fix(ws_transport): fixed server-key corruption

When first fragment is sent over HTTP during websocket
connection, defer buffering of fragment until after the
websocket server-key is validated.

This order is required because the first fragment buffering
overwrites the memory holding the server-key headers.

Fixes 2267d4b
Fixes espressif/esp-protocols#396
PR #13724

components/tcp_transport/transport_ws.c

@@ -307,20 +307,6 @@ static int ws_connect(esp_transport_handle_t t, const char *host, int port, int
  return -1;
  }
 
- if (delim_ptr != NULL) {
- size_t delim_pos = delim_ptr - ws->buffer + sizeof(delimiter) - 1;
- size_t remaining_len = ws->buffer_len - delim_pos;
- if (remaining_len > 0) {
- memmove(ws->buffer, ws->buffer + delim_pos, remaining_len);
- ws->buffer_len = remaining_len;
- } else {
-#ifdef CONFIG_WS_DYNAMIC_BUFFER
- free(ws->buffer);
- ws->buffer = NULL;
-#endif
- ws->buffer_len = 0;
- }
- }
  // See esp_crypto_sha1() arg size
  unsigned char expected_server_sha1[20];
  // Size of base64 coded string see above
@@ -340,6 +326,22 @@ static int ws_connect(esp_transport_handle_t t, const char *host, int port, int
  ESP_LOGE(TAG, "Invalid websocket key");
  return -1;
  }
+
+ if (delim_ptr != NULL) {
+ size_t delim_pos = delim_ptr - ws->buffer + sizeof(delimiter) - 1;
+ size_t remaining_len = ws->buffer_len - delim_pos;
+ if (remaining_len > 0) {
+ memmove(ws->buffer, ws->buffer + delim_pos, remaining_len);
+ ws->buffer_len = remaining_len;
+ } else {
+#ifdef CONFIG_WS_DYNAMIC_BUFFER
+ free(ws->buffer);
+ ws->buffer = NULL;
+#endif
+ ws->buffer_len = 0;
+ }
+ }
+
  return 0;
 }