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
null_cipher_alloc(cipher_t ** c,int key_len)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
null_cipher_dealloc(cipher_t * c)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
null_cipher_init(null_cipher_ctx_t * ctx,const uint8_t * key)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
null_cipher_set_iv(null_cipher_ctx_t * c,void * iv)110 null_cipher_set_iv(null_cipher_ctx_t *c, void *iv) {
111 return err_status_ok;
112 }
113
114 err_status_t
null_cipher_encrypt(null_cipher_ctx_t * c,unsigned char * buf,unsigned int * bytes_to_encr)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