Test existing AuthSource class tree

Includes relevant tweaks to assorted classes

5 files changed, 121 insertions, 6 deletions

diff --git a/paramiko/__init__.py b/paramiko/__init__.py
index 4bb261e0..aa1463e7 100644
--- a/paramiko/__init__.py
+++ b/paramiko/__init__.py
@@ -36,7 +36,12 @@ from paramiko.auth_strategy import (
     AuthStrategy,
     AuthResult,
     AuthSource,
+    InMemoryPrivateKey,
     NoneAuth,
+    OnDiskPrivateKey,
+    Password,
+    PrivateKey,
+    SourceResult,
 )
 from paramiko.ssh_gss import GSSAuth, GSS_AUTH_AVAILABLE, GSS_EXCEPTIONS
 from paramiko.channel import (
diff --git a/paramiko/auth_strategy.py b/paramiko/auth_strategy.py
index bbb52141..524ae349 100644
--- a/paramiko/auth_strategy.py
+++ b/paramiko/auth_strategy.py
@@ -81,6 +81,10 @@ class Password(AuthSource):
         return transport.auth_password(self.username, password)
 
 
+# TODO 4.0: twiddle this, or PKey, or both, so they're more obviously distinct.
+# TODO 4.0: the obvious is to make this more wordy (PrivateKeyAuth), the
+# minimalist approch might be to rename PKey to just Key (esp given all the
+# subclasses are WhateverKey and not WhateverPKey)
 class PrivateKey(AuthSource):
     """
     Essentially a mixin for private keys.
@@ -130,13 +134,12 @@ class OnDiskPrivateKey(PrivateKey):
         The `PKey` object this auth source uses/represents.
     """
 
-    # TODO: how to log/note how this path came to our attention (ssh_config,
-    # fabric config, some direct kwarg somewhere, CLI flag, etc)? Different
-    # subclasses for all of those seems like massive overkill, so just some
-    # sort of "via" or "source" string argument?
     def __init__(self, username, source, path, pkey):
         super().__init__(username=username)
         self.source = source
+        allowed = ("ssh-config", "python-config", "implicit-home")
+        if source not in allowed:
+            raise ValueError(f"source argument must be one of: {allowed!r}")
         self.path = path
         # Superclass wants .pkey, other two are mostly for display/debugging.
         self.pkey = pkey
diff --git a/paramiko/pkey.py b/paramiko/pkey.py
index 26c11e95..4f9f6d57 100644
--- a/paramiko/pkey.py
+++ b/paramiko/pkey.py
@@ -252,7 +252,7 @@ class PKey:
     def __repr__(self):
         comment = ""
         # Works for AgentKey, may work for others?
-        if hasattr(self, "comment"):
+        if hasattr(self, "comment") and self.comment:
             comment = f", comment={self.comment!r}"
         return f"{self.__class__.__name__}(alg={self.algorithm_name}, bits={self.get_bits()}, fp={self.fingerprint}{comment})"  # noqa
 
diff --git a/tests/auth.py b/tests/auth.py
index eacaf210..4c901c75 100644
--- a/tests/auth.py
+++ b/tests/auth.py
@@ -9,11 +9,16 @@ from unittest.mock import Mock
 from pytest import raises
 
 from paramiko import (
+    AgentKey,
     AuthenticationException,
     AuthSource,
     BadAuthenticationType,
     DSSKey,
+    InMemoryPrivateKey,
     NoneAuth,
+    OnDiskPrivateKey,
+    Password,
+    PrivateKey,
     PKey,
     RSAKey,
     SSHException,
@@ -345,8 +350,104 @@ class AuthSource_:
     class NoneAuth_:
         def authenticate_auths_none(self):
             trans = Mock()
-            NoneAuth("foo").authenticate(trans)
+            result = NoneAuth("foo").authenticate(trans)
             trans.auth_none.assert_called_once_with("foo")
+            assert result is trans.auth_none.return_value
+
+        def repr_shows_class(self):
+            assert repr(NoneAuth("foo")) == "NoneAuth()"
+
+    class Password_:
+        def init_takes_and_stores_password_getter(self):
+            with raises(TypeError):
+                Password("foo")
+            getter = Mock()
+            pw = Password("foo", password_getter=getter)
+            assert pw.password_getter is getter
+
+        def repr_adds_username(self):
+            pw = Password("foo", password_getter=Mock())
+            assert repr(pw) == "Password(user='foo')"
+
+        def authenticate_gets_and_supplies_password(self):
+            getter = Mock(return_value="bar")
+            trans = Mock()
+            pw = Password("foo", password_getter=getter)
+            result = pw.authenticate(trans)
+            trans.auth_password.assert_called_once_with("foo", "bar")
+            assert result is trans.auth_password.return_value
+
+    class PrivateKey_:
+        def authenticate_calls_publickey_with_pkey(self):
+            source = PrivateKey(username="foo")
+            source.pkey = Mock()  # set by subclasses
+            trans = Mock()
+            result = source.authenticate(trans)
+            trans.auth_publickey.assert_called_once_with("foo", source.pkey)
+            assert result is trans.auth_publickey.return_value
+
+    class InMemoryPrivateKey_:
+        def init_takes_pkey_object(self):
+            with raises(TypeError):
+                InMemoryPrivateKey("foo")
+            pkey = Mock()
+            source = InMemoryPrivateKey(username="foo", pkey=pkey)
+            assert source.pkey is pkey
+
+        def repr_shows_pkey_repr(self):
+            pkey = PKey.from_path(_support("ed25519.key"))
+            source = InMemoryPrivateKey("foo", pkey)
+            assert (
+                repr(source)
+                == "InMemoryPrivateKey(pkey=Ed25519Key(alg=ED25519, bits=256, fp=SHA256:J6VESFdD3xSChn8y9PzWzeF+1tl892mOy2TqkMLO4ow))"  # noqa
+            )
+
+        def repr_appends_agent_flag_when_AgentKey(self):
+            real_key = PKey.from_path(_support("ed25519.key"))
+            pkey = AgentKey(agent=None, blob=bytes(real_key))
+            source = InMemoryPrivateKey("foo", pkey)
+            assert (
+                repr(source)
+                == "InMemoryPrivateKey(pkey=AgentKey(alg=ED25519, bits=256, fp=SHA256:J6VESFdD3xSChn8y9PzWzeF+1tl892mOy2TqkMLO4ow)) [agent]"  # noqa
+            )
+
+    class OnDiskPrivateKey_:
+        def init_takes_source_path_and_pkey(self):
+            with raises(TypeError):
+                OnDiskPrivateKey("foo")
+            with raises(TypeError):
+                OnDiskPrivateKey("foo", "bar")
+            with raises(TypeError):
+                OnDiskPrivateKey("foo", "bar", "biz")
+            source = OnDiskPrivateKey(
+                username="foo",
+                source="ssh-config",
+                path="of-exile",
+                pkey="notreally",
+            )
+            assert source.username == "foo"
+            assert source.source == "ssh-config"
+            assert source.path == "of-exile"
+            assert source.pkey == "notreally"
+
+        def init_requires_specific_value_for_source(self):
+            with raises(
+                ValueError,
+                match=r"source argument must be one of: \('ssh-config', 'python-config', 'implicit-home'\)",  # noqa
+            ):
+                OnDiskPrivateKey("foo", source="what?", path="meh", pkey="no")
+
+        def repr_reflects_source_path_and_pkey(self):
+            source = OnDiskPrivateKey(
+                username="foo",
+                source="ssh-config",
+                path="of-exile",
+                pkey="notreally",
+            )
+            assert (
+                repr(source)
+                == "OnDiskPrivateKey(key='notreally', source='ssh-config', path='of-exile')"  # noqa
+            )
 
 
 class AuthStrategy_:
diff --git a/tests/test_util.py b/tests/test_util.py
index 4a8cf972..060e6249 100644
--- a/tests/test_util.py
+++ b/tests/test_util.py
@@ -50,6 +50,7 @@ class UtilTest(unittest.TestCase):
             "AgentKey",
             "AuthenticationException",
             "AuthHandler",
+            "AuthResult",
             "AuthSource",
             "AuthStrategy",
             "AutoAddPolicy",
@@ -61,10 +62,14 @@ class UtilTest(unittest.TestCase):
             "CouldNotCanonicalize",
             "DSSKey",
             "HostKeys",
+            "InMemoryPrivateKey",
             "Message",
             "MissingHostKeyPolicy",
             "NoneAuth",
+            "OnDiskPrivateKey",
+            "Password",
             "PasswordRequiredException",
+            "PrivateKey",
             "RSAKey",
             "RejectPolicy",
             "SFTP",
@@ -81,6 +86,7 @@ class UtilTest(unittest.TestCase):
             "SSHException",
             "SecurityOptions",
             "ServerInterface",
+            "SourceResult",
             "SubsystemHandler",
             "Transport",
             "WarningPolicy",