Fix generating authentication response with long strings

netch80 · netch80 · commit ab82515001a2 · 2021-06-25T21:32:10.000+03:00
MySQL protocol uses special rules for string longer than
251 characters.
diff --git a/pymysql/connections.py b/pymysql/connections.py
@@ -879,10 +879,11 @@ def _request_authentication(self):
             else:
                 authresp = b"\0"  # empty password
 
-        if self.server_capabilities & CLIENT.PLUGIN_AUTH_LENENC_CLIENT_DATA:
+        if (
+            self.server_capabilities & CLIENT.PLUGIN_AUTH_LENENC_CLIENT_DATA
+            or self.server_capabilities & CLIENT.SECURE_CONNECTION
+        ):
             data += _lenenc_int(len(authresp)) + authresp
-        elif self.server_capabilities & CLIENT.SECURE_CONNECTION:
-            data += struct.pack("B", len(authresp)) + authresp
         else:  # pragma: no cover - not testing against servers without secure auth (>=5.0)
             data += authresp + b"\0"
 
@@ -898,10 +899,10 @@ def _request_authentication(self):
             connect_attrs = b""
             for k, v in self._connect_attrs.items():
                 k = k.encode("utf-8")
-                connect_attrs += struct.pack("B", len(k)) + k
+                connect_attrs += _lenenc_int(len(k)) + k
                 v = v.encode("utf-8")
-                connect_attrs += struct.pack("B", len(v)) + v
-            data += struct.pack("B", len(connect_attrs)) + connect_attrs
+                connect_attrs += _lenenc_int(len(v)) + v
+            data += _lenenc_int(len(connect_attrs)) + connect_attrs
 
         self.write_packet(data)
         auth_packet = self._read_packet()
