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
53extern debug_module_t mod_cipher;
54
55err_status_t
56null_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
83err_status_t
84null_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
101err_status_t
102null_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
109err_status_t
110null_cipher_set_iv(null_cipher_ctx_t *c, void *iv) {
111  return err_status_ok;
112}
113
114err_status_t
115null_cipher_encrypt(null_cipher_ctx_t *c,
116		    unsigned char *buf, unsigned int *bytes_to_encr) {
117  return err_status_ok;
118}
119
120char
121null_cipher_description[] = "null cipher";
122
123cipher_test_case_t
124null_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
140cipher_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