Catch sshpass authentication errors and don't retry multiple times to prevent account lockout (#50776)

* Catch SSH authentication errors and don't retry multiple times to prevent account lock out

Signed-off-by: Sam Doran <sdoran@redhat.com>

* Subclass AnsibleAuthenticationFailure from AnsibleConnectionFailure

Use comparison rather than range() because it's much more efficient.

Signed-off-by: Sam Doran <sdoran@redhat.com>

* Add tests

Signed-off-by: Sam Doran <sdoran@redhat.com>

* Make paramiko_ssh connection plugin behave the same way

Signed-off-by: Sam Doran <sdoran@redhat.com>

* Add changelog

Signed-off-by: Sam Doran <sdoran@redhat.com>

changelogs/fragments/ssh_connection_invalid_password.yaml

@@ -0,0 +1,2 @@
+bugfixes:
+  - ssh connection - do not retry with invalid credentials to prevent account lockout (https://github.com/ansible/ansible/issues/48422)

lib/ansible/errors/__init__.py

@@ -219,6 +219,11 @@ class AnsibleConnectionFailure(AnsibleRuntimeError):
     pass
 
 
+class AnsibleAuthenticationFailure(AnsibleConnectionFailure):
+    '''invalid username/password/key'''
+    pass
+
+
 class AnsibleCallbackError(AnsibleRuntimeError):
     ''' a callback failure '''
     pass

lib/ansible/plugins/connection/paramiko_ssh.py

@@ -141,7 +141,12 @@ from distutils.version import LooseVersion
 from binascii import hexlify
 
 from ansible import constants as C
-from ansible.errors import AnsibleError, AnsibleConnectionFailure, AnsibleFileNotFound
+from ansible.errors import (
+    AnsibleAuthenticationFailure,
+    AnsibleConnectionFailure,
+    AnsibleError,
+    AnsibleFileNotFound,
+)
 from ansible.module_utils.six import iteritems
 from ansible.module_utils.six.moves import input
 from ansible.plugins.connection import ConnectionBase
@@ -355,6 +360,9 @@ class Connection(ConnectionBase):
             )
         except paramiko.ssh_exception.BadHostKeyException as e:
             raise AnsibleConnectionFailure('host key mismatch for %s' % e.hostname)
+        except paramiko.ssh_exception.AuthenticationException as e:
+            msg = 'Invalid/incorrect username/password. {0}'.format(to_text(e))
+            raise AnsibleAuthenticationFailure(msg)
         except Exception as e:
             msg = to_text(e)
             if u"PID check failed" in msg:

lib/ansible/plugins/connection/ssh.py

@@ -280,7 +280,12 @@ import time
 
 from functools import wraps
 from ansible import constants as C
-from ansible.errors import AnsibleError, AnsibleConnectionFailure, AnsibleFileNotFound
+from ansible.errors import (
+    AnsibleAuthenticationFailure,
+    AnsibleConnectionFailure,
+    AnsibleError,
+    AnsibleFileNotFound,
+)
 from ansible.errors import AnsibleOptionsError
 from ansible.compat import selectors
 from ansible.module_utils.six import PY3, text_type, binary_type
@@ -307,6 +312,55 @@ class AnsibleControlPersistBrokenPipeError(AnsibleError):
     pass
 
 
+def _handle_error(remaining_retries, command, return_tuple, no_log, host, display=display):
+
+    # sshpass errors
+    if command == b'sshpass':
+        # Error 5 is invalid/incorrect password. Raise an exception to prevent retries from locking the account.
+        if return_tuple[0] == 5:
+            msg = 'Invalid/incorrect username/password. Skipping remaining {0} retries to prevent account lockout:'.format(remaining_retries)
+            if remaining_retries <= 0:
+                msg = 'Invalid/incorrect password:'
+            if no_log:
+                msg = '{0} <error censored due to no log>'.format(msg)
+            else:
+                msg = '{0} {1}'.format(msg, to_native(return_tuple[2].rstrip()))
+            raise AnsibleAuthenticationFailure(msg)
+
+        # sshpass returns codes are 1-6. We handle 5 previously, so this catches other scenarios.
+        # No exception is raised, so the connection is retried.
+        elif return_tuple[0] in [1, 2, 3, 4, 6]:
+            msg = 'sshpass error:'
+            if no_log:
+                msg = '{0} <error censored due to no log>'.format(msg)
+            else:
+                msg = '{0} {1}'.format(msg, to_native(return_tuple[2].rstrip()))
+
+    if return_tuple[0] == 255:
+        SSH_ERROR = True
+        for signature in b_NOT_SSH_ERRORS:
+            if signature in return_tuple[1]:
+                SSH_ERROR = False
+                break
+
+        if SSH_ERROR:
+            msg = "Failed to connect to the host via ssh:"
+            if no_log:
+                msg = '{0} <error censored due to no log>'.format(msg)
+            else:
+                msg = '{0} {1}'.format(msg, to_native(return_tuple[2]).rstrip())
+            raise AnsibleConnectionFailure(msg)
+
+    # For other errors, no execption is raised so the connection is retried and we only log the messages
+    if 1 <= return_tuple[0] <= 254:
+        msg = "Failed to connect to the host via ssh:"
+        if no_log:
+            msg = '{0} <error censored due to no log>'.format(msg)
+        else:
+            msg = '{0} {1}'.format(msg, to_native(return_tuple[2]).rstrip())
+        display.vvv(msg, host=host)
+
+
 def _ssh_retry(func):
     """
     Decorator to retry ssh/scp/sftp in the case of a connection failure
@@ -315,7 +369,8 @@ def _ssh_retry(func):
     * an exception is caught
     * ssh returns 255
     Will not retry if
-    * remaining_tries is <2
+    * sshpass returns 5 (invalid password, to prevent account lockouts)
+    * remaining_tries is < 2
     * retries limit reached
     """
     @wraps(func)
@@ -333,7 +388,7 @@ def _ssh_retry(func):
                 try:
                     return_tuple = func(self, *args, **kwargs)
                     if self._play_context.no_log:
-                        display.vvv('rc=%s, stdout & stderr censored due to no log' % return_tuple[0], host=self.host)
+                        display.vvv('rc=%s, stdout and stderr censored due to no log' % return_tuple[0], host=self.host)
                     else:
                         display.vvv(return_tuple, host=self.host)
                     # 0 = success
@@ -349,24 +404,18 @@ def _ssh_retry(func):
                     display.vvv(u"RETRYING BECAUSE OF CONTROLPERSIST BROKEN PIPE")
                     return_tuple = func(self, *args, **kwargs)
 
-                if return_tuple[0] == 255:
-                    SSH_ERROR = True
-                    for signature in b_NOT_SSH_ERRORS:
-                        if signature in return_tuple[1]:
-                            SSH_ERROR = False
-                            break
-
-                    if SSH_ERROR:
-                        msg = "Failed to connect to the host via ssh: "
-                        if self._play_context.no_log:
-                            msg += '<error censored due to no log>'
-                        else:
-                            msg += to_native(return_tuple[2])
-                        raise AnsibleConnectionFailure(msg)
+                remaining_retries = remaining_tries - attempt - 1
+                _handle_error(remaining_retries, cmd[0], return_tuple, self._play_context.no_log, self.host)
 
                 break
 
+            # 5 = Invalid/incorrect password from sshpass
+            except AnsibleAuthenticationFailure as e:
+                # Raising this exception, which is subclassed from AnsibleConnectionFailure, prevents further retries
+                raise
+
             except (AnsibleConnectionFailure, Exception) as e:
+
                 if attempt == remaining_tries - 1:
                     raise
                 else:
@@ -375,9 +424,9 @@ def _ssh_retry(func):
                         pause = 30
 
                     if isinstance(e, AnsibleConnectionFailure):
-                        msg = "ssh_retry: attempt: %d, ssh return code is 255. cmd (%s), pausing for %d seconds" % (attempt, cmd_summary, pause)
+                        msg = "ssh_retry: attempt: %d, ssh return code is 255. cmd (%s), pausing for %d seconds" % (attempt + 1, cmd_summary, pause)
                     else:
-                        msg = "ssh_retry: attempt: %d, caught exception(%s) from cmd (%s), pausing for %d seconds" % (attempt, e, cmd_summary, pause)
+                        msg = "ssh_retry: attempt: %d, caught exception(%s) from cmd (%s), pausing for %d seconds" % (attempt + 1, e, cmd_summary, pause)
 
                     display.vv(msg, host=self.host)
 

test/units/plugins/connection/test_ssh.py

@@ -25,6 +25,7 @@ import pytest
 
 
 from ansible import constants as C
+from ansible.errors import AnsibleAuthenticationFailure
 from ansible.compat.selectors import SelectorKey, EVENT_READ
 from units.compat import unittest
 from units.compat.mock import patch, MagicMock, PropertyMock
@@ -501,6 +502,33 @@ class TestSSHConnectionRun(object):
 
 @pytest.mark.usefixtures('mock_run_env')
 class TestSSHConnectionRetries(object):
+    def test_incorrect_password(self, monkeypatch):
+        monkeypatch.setattr(C, 'HOST_KEY_CHECKING', False)
+        monkeypatch.setattr(C, 'ANSIBLE_SSH_RETRIES', 5)
+        monkeypatch.setattr('time.sleep', lambda x: None)
+
+        self.mock_popen_res.stdout.read.side_effect = [b'']
+        self.mock_popen_res.stderr.read.side_effect = [b'Permission denied, please try again.\r\n']
+        type(self.mock_popen_res).returncode = PropertyMock(side_effect=[5] * 4)
+
+        self.mock_selector.select.side_effect = [
+            [(SelectorKey(self.mock_popen_res.stdout, 1001, [EVENT_READ], None), EVENT_READ)],
+            [(SelectorKey(self.mock_popen_res.stderr, 1002, [EVENT_READ], None), EVENT_READ)],
+            [],
+        ]
+
+        self.mock_selector.get_map.side_effect = lambda: True
+
+        self.conn._build_command = MagicMock()
+        self.conn._build_command.return_value = [b'sshpass', b'-d41', b'ssh', b'-C']
+        self.conn.get_option = MagicMock()
+        self.conn.get_option.return_value = True
+
+        exception_info = pytest.raises(AnsibleAuthenticationFailure, self.conn.exec_command, 'sshpass', 'some data')
+        assert exception_info.value.message == ('Invalid/incorrect username/password. Skipping remaining 5 retries to prevent account lockout: '
+                                                'Permission denied, please try again.')
+        assert self.mock_popen.call_count == 1
+
     def test_retry_then_success(self, monkeypatch):
         monkeypatch.setattr(C, 'HOST_KEY_CHECKING', False)
         monkeypatch.setattr(C, 'ANSIBLE_SSH_RETRIES', 3)