fix(esp_tls): check tls connection finished before read/write operation

components/esp-tls/esp_tls.c

@@ -137,6 +137,15 @@ ssize_t esp_tls_conn_read(esp_tls_t *tls, void  *data, size_t datalen)
     if (!tls) {
         return -1;
     }
+    if (!tls->read) {
+        return -1;
+    }
+#if CONFIG_MBEDTLS_DYNAMIC_BUFFER
+    if (tls->is_tls && tls->conn_state != ESP_TLS_DONE) {
+        ESP_LOGE(TAG, "TLS handshake has not completed, read operation not permitted");
+        return -1;
+    }
+#endif
     return tls->read(tls, (char *)data, datalen);
 }
 
@@ -145,6 +154,15 @@ ssize_t esp_tls_conn_write(esp_tls_t *tls, const void  *data, size_t datalen)
     if (!tls || !data) {
         return -1;
     }
+    if (!tls->write) {
+        return -1;
+    }
+#if CONFIG_MBEDTLS_DYNAMIC_BUFFER
+    if (tls->is_tls && tls->conn_state != ESP_TLS_DONE) {
+        ESP_LOGE(TAG, "TLS handshake has not completed, write operation not permitted");
+        return -1;
+    }
+#endif
     return tls->write(tls, (char *)data, datalen);
 }
 
@@ -566,12 +584,12 @@ int esp_tls_conn_new_sync(const char *hostname, int hostlen, int port, const esp
         } else if (ret == -1) {
             ESP_LOGE(TAG, "Failed to open new connection");
             return -1;
-        } else if (ret == 0 && cfg->timeout_ms >= 0) {
+        } else if (ret == 0 && cfg->timeout_ms > 0) {
             uint64_t elapsed_time_us = esp_tls_get_platform_time() - start_time_us;
             if ((elapsed_time_us / 1000) >= cfg->timeout_ms) {
                 ESP_LOGW(TAG, "Failed to open new connection in specified timeout");
                 ESP_INT_EVENT_TRACKER_CAPTURE(tls->error_handle, ESP_TLS_ERR_TYPE_ESP, ESP_ERR_ESP_TLS_CONNECTION_TIMEOUT);
-                return 0;
+                return -1;
             }
         }
     }

components/esp-tls/esp_tls.h

@@ -438,10 +438,17 @@ esp_tls_t *esp_tls_conn_http_new(const char *url, const esp_tls_cfg_t *cfg) __at
  *                       structure should be zero-initialized
  * @param[in]  tls       Pointer to esp-tls as esp-tls handle.
  *
+ * @note       The cfg->timeout_ms parameter controls the connection timeout:
+ *             - timeout_ms > 0:  The connection attempt will be aborted if it does not
+ *                                complete within the specified duration.
+ *             - timeout_ms <= 0: No application-level timeout is applied. The connection
+ *                                relies on the underlying socket timeout (ESP_TLS_DEFAULT_CONN_TIMEOUT).
+ *             On timeout, the function returns -1 and records
+ *             ESP_ERR_ESP_TLS_CONNECTION_TIMEOUT in the error handle.
+ *
  * @return
- *             - -1      If connection establishment fails.
+ *             - -1      If connection establishment fails (including timeout).
  *             -  1      If connection establishment is successful.
- *             -  0      If connection state is in progress.
  */
 int esp_tls_conn_new_sync(const char *hostname, int hostlen, int port, const esp_tls_cfg_t *cfg, esp_tls_t *tls);
 

components/esp-tls/esp_tls_mbedtls.c

@@ -1148,6 +1148,7 @@ int esp_mbedtls_server_session_create(esp_tls_cfg_server_t *cfg, int sockfd, esp
             return ESP_ERR_ESP_TLS_SERVER_HANDSHAKE_TIMEOUT;
         }
     }
+    tls->conn_state = ESP_TLS_DONE;
     return ret;
 }