feat: added semaphore around `TLSSocket_performHandshake`

hal/tls/mbedtls/tls_mbedtls.c

@@ -99,6 +99,7 @@ struct sTLSSocket {
 
     /* time of last session renegotiation (used to calculate next renegotiation time) */
     uint64_t lastRenegotiationTime;
+    Semaphore renegotiationLock;
 
     /* time of the last CRL update */
     uint64_t crlUpdated;
@@ -708,6 +709,7 @@ TLSSocket_create(Socket socket, TLSConfiguration configuration, bool storeClient
         self->storePeerCert = storeClientCert;
         self->peerCert = NULL;
         self->peerCertLength = 0;
+        self->renegotiationLock = Semaphore_create(1);
 
         TLSConfiguration_setupComplete(configuration);
 
@@ -850,6 +852,7 @@ TLSSocket_getPeerCertificate(TLSSocket self, int* certSize)
 bool
 TLSSocket_performHandshake(TLSSocket self)
 {
+    Semaphore_wait(self->renegotiationLock);
     int ret = mbedtls_ssl_renegotiate(&(self->ssl));
 
     if (ret == 0) {
@@ -857,6 +860,9 @@ TLSSocket_performHandshake(TLSSocket self)
             raiseSecurityEvent(self->tlsConfig, TLS_SEC_EVT_WARNING, TLS_EVENT_CODE_WRN_INSECURE_TLS_VERSION, "Warning: Insecure TLS version", self);
         }
 
+        Semaphore_post(self->renegotiationLock);
+
+        DEBUG_PRINT("TLS", "TLSSocket_performHandshake Success -> ret=%i\n", ret);
         return true;
     }
     else {
@@ -868,6 +874,7 @@ TLSSocket_performHandshake(TLSSocket self)
             createSecurityEvents(self->tlsConfig, ret, flags, self);
         }
 
+        Semaphore_post(self->renegotiationLock);
         return false;
     }
 }
@@ -1008,6 +1015,8 @@ TLSSocket_close(TLSSocket self)
     if (self->peerCert)
         GLOBAL_FREEMEM(self->peerCert);
 
+    Semaphore_destroy(self->renegotiationLock);
+
     GLOBAL_FREEMEM(self);
 }