proxy: decode username and password (#6700)

## Problem

usernames and passwords can be URL 'percent' encoded in the connection
string URL provided by serverless driver.

## Summary of changes

Decode the parameters when getting conn info

test_runner/fixtures/neon_fixtures.py

@@ -23,7 +23,7 @@ from itertools import chain, product
 from pathlib import Path
 from types import TracebackType
 from typing import Any, Callable, Dict, Iterator, List, Optional, Tuple, Type, Union, cast
-from urllib.parse import urlparse
+from urllib.parse import quote, urlparse
 
 import asyncpg
 import backoff
@@ -2822,8 +2822,8 @@ class NeonProxy(PgProtocol):
 
     def http_query(self, query, args, **kwargs):
         # TODO maybe use default values if not provided
-        user = kwargs["user"]
-        password = kwargs["password"]
+        user = quote(kwargs["user"])
+        password = quote(kwargs["password"])
         expected_code = kwargs.get("expected_code")
 
         connstr = f"postgresql://{user}:{password}@{self.domain}:{self.proxy_port}/postgres"

test_runner/regress/test_proxy.py

@@ -462,6 +462,18 @@ def test_sql_over_http_pool(static_proxy: NeonProxy):
     assert "password authentication failed for user" in res["message"]
 
 
+def test_sql_over_http_urlencoding(static_proxy: NeonProxy):
+    static_proxy.safe_psql("create user \"http+auth$$\" with password '%+$^&*@!' superuser")
+
+    static_proxy.http_query(
+        "select 1",
+        [],
+        user="http+auth$$",
+        password="%+$^&*@!",
+        expected_code=200,
+    )
+
+
 # Beginning a transaction should not impact the next query,
 # which might come from a completely different client.
 def test_http_pool_begin(static_proxy: NeonProxy):