Add current version of libSRTP from CVS.

libsrtp/crypto/cipher/aes_cbc.c

+/*
+ * 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 = {
+  0,                 /* 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] = {
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f
+};
+
+uint8_t aes_cbc_test_case_0_plaintext[64] =  {
+  0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
+  0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff 
+};
+
+uint8_t aes_cbc_test_case_0_ciphertext[80] = {
+  0x69, 0xc4, 0xe0, 0xd8, 0x6a, 0x7b, 0x04, 0x30, 
+  0xd8, 0xcd, 0xb7, 0x80, 0x70, 0xb4, 0xc5, 0x5a,
+  0x03, 0x35, 0xed, 0x27, 0x67, 0xf2, 0x6d, 0xf1, 
+  0x64, 0x83, 0x2e, 0x23, 0x44, 0x38, 0x70, 0x8b
+
+};
+
+uint8_t aes_cbc_test_case_0_iv[16] = {
+  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
+  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+
+cipher_test_case_t aes_cbc_test_case_0 = {
+  16,                                    /* octets in key            */
+  aes_cbc_test_case_0_key,               /* key                      */
+  aes_cbc_test_case_0_iv,                /* initialization vector    */
+  16,                                    /* octets in plaintext      */
+  aes_cbc_test_case_0_plaintext,         /* plaintext                */
+  32,                                    /* 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] = {
+  0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6,
+  0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c,
+};
+
+uint8_t aes_cbc_test_case_1_plaintext[64] =  {
+  0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 
+  0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
+  0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 
+  0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
+  0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11,
+  0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
+  0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 
+  0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10
+};
+
+uint8_t aes_cbc_test_case_1_ciphertext[80] = {
+  0x76, 0x49, 0xab, 0xac, 0x81, 0x19, 0xb2, 0x46,
+  0xce, 0xe9, 0x8e, 0x9b, 0x12, 0xe9, 0x19, 0x7d,
+  0x50, 0x86, 0xcb, 0x9b, 0x50, 0x72, 0x19, 0xee,
+  0x95, 0xdb, 0x11, 0x3a, 0x91, 0x76, 0x78, 0xb2,
+  0x73, 0xbe, 0xd6, 0xb8, 0xe3, 0xc1, 0x74, 0x3b,
+  0x71, 0x16, 0xe6, 0x9e, 0x22, 0x22, 0x95, 0x16, 
+  0x3f, 0xf1, 0xca, 0xa1, 0x68, 0x1f, 0xac, 0x09, 
+  0x12, 0x0e, 0xca, 0x30, 0x75, 0x86, 0xe1, 0xa7,
+  0x39, 0x34, 0x07, 0x03, 0x36, 0xd0, 0x77, 0x99, 
+  0xe0, 0xc4, 0x2f, 0xdd, 0xa8, 0xdf, 0x4c, 0xa3
+};
+
+uint8_t aes_cbc_test_case_1_iv[16] = {
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f
+};
+
+cipher_test_case_t aes_cbc_test_case_1 = {
+  16,                                    /* octets in key            */
+  aes_cbc_test_case_1_key,               /* key                      */
+  aes_cbc_test_case_1_iv,                /* initialization vector    */
+  64,                                    /* octets in plaintext      */
+  aes_cbc_test_case_1_plaintext,         /* plaintext                */
+  80,                                    /* 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] = {
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
+  0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 
+  0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f
+};
+
+uint8_t aes_cbc_test_case_2_plaintext[64] =  {
+  0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77,
+  0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff 
+};
+
+uint8_t aes_cbc_test_case_2_ciphertext[80] = {
+  0x8e, 0xa2, 0xb7, 0xca, 0x51, 0x67, 0x45, 0xbf,
+  0xea, 0xfc, 0x49, 0x90, 0x4b, 0x49, 0x60, 0x89,  
+  0x72, 0x72, 0x6e, 0xe7, 0x71, 0x39, 0xbf, 0x11,
+  0xe5, 0x40, 0xe2, 0x7c, 0x54, 0x65, 0x1d, 0xee
+};
+
+uint8_t aes_cbc_test_case_2_iv[16] = {
+  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 
+  0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+};
+
+cipher_test_case_t aes_cbc_test_case_2 = {
+  32,                                    /* octets in key            */
+  aes_cbc_test_case_2_key,               /* key                      */
+  aes_cbc_test_case_2_iv,                /* initialization vector    */
+  16,                                    /* octets in plaintext      */
+  aes_cbc_test_case_2_plaintext,         /* plaintext                */
+  32,                                    /* 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] = {
+  0x60, 0x3d, 0xeb, 0x10, 0x15, 0xca, 0x71, 0xbe,
+  0x2b, 0x73, 0xae, 0xf0, 0x85, 0x7d, 0x77, 0x81,
+  0x1f, 0x35, 0x2c, 0x07, 0x3b, 0x61, 0x08, 0xd7,
+  0x2d, 0x98, 0x10, 0xa3, 0x09, 0x14, 0xdf, 0xf4
+};
+
+uint8_t aes_cbc_test_case_3_plaintext[64] =  {
+  0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 
+  0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
+  0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 
+  0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
+  0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11,
+  0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
+  0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 
+  0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10
+};
+
+uint8_t aes_cbc_test_case_3_ciphertext[80] = {
+  0xf5, 0x8c, 0x4c, 0x04, 0xd6, 0xe5, 0xf1, 0xba,
+  0x77, 0x9e, 0xab, 0xfb, 0x5f, 0x7b, 0xfb, 0xd6,
+  0x9c, 0xfc, 0x4e, 0x96, 0x7e, 0xdb, 0x80, 0x8d,
+  0x67, 0x9f, 0x77, 0x7b, 0xc6, 0x70, 0x2c, 0x7d,
+  0x39, 0xf2, 0x33, 0x69, 0xa9, 0xd9, 0xba, 0xcf,
+  0xa5, 0x30, 0xe2, 0x63, 0x04, 0x23, 0x14, 0x61,
+  0xb2, 0xeb, 0x05, 0xe2, 0xc3, 0x9b, 0xe9, 0xfc,
+  0xda, 0x6c, 0x19, 0x07, 0x8c, 0x6a, 0x9d, 0x1b,
+  0xfb, 0x98, 0x20, 0x2c, 0x45, 0xb2, 0xe4, 0xa0,
+  0x63, 0xc4, 0x68, 0xba, 0x84, 0x39, 0x16, 0x5a
+};
+
+uint8_t aes_cbc_test_case_3_iv[16] = {
+  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 
+  0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f
+};
+
+cipher_test_case_t aes_cbc_test_case_3 = {
+  32,                                    /* octets in key            */
+  aes_cbc_test_case_3_key,               /* key                      */
+  aes_cbc_test_case_3_iv,                /* initialization vector    */
+  64,                                    /* octets in plaintext      */
+  aes_cbc_test_case_3_plaintext,         /* plaintext                */
+  80,                                    /* 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
+};
+
+