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/*
* libjingle
* Copyright 2014 Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
*/
#if defined(HAVE_SRTP) && defined(ENABLE_EXTERNAL_AUTH)
#include "talk/session/media/externalhmac.h"
#include <stdlib.h> // For malloc/free.
extern "C" {
#ifdef SRTP_RELATIVE_PATH
#include "srtp.h" // NOLINT
#include "crypto_kernel.h" // NOLINT
#else
#include "third_party/libsrtp/srtp/include/srtp.h"
#include "third_party/libsrtp/srtp/crypto/include/crypto_kernel.h"
#endif // SRTP_RELATIVE_PATH
}
#include "webrtc/base/logging.h"
// Begin test case 0 */
static const uint8_t kExternalHmacTestCase0Key[20] = {
0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b,
0x0b, 0x0b, 0x0b, 0x0b
};
static const uint8_t kExternalHmacTestCase0Data[8] = {
0x48, 0x69, 0x20, 0x54, 0x68, 0x65, 0x72, 0x65 // "Hi There"
};
static const uint8_t kExternalHmacFakeTag[10] = {
0xba, 0xdd, 0xba, 0xdd, 0xba, 0xdd, 0xba, 0xdd, 0xba, 0xdd
};
static const auth_test_case_t kExternalHmacTestCase0 = {
20, // Octets in key
const_cast<uint8_t*>(kExternalHmacTestCase0Key), // Key
8, // Octets in data
const_cast<uint8_t*>(kExternalHmacTestCase0Data), // Data
10, // Octets in tag
const_cast<uint8_t*>(kExternalHmacFakeTag), // Tag
NULL // Pointer to next
// testcase
};
static const char kExternalHmacDescription[] =
"external hmac sha-1 authentication";
// auth_type_t external_hmac is the hmac metaobject
static const auth_type_t external_hmac = {
external_hmac_alloc,
external_hmac_dealloc,
(auth_init_func) external_hmac_init,
(auth_compute_func) external_hmac_compute,
(auth_update_func) external_hmac_update,
(auth_start_func) external_hmac_start,
const_cast<char*>(kExternalHmacDescription),
0, // Instance count.
const_cast<auth_test_case_t*>(&kExternalHmacTestCase0),
NULL, // No debugging module.
EXTERNAL_HMAC_SHA1
};
err_status_t external_hmac_alloc(auth_t** a, int key_len, int out_len) {
uint8_t* pointer;
// Check key length - note that we don't support keys larger
// than 20 bytes yet
if (key_len > 20)
return err_status_bad_param;
// Check output length - should be less than 20 bytes/
if (out_len > 20)
return err_status_bad_param;
// Allocate memory for auth and hmac_ctx_t structures.
pointer = new uint8_t[(sizeof(ExternalHmacContext) + sizeof(auth_t))];
if (pointer == NULL)
return err_status_alloc_fail;
// Set pointers
*a = (auth_t *)pointer;
// |external_hmac| is const and libsrtp expects |type| to be non-const.
// const conversion is required. |external_hmac| is constant because we don't
// want to increase global count in Chrome.
(*a)->type = const_cast<auth_type_t*>(&external_hmac);
(*a)->state = pointer + sizeof(auth_t);
(*a)->out_len = out_len;
(*a)->key_len = key_len;
(*a)->prefix_len = 0;
return err_status_ok;
}
err_status_t external_hmac_dealloc(auth_t* a) {
// Zeroize entire state
memset((uint8_t *)a, 0, sizeof(ExternalHmacContext) + sizeof(auth_t));
// Free memory
delete[] a;
return err_status_ok;
}
err_status_t external_hmac_init(ExternalHmacContext* state,
const uint8_t* key,
int key_len) {
if (key_len > HMAC_KEY_LENGTH)
return err_status_bad_param;
memset(state->key, 0, key_len);
memcpy(state->key, key, key_len);
state->key_length = key_len;
return err_status_ok;
}
err_status_t external_hmac_start(ExternalHmacContext* state) {
return err_status_ok;
}
err_status_t external_hmac_update(ExternalHmacContext* state,
const uint8_t* message,
int msg_octets) {
return err_status_ok;
}
err_status_t external_hmac_compute(ExternalHmacContext* state,
const void* message,
int msg_octets,
int tag_len,
uint8_t* result) {
memcpy(result, kExternalHmacFakeTag, tag_len);
return err_status_ok;
}
err_status_t external_crypto_init() {
// |external_hmac| is const. const_cast is required as libsrtp expects
// non-const.
err_status_t status = crypto_kernel_replace_auth_type(
const_cast<auth_type_t*>(&external_hmac), EXTERNAL_HMAC_SHA1);
if (status) {
LOG(LS_ERROR) << "Error in replacing default auth module, error: "
<< status;
return err_status_fail;
}
return err_status_ok;
}
#endif // defined(HAVE_SRTP) && defined(ENABLE_EXTERNAL_AUTH)
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