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authorErwin Nindl <nine@wirdorange.org>2007-06-22 13:59:20 +0000
committerErwin Nindl <nine@wirdorange.org>2007-06-22 13:59:20 +0000
commit0275479cb56c7f562f3513fef66c83fc44d1d8c9 (patch)
treef6fbb703cebf62d18b05e2a5e7591ac08c5b6702 /srtp/crypto/cipher/cipher.c
parentsatp internet draft 00 final ietf version (diff)
added libsrtp to svn
Diffstat (limited to 'srtp/crypto/cipher/cipher.c')
-rw-r--r--srtp/crypto/cipher/cipher.c407
1 files changed, 407 insertions, 0 deletions
diff --git a/srtp/crypto/cipher/cipher.c b/srtp/crypto/cipher/cipher.c
new file mode 100644
index 0000000..573c5e2
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+++ b/srtp/crypto/cipher/cipher.c
@@ -0,0 +1,407 @@
+/*
+ * cipher.c
+ *
+ * cipher meta-functions
+ *
+ * David A. McGrew
+ * Cisco Systems, Inc.
+ *
+ */
+
+/*
+ *
+ * Copyright (c) 2001-2006, 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.
+ *
+ */
+
+#include "cipher.h"
+#include "rand_source.h" /* used in invertibiltiy tests */
+#include "alloc.h" /* for crypto_alloc(), crypto_free() */
+
+debug_module_t mod_cipher = {
+ 0, /* debugging is off by default */
+ "cipher" /* printable module name */
+};
+
+err_status_t
+cipher_output(cipher_t *c, uint8_t *buffer, int num_octets_to_output) {
+
+ /* zeroize the buffer */
+ octet_string_set_to_zero(buffer, num_octets_to_output);
+
+ /* exor keystream into buffer */
+ return cipher_encrypt(c, buffer, (unsigned int *) &num_octets_to_output);
+}
+
+/* some bookkeeping functions */
+
+int
+cipher_get_key_length(const cipher_t *c) {
+ return c->key_len;
+}
+
+/*
+ * cipher_type_self_test(ct) tests a cipher of type ct against test cases
+ * provided in an array of values of key, salt, xtd_seq_num_t,
+ * plaintext, and ciphertext that is known to be good
+ */
+
+#define SELF_TEST_BUF_OCTETS 128
+#define NUM_RAND_TESTS 128
+#define MAX_KEY_LEN 64
+
+err_status_t
+cipher_type_self_test(const cipher_type_t *ct) {
+ const cipher_test_case_t *test_case = ct->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 != 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 != 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 = ct->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 != 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;
+ }
+
+ }
+
+ return err_status_ok;
+}
+
+
+/*
+ * 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
+cipher_bits_per_second(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*) 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);
+ cipher_encrypt(c, enc_buf, &len);
+ }
+ timer = clock() - timer;
+
+ crypto_free(enc_buf);
+
+ if (timer == 0) {
+ /* Too fast! */
+ return 0;
+ }
+
+ return (uint64_t)CLOCKS_PER_SEC * num_trials * 8 * octets_in_buffer / timer;
+}