common: Fix crash with RCE_SRTP without Crypto++

src/session.cc

@@ -107,17 +107,18 @@ uvgrtp::media_stream* uvgrtp::session::create_stream(uint16_t src_port, uint16_t
         rtp_errno = RTP_INVALID_VALUE;
         return  nullptr;
     }
+
+    if (rce_flags & RCE_SRTP && !uvgrtp::crypto::enabled()) 
+    {
+        UVG_LOG_ERROR("RCE_SRTP requires inclusion of Crypto++ during compilation!");
+        rtp_errno = RTP_GENERIC_ERROR;
+        return nullptr;
+    }
 
     uvgrtp::media_stream* stream =
         new uvgrtp::media_stream(cname_, remote_address_, local_address_, src_port, dst_port, fmt, sf_, rce_flags);
 
     if (rce_flags & RCE_SRTP) {
-        if (!uvgrtp::crypto::enabled()) {
-            UVG_LOG_ERROR("Recompile uvgRTP with -D__RTP_CRYPTO__");
-            delete stream;
-            rtp_errno = RTP_GENERIC_ERROR;
-            return nullptr;
-        }
 
         session_mtx_.lock();
         if (!zrtp_) {

test/test_5_srtp_zrtp.cpp

@@ -50,13 +50,6 @@ void test_user_key(Key_length len)
     std::cout << "Starting ZRTP sender thread" << std::endl;
     uvgrtp::context ctx;
 
-    if (!ctx.crypto_enabled())
-    {
-        std::cout << "Please link crypto to uvgRTP library in order to tests its SRTP user keys!" << std::endl;
-        FAIL();
-        return;
-    }
-
     uint8_t *key = new uint8_t[len];
     uint8_t salt[SALT_SIZE_BYTES] = { 0 };
 
@@ -188,13 +181,6 @@ TEST(EncryptionTests, zrtp)
 {
     uvgrtp::context ctx;
 
-    if (!ctx.crypto_enabled())
-    {
-        std::cout << "Please link crypto to uvgRTP library in order to tests its ZRTP feature!" << std::endl;
-        FAIL();
-        return;
-    }
-
     uvgrtp::session* sender_session = ctx.create_session(RECEIVER_ADDRESS, SENDER_ADDRESS);
     uvgrtp::session* receiver_session = ctx.create_session(SENDER_ADDRESS, RECEIVER_ADDRESS);