michael@0: /*
michael@0:  * aes_calc.c
michael@0:  * 
michael@0:  * A simple AES calculator for generating AES encryption values
michael@0:  *
michael@0:  * David A. McGrew
michael@0:  * Cisco Systems, Inc.
michael@0:  */
michael@0: /*
michael@0:  *	
michael@0:  * Copyright (c) 2001-2006, Cisco Systems, Inc.
michael@0:  * All rights reserved.
michael@0:  * 
michael@0:  * Redistribution and use in source and binary forms, with or without
michael@0:  * modification, are permitted provided that the following conditions
michael@0:  * are met:
michael@0:  * 
michael@0:  *   Redistributions of source code must retain the above copyright
michael@0:  *   notice, this list of conditions and the following disclaimer.
michael@0:  * 
michael@0:  *   Redistributions in binary form must reproduce the above
michael@0:  *   copyright notice, this list of conditions and the following
michael@0:  *   disclaimer in the documentation and/or other materials provided
michael@0:  *   with the distribution.
michael@0:  * 
michael@0:  *   Neither the name of the Cisco Systems, Inc. nor the names of its
michael@0:  *   contributors may be used to endorse or promote products derived
michael@0:  *   from this software without specific prior written permission.
michael@0:  * 
michael@0:  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
michael@0:  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
michael@0:  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
michael@0:  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
michael@0:  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
michael@0:  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
michael@0:  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
michael@0:  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
michael@0:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
michael@0:  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
michael@0:  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
michael@0:  * OF THE POSSIBILITY OF SUCH DAMAGE.
michael@0:  *
michael@0:  */
michael@0: 
michael@0: /*
michael@0:   
michael@0:  Example usage (with first NIST FIPS 197 test case):
michael@0:  
michael@0: [sh]$ test/aes_calc 000102030405060708090a0b0c0d0e0f 00112233445566778899aabbccddeeff -v
michael@0:  plaintext:      00112233445566778899aabbccddeeff
michael@0:  key:            000102030405060708090a0b0c0d0e0f
michael@0:  ciphertext:     69c4e0d86a7b0430d8cdb78070b4c55a
michael@0: 
michael@0:  */
michael@0: 
michael@0: #include "aes.h"
michael@0: #include <stdio.h>
michael@0: #include <string.h>
michael@0: 
michael@0: void
michael@0: usage(char *prog_name) {
michael@0:   printf("usage: %s <key> <plaintext> [-v]\n", prog_name);
michael@0:   exit(255);
michael@0: }
michael@0: 
michael@0: #define AES_MAX_KEY_LEN 32
michael@0: 
michael@0: int
michael@0: main (int argc, char *argv[]) {
michael@0:   v128_t data;
michael@0:   uint8_t key[AES_MAX_KEY_LEN];
michael@0:   aes_expanded_key_t exp_key;
michael@0:   int key_len, len;
michael@0:   int verbose;
michael@0:   err_status_t status;
michael@0: 
michael@0:   if (argc == 3) {
michael@0:     /* we're not in verbose mode */
michael@0:     verbose = 0;
michael@0:   } else if (argc == 4) {
michael@0:     if (strncmp(argv[3], "-v", 2) == 0) {
michael@0:       /* we're in verbose mode */
michael@0:       verbose = 1;
michael@0:     } else {
michael@0:       /* unrecognized flag, complain and exit */
michael@0:       usage(argv[0]);
michael@0:     }
michael@0:   } else {
michael@0:     /* we've been fed the wrong number of arguments - compain and exit */
michael@0:     usage(argv[0]);
michael@0:   }
michael@0:   
michael@0:   /* read in key, checking length */
michael@0:   if (strlen(argv[1]) > AES_MAX_KEY_LEN*2) {
michael@0:     fprintf(stderr, 
michael@0: 	    "error: too many digits in key "
michael@0: 	    "(should be at most %d hexadecimal digits, found %u)\n",
michael@0: 	    AES_MAX_KEY_LEN*2, (unsigned)strlen(argv[1]));
michael@0:     exit(1);    
michael@0:   }
michael@0:   len = hex_string_to_octet_string((char*)key, argv[1], AES_MAX_KEY_LEN*2);
michael@0:   /* check that hex string is the right length */
michael@0:   if (len != 32 && len != 48 && len != 64) {
michael@0:     fprintf(stderr, 
michael@0: 	    "error: bad number of digits in key "
michael@0: 	    "(should be 32/48/64 hexadecimal digits, found %d)\n",
michael@0: 	    len);
michael@0:     exit(1);    
michael@0:   } 
michael@0:   key_len = len/2;
michael@0:       
michael@0:   /* read in plaintext, checking length */
michael@0:   if (strlen(argv[2]) > 16*2) {
michael@0:     fprintf(stderr, 
michael@0: 	    "error: too many digits in plaintext "
michael@0: 	    "(should be %d hexadecimal digits, found %u)\n",
michael@0: 	    16*2, (unsigned)strlen(argv[2]));
michael@0:     exit(1);    
michael@0:   }
michael@0:   len = hex_string_to_octet_string((char *)(&data), argv[2], 16*2);
michael@0:   /* check that hex string is the right length */
michael@0:   if (len < 16*2) {
michael@0:     fprintf(stderr, 
michael@0: 	    "error: too few digits in plaintext "
michael@0: 	    "(should be %d hexadecimal digits, found %d)\n",
michael@0: 	    16*2, len);
michael@0:     exit(1);    
michael@0:   }
michael@0: 
michael@0:   if (verbose) {
michael@0:     /* print out plaintext */
michael@0:     printf("plaintext:\t%s\n", octet_string_hex_string((uint8_t *)&data, 16));
michael@0:   }
michael@0: 
michael@0:   /* encrypt plaintext */
michael@0:   status = aes_expand_encryption_key(key, key_len, &exp_key);
michael@0:   if (status) {
michael@0:     fprintf(stderr,
michael@0: 	    "error: AES key expansion failed.\n");
michael@0:     exit(1);
michael@0:   }
michael@0: 
michael@0:   aes_encrypt(&data, &exp_key);
michael@0: 
michael@0:   /* write ciphertext to output */
michael@0:   if (verbose) {
michael@0:     printf("key:\t\t%s\n", octet_string_hex_string(key, key_len));
michael@0:     printf("ciphertext:\t");
michael@0:   }
michael@0:   printf("%s\n", v128_hex_string(&data));
michael@0: 
michael@0:   return 0;
michael@0: }
michael@0: