Implemented WebRTC

lib/dtls_srtp_handshake.h

@@ -0,0 +1,59 @@
+#pragma once
+
+#include <stdint.h>
+#include <deque>
+#include <mbedtls/config.h>
+#include <mbedtls/entropy.h>
+#include <mbedtls/ctr_drbg.h>
+#include <mbedtls/certs.h>
+#include <mbedtls/x509.h>
+#include <mbedtls/ssl.h>
+#include <mbedtls/ssl_cookie.h>
+#include <mbedtls/error.h>
+#include <mbedtls/debug.h>
+#include <mbedtls/timing.h>
+
+/* ----------------------------------------- */
+
+class DTLSSRTPHandshake {
+public:
+  DTLSSRTPHandshake();
+  int init(mbedtls_x509_crt* certificate, mbedtls_pk_context* privateKey, int(*writeCallback)(const uint8_t* data, int* nbytes)); // writeCallback should return 0 on succes < 0 on error. nbytes holds the number of bytes to be sent and needs to be set to the number of bytes actually sent. 
+  int shutdown();
+  int parse(const uint8_t* data, size_t nbytes);
+  bool hasKeyingMaterial();
+                 
+private:
+  int extractKeyingMaterial();
+  int resetSession();
+    
+private:
+  mbedtls_x509_crt* cert;                                  /* Certificate, we do not own the key. Make sure it's kept alive during the livetime of this class instance. */
+  mbedtls_pk_context* key;                                 /* Private key, we do not own the key. Make sure it's kept alive during the livetime of this class instance. */
+  mbedtls_entropy_context entropy_ctx; 
+  mbedtls_ctr_drbg_context rand_ctx;
+  mbedtls_ssl_context ssl_ctx;
+  mbedtls_ssl_config ssl_conf;
+  mbedtls_ssl_cookie_ctx cookie_ctx;
+  mbedtls_timing_delay_context timer_ctx;
+
+public:
+  int (*write_callback)(const uint8_t* data, int* nbytes); 
+  std::deque<uint8_t> buffer;                              /* Accessed from BIO callbback. We copy the bytes you pass into `parse()` into this temporary buffer which is read by a trigger to `mbedlts_ssl_handshake()`. */
+  std::string cipher;                                      /* selected SRTP cipher. */
+  std::string remote_key;
+  std::string remote_salt;
+  std::string local_key;
+  std::string local_salt;
+};
+
+/* ----------------------------------------- */
+  
+inline bool DTLSSRTPHandshake::hasKeyingMaterial() {
+  return (0 != remote_key.size()
+          && 0 != remote_salt.size()
+          && 0 != local_key.size()
+          && 0 != local_salt.size());
+}
+
+/* ----------------------------------------- */