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 12 Example usage (with first NIST FIPS 197 test case): 13 14 [sh]$ test/aes_calc 000102030405060708090a0b0c0d0e0f 00112233445566778899aabbccddeeff -v 15 plaintext: 00112233445566778899aabbccddeeff 16 key: 000102030405060708090a0b0c0d0e0f 17 ciphertext: 69c4e0d86a7b0430d8cdb78070b4c55a 18 19 */ 20 21 #include "aes.h" 22 #include <stdio.h> 23 #include <string.h> 24 25 void 26 usage(char *prog_name) { 27 printf("usage: %s <key> <plaintext> [-v]\n", prog_name); 28 exit(255); 29 } 30 31 #define AES_KEY_LEN 16 32 33 int 34 main (int argc, char *argv[]) { 35 v128_t data, key; 36 aes_expanded_key_t exp_key; 37 int len; 38 int verbose; 39 40 if (argc == 3) { 41 /* we're not in verbose mode */ 42 verbose = 0; 43 } else if (argc == 4) { 44 if (strncmp(argv[3], "-v", 2) == 0) { 45 /* we're in verbose mode */ 46 verbose = 1; 47 } else { 48 /* unrecognized flag, complain and exit */ 49 usage(argv[0]); 50 } 51 } else { 52 /* we've been fed the wrong number of arguments - compain and exit */ 53 usage(argv[0]); 54 } 55 56 /* read in key, checking length */ 57 if (strlen(argv[1]) > AES_KEY_LEN*2) { 58 fprintf(stderr, 59 "error: too many digits in key " 60 "(should be %d hexadecimal digits, found %u)\n", 61 AES_KEY_LEN*2, (unsigned)strlen(argv[1])); 62 exit(1); 63 } 64 len = hex_string_to_octet_string((char *)&key, argv[1], AES_KEY_LEN*2); 65 /* check that hex string is the right length */ 66 if (len < AES_KEY_LEN*2) { 67 fprintf(stderr, 68 "error: too few digits in key " 69 "(should be %d hexadecimal digits, found %d)\n", 70 AES_KEY_LEN*2, len); 71 exit(1); 72 } 73 74 /* read in plaintext, checking length */ 75 if (strlen(argv[2]) > 16*2) { 76 fprintf(stderr, 77 "error: too many digits in plaintext " 78 "(should be %d hexadecimal digits, found %u)\n", 79 16*2, (unsigned)strlen(argv[2])); 80 exit(1); 81 } 82 len = hex_string_to_octet_string((char *)(&data), argv[2], 16*2); 83 /* check that hex string is the right length */ 84 if (len < 16*2) { 85 fprintf(stderr, 86 "error: too few digits in plaintext " 87 "(should be %d hexadecimal digits, found %d)\n", 88 16*2, len); 89 exit(1); 90 } 91 92 if (verbose) { 93 /* print out plaintext */ 94 printf("plaintext:\t%s\n", octet_string_hex_string((uint8_t *)&data, 16)); 95 } 96 97 /* encrypt plaintext */ 98 aes_expand_encryption_key(&key, exp_key); 99 100 aes_encrypt(&data, exp_key); 101 102 /* write ciphertext to output */ 103 if (verbose) { 104 printf("key:\t\t%s\n", v128_hex_string(&key)); 105 printf("ciphertext:\t"); 106 } 107 printf("%s\n", v128_hex_string(&data)); 108 109 return 0; 110 } 111 112
