| /* |
| * null_cipher.c |
| * |
| * A null cipher implementation. This cipher leaves the plaintext |
| * unchanged. |
| * |
| * 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 "datatypes.h" |
| #include "null_cipher.h" |
| #include "alloc.h" |
| |
| /* the null_cipher uses the cipher debug module */ |
| |
| extern srtp_debug_module_t srtp_mod_cipher; |
| |
| static srtp_err_status_t srtp_null_cipher_alloc (srtp_cipher_t **c, int key_len, int tlen) |
| { |
| extern srtp_cipher_type_t srtp_null_cipher; |
| uint8_t *pointer; |
| |
| debug_print(srtp_mod_cipher, |
| "allocating cipher with key length %d", key_len); |
| |
| /* allocate memory a cipher of type null_cipher */ |
| pointer = (uint8_t*)srtp_crypto_alloc(sizeof(srtp_null_cipher_ctx_t) + sizeof(srtp_cipher_t)); |
| if (pointer == NULL) { |
| return srtp_err_status_alloc_fail; |
| } |
| |
| /* set pointers */ |
| *c = (srtp_cipher_t*)pointer; |
| (*c)->algorithm = SRTP_NULL_CIPHER; |
| (*c)->type = &srtp_null_cipher; |
| (*c)->state = pointer + sizeof(srtp_cipher_t); |
| |
| /* set key size */ |
| (*c)->key_len = key_len; |
| |
| return srtp_err_status_ok; |
| |
| } |
| |
| static srtp_err_status_t srtp_null_cipher_dealloc (srtp_cipher_t *c) |
| { |
| extern srtp_cipher_type_t srtp_null_cipher; |
| |
| /* zeroize entire state*/ |
| octet_string_set_to_zero((uint8_t*)c, |
| sizeof(srtp_null_cipher_ctx_t) + sizeof(srtp_cipher_t)); |
| |
| /* free memory of type null_cipher */ |
| srtp_crypto_free(c); |
| |
| return srtp_err_status_ok; |
| |
| } |
| |
| static srtp_err_status_t srtp_null_cipher_init (srtp_null_cipher_ctx_t *ctx, const uint8_t *key) |
| { |
| |
| debug_print(srtp_mod_cipher, "initializing null cipher", NULL); |
| |
| return srtp_err_status_ok; |
| } |
| |
| static srtp_err_status_t srtp_null_cipher_set_iv (srtp_null_cipher_ctx_t *c, void *iv) |
| { |
| return srtp_err_status_ok; |
| } |
| |
| static srtp_err_status_t srtp_null_cipher_encrypt (srtp_null_cipher_ctx_t *c, |
| unsigned char *buf, unsigned int *bytes_to_encr) |
| { |
| return srtp_err_status_ok; |
| } |
| |
| static char srtp_null_cipher_description[] = "null cipher"; |
| |
| static srtp_cipher_test_case_t srtp_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 */ |
| 0, |
| NULL, |
| 0, |
| NULL /* pointer to next testcase */ |
| }; |
| |
| |
| /* |
| * note: the decrypt function is idential to the encrypt function |
| */ |
| |
| srtp_cipher_type_t srtp_null_cipher = { |
| (cipher_alloc_func_t)srtp_null_cipher_alloc, |
| (cipher_dealloc_func_t)srtp_null_cipher_dealloc, |
| (cipher_init_func_t)srtp_null_cipher_init, |
| (cipher_set_aad_func_t)0, |
| (cipher_encrypt_func_t)srtp_null_cipher_encrypt, |
| (cipher_decrypt_func_t)srtp_null_cipher_encrypt, |
| (cipher_set_iv_func_t)srtp_null_cipher_set_iv, |
| (cipher_get_tag_func_t)0, |
| (char*)srtp_null_cipher_description, |
| (srtp_cipher_test_case_t*)&srtp_null_cipher_test_0, |
| (srtp_debug_module_t*)NULL, |
| (srtp_cipher_type_id_t)SRTP_NULL_CIPHER |
| }; |
| |