예제 #1
0
err_status_t
cipher_array_delete(cipher_t *cipher_array[], int num_cipher) {
  int i;
  
  for (i=0; i < num_cipher; i++) {
    cipher_dealloc(cipher_array[i]);
  }

  free(cipher_array);
  
  return err_status_ok;
}
예제 #2
0
int
main (int argc, char *argv[]) {
  uint8_t buffer[2532];
  unsigned int buf_len = 2500;
  int i, j;
  extern cipher_type_t aes_icm;
#ifdef OPENSSL
  extern cipher_type_t aes_gcm_128_openssl;
  extern cipher_type_t aes_gcm_256_openssl;
#endif
  cipher_t *c;
  uint8_t key[46] = {
    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 
    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 
    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 
    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 
    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 
    0x00, 0x01, 0x02, 0x03, 0x04, 0x05
    };
  v128_t nonce;
  int num_trials = 500;
  int num_fail;

  printf("statistical tests driver\n");

  v128_set_to_zero(&nonce);
  for (i=0; i < 2500; i++)
    buffer[i] = 0;

  /* run tests */
  printf("running stat_tests on all-null buffer, expecting failure\n");
  printf("monobit %d\n", stat_test_monobit(buffer));
  printf("poker   %d\n", stat_test_poker(buffer));
  printf("runs    %d\n", stat_test_runs(buffer));

  for (i=0; i < 2500; i++)
    buffer[i] = rand();
  printf("running stat_tests on rand(), expecting success\n");
  printf("monobit %d\n", stat_test_monobit(buffer));
  printf("poker   %d\n", stat_test_poker(buffer));
  printf("runs    %d\n", stat_test_runs(buffer));

  printf("running stat_tests on AES-128-ICM, expecting success\n");
  /* set buffer to cipher output */
  for (i=0; i < 2500; i++)
    buffer[i] = 0;
  err_check(cipher_type_alloc(&aes_icm, &c, 30, 0));
  err_check(cipher_init(c, key));
  err_check(cipher_set_iv(c, &nonce, direction_encrypt));
  err_check(cipher_encrypt(c, buffer, &buf_len));
  /* run tests on cipher outout */
  printf("monobit %d\n", stat_test_monobit(buffer));
  printf("poker   %d\n", stat_test_poker(buffer));
  printf("runs    %d\n", stat_test_runs(buffer));

  printf("runs test (please be patient): ");
  fflush(stdout);
  num_fail = 0;
  v128_set_to_zero(&nonce);
  for(j=0; j < num_trials; j++) {
    for (i=0; i < 2500; i++)
      buffer[i] = 0;
    nonce.v32[3] = i;
    err_check(cipher_set_iv(c, &nonce, direction_encrypt));
    err_check(cipher_encrypt(c, buffer, &buf_len));
    if (stat_test_runs(buffer)) {
      num_fail++;
    }
  }

  printf("%d failures in %d tests\n", num_fail, num_trials);
  printf("(nota bene: a small fraction of stat_test failures does not \n"
	 "indicate that the random source is invalid)\n");

  err_check(cipher_dealloc(c));

  printf("running stat_tests on AES-256-ICM, expecting success\n");
  /* set buffer to cipher output */
  for (i=0; i < 2500; i++)
    buffer[i] = 0;
  err_check(cipher_type_alloc(&aes_icm, &c, 46, 0));
  err_check(cipher_init(c, key));
  err_check(cipher_set_iv(c, &nonce, direction_encrypt));
  err_check(cipher_encrypt(c, buffer, &buf_len));
  /* run tests on cipher outout */
  printf("monobit %d\n", stat_test_monobit(buffer));
  printf("poker   %d\n", stat_test_poker(buffer));
  printf("runs    %d\n", stat_test_runs(buffer));

  printf("runs test (please be patient): ");
  fflush(stdout);
  num_fail = 0;
  v128_set_to_zero(&nonce);
  for(j=0; j < num_trials; j++) {
    for (i=0; i < 2500; i++)
      buffer[i] = 0;
    nonce.v32[3] = i;
    err_check(cipher_set_iv(c, &nonce, direction_encrypt));
    err_check(cipher_encrypt(c, buffer, &buf_len));
    if (stat_test_runs(buffer)) {
      num_fail++;
    }
  }

#ifdef OPENSSL
  {
    printf("running stat_tests on AES-128-GCM, expecting success\n");
    /* set buffer to cipher output */
    for (i=0; i < 2500; i++) {
	buffer[i] = 0;
    }
    err_check(cipher_type_alloc(&aes_gcm_128_openssl, &c, AES_128_GCM_KEYSIZE_WSALT, 8));
    err_check(cipher_init(c, key));
    err_check(cipher_set_iv(c, &nonce, direction_encrypt));
    err_check(cipher_encrypt(c, buffer, &buf_len));
    /* run tests on cipher outout */
    printf("monobit %d\n", stat_test_monobit(buffer));
    printf("poker   %d\n", stat_test_poker(buffer));
    printf("runs    %d\n", stat_test_runs(buffer));
    fflush(stdout);
    num_fail = 0;
    v128_set_to_zero(&nonce);
    for(j=0; j < num_trials; j++) {
	for (i=0; i < 2500; i++) {
	    buffer[i] = 0;
	}
	nonce.v32[3] = i;
	err_check(cipher_set_iv(c, &nonce, direction_encrypt));
	err_check(cipher_encrypt(c, buffer, &buf_len));
	buf_len = 2500;
	if (stat_test_runs(buffer)) {
	    num_fail++;
	}
    }

    printf("running stat_tests on AES-256-GCM, expecting success\n");
    /* set buffer to cipher output */
    for (i=0; i < 2500; i++) {
	buffer[i] = 0;
    }
    err_check(cipher_type_alloc(&aes_gcm_256_openssl, &c, AES_256_GCM_KEYSIZE_WSALT, 16));
    err_check(cipher_init(c, key));
    err_check(cipher_set_iv(c, &nonce, direction_encrypt));
    err_check(cipher_encrypt(c, buffer, &buf_len));
    /* run tests on cipher outout */
    printf("monobit %d\n", stat_test_monobit(buffer));
    printf("poker   %d\n", stat_test_poker(buffer));
    printf("runs    %d\n", stat_test_runs(buffer));
    fflush(stdout);
    num_fail = 0;
    v128_set_to_zero(&nonce);
    for(j=0; j < num_trials; j++) {
	for (i=0; i < 2500; i++) {
	    buffer[i] = 0;
	}
	nonce.v32[3] = i;
	err_check(cipher_set_iv(c, &nonce, direction_encrypt));
	err_check(cipher_encrypt(c, buffer, &buf_len));
	buf_len = 2500;
	if (stat_test_runs(buffer)) {
	    num_fail++;
	}
    }
  }
#endif

  printf("%d failures in %d tests\n", num_fail, num_trials);
  printf("(nota bene: a small fraction of stat_test failures does not \n"
	 "indicate that the random source is invalid)\n");

  err_check(cipher_dealloc(c));

  return 0;
}
예제 #3
0
int
main (int argc, char *argv[])
{
    cipher_t *c = NULL;
    err_status_t status;
    unsigned char test_key[32] = {
        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
        0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
        0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
        0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
    };
    int q;
    unsigned do_timing_test = 0;
    unsigned do_validation = 0;
    unsigned do_array_timing_test = 0;

    /* process input arguments */
    while (1) {
        q = getopt(argc, argv, "tva");
        if (q == -1) {
            break;
        }
        switch (q) {
        case 't':
            do_timing_test = 1;
            break;
        case 'v':
            do_validation = 1;
            break;
        case 'a':
            do_array_timing_test = 1;
            break;
        default:
            usage(argv[0]);
        }
    }

    printf("cipher test driver\n"
           "David A. McGrew\n"
           "Cisco Systems, Inc.\n");

    if (!do_validation && !do_timing_test && !do_array_timing_test) {
        usage(argv[0]);
    }

    /* arry timing (cache thrash) test */
    if (do_array_timing_test) {
        int max_num_cipher = 1 << 16; /* number of ciphers in cipher_array */
        int num_cipher;

        for (num_cipher = 1; num_cipher < max_num_cipher; num_cipher *= 8) {
            cipher_driver_test_array_throughput(&null_cipher, 0, num_cipher);
        }

        for (num_cipher = 1; num_cipher < max_num_cipher; num_cipher *= 8) {
            cipher_driver_test_array_throughput(&aes_icm_openssl, 30, num_cipher);
        }

        for (num_cipher = 1; num_cipher < max_num_cipher; num_cipher *= 8) {
            cipher_driver_test_array_throughput(&aes_icm_192_openssl, 38, num_cipher);
        }

        for (num_cipher = 1; num_cipher < max_num_cipher; num_cipher *= 8) {
            cipher_driver_test_array_throughput(&aes_icm_256_openssl, 46, num_cipher);
        }

	for (num_cipher=1; num_cipher < max_num_cipher; num_cipher *=8) {
	    cipher_driver_test_array_throughput(&aes_gcm_128_8_openssl, 16, num_cipher); 
	}
    }

    if (do_validation) {
        cipher_driver_self_test(&null_cipher);
        cipher_driver_self_test(&aes_icm_openssl);
        cipher_driver_self_test(&aes_icm_192_openssl);
        cipher_driver_self_test(&aes_icm_256_openssl);
        cipher_driver_self_test(&aes_gcm_128_8_openssl);
    }

    /* do timing and/or buffer_test on null_cipher */
    status = cipher_type_alloc(&null_cipher, &c, 0);
    check_status(status);

    status = cipher_init(c, NULL);
    check_status(status);

    if (do_timing_test) {
        cipher_driver_test_throughput(c);
    }
    if (do_validation) {
        status = cipher_driver_test_buffering(c);
        check_status(status);
    }
    status = cipher_dealloc(c);
    check_status(status);


    /* run the throughput test on the aes_icm_openssl cipher */
    status = cipher_type_alloc(&aes_icm_openssl, &c, 30);
    if (status) {
        fprintf(stderr, "error: can't allocate cipher\n");
        exit(status);
    }
    status = cipher_init(c, test_key);
    check_status(status);
    if (do_timing_test) {
        cipher_driver_test_throughput(c);
    }

    if (do_validation) {
        status = cipher_driver_test_buffering(c);
        check_status(status);
    }
    status = cipher_dealloc(c);
    check_status(status);

    /* run the throughput test on the aes_icm_192_openssl cipher */
    status = cipher_type_alloc(&aes_icm_192_openssl, &c, 38);
    if (status) {
        fprintf(stderr, "error: can't allocate cipher\n");
        exit(status);
    }
    status = cipher_init(c, test_key);
    check_status(status);
    if (do_timing_test) {
        cipher_driver_test_throughput(c);
    }

    if (do_validation) {
        status = cipher_driver_test_buffering(c);
        check_status(status);
    }
    status = cipher_dealloc(c);
    check_status(status);

    /* run the throughput test on the aes_icm_256_openssl cipher */
    status = cipher_type_alloc(&aes_icm_256_openssl, &c, 46);
    if (status) {
        fprintf(stderr, "error: can't allocate cipher\n");
        exit(status);
    }
    status = cipher_init(c, test_key);
    check_status(status);
    if (do_timing_test) {
        cipher_driver_test_throughput(c);
    }

    if (do_validation) {
        status = cipher_driver_test_buffering(c);
        check_status(status);
    }
    status = cipher_dealloc(c);
    check_status(status);

    /* run the throughput test on the aes_gcm_128_8_openssl cipher */
    status = cipher_type_alloc(&aes_gcm_128_8_openssl, &c, 16);  
    if (status) {
	fprintf(stderr, "error: can't allocate cipher\n");
	exit(status);
    }
    status = cipher_init(c, test_key);
    check_status(status);
    if (do_timing_test) {
	cipher_driver_test_throughput(c);
    }
    
    if (do_validation) {
	status = cipher_driver_test_buffering(c);
	check_status(status);
    }
    status = cipher_dealloc(c);
    check_status(status);
    
    return 0;
}
예제 #4
0
int
main(int argc, char *argv[]) {
  cipher_t *c = NULL;
  err_status_t status;
  unsigned char test_key[48] = {
    0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
    0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
    0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
    0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
    0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
  };
  int q;
  unsigned do_timing_test = 0;
  unsigned do_validation = 0;
  unsigned do_array_timing_test = 0;

  /* process input arguments */
  while (1) {
    q = getopt(argc, argv, "tva");
    if (q == -1) 
      break;
    switch (q) {
    case 't':
      do_timing_test = 1;
      break;
    case 'v':
      do_validation = 1;
      break;
    case 'a':
      do_array_timing_test = 1;
      break;
    default:
      usage(argv[0]);
    }    
  }
   
  printf("cipher test driver\n"
	 "David A. McGrew\n"
	 "Cisco Systems, Inc.\n");

  if (!do_validation && !do_timing_test && !do_array_timing_test)
    usage(argv[0]);

   /* arry timing (cache thrash) test */
  if (do_array_timing_test) {
    int max_num_cipher = 1 << 16;   /* number of ciphers in cipher_array */
    int num_cipher;
    
    for (num_cipher=1; num_cipher < max_num_cipher; num_cipher *=8)
      cipher_driver_test_array_throughput(&null_cipher, 0, num_cipher); 

    for (num_cipher=1; num_cipher < max_num_cipher; num_cipher *=8)
      cipher_driver_test_array_throughput(&aes_icm, 30, num_cipher); 

#ifndef OPENSSL
    for (num_cipher=1; num_cipher < max_num_cipher; num_cipher *=8)
      cipher_driver_test_array_throughput(&aes_icm, 46, num_cipher); 

    for (num_cipher=1; num_cipher < max_num_cipher; num_cipher *=8)
      cipher_driver_test_array_throughput(&aes_cbc, 16, num_cipher); 
 
    for (num_cipher=1; num_cipher < max_num_cipher; num_cipher *=8)
      cipher_driver_test_array_throughput(&aes_cbc, 32, num_cipher); 
#else
#ifndef BORINGSSL
    for (num_cipher=1; num_cipher < max_num_cipher; num_cipher *=8)
      cipher_driver_test_array_throughput(&aes_icm_192, 38, num_cipher); 
#endif

    for (num_cipher=1; num_cipher < max_num_cipher; num_cipher *=8)
      cipher_driver_test_array_throughput(&aes_icm_256, 46, num_cipher); 

    for (num_cipher=1; num_cipher < max_num_cipher; num_cipher *=8) {
	cipher_driver_test_array_throughput(&aes_gcm_128_openssl, AES_128_GCM_KEYSIZE_WSALT, num_cipher);         
    }

    for (num_cipher=1; num_cipher < max_num_cipher; num_cipher *=8) {
	cipher_driver_test_array_throughput(&aes_gcm_256_openssl, AES_256_GCM_KEYSIZE_WSALT, num_cipher);         
    }
#endif
  }

  if (do_validation) {
    cipher_driver_self_test(&null_cipher);
    cipher_driver_self_test(&aes_icm);
#ifndef OPENSSL
    cipher_driver_self_test(&aes_cbc);
#else
#ifndef BORINGSSL
    cipher_driver_self_test(&aes_icm_192);
#endif
    cipher_driver_self_test(&aes_icm_256);
    cipher_driver_self_test(&aes_gcm_128_openssl);
    cipher_driver_self_test(&aes_gcm_256_openssl);
#endif
  }

  /* do timing and/or buffer_test on null_cipher */
  status = cipher_type_alloc(&null_cipher, &c, 0, 0); 
  check_status(status);

  status = cipher_init(c, NULL);
  check_status(status);

  if (do_timing_test) 
    cipher_driver_test_throughput(c);
  if (do_validation) {
    status = cipher_driver_test_buffering(c);
    check_status(status);
  }
  status = cipher_dealloc(c);
  check_status(status);
  

  /* run the throughput test on the aes_icm cipher (128-bit key) */
    status = cipher_type_alloc(&aes_icm, &c, 30, 0);  
    if (status) {
      fprintf(stderr, "error: can't allocate cipher\n");
      exit(status);
    }

    status = cipher_init(c, test_key);
    check_status(status);

    if (do_timing_test)
      cipher_driver_test_throughput(c);
    
    if (do_validation) {
      status = cipher_driver_test_buffering(c);
      check_status(status);
    }
    
    status = cipher_dealloc(c);
    check_status(status);

  /* repeat the tests with 256-bit keys */
#ifndef OPENSSL
    status = cipher_type_alloc(&aes_icm, &c, 46, 0);  
#else
    status = cipher_type_alloc(&aes_icm_256, &c, 46, 0);  
#endif
    if (status) {
      fprintf(stderr, "error: can't allocate cipher\n");
      exit(status);
    }

    status = cipher_init(c, test_key);
    check_status(status);

    if (do_timing_test)
      cipher_driver_test_throughput(c);
    
    if (do_validation) {
      status = cipher_driver_test_buffering(c);
      check_status(status);
    }
    
    status = cipher_dealloc(c);
    check_status(status);

#ifdef OPENSSL
    /* run the throughput test on the aes_gcm_128_openssl cipher */
    status = cipher_type_alloc(&aes_gcm_128_openssl, &c, AES_128_GCM_KEYSIZE_WSALT, 8);
    if (status) {
        fprintf(stderr, "error: can't allocate GCM 128 cipher\n");
        exit(status);
    }
    status = cipher_init(c, test_key);
    check_status(status);
    if (do_timing_test) {
        cipher_driver_test_throughput(c);
    }

    if (do_validation) {
        status = cipher_driver_test_buffering(c);
        check_status(status);
    }
    status = cipher_dealloc(c);
    check_status(status);

    /* run the throughput test on the aes_gcm_256_openssl cipher */
    status = cipher_type_alloc(&aes_gcm_256_openssl, &c, AES_256_GCM_KEYSIZE_WSALT, 16);
    if (status) {
        fprintf(stderr, "error: can't allocate GCM 256 cipher\n");
        exit(status);
    }
    status = cipher_init(c, test_key);
    check_status(status);
    if (do_timing_test) {
        cipher_driver_test_throughput(c);
    }

    if (do_validation) {
        status = cipher_driver_test_buffering(c);
        check_status(status);
    }
    status = cipher_dealloc(c);
    check_status(status);
#endif 

    return 0;
}
예제 #5
0
err_status_t
cipher_type_test(const cipher_type_t *ct, const cipher_test_case_t *test_data) {
  const cipher_test_case_t *test_case = test_data;
  cipher_t *c;
  err_status_t status;
  uint8_t buffer[SELF_TEST_BUF_OCTETS];
  uint8_t buffer2[SELF_TEST_BUF_OCTETS];
  unsigned int len;
  int i, j, case_num = 0;

  debug_print(mod_cipher, "running self-test for cipher %s", 
	      ct->description);
  
  /*
   * check to make sure that we have at least one test case, and
   * return an error if we don't - we need to be paranoid here
   */
  if (test_case == NULL)
    return err_status_cant_check;

  /*
   * loop over all test cases, perform known-answer tests of both the
   * encryption and decryption functions
   */  
  while (test_case != NULL) {

    /* allocate cipher */
    status = cipher_type_alloc(ct, &c, test_case->key_length_octets);
    if (status)
      return status;
    
    /*
     * test the encrypt function 
     */
    debug_print(mod_cipher, "testing encryption", NULL);    
    
    /* initialize cipher */
    status = cipher_init(c, test_case->key, direction_encrypt);
    if (status) {
      cipher_dealloc(c);
      return status;
    }
    
    /* copy plaintext into test buffer */
    if (test_case->ciphertext_length_octets > SELF_TEST_BUF_OCTETS) {
      cipher_dealloc(c);    
      return err_status_bad_param;
    }
    for (i=0; i < test_case->plaintext_length_octets; i++)
      buffer[i] = test_case->plaintext[i];

    debug_print(mod_cipher, "plaintext:    %s",
	     octet_string_hex_string(buffer,
				     test_case->plaintext_length_octets));

    /* set the initialization vector */
    status = cipher_set_iv(c, test_case->idx);
    if (status) {
      cipher_dealloc(c);
      return status;
    } 
    
    /* encrypt */
    len = test_case->plaintext_length_octets;
    status = cipher_encrypt(c, buffer, &len);
    if (status) {
      cipher_dealloc(c);
      return status;
    }
    
    debug_print(mod_cipher, "ciphertext:   %s",
	     octet_string_hex_string(buffer,
				     test_case->ciphertext_length_octets));

    /* compare the resulting ciphertext with that in the test case */
    if (len != (unsigned int)test_case->ciphertext_length_octets)
      return err_status_algo_fail;
    status = err_status_ok;
    for (i=0; i < test_case->ciphertext_length_octets; i++)
      if (buffer[i] != test_case->ciphertext[i]) {
	status = err_status_algo_fail;
	debug_print(mod_cipher, "test case %d failed", case_num);
	debug_print(mod_cipher, "(failure at byte %d)", i);
	break;
      }
    if (status) {

      debug_print(mod_cipher, "c computed: %s",
	     octet_string_hex_string(buffer,
		  2*test_case->plaintext_length_octets));
      debug_print(mod_cipher, "c expected: %s",
		  octet_string_hex_string(test_case->ciphertext,
			  2*test_case->plaintext_length_octets));

      cipher_dealloc(c);
      return err_status_algo_fail;
    }

    /*
     * test the decrypt function
     */
    debug_print(mod_cipher, "testing decryption", NULL);    

    /* re-initialize cipher for decryption */
    status = cipher_init(c, test_case->key, direction_decrypt);
    if (status) {
      cipher_dealloc(c);
      return status;
    }

    /* copy ciphertext into test buffer */
    if (test_case->ciphertext_length_octets > SELF_TEST_BUF_OCTETS) {
      cipher_dealloc(c);    
      return err_status_bad_param;
    }
    for (i=0; i < test_case->ciphertext_length_octets; i++)
      buffer[i] = test_case->ciphertext[i];

    debug_print(mod_cipher, "ciphertext:    %s",
		octet_string_hex_string(buffer,
					test_case->plaintext_length_octets));

    /* set the initialization vector */
    status = cipher_set_iv(c, test_case->idx);
    if (status) {
      cipher_dealloc(c);
      return status;
    } 
    
    /* decrypt */
    len = test_case->ciphertext_length_octets;
    status = cipher_decrypt(c, buffer, &len);
    if (status) {
      cipher_dealloc(c);
      return status;
    }
    
    debug_print(mod_cipher, "plaintext:   %s",
	     octet_string_hex_string(buffer,
				     test_case->plaintext_length_octets));

    /* compare the resulting plaintext with that in the test case */
    if (len != (unsigned int)test_case->plaintext_length_octets)
      return err_status_algo_fail;
    status = err_status_ok;
    for (i=0; i < test_case->plaintext_length_octets; i++)
      if (buffer[i] != test_case->plaintext[i]) {
	status = err_status_algo_fail;
	debug_print(mod_cipher, "test case %d failed", case_num);
	debug_print(mod_cipher, "(failure at byte %d)", i);
      }
    if (status) {

      debug_print(mod_cipher, "p computed: %s",
	     octet_string_hex_string(buffer,
		  2*test_case->plaintext_length_octets));
      debug_print(mod_cipher, "p expected: %s",
		  octet_string_hex_string(test_case->plaintext,
			  2*test_case->plaintext_length_octets));

      cipher_dealloc(c);
      return err_status_algo_fail;
    }

    /* deallocate the cipher */
    status = cipher_dealloc(c);
    if (status)
      return status;
    
    /* 
     * the cipher passed the test case, so move on to the next test
     * case in the list; if NULL, we'l proceed to the next test
     */   
    test_case = test_case->next_test_case;
    ++case_num;
  }
  
  /* now run some random invertibility tests */

  /* allocate cipher, using paramaters from the first test case */
  test_case = test_data;
  status = cipher_type_alloc(ct, &c, test_case->key_length_octets);
  if (status)
      return status;
  
  rand_source_init();
  
  for (j=0; j < NUM_RAND_TESTS; j++) {
    unsigned length;
    int plaintext_len;
    uint8_t key[MAX_KEY_LEN];
    uint8_t  iv[MAX_KEY_LEN];

    /* choose a length at random (leaving room for IV and padding) */
    length = rand() % (SELF_TEST_BUF_OCTETS - 64);
    debug_print(mod_cipher, "random plaintext length %d\n", length);
    status = rand_source_get_octet_string(buffer, length);
    if (status) return status;

    debug_print(mod_cipher, "plaintext:    %s",
		octet_string_hex_string(buffer, length));

    /* copy plaintext into second buffer */
    for (i=0; (unsigned int)i < length; i++)
      buffer2[i] = buffer[i];
    
    /* choose a key at random */
    if (test_case->key_length_octets > MAX_KEY_LEN)
      return err_status_cant_check;
    status = rand_source_get_octet_string(key, test_case->key_length_octets);
    if (status) return status;

   /* chose a random initialization vector */
    status = rand_source_get_octet_string(iv, MAX_KEY_LEN);
    if (status) return status;
        
    /* initialize cipher */
    status = cipher_init(c, key, direction_encrypt);
    if (status) {
      cipher_dealloc(c);
      return status;
    }

    /* set initialization vector */
    status = cipher_set_iv(c, test_case->idx);
    if (status) {
      cipher_dealloc(c);
      return status;
    } 

    /* encrypt buffer with cipher */
    plaintext_len = length;
    status = cipher_encrypt(c, buffer, &length);
    if (status) {
      cipher_dealloc(c);
      return status;
    }
    debug_print(mod_cipher, "ciphertext:   %s",
		octet_string_hex_string(buffer, length));

    /* 
     * re-initialize cipher for decryption, re-set the iv, then
     * decrypt the ciphertext
     */
    status = cipher_init(c, key, direction_decrypt);
    if (status) {
      cipher_dealloc(c);
      return status;
    }
    status = cipher_set_iv(c, test_case->idx);
    if (status) {
      cipher_dealloc(c);
      return status;
    } 
    status = cipher_decrypt(c, buffer, &length);
    if (status) {
      cipher_dealloc(c);
      return status;
    }    

    debug_print(mod_cipher, "plaintext[2]: %s",
		octet_string_hex_string(buffer, length));    

    /* compare the resulting plaintext with the original one */
    if (length != (unsigned int)plaintext_len)
      return err_status_algo_fail;
    status = err_status_ok;
    for (i=0; i < plaintext_len; i++)
      if (buffer[i] != buffer2[i]) {
	status = err_status_algo_fail;
	debug_print(mod_cipher, "random test case %d failed", case_num);
	debug_print(mod_cipher, "(failure at byte %d)", i);
      }
    if (status) {
      cipher_dealloc(c);
      return err_status_algo_fail;
    }
        
  }

  status = cipher_dealloc(c);
  if (status)
    return status;

  return err_status_ok;
}