| Benny Prijono | 8a0ab28 | 2008-01-23 20:17:42 +0000 | [diff] [blame^] | 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 | |