Revert "Remove useless check for valid certificate"

This reverts commit a1f93fc.

Author: archigup

platform/posix/transport/src/openssl_posix.c

@@ -282,6 +282,19 @@ static OpensslStatus_t tlsHandshake( OpensslParams_t * pOpensslParams,
         }
     }
 
+    /* Verify X509 certificate from peer. */
+    if( returnStatus == OPENSSL_SUCCESS )
+    {
+        verifyPeerCertStatus = ( int32_t ) SSL_get_verify_result( pOpensslParams->pSsl );
+
+        if( verifyPeerCertStatus != X509_V_OK )
+        {
+            LogError( ( "SSL_get_verify_result failed to verify X509 "
+                        "certificate from peer." ) );
+            returnStatus = OPENSSL_HANDSHAKE_FAILED;
+        }
+    }
+
     return returnStatus;
 }