| /* |
| * Copyright 2014 The WebRTC project authors. All Rights Reserved. |
| * |
| * Use of this source code is governed by a BSD-style license |
| * that can be found in the LICENSE file in the root of the source |
| * tree. An additional intellectual property rights grant can be found |
| * in the file PATENTS. All contributing project authors may |
| * be found in the AUTHORS file in the root of the source tree. |
| */ |
| |
| #ifndef WEBRTC_PC_EXTERNALHMAC_H_ |
| #define WEBRTC_PC_EXTERNALHMAC_H_ |
| |
| // External libsrtp HMAC auth module which implements methods defined in |
| // auth_type_t. |
| // The default auth module will be replaced only when the ENABLE_EXTERNAL_AUTH |
| // flag is enabled. This allows us to access to authentication keys, |
| // as the default auth implementation doesn't provide access and avoids |
| // hashing each packet twice. |
| |
| // How will libsrtp select this module? |
| // Libsrtp defines authentication function types identified by an unsigned |
| // integer, e.g. HMAC_SHA1 is 3. Using authentication ids, the application |
| // can plug any desired authentication modules into libsrtp. |
| // libsrtp also provides a mechanism to select different auth functions for |
| // individual streams. This can be done by setting the right value in |
| // the auth_type of srtp_policy_t. The application must first register auth |
| // functions and the corresponding authentication id using |
| // crypto_kernel_replace_auth_type function. |
| |
| #include "webrtc/base/basictypes.h" |
| #ifdef HAVE_SRTP |
| extern "C" { |
| #ifdef SRTP_RELATIVE_PATH |
| #include "auth.h" // NOLINT |
| #else |
| #include "third_party/libsrtp/crypto/include/auth.h" |
| #endif // SRTP_RELATIVE_PATH |
| } |
| #endif // HAVE_SRTP |
| |
| #if defined(HAVE_SRTP) && defined(ENABLE_EXTERNAL_AUTH) |
| |
| #define EXTERNAL_HMAC_SHA1 HMAC_SHA1 + 1 |
| #define HMAC_KEY_LENGTH 20 |
| |
| // The HMAC context structure used to store authentication keys. |
| // The pointer to the key will be allocated in the external_hmac_init function. |
| // This pointer is owned by srtp_t in a template context. |
| typedef struct { |
| uint8_t key[HMAC_KEY_LENGTH]; |
| int key_length; |
| } ExternalHmacContext; |
| |
| err_status_t external_hmac_alloc(auth_t** a, int key_len, int out_len); |
| |
| err_status_t external_hmac_dealloc(auth_t* a); |
| |
| err_status_t external_hmac_init(ExternalHmacContext* state, |
| const uint8_t* key, |
| int key_len); |
| |
| err_status_t external_hmac_start(ExternalHmacContext* state); |
| |
| err_status_t external_hmac_update(ExternalHmacContext* state, |
| const uint8_t* message, |
| int msg_octets); |
| |
| err_status_t external_hmac_compute(ExternalHmacContext* state, |
| const void* message, |
| int msg_octets, |
| int tag_len, |
| uint8_t* result); |
| |
| err_status_t external_crypto_init(); |
| |
| #endif // defined(HAVE_SRTP) && defined(ENABLE_EXTERNAL_AUTH) |
| #endif // WEBRTC_PC_EXTERNALHMAC_H_ |