freeswitch/libs/srtp/crypto/cipher/null_cipher.c
Anthony Minessale b3d890ef25 add srtp
git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@1086 d0543943-73ff-0310-b7d9-9358b9ac24b2
2006-04-07 16:10:03 +00:00

153 lines
4.3 KiB
C

/*
* null_cipher.c
*
* A null cipher implementation. This cipher leaves the plaintext
* unchanged.
*
* David A. McGrew
* Cisco Systems, Inc.
*/
/*
*
* Copyright (c) 2001-2005, 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 "datatypes.h"
#include "null_cipher.h"
#include "alloc.h"
/* the null_cipher uses the cipher debug module */
extern debug_module_t mod_cipher;
err_status_t
null_cipher_alloc(cipher_t **c, int key_len) {
extern cipher_type_t null_cipher;
uint8_t *pointer;
debug_print(mod_cipher,
"allocating cipher with key length %d", key_len);
/* allocate memory a cipher of type null_cipher */
pointer = crypto_alloc(sizeof(null_cipher_ctx_t) + sizeof(cipher_t));
if (pointer == NULL)
return err_status_alloc_fail;
/* set pointers */
*c = (cipher_t *)pointer;
(*c)->type = &null_cipher;
(*c)->state = pointer + sizeof(cipher_t);
/* set key size */
(*c)->key_len = key_len;
/* increment ref_count */
null_cipher.ref_count++;
return err_status_ok;
}
err_status_t
null_cipher_dealloc(cipher_t *c) {
extern cipher_type_t null_cipher;
/* zeroize entire state*/
octet_string_set_to_zero((uint8_t *)c,
sizeof(null_cipher_ctx_t) + sizeof(cipher_t));
/* free memory of type null_cipher */
crypto_free(c);
/* decrement reference count */
null_cipher.ref_count--;
return err_status_ok;
}
err_status_t
null_cipher_init(null_cipher_ctx_t *ctx, const uint8_t *key) {
debug_print(mod_cipher, "initializing null cipher", NULL);
return err_status_ok;
}
err_status_t
null_cipher_set_iv(null_cipher_ctx_t *c, void *iv) {
return err_status_ok;
}
err_status_t
null_cipher_encrypt(null_cipher_ctx_t *c,
unsigned char *buf, unsigned int *bytes_to_encr) {
return err_status_ok;
}
char
null_cipher_description[] = "null cipher";
cipher_test_case_t
null_cipher_test_0 = {
0, /* octets in key */
NULL, /* key */
0, /* packet index */
0, /* octets in plaintext */
NULL, /* plaintext */
0, /* octets in plaintext */
NULL, /* ciphertext */
NULL /* pointer to next testcase */
};
/*
* note: the decrypt function is idential to the encrypt function
*/
cipher_type_t null_cipher = {
(cipher_alloc_func_t) null_cipher_alloc,
(cipher_dealloc_func_t) null_cipher_dealloc,
(cipher_init_func_t) null_cipher_init,
(cipher_encrypt_func_t) null_cipher_encrypt,
(cipher_decrypt_func_t) null_cipher_encrypt,
(cipher_set_iv_func_t) null_cipher_set_iv,
(char *) null_cipher_description,
(int) 0,
(cipher_test_case_t *) &null_cipher_test_0,
(debug_module_t *) NULL
};