mirror of
https://github.com/ZLMediaKit/ZLMediaKit.git
synced 2024-10-06 12:13:49 +08:00
311 lines
8.9 KiB
C++
311 lines
8.9 KiB
C++
#define MS_CLASS "RTC::SrtpSession"
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// #define MS_LOG_DEV_LEVEL 3
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#include "SrtpSession.hpp"
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#include <cstring> // std::memset(), std::memcpy()
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#include "logger.h"
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#include "Util/util.h"
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#include "Util/logger.h"
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using namespace toolkit;
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namespace RTC
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{
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/* Static. */
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static std::vector<const char *> errors = {
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// From 0 (srtp_err_status_ok) to 24 (srtp_err_status_pfkey_err).
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"success (srtp_err_status_ok)",
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"unspecified failure (srtp_err_status_fail)",
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"unsupported parameter (srtp_err_status_bad_param)",
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"couldn't allocate memory (srtp_err_status_alloc_fail)",
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"couldn't deallocate memory (srtp_err_status_dealloc_fail)",
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"couldn't initialize (srtp_err_status_init_fail)",
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"can’t process as much data as requested (srtp_err_status_terminus)",
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"authentication failure (srtp_err_status_auth_fail)",
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"cipher failure (srtp_err_status_cipher_fail)",
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"replay check failed (bad index) (srtp_err_status_replay_fail)",
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"replay check failed (index too old) (srtp_err_status_replay_old)",
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"algorithm failed test routine (srtp_err_status_algo_fail)",
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"unsupported operation (srtp_err_status_no_such_op)",
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"no appropriate context found (srtp_err_status_no_ctx)",
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"unable to perform desired validation (srtp_err_status_cant_check)",
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"can’t use key any more (srtp_err_status_key_expired)",
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"error in use of socket (srtp_err_status_socket_err)",
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"error in use POSIX signals (srtp_err_status_signal_err)",
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"nonce check failed (srtp_err_status_nonce_bad)",
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"couldn’t read data (srtp_err_status_read_fail)",
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"couldn’t write data (srtp_err_status_write_fail)",
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"error parsing data (srtp_err_status_parse_err)",
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"error encoding data (srtp_err_status_encode_err)",
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"error while using semaphores (srtp_err_status_semaphore_err)",
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"error while using pfkey (srtp_err_status_pfkey_err)"};
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// clang-format on
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/* Static methods. */
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const char *DepLibSRTP::GetErrorString(srtp_err_status_t code) {
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// This throws out_of_range if the given index is not in the vector.
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return errors.at(code);
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}
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bool DepLibSRTP::IsError(srtp_err_status_t code) {
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return (code != srtp_err_status_ok);
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}
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INSTANCE_IMP(DepLibSRTP);
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DepLibSRTP::DepLibSRTP(){
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MS_TRACE();
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MS_DEBUG_TAG(info, "libsrtp version: \"%s\"", srtp_get_version_string());
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srtp_err_status_t err = srtp_init();
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#if 0
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srtp_install_log_handler([](srtp_log_level_t level,
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const char *msg,
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void *data) {
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printf("%s\n", msg);
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}, nullptr);
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srtp_set_debug_module("srtp", 1);
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srtp_set_debug_module("hmac sha-1", 1);
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srtp_set_debug_module("aes icm", 1);
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srtp_set_debug_module("alloc", 1);
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srtp_set_debug_module("stat test", 1);
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srtp_set_debug_module("cipher", 1);
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srtp_set_debug_module("auth func", 1);
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srtp_set_debug_module("crypto kernel", 1);
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srtp_list_debug_modules();
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#endif
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if (DepLibSRTP::IsError(err)) {
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MS_THROW_ERROR("srtp_init() failed: %s", DepLibSRTP::GetErrorString(err));
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}
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// Set libsrtp event handler.
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err = srtp_install_event_handler([](srtp_event_data_t *data){
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MS_TRACE();
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switch (data->event)
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{
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case event_ssrc_collision:
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MS_WARN_TAG(srtp, "SSRC collision occurred");
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break;
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case event_key_soft_limit:
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MS_WARN_TAG(srtp, "stream reached the soft key usage limit and will expire soon");
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break;
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case event_key_hard_limit:
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MS_WARN_TAG(srtp, "stream reached the hard key usage limit and has expired");
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break;
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case event_packet_index_limit:
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MS_WARN_TAG(srtp, "stream reached the hard packet limit (2^48 packets)");
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break;
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}
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});
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if (DepLibSRTP::IsError(err))
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{
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MS_THROW_ERROR("srtp_install_event_handler() failed: %s", DepLibSRTP::GetErrorString(err));
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}
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}
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DepLibSRTP::~DepLibSRTP(){
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MS_TRACE();
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srtp_shutdown();
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}
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/////////////////////////////////////////////////////////////////////////////////////
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/* Instance methods. */
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SrtpSession::SrtpSession(Type type, CryptoSuite cryptoSuite, uint8_t* key, size_t keyLen)
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{
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_env = DepLibSRTP::Instance().shared_from_this();
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MS_TRACE();
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srtp_policy_t policy; // NOLINT(cppcoreguidelines-pro-type-member-init)
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// Set all policy fields to 0.
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std::memset(&policy, 0, sizeof(srtp_policy_t));
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switch (cryptoSuite)
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{
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case CryptoSuite::AES_CM_128_HMAC_SHA1_80:
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{
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srtp_crypto_policy_set_aes_cm_128_hmac_sha1_80(&policy.rtp);
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srtp_crypto_policy_set_aes_cm_128_hmac_sha1_80(&policy.rtcp);
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break;
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}
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case CryptoSuite::AES_CM_128_HMAC_SHA1_32:
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{
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srtp_crypto_policy_set_aes_cm_128_hmac_sha1_32(&policy.rtp);
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// NOTE: Must be 80 for RTCP.
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srtp_crypto_policy_set_aes_cm_128_hmac_sha1_80(&policy.rtcp);
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break;
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}
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case CryptoSuite::AEAD_AES_256_GCM:
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{
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srtp_crypto_policy_set_aes_gcm_256_16_auth(&policy.rtp);
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srtp_crypto_policy_set_aes_gcm_256_16_auth(&policy.rtcp);
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break;
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}
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case CryptoSuite::AEAD_AES_128_GCM:
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{
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srtp_crypto_policy_set_aes_gcm_128_16_auth(&policy.rtp);
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srtp_crypto_policy_set_aes_gcm_128_16_auth(&policy.rtcp);
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break;
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}
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default:
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{
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MS_ABORT("unknown SRTP crypto suite");
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}
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}
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MS_ASSERT(
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(int)keyLen == policy.rtp.cipher_key_len,
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"given keyLen does not match policy.rtp.cipher_keyLen");
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switch (type)
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{
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case Type::INBOUND:
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policy.ssrc.type = ssrc_any_inbound;
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break;
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case Type::OUTBOUND:
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policy.ssrc.type = ssrc_any_outbound;
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break;
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}
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policy.ssrc.value = 0;
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policy.key = key;
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// Required for sending RTP retransmission without RTX.
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policy.allow_repeat_tx = 1;
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policy.window_size = 1024;
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policy.next = nullptr;
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// Set the SRTP session.
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srtp_err_status_t err = srtp_create(&this->session, &policy);
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if (DepLibSRTP::IsError(err))
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MS_THROW_ERROR("srtp_create() failed: %s", DepLibSRTP::GetErrorString(err));
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}
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SrtpSession::~SrtpSession()
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{
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MS_TRACE();
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if (this->session != nullptr)
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{
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srtp_err_status_t err = srtp_dealloc(this->session);
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if (DepLibSRTP::IsError(err))
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MS_ABORT("srtp_dealloc() failed: %s", DepLibSRTP::GetErrorString(err));
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}
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}
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bool SrtpSession::EncryptRtp(const uint8_t** data, size_t* len, uint8_t pt)
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{
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MS_TRACE();
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// Ensure that the resulting SRTP packet fits into the encrypt buffer.
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if (*len + SRTP_MAX_TRAILER_LEN > EncryptBufferSize)
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{
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MS_WARN_TAG(srtp, "cannot encrypt RTP packet, size too big (%zu bytes)", *len);
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return false;
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}
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std::memcpy(EncryptBuffer, *data, *len);
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EncryptBuffer[1] |= (pt & 0x7F);
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srtp_err_status_t err =
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srtp_protect(this->session, static_cast<void*>(EncryptBuffer), reinterpret_cast<int*>(len));
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if (DepLibSRTP::IsError(err))
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{
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MS_WARN_TAG(srtp, "srtp_protect() failed: %s", DepLibSRTP::GetErrorString(err));
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return false;
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}
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// Update the given data pointer.
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*data = (const uint8_t*)EncryptBuffer;
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return true;
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}
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bool SrtpSession::DecryptSrtp(uint8_t* data, size_t* len)
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{
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MS_TRACE();
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srtp_err_status_t err =
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srtp_unprotect(this->session, static_cast<void*>(data), reinterpret_cast<int*>(len));
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if (DepLibSRTP::IsError(err))
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{
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MS_DEBUG_TAG(srtp, "srtp_unprotect() failed: %s", DepLibSRTP::GetErrorString(err));
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return false;
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}
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return true;
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}
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bool SrtpSession::EncryptRtcp(const uint8_t** data, size_t* len)
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{
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MS_TRACE();
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// Ensure that the resulting SRTCP packet fits into the encrypt buffer.
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if (*len + SRTP_MAX_TRAILER_LEN > EncryptBufferSize)
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{
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MS_WARN_TAG(srtp, "cannot encrypt RTCP packet, size too big (%zu bytes)", *len);
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return false;
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}
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std::memcpy(EncryptBuffer, *data, *len);
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srtp_err_status_t err = srtp_protect_rtcp(
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this->session, static_cast<void*>(EncryptBuffer), reinterpret_cast<int*>(len));
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if (DepLibSRTP::IsError(err))
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{
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MS_WARN_TAG(srtp, "srtp_protect_rtcp() failed: %s", DepLibSRTP::GetErrorString(err));
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return false;
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}
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// Update the given data pointer.
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*data = (const uint8_t*)EncryptBuffer;
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return true;
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}
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bool SrtpSession::DecryptSrtcp(uint8_t* data, size_t* len)
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{
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MS_TRACE();
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srtp_err_status_t err =
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srtp_unprotect_rtcp(this->session, static_cast<void*>(data), reinterpret_cast<int*>(len));
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if (DepLibSRTP::IsError(err))
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{
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MS_DEBUG_TAG(srtp, "srtp_unprotect_rtcp() failed: %s", DepLibSRTP::GetErrorString(err));
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return false;
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}
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return true;
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}
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} // namespace RTC
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