| /* |
| * cipher.c |
| * |
| * cipher meta-functions |
| * |
| * David A. McGrew |
| * Cisco Systems, Inc. |
| * |
| */ |
| |
| /* |
| * |
| * Copyright (c) 2001-2006,2013 Cisco Systems, Inc. |
| * All rights reserved. |
| * |
| * Redistribution and use in source and binary forms, with or without |
| * modification, are permitted provided that the following conditions |
| * are met: |
| * |
| * Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * |
| * Redistributions in binary form must reproduce the above |
| * copyright notice, this list of conditions and the following |
| * disclaimer in the documentation and/or other materials provided |
| * with the distribution. |
| * |
| * Neither the name of the Cisco Systems, Inc. nor the names of its |
| * contributors may be used to endorse or promote products derived |
| * from this software without specific prior written permission. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS |
| * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE |
| * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, |
| * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
| * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
| * OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| */ |
| |
| #ifdef HAVE_CONFIG_H |
| #include <config.h> |
| #endif |
| |
| #include "cipher.h" |
| #include "crypto_types.h" |
| #include "rand_source.h" /* used in invertibiltiy tests */ |
| #include "alloc.h" /* for crypto_alloc(), crypto_free() */ |
| |
| srtp_debug_module_t srtp_mod_cipher = { |
| 0, /* debugging is off by default */ |
| "cipher" /* printable module name */ |
| }; |
| |
| srtp_err_status_t srtp_cipher_output (srtp_cipher_t *c, uint8_t *buffer, uint32_t *num_octets_to_output) |
| { |
| |
| /* zeroize the buffer */ |
| octet_string_set_to_zero(buffer, *num_octets_to_output); |
| |
| /* exor keystream into buffer */ |
| return (((c)->type)->encrypt(((c)->state), buffer, num_octets_to_output)); |
| } |
| |
| srtp_err_status_t srtp_cipher_encrypt (srtp_cipher_t *c, uint8_t *buffer, uint32_t *num_octets_to_output) |
| { |
| return (((c)->type)->encrypt(((c)->state), buffer, num_octets_to_output)); |
| } |
| |
| srtp_err_status_t srtp_cipher_decrypt (srtp_cipher_t *c, uint8_t *buffer, uint32_t *num_octets_to_output) |
| { |
| return (((c)->type)->decrypt(((c)->state), buffer, num_octets_to_output)); |
| } |
| |
| /* some bookkeeping functions */ |
| |
| int srtp_cipher_get_key_length (const srtp_cipher_t *c) |
| { |
| return c->key_len; |
| } |
| |
| #define SELF_TEST_BUF_OCTETS 128 |
| #define NUM_RAND_TESTS 128 |
| #define MAX_KEY_LEN 64 |
| /* |
| * srtp_cipher_type_test(ct, test_data) tests a cipher of type ct against |
| * test cases provided in a list test_data of values of key, salt, iv, |
| * plaintext, and ciphertext that is known to be good |
| */ |
| srtp_err_status_t srtp_cipher_type_test (const srtp_cipher_type_t *ct, const srtp_cipher_test_case_t *test_data) |
| { |
| const srtp_cipher_test_case_t *test_case = test_data; |
| srtp_cipher_t *c; |
| srtp_err_status_t status; |
| uint8_t buffer[SELF_TEST_BUF_OCTETS]; |
| uint8_t buffer2[SELF_TEST_BUF_OCTETS]; |
| int tag_len; |
| unsigned int len; |
| int i, j, case_num = 0; |
| |
| debug_print(srtp_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 srtp_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, test_case->tag_length_octets); |
| if (status) { |
| return status; |
| } |
| |
| /* |
| * test the encrypt function |
| */ |
| debug_print(srtp_mod_cipher, "testing encryption", NULL); |
| |
| /* initialize cipher */ |
| status = cipher_init(c, test_case->key); |
| 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 srtp_err_status_bad_param; |
| } |
| for (i = 0; i < test_case->plaintext_length_octets; i++) { |
| buffer[i] = test_case->plaintext[i]; |
| } |
| |
| debug_print(srtp_mod_cipher, "plaintext: %s", |
| srtp_octet_string_hex_string(buffer, |
| test_case->plaintext_length_octets)); |
| |
| /* set the initialization vector */ |
| status = cipher_set_iv(c, test_case->idx, direction_encrypt); |
| if (status) { |
| cipher_dealloc(c); |
| return status; |
| } |
| |
| if (c->algorithm == SRTP_AES_128_GCM || c->algorithm == SRTP_AES_256_GCM) { |
| debug_print(srtp_mod_cipher, "IV: %s", |
| srtp_octet_string_hex_string(test_case->idx, 12)); |
| |
| /* |
| * Set the AAD |
| */ |
| status = cipher_set_aad(c, test_case->aad, |
| test_case->aad_length_octets); |
| if (status) { |
| cipher_dealloc(c); |
| return status; |
| } |
| debug_print(srtp_mod_cipher, "AAD: %s", |
| srtp_octet_string_hex_string(test_case->aad, |
| test_case->aad_length_octets)); |
| } |
| |
| /* encrypt */ |
| len = test_case->plaintext_length_octets; |
| status = srtp_cipher_encrypt(c, buffer, &len); |
| if (status) { |
| cipher_dealloc(c); |
| return status; |
| } |
| |
| if (c->algorithm == SRTP_AES_128_GCM || c->algorithm == SRTP_AES_256_GCM) { |
| /* |
| * Get the GCM tag |
| */ |
| status = cipher_get_tag(c, buffer + len, &tag_len); |
| if (status) { |
| cipher_dealloc(c); |
| return status; |
| } |
| len += tag_len; |
| } |
| |
| debug_print(srtp_mod_cipher, "ciphertext: %s", |
| srtp_octet_string_hex_string(buffer, |
| test_case->ciphertext_length_octets)); |
| |
| /* compare the resulting ciphertext with that in the test case */ |
| if (len != test_case->ciphertext_length_octets) { |
| return srtp_err_status_algo_fail; |
| } |
| status = srtp_err_status_ok; |
| for (i = 0; i < test_case->ciphertext_length_octets; i++) { |
| if (buffer[i] != test_case->ciphertext[i]) { |
| status = srtp_err_status_algo_fail; |
| debug_print(srtp_mod_cipher, "test case %d failed", case_num); |
| debug_print(srtp_mod_cipher, "(failure at byte %d)", i); |
| break; |
| } |
| } |
| if (status) { |
| |
| debug_print(srtp_mod_cipher, "c computed: %s", |
| srtp_octet_string_hex_string(buffer, |
| 2 * test_case->plaintext_length_octets)); |
| debug_print(srtp_mod_cipher, "c expected: %s", |
| srtp_octet_string_hex_string(test_case->ciphertext, |
| 2 * test_case->plaintext_length_octets)); |
| |
| cipher_dealloc(c); |
| return srtp_err_status_algo_fail; |
| } |
| |
| /* |
| * test the decrypt function |
| */ |
| debug_print(srtp_mod_cipher, "testing decryption", NULL); |
| |
| /* re-initialize cipher for decryption */ |
| status = cipher_init(c, test_case->key); |
| 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 srtp_err_status_bad_param; |
| } |
| for (i = 0; i < test_case->ciphertext_length_octets; i++) { |
| buffer[i] = test_case->ciphertext[i]; |
| } |
| |
| debug_print(srtp_mod_cipher, "ciphertext: %s", |
| srtp_octet_string_hex_string(buffer, |
| test_case->plaintext_length_octets)); |
| |
| /* set the initialization vector */ |
| status = cipher_set_iv(c, test_case->idx, direction_decrypt); |
| if (status) { |
| cipher_dealloc(c); |
| return status; |
| } |
| |
| if (c->algorithm == SRTP_AES_128_GCM || c->algorithm == SRTP_AES_256_GCM) { |
| /* |
| * Set the AAD |
| */ |
| status = cipher_set_aad(c, test_case->aad, |
| test_case->aad_length_octets); |
| if (status) { |
| cipher_dealloc(c); |
| return status; |
| } |
| debug_print(srtp_mod_cipher, "AAD: %s", |
| srtp_octet_string_hex_string(test_case->aad, |
| test_case->aad_length_octets)); |
| } |
| |
| /* decrypt */ |
| len = test_case->ciphertext_length_octets; |
| status = srtp_cipher_decrypt(c, buffer, &len); |
| if (status) { |
| cipher_dealloc(c); |
| return status; |
| } |
| |
| debug_print(srtp_mod_cipher, "plaintext: %s", |
| srtp_octet_string_hex_string(buffer, |
| test_case->plaintext_length_octets)); |
| |
| /* compare the resulting plaintext with that in the test case */ |
| if (len != test_case->plaintext_length_octets) { |
| return srtp_err_status_algo_fail; |
| } |
| status = srtp_err_status_ok; |
| for (i = 0; i < test_case->plaintext_length_octets; i++) { |
| if (buffer[i] != test_case->plaintext[i]) { |
| status = srtp_err_status_algo_fail; |
| debug_print(srtp_mod_cipher, "test case %d failed", case_num); |
| debug_print(srtp_mod_cipher, "(failure at byte %d)", i); |
| } |
| } |
| if (status) { |
| |
| debug_print(srtp_mod_cipher, "p computed: %s", |
| srtp_octet_string_hex_string(buffer, |
| 2 * test_case->plaintext_length_octets)); |
| debug_print(srtp_mod_cipher, "p expected: %s", |
| srtp_octet_string_hex_string(test_case->plaintext, |
| 2 * test_case->plaintext_length_octets)); |
| |
| cipher_dealloc(c); |
| return srtp_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, test_case->tag_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(srtp_mod_cipher, "random plaintext length %d\n", length); |
| status = rand_source_get_octet_string(buffer, length); |
| if (status) { |
| return status; |
| } |
| |
| debug_print(srtp_mod_cipher, "plaintext: %s", |
| srtp_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 srtp_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); |
| if (status) { |
| cipher_dealloc(c); |
| return status; |
| } |
| |
| /* set initialization vector */ |
| status = cipher_set_iv(c, test_case->idx, direction_encrypt); |
| if (status) { |
| cipher_dealloc(c); |
| return status; |
| } |
| |
| if (c->algorithm == SRTP_AES_128_GCM || c->algorithm == SRTP_AES_256_GCM) { |
| /* |
| * Set the AAD |
| */ |
| status = cipher_set_aad(c, test_case->aad, |
| test_case->aad_length_octets); |
| if (status) { |
| cipher_dealloc(c); |
| return status; |
| } |
| debug_print(srtp_mod_cipher, "AAD: %s", |
| srtp_octet_string_hex_string(test_case->aad, |
| test_case->aad_length_octets)); |
| } |
| |
| /* encrypt buffer with cipher */ |
| plaintext_len = length; |
| status = srtp_cipher_encrypt(c, buffer, &length); |
| if (status) { |
| cipher_dealloc(c); |
| return status; |
| } |
| if (c->algorithm == SRTP_AES_128_GCM || c->algorithm == SRTP_AES_256_GCM) { |
| /* |
| * Get the GCM tag |
| */ |
| status = cipher_get_tag(c, buffer + length, &tag_len); |
| if (status) { |
| cipher_dealloc(c); |
| return status; |
| } |
| length += tag_len; |
| } |
| debug_print(srtp_mod_cipher, "ciphertext: %s", |
| srtp_octet_string_hex_string(buffer, length)); |
| |
| /* |
| * re-initialize cipher for decryption, re-set the iv, then |
| * decrypt the ciphertext |
| */ |
| status = cipher_init(c, key); |
| if (status) { |
| cipher_dealloc(c); |
| return status; |
| } |
| status = cipher_set_iv(c, test_case->idx, direction_decrypt); |
| if (status) { |
| cipher_dealloc(c); |
| return status; |
| } |
| if (c->algorithm == SRTP_AES_128_GCM || c->algorithm == SRTP_AES_256_GCM) { |
| /* |
| * Set the AAD |
| */ |
| status = cipher_set_aad(c, test_case->aad, |
| test_case->aad_length_octets); |
| if (status) { |
| cipher_dealloc(c); |
| return status; |
| } |
| debug_print(srtp_mod_cipher, "AAD: %s", |
| srtp_octet_string_hex_string(test_case->aad, |
| test_case->aad_length_octets)); |
| } |
| status = srtp_cipher_decrypt(c, buffer, &length); |
| if (status) { |
| cipher_dealloc(c); |
| return status; |
| } |
| |
| debug_print(srtp_mod_cipher, "plaintext[2]: %s", |
| srtp_octet_string_hex_string(buffer, length)); |
| |
| /* compare the resulting plaintext with the original one */ |
| if (length != plaintext_len) { |
| return srtp_err_status_algo_fail; |
| } |
| status = srtp_err_status_ok; |
| for (i = 0; i < plaintext_len; i++) { |
| if (buffer[i] != buffer2[i]) { |
| status = srtp_err_status_algo_fail; |
| debug_print(srtp_mod_cipher, "random test case %d failed", case_num); |
| debug_print(srtp_mod_cipher, "(failure at byte %d)", i); |
| } |
| } |
| if (status) { |
| cipher_dealloc(c); |
| return srtp_err_status_algo_fail; |
| } |
| |
| } |
| |
| status = cipher_dealloc(c); |
| if (status) { |
| return status; |
| } |
| |
| return srtp_err_status_ok; |
| } |
| |
| |
| /* |
| * srtp_cipher_type_self_test(ct) performs srtp_cipher_type_test on ct's internal |
| * list of test data. |
| */ |
| srtp_err_status_t srtp_cipher_type_self_test (const srtp_cipher_type_t *ct) |
| { |
| return srtp_cipher_type_test(ct, ct->test_data); |
| } |
| |
| /* |
| * cipher_bits_per_second(c, l, t) computes (an estimate of) the |
| * number of bits that a cipher implementation can encrypt in a second |
| * |
| * c is a cipher (which MUST be allocated and initialized already), l |
| * is the length in octets of the test data to be encrypted, and t is |
| * the number of trials |
| * |
| * if an error is encountered, the value 0 is returned |
| */ |
| uint64_t srtp_cipher_bits_per_second (srtp_cipher_t *c, int octets_in_buffer, int num_trials) |
| { |
| int i; |
| v128_t nonce; |
| clock_t timer; |
| unsigned char *enc_buf; |
| unsigned int len = octets_in_buffer; |
| |
| enc_buf = (unsigned char*)srtp_crypto_alloc(octets_in_buffer); |
| if (enc_buf == NULL) { |
| return 0; /* indicate bad parameters by returning null */ |
| |
| } |
| /* time repeated trials */ |
| v128_set_to_zero(&nonce); |
| timer = clock(); |
| for (i = 0; i < num_trials; i++, nonce.v32[3] = i) { |
| cipher_set_iv(c, &nonce, direction_encrypt); |
| srtp_cipher_encrypt(c, enc_buf, &len); |
| } |
| timer = clock() - timer; |
| |
| srtp_crypto_free(enc_buf); |
| |
| if (timer == 0) { |
| /* Too fast! */ |
| return 0; |
| } |
| |
| return (uint64_t)CLOCKS_PER_SEC * num_trials * 8 * octets_in_buffer / timer; |
| } |