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

netwerk/srtp/src/crypto/cipher/aes_cbc.c@6474c204b198 (annotated)

netwerk/srtp/src/crypto/cipher/aes_cbc.c

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

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

 /*
  * aes_cbc.c
  *
  * AES Cipher Block Chaining Mode
  *
  * David A. McGrew
  * Cisco Systems, Inc.
  */
 /*
  *
  * Copyright (c) 2001-2006, Cisco Systems, Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  *   Redistributions of source code must retain the above copyright
  *   notice, this list of conditions and the following disclaimer.
  *
  *   Redistributions in binary form must reproduce the above
  *   copyright notice, this list of conditions and the following
  *   disclaimer in the documentation and/or other materials provided
  *   with the distribution.
  *
  *   Neither the name of the Cisco Systems, Inc. nor the names of its
  *   contributors may be used to endorse or promote products derived
  *   from this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  * OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */
 #include "aes_cbc.h"
 #include "alloc.h"
 debug_module_t mod_aes_cbc = {
 ,                 /* debugging is off by default */
   "aes cbc"          /* printable module name       */
 };
 err_status_t
 aes_cbc_alloc(cipher_t **c, int key_len) {
   extern cipher_type_t aes_cbc;
   uint8_t *pointer;
   int tmp;
   debug_print(mod_aes_cbc,
 	      "allocating cipher with key length %d", key_len);
   if (key_len != 16 && key_len != 24 && key_len != 32)
     return err_status_bad_param;
   /* allocate memory a cipher of type aes_cbc */
   tmp = (sizeof(aes_cbc_ctx_t) + sizeof(cipher_t));
   pointer = (uint8_t*)crypto_alloc(tmp);
   if (pointer == NULL)
     return err_status_alloc_fail;
   /* set pointers */
   *c = (cipher_t *)pointer;
   (*c)->type = &aes_cbc;
   (*c)->state = pointer + sizeof(cipher_t);
   /* increment ref_count */
   aes_cbc.ref_count++;
   /* set key size        */
   (*c)->key_len = key_len;
   return err_status_ok;
 }
 err_status_t
 aes_cbc_dealloc(cipher_t *c) {
   extern cipher_type_t aes_cbc;
   /* zeroize entire state*/
   octet_string_set_to_zero((uint8_t *)c,
 			   sizeof(aes_cbc_ctx_t) + sizeof(cipher_t));
   /* free memory */
   crypto_free(c);
   /* decrement ref_count */
   aes_cbc.ref_count--;
   return err_status_ok;
 }
 err_status_t
 aes_cbc_context_init(aes_cbc_ctx_t *c, const uint8_t *key, int key_len,
 		     cipher_direction_t dir) {
   err_status_t status;
   debug_print(mod_aes_cbc,
 	      "key:  %s", octet_string_hex_string(key, key_len));
   /* expand key for the appropriate direction */
   switch (dir) {
   case (direction_encrypt):
     status = aes_expand_encryption_key(key, key_len, &c->expanded_key);
     if (status)
       return status;
     break;
   case (direction_decrypt):
     status = aes_expand_decryption_key(key, key_len, &c->expanded_key);
     if (status)
       return status;
     break;
   default:
     return err_status_bad_param;
   }
   return err_status_ok;
 }
 err_status_t
 aes_cbc_set_iv(aes_cbc_ctx_t *c, void *iv) {
   int i;
 /*   v128_t *input = iv; */
   uint8_t *input = (uint8_t*) iv;
   /* set state and 'previous' block to iv */
   for (i=0; i < 16; i++)
     c->previous.v8[i] = c->state.v8[i] = input[i];
   debug_print(mod_aes_cbc, "setting iv: %s", v128_hex_string(&c->state));
   return err_status_ok;
 }
 err_status_t
 aes_cbc_encrypt(aes_cbc_ctx_t *c,
 		unsigned char *data,
 		unsigned int *bytes_in_data) {
   int i;
   unsigned char *input  = data;   /* pointer to data being read    */
   unsigned char *output = data;   /* pointer to data being written */
   int bytes_to_encr = *bytes_in_data;
   /*
    * verify that we're 16-octet aligned
    */
   if (*bytes_in_data & 0xf)
     return err_status_bad_param;
   /*
    * note that we assume that the initialization vector has already
    * been set, e.g. by calling aes_cbc_set_iv()
    */
   debug_print(mod_aes_cbc, "iv: %s",
 	      v128_hex_string(&c->state));
   /*
    * loop over plaintext blocks, exoring state into plaintext then
    * encrypting and writing to output
    */
   while (bytes_to_encr > 0) {
     /* exor plaintext into state */
     for (i=0; i < 16; i++)
       c->state.v8[i] ^= *input++;
     debug_print(mod_aes_cbc, "inblock:  %s",
 	      v128_hex_string(&c->state));
     aes_encrypt(&c->state, &c->expanded_key);
     debug_print(mod_aes_cbc, "outblock: %s",
 	      v128_hex_string(&c->state));
     /* copy ciphertext to output */
     for (i=0; i < 16; i++)
       *output++ = c->state.v8[i];
     bytes_to_encr -= 16;
   }
   return err_status_ok;
 }
 err_status_t
 aes_cbc_decrypt(aes_cbc_ctx_t *c,
 		unsigned char *data,
 		unsigned int *bytes_in_data) {
   int i;
   v128_t state, previous;
   unsigned char *input  = data;   /* pointer to data being read    */
   unsigned char *output = data;   /* pointer to data being written */
   int bytes_to_encr = *bytes_in_data;
   uint8_t tmp;
   /*
    * verify that we're 16-octet aligned
    */
   if (*bytes_in_data & 0x0f)
     return err_status_bad_param;
   /* set 'previous' block to iv*/
   for (i=0; i < 16; i++) {
     previous.v8[i] = c->previous.v8[i];
   }
   debug_print(mod_aes_cbc, "iv: %s",
 	      v128_hex_string(&previous));
   /*
    * loop over ciphertext blocks, decrypting then exoring with state
    * then writing plaintext to output
    */
   while (bytes_to_encr > 0) {
     /* set state to ciphertext input block */
     for (i=0; i < 16; i++) {
      state.v8[i] = *input++;
     }
     debug_print(mod_aes_cbc, "inblock:  %s",
 	      v128_hex_string(&state));
     /* decrypt state */
     aes_decrypt(&state, &c->expanded_key);
     debug_print(mod_aes_cbc, "outblock: %s",
 	      v128_hex_string(&state));
     /*
      * exor previous ciphertext block out of plaintext, and write new
      * plaintext block to output, while copying old ciphertext block
      * to the 'previous' block
      */
     for (i=0; i < 16; i++) {
       tmp = *output;
       *output++ = state.v8[i] ^ previous.v8[i];
       previous.v8[i] = tmp;
     }
     bytes_to_encr -= 16;
   }
   return err_status_ok;
 }
 err_status_t
 aes_cbc_nist_encrypt(aes_cbc_ctx_t *c,
 		     unsigned char *data,
 		     unsigned int *bytes_in_data) {
   int i;
   unsigned char *pad_start;
   int num_pad_bytes;
   err_status_t status;
   /*
    * determine the number of padding bytes that we need to add -
    * this value is always between 1 and 16, inclusive.
    */
   num_pad_bytes = 16 - (*bytes_in_data & 0xf);
   pad_start = data;
   pad_start += *bytes_in_data;
   *pad_start++ = 0xa0;
   for (i=0; i < num_pad_bytes; i++)
     *pad_start++ = 0x00;
   /*
    * increment the data size
    */
   *bytes_in_data += num_pad_bytes;
   /*
    * now cbc encrypt the padded data
    */
   status = aes_cbc_encrypt(c, data, bytes_in_data);
   if (status)
     return status;
   return err_status_ok;
 }
 err_status_t
 aes_cbc_nist_decrypt(aes_cbc_ctx_t *c,
 		     unsigned char *data,
 		     unsigned int *bytes_in_data) {
   unsigned char *pad_end;
   int num_pad_bytes;
   err_status_t status;
   /*
    * cbc decrypt the padded data
    */
   status = aes_cbc_decrypt(c, data, bytes_in_data);
   if (status)
     return status;
   /*
    * determine the number of padding bytes in the decrypted plaintext
    * - this value is always between 1 and 16, inclusive.
    */
   num_pad_bytes = 1;
   pad_end = data + (*bytes_in_data - 1);
   while (*pad_end != 0xa0) {   /* note: should check padding correctness */
     pad_end--;
     num_pad_bytes++;
   }
   /* decrement data size */
   *bytes_in_data -= num_pad_bytes;
   return err_status_ok;
 }
 char
 aes_cbc_description[] = "aes cipher block chaining (cbc) mode";
 /*
  * Test case 0 is derived from FIPS 197 Appendix C; it uses an
  * all-zero IV, so that the first block encryption matches the test
  * case in that appendix.  This property provides a check of the base
  * AES encryption and decryption algorithms; if CBC fails on some
  * particular platform, then you should print out AES intermediate
  * data and compare with the detailed info provided in that appendix.
  *
  */
 uint8_t aes_cbc_test_case_0_key[16] = {
 x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
 x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f
 };
 uint8_t aes_cbc_test_case_0_plaintext[64] =  {
 x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
 x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff
 };
 uint8_t aes_cbc_test_case_0_ciphertext[80] = {
 x69, 0xc4, 0xe0, 0xd8, 0x6a, 0x7b, 0x04, 0x30,
 xd8, 0xcd, 0xb7, 0x80, 0x70, 0xb4, 0xc5, 0x5a,
 x03, 0x35, 0xed, 0x27, 0x67, 0xf2, 0x6d, 0xf1,
 x64, 0x83, 0x2e, 0x23, 0x44, 0x38, 0x70, 0x8b
 };
 uint8_t aes_cbc_test_case_0_iv[16] = {
 x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 };
 cipher_test_case_t aes_cbc_test_case_0 = {
 ,                                    /* octets in key            */
   aes_cbc_test_case_0_key,               /* key                      */
   aes_cbc_test_case_0_iv,                /* initialization vector    */
 ,                                    /* octets in plaintext      */
   aes_cbc_test_case_0_plaintext,         /* plaintext                */
 ,                                    /* octets in ciphertext     */
   aes_cbc_test_case_0_ciphertext,        /* ciphertext               */
   NULL                                   /* pointer to next testcase */
 };
 /*
  * this test case is taken directly from Appendix F.2 of NIST Special
  * Publication SP 800-38A
  */
 uint8_t aes_cbc_test_case_1_key[16] = {
 x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6,
 xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c,
 };
 uint8_t aes_cbc_test_case_1_plaintext[64] =  {
 x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96,
 xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
 xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c,
 x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
 x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11,
 xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
 xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17,
 xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10
 };
 uint8_t aes_cbc_test_case_1_ciphertext[80] = {
 x76, 0x49, 0xab, 0xac, 0x81, 0x19, 0xb2, 0x46,
 xce, 0xe9, 0x8e, 0x9b, 0x12, 0xe9, 0x19, 0x7d,
 x50, 0x86, 0xcb, 0x9b, 0x50, 0x72, 0x19, 0xee,
 x95, 0xdb, 0x11, 0x3a, 0x91, 0x76, 0x78, 0xb2,
 x73, 0xbe, 0xd6, 0xb8, 0xe3, 0xc1, 0x74, 0x3b,
 x71, 0x16, 0xe6, 0x9e, 0x22, 0x22, 0x95, 0x16,
 x3f, 0xf1, 0xca, 0xa1, 0x68, 0x1f, 0xac, 0x09,
 x12, 0x0e, 0xca, 0x30, 0x75, 0x86, 0xe1, 0xa7,
 x39, 0x34, 0x07, 0x03, 0x36, 0xd0, 0x77, 0x99,
 xe0, 0xc4, 0x2f, 0xdd, 0xa8, 0xdf, 0x4c, 0xa3
 };
 uint8_t aes_cbc_test_case_1_iv[16] = {
 x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
 x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f
 };
 cipher_test_case_t aes_cbc_test_case_1 = {
 ,                                    /* octets in key            */
   aes_cbc_test_case_1_key,               /* key                      */
   aes_cbc_test_case_1_iv,                /* initialization vector    */
 ,                                    /* octets in plaintext      */
   aes_cbc_test_case_1_plaintext,         /* plaintext                */
 ,                                    /* octets in ciphertext     */
   aes_cbc_test_case_1_ciphertext,        /* ciphertext               */
   &aes_cbc_test_case_0                    /* pointer to next testcase */
 };
 /*
  * Test case 2 is like test case 0, but for 256-bit keys. (FIPS 197
  * appendix C.3).
  */
 uint8_t aes_cbc_test_case_2_key[32] = {
 x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
 x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
 x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
 x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f
 };
 uint8_t aes_cbc_test_case_2_plaintext[64] =  {
 x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
 x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff
 };
 uint8_t aes_cbc_test_case_2_ciphertext[80] = {
 x8e, 0xa2, 0xb7, 0xca, 0x51, 0x67, 0x45, 0xbf,
 xea, 0xfc, 0x49, 0x90, 0x4b, 0x49, 0x60, 0x89,
 x72, 0x72, 0x6e, 0xe7, 0x71, 0x39, 0xbf, 0x11,
 xe5, 0x40, 0xe2, 0x7c, 0x54, 0x65, 0x1d, 0xee
 };
 uint8_t aes_cbc_test_case_2_iv[16] = {
 x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
 x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
 };
 cipher_test_case_t aes_cbc_test_case_2 = {
 ,                                    /* octets in key            */
   aes_cbc_test_case_2_key,               /* key                      */
   aes_cbc_test_case_2_iv,                /* initialization vector    */
 ,                                    /* octets in plaintext      */
   aes_cbc_test_case_2_plaintext,         /* plaintext                */
 ,                                    /* octets in ciphertext     */
   aes_cbc_test_case_2_ciphertext,        /* ciphertext               */
   &aes_cbc_test_case_1                   /* pointer to next testcase */
 };
 /*
  * this test case is taken directly from Appendix F.2 of NIST Special
  * Publication SP 800-38A
  */
 uint8_t aes_cbc_test_case_3_key[32] = {
 x60, 0x3d, 0xeb, 0x10, 0x15, 0xca, 0x71, 0xbe,
 x2b, 0x73, 0xae, 0xf0, 0x85, 0x7d, 0x77, 0x81,
 x1f, 0x35, 0x2c, 0x07, 0x3b, 0x61, 0x08, 0xd7,
 x2d, 0x98, 0x10, 0xa3, 0x09, 0x14, 0xdf, 0xf4
 };
 uint8_t aes_cbc_test_case_3_plaintext[64] =  {
 x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96,
 xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
 xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c,
 x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
 x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11,
 xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
 xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17,
 xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10
 };
 uint8_t aes_cbc_test_case_3_ciphertext[80] = {
 xf5, 0x8c, 0x4c, 0x04, 0xd6, 0xe5, 0xf1, 0xba,
 x77, 0x9e, 0xab, 0xfb, 0x5f, 0x7b, 0xfb, 0xd6,
 x9c, 0xfc, 0x4e, 0x96, 0x7e, 0xdb, 0x80, 0x8d,
 x67, 0x9f, 0x77, 0x7b, 0xc6, 0x70, 0x2c, 0x7d,
 x39, 0xf2, 0x33, 0x69, 0xa9, 0xd9, 0xba, 0xcf,
 xa5, 0x30, 0xe2, 0x63, 0x04, 0x23, 0x14, 0x61,
 xb2, 0xeb, 0x05, 0xe2, 0xc3, 0x9b, 0xe9, 0xfc,
 xda, 0x6c, 0x19, 0x07, 0x8c, 0x6a, 0x9d, 0x1b,
 xfb, 0x98, 0x20, 0x2c, 0x45, 0xb2, 0xe4, 0xa0,
 x63, 0xc4, 0x68, 0xba, 0x84, 0x39, 0x16, 0x5a
 };
 uint8_t aes_cbc_test_case_3_iv[16] = {
 x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
 x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f
 };
 cipher_test_case_t aes_cbc_test_case_3 = {
 ,                                    /* octets in key            */
   aes_cbc_test_case_3_key,               /* key                      */
   aes_cbc_test_case_3_iv,                /* initialization vector    */
 ,                                    /* octets in plaintext      */
   aes_cbc_test_case_3_plaintext,         /* plaintext                */
 ,                                    /* octets in ciphertext     */
   aes_cbc_test_case_3_ciphertext,        /* ciphertext               */
   &aes_cbc_test_case_2                    /* pointer to next testcase */
 };
 cipher_type_t aes_cbc = {
   (cipher_alloc_func_t)          aes_cbc_alloc,
   (cipher_dealloc_func_t)        aes_cbc_dealloc,
   (cipher_init_func_t)           aes_cbc_context_init,
   (cipher_encrypt_func_t)        aes_cbc_nist_encrypt,
   (cipher_decrypt_func_t)        aes_cbc_nist_decrypt,
   (cipher_set_iv_func_t)         aes_cbc_set_iv,
   (char *)                       aes_cbc_description,
   (int)                          0,   /* instance count */
   (cipher_test_case_t *)        &aes_cbc_test_case_3,
   (debug_module_t *)            &mod_aes_cbc,
   (cipher_type_id_t)             AES_CBC
 };

The Tor Browser / annotate

netwerk/srtp/src/crypto/cipher/aes_cbc.c@6474c204b198 (annotated)

netwerk/srtp/src/crypto/cipher/aes_cbc.c