16));
133  }
134
135  /* encrypt plaintext */
136  status = aes_expand_encryption_key(key, key_len, &exp_key);
137  if (status) {
138    fprintf(stderr,
139	    "error: AES key expansion failed.\n");
140    exit(1);
141  }
142
143  aes_encrypt(&data, &exp_key);
144
145  /* write ciphertext to output */
146  if (verbose) {
147    printf("key:\t\t%s\n", octet_string_hex_string(key, key_len));
148    printf("ciphertext:\t");
149  }
150  printf("%s\n", v128_hex_string(&data));
151
152  return 0;
153}
154
155