Add ssl_password support to async Redis client (#3878)

* Add ssl_password support to async Redis client (#3347)

Add ssl_password parameter to the async Redis client and SSLConnection
to enable using encrypted private keys, matching the sync client's
functionality.

Changes:
- Add ssl_password parameter to Redis.__init__
- Add ssl_password parameter to SSLConnection.__init__
- Add password parameter to RedisSSLContext
- Pass password to ssl.SSLContext.load_cert_chain()

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

* Add test for ssl_password parameter

Add test_ssl_password_parameter test to verify ssl_password is properly
passed through to SSLConnection for encrypted private key support.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

---------

Co-authored-by: Claude <noreply@anthropic.com>
Co-authored-by: petyaslavova <petya.slavova@redis.com>

Author: 3 people

redis/asyncio/client.py

@@ -247,6 +247,7 @@ def __init__(
         ssl_check_hostname: bool = True,
         ssl_min_version: Optional[TLSVersion] = None,
         ssl_ciphers: Optional[str] = None,
+        ssl_password: Optional[str] = None,
         max_connections: Optional[int] = None,
         single_connection_client: bool = False,
         health_check_interval: int = 0,
@@ -359,6 +360,7 @@ def __init__(
                             "ssl_check_hostname": ssl_check_hostname,
                             "ssl_min_version": ssl_min_version,
                             "ssl_ciphers": ssl_ciphers,
+                            "ssl_password": ssl_password,
                         }
                     )
             # This arg only used if no pool is passed in

redis/asyncio/connection.py

@@ -817,6 +817,7 @@ def __init__(
         ssl_check_hostname: bool = True,
         ssl_min_version: Optional[TLSVersion] = None,
         ssl_ciphers: Optional[str] = None,
+        ssl_password: Optional[str] = None,
         **kwargs,
     ):
         if not SSL_AVAILABLE:
@@ -834,6 +835,7 @@ def __init__(
             check_hostname=ssl_check_hostname,
             min_version=ssl_min_version,
             ciphers=ssl_ciphers,
+            password=ssl_password,
         )
         super().__init__(**kwargs)
 
@@ -893,6 +895,7 @@ class RedisSSLContext:
         "check_hostname",
         "min_version",
         "ciphers",
+        "password",
     )
 
     def __init__(
@@ -908,6 +911,7 @@ def __init__(
         check_hostname: bool = False,
         min_version: Optional[TLSVersion] = None,
         ciphers: Optional[str] = None,
+        password: Optional[str] = None,
     ):
         if not SSL_AVAILABLE:
             raise RedisError("Python wasn't built with SSL support")
@@ -938,6 +942,7 @@ def __init__(
         )
         self.min_version = min_version
         self.ciphers = ciphers
+        self.password = password
         self.context: Optional[SSLContext] = None
 
     def get(self) -> SSLContext:
@@ -951,8 +956,12 @@ def get(self) -> SSLContext:
             if self.exclude_verify_flags:
                 for flag in self.exclude_verify_flags:
                     context.verify_flags &= ~flag
-            if self.certfile and self.keyfile:
-                context.load_cert_chain(certfile=self.certfile, keyfile=self.keyfile)
+            if self.certfile or self.keyfile:
+                context.load_cert_chain(
+                    certfile=self.certfile,
+                    keyfile=self.keyfile,
+                    password=self.password,
+                )
             if self.ca_certs or self.ca_data or self.ca_path:
                 context.load_verify_locations(
                     cafile=self.ca_certs, capath=self.ca_path, cadata=self.ca_data

tests/test_asyncio/test_ssl.py

@@ -167,3 +167,29 @@ async def test_ssl_ca_path_parameter(self, request):
             assert conn.ssl_context.ca_path == test_ca_path
         finally:
             await r.aclose()
+
+    async def test_ssl_password_parameter(self, request):
+        """Test that ssl_password parameter is properly passed to SSLConnection"""
+        ssl_url = request.config.option.redis_ssl_url
+        parsed_url = urlparse(ssl_url)
+
+        # Test with a mock password for encrypted private key
+        test_password = "test_key_password"
+
+        r = redis.Redis(
+            host=parsed_url.hostname,
+            port=parsed_url.port,
+            ssl=True,
+            ssl_cert_reqs="none",
+            ssl_password=test_password,
+        )
+
+        try:
+            # Get the connection to verify ssl_password is passed through
+            conn = r.connection_pool.make_connection()
+            assert isinstance(conn, redis.SSLConnection)
+
+            # Verify the password is stored in the SSL context
+            assert conn.ssl_context.password == test_password
+        finally:
+            await r.aclose()