test(ssh-tunnel): assert ed25519 SSH keys load for tunnel setup

Closes #24180

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/unit_tests/extensions/ssh_test.py

@@ -14,11 +14,17 @@
 # KIND, either express or implied.  See the License for the
 # specific language governing permissions and limitations
 # under the License.
-from unittest.mock import Mock
+from unittest.mock import Mock, patch
 
 import sshtunnel
+from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PrivateKey
+from cryptography.hazmat.primitives.serialization import (
+    Encoding,
+    NoEncryption,
+    PrivateFormat,
+)
 
-from superset.extensions.ssh import SSHManagerFactory
+from superset.extensions.ssh import SSHManager, SSHManagerFactory
 
 
 def test_ssh_tunnel_timeout_setting() -> None:
@@ -34,3 +40,100 @@ def test_ssh_tunnel_timeout_setting() -> None:
     factory.init_app(app)
     assert sshtunnel.TUNNEL_TIMEOUT == 123.0
     assert sshtunnel.SSH_TIMEOUT == 321.0
+
+
+def _make_ed25519_pem() -> str:
+    """Generate a fresh OpenSSH-format ed25519 private key PEM."""
+    key = Ed25519PrivateKey.generate()
+    return key.private_bytes(
+        encoding=Encoding.PEM,
+        format=PrivateFormat.OpenSSH,
+        encryption_algorithm=NoEncryption(),
+    ).decode()
+
+
+def test_create_tunnel_accepts_ed25519_private_key() -> None:
+    """
+    Regression for #24180: ed25519 SSH keys must be loadable for tunnel
+    setup. The bug surfaces as ``unpack requires 4 bytes`` because the
+    code unconditionally calls ``RSAKey.from_private_key`` regardless of
+    key type, which mis-parses the ed25519 byte stream.
+
+    The Superset UI accepts any key the user pastes, so the fix is to
+    detect the key type (or use ``paramiko.PKey.from_private_key`` once
+    paramiko exposes a polymorphic loader) rather than hard-coding RSA.
+
+    This test exercises ``create_tunnel`` end-to-end with a freshly
+    generated ed25519 key. It mocks ``sshtunnel.open_tunnel`` so the
+    test does not actually open a network connection — only the key
+    parsing path is exercised.
+    """
+    app = Mock()
+    app.config = {
+        "SSH_TUNNEL_LOCAL_BIND_ADDRESS": "127.0.0.1",
+        "SSH_TUNNEL_TIMEOUT_SEC": 10.0,
+        "SSH_TUNNEL_PACKET_TIMEOUT_SEC": 10.0,
+    }
+    manager = SSHManager(app)
+
+    ssh_tunnel = Mock()
+    ssh_tunnel.server_address = "ssh.example.com"
+    ssh_tunnel.server_port = 22
+    ssh_tunnel.username = "tunneluser"
+    ssh_tunnel.password = None
+    ssh_tunnel.private_key = _make_ed25519_pem()
+    ssh_tunnel.private_key_password = None
+
+    with patch("superset.extensions.ssh.sshtunnel.open_tunnel") as mock_open:
+        manager.create_tunnel(
+            ssh_tunnel, "postgresql://user:pass@db.example.com:5432/x"
+        )
+
+    # Key-type-agnostic loader must produce a paramiko PKey usable as ssh_pkey.
+    assert mock_open.called, "open_tunnel was never invoked — key parsing aborted"
+    forwarded_pkey = mock_open.call_args.kwargs["ssh_pkey"]
+    assert forwarded_pkey is not None
+
+
+def test_create_tunnel_accepts_rsa_private_key_unchanged() -> None:
+    """
+    Companion to test_create_tunnel_accepts_ed25519_private_key: pin the
+    backward-compatible RSA path so a fix for ed25519 doesn't regress the
+    historically-supported RSA case. Uses a freshly generated RSA key in
+    OpenSSH format.
+    """
+    from cryptography.hazmat.primitives.asymmetric.rsa import generate_private_key
+
+    rsa_pem = (
+        generate_private_key(public_exponent=65537, key_size=2048)
+        .private_bytes(
+            encoding=Encoding.PEM,
+            format=PrivateFormat.OpenSSH,
+            encryption_algorithm=NoEncryption(),
+        )
+        .decode()
+    )
+
+    app = Mock()
+    app.config = {
+        "SSH_TUNNEL_LOCAL_BIND_ADDRESS": "127.0.0.1",
+        "SSH_TUNNEL_TIMEOUT_SEC": 10.0,
+        "SSH_TUNNEL_PACKET_TIMEOUT_SEC": 10.0,
+    }
+    manager = SSHManager(app)
+
+    ssh_tunnel = Mock()
+    ssh_tunnel.server_address = "ssh.example.com"
+    ssh_tunnel.server_port = 22
+    ssh_tunnel.username = "tunneluser"
+    ssh_tunnel.password = None
+    ssh_tunnel.private_key = rsa_pem
+    ssh_tunnel.private_key_password = None
+
+    with patch("superset.extensions.ssh.sshtunnel.open_tunnel") as mock_open:
+        manager.create_tunnel(
+            ssh_tunnel, "postgresql://user:pass@db.example.com:5432/x"
+        )
+
+    assert mock_open.called
+    assert mock_open.call_args.kwargs["ssh_pkey"] is not None