The Tor Browser: netwerk/srtp/src/crypto/cipher/null

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

     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  */

    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  */

    47 #include "datatypes.h"

    48 #include "null_cipher.h"

    49 #include "alloc.h"

    51 /* the null_cipher uses the cipher debug module  */

    53 extern debug_module_t mod_cipher;

    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;

    60   debug_print(mod_cipher,

    61 	      "allocating cipher with key length %d", key_len);

    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;

    68   /* set pointers */

    69   *c = (cipher_t *)pointer;

    70   (*c)->type = &null_cipher;

    71   (*c)->state = pointer + sizeof(cipher_t);

    73   /* set key size */

    74   (*c)->key_len = key_len;

    76   /* increment ref_count */

    77   null_cipher.ref_count++;

    79   return err_status_ok;

    81 }

    83 err_status_t

    84 null_cipher_dealloc(cipher_t *c) {

    85   extern cipher_type_t null_cipher;

    87   /* zeroize entire state*/

    88   octet_string_set_to_zero((uint8_t *)c,

    89 			   sizeof(null_cipher_ctx_t) + sizeof(cipher_t));

    91   /* free memory of type null_cipher */

    92   crypto_free(c);

    94   /* decrement reference count */

    95   null_cipher.ref_count--;

    97   return err_status_ok;

    99 }

   101 err_status_t

   102 null_cipher_init(null_cipher_ctx_t *ctx, const uint8_t *key, int key_len) {

   104   debug_print(mod_cipher, "initializing null cipher", NULL);

   106   return err_status_ok;

   107 }

   109 err_status_t

   110 null_cipher_set_iv(null_cipher_ctx_t *c, void *iv) {

   111   return err_status_ok;

   112 }

   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 }

   120 char

   121 null_cipher_description[] = "null cipher";

   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 };

   136 /*

   137  * note: the decrypt function is idential to the encrypt function

   138  */

   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   (cipher_type_id_t)            NULL_CIPHER

   152 };

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