1 /* 2 * null_cipher.c 3 * 4 * A null cipher implementation. This cipher leaves the plaintext 5 * unchanged. 6 * 7 * David A. McGrew 8 * Cisco Systems, Inc. 9 */ 10 11 /* 12 * 13 * Copyright (c) 2001-2006, Cisco Systems, Inc. 14 * All rights reserved. 15 * 16 * Redistribution and use in source and binary forms, with or without 17 * modification, are permitted provided that the following conditions 18 * are met: 19 * 20 * Redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer. 22 * 23 * Redistributions in binary form must reproduce the above 24 * copyright notice, this list of conditions and the following 25 * disclaimer in the documentation and/or other materials provided 26 * with the distribution. 27 * 28 * Neither the name of the Cisco Systems, Inc. nor the names of its 29 * contributors may be used to endorse or promote products derived 30 * from this software without specific prior written permission. 31 * 32 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 33 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 34 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 35 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 36 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 37 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 38 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 39 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 40 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 41 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 42 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 43 * OF THE POSSIBILITY OF SUCH DAMAGE. 44 * 45 */ 46 47 #include "datatypes.h" 48 #include "null_cipher.h" 49 #include "alloc.h" 50 51 /* the null_cipher uses the cipher debug module */ 52 53 extern debug_module_t mod_cipher; 54 55 err_status_t 56 null_cipher_alloc(cipher_t **c, int key_len) { 57 extern cipher_type_t null_cipher; 58 uint8_t *pointer; 59 60 debug_print(mod_cipher, 61 "allocating cipher with key length %d", key_len); 62 63 /* allocate memory a cipher of type null_cipher */ 64 pointer = (uint8_t*)crypto_alloc(sizeof(null_cipher_ctx_t) + sizeof(cipher_t)); 65 if (pointer == NULL) 66 return err_status_alloc_fail; 67 68 /* set pointers */ 69 *c = (cipher_t *)pointer; 70 (*c)->type = &null_cipher; 71 (*c)->state = pointer + sizeof(cipher_t); 72 73 /* set key size */ 74 (*c)->key_len = key_len; 75 76 /* increment ref_count */ 77 null_cipher.ref_count++; 78 79 return err_status_ok; 80 81 } 82 83 err_status_t 84 null_cipher_dealloc(cipher_t *c) { 85 extern cipher_type_t null_cipher; 86 87 /* zeroize entire state*/ 88 octet_string_set_to_zero((uint8_t *)c, 89 sizeof(null_cipher_ctx_t) + sizeof(cipher_t)); 90 91 /* free memory of type null_cipher */ 92 crypto_free(c); 93 94 /* decrement reference count */ 95 null_cipher.ref_count--; 96 97 return err_status_ok; 98 99 } 100 101 err_status_t 102 null_cipher_init(null_cipher_ctx_t *ctx, const uint8_t *key) { 103 104 debug_print(mod_cipher, "initializing null cipher", NULL); 105 106 return err_status_ok; 107 } 108 109 err_status_t 110 null_cipher_set_iv(null_cipher_ctx_t *c, void *iv) { 111 return err_status_ok; 112 } 113 114 err_status_t 115 null_cipher_encrypt(null_cipher_ctx_t *c, 116 unsigned char *buf, unsigned int *bytes_to_encr) { 117 return err_status_ok; 118 } 119 120 char 121 null_cipher_description[] = "null cipher"; 122 123 cipher_test_case_t 124 null_cipher_test_0 = { 125 0, /* octets in key */ 126 NULL, /* key */ 127 0, /* packet index */ 128 0, /* octets in plaintext */ 129 NULL, /* plaintext */ 130 0, /* octets in plaintext */ 131 NULL, /* ciphertext */ 132 NULL /* pointer to next testcase */ 133 }; 134 135 136 /* 137 * note: the decrypt function is idential to the encrypt function 138 */ 139 140 cipher_type_t null_cipher = { 141 (cipher_alloc_func_t) null_cipher_alloc, 142 (cipher_dealloc_func_t) null_cipher_dealloc, 143 (cipher_init_func_t) null_cipher_init, 144 (cipher_encrypt_func_t) null_cipher_encrypt, 145 (cipher_decrypt_func_t) null_cipher_encrypt, 146 (cipher_set_iv_func_t) null_cipher_set_iv, 147 (char *) null_cipher_description, 148 (int) 0, 149 (cipher_test_case_t *) &null_cipher_test_0, 150 (debug_module_t *) NULL 151 }; 152 153
