Fixing module 'paramiko' has no attribute 'open_failed_adminstratively_prohibited' Error

The paramiko library is a popular Python implementation of the SSHv2 protocol, providing both client and server functionality. However, users may encounter the error "module 'paramiko' has no attribute 'open_failed_adminstratively_prohibited'" when attempting to handle specific SSH-related exceptions. This article addresses the cause of this error and provides guidance on how to properly handle SSH exceptions in paramiko.

Understanding the Error

The error message indicates that the paramiko module does not have an attribute named open_failed_adminstratively_prohibited. This suggests that the code is attempting to access a non-existent exception or attribute within the paramiko library.

Correct Exception Handling in Paramiko

In paramiko, SSH-related exceptions are typically handled using specific exception classes. The correct exception for handling administrative prohibition errors is actually paramiko.ssh_exception.OpenSSHException or more specifically, paramiko.ssh_exception.AuthenticationException for authentication issues, and paramiko.ssh_exception.SSHException for general SSH exceptions.

Exception Class	Description
`paramiko.ssh_exception.AuthenticationException`	Raised when authentication fails.
`paramiko.ssh_exception.SSHException`	Base class for all Paramiko-related exceptions.
`paramiko.ssh_exception.OpenSSHException`	Can be raised for various OpenSSH-specific errors.

💡 When handling SSH exceptions in paramiko, it's crucial to catch specific exceptions rather than relying on non-existent attributes. This approach ensures robust and accurate error handling in your SSH client or server implementations.

Resolving the Issue

To fix the error, update your exception handling code to use the correct paramiko exception classes. Here’s an example of how to handle exceptions properly:

import paramiko
from paramiko.ssh_exception import SSHException, AuthenticationException

try:
    # Establish SSH connection
    ssh = paramiko.SSHClient()
    ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
    ssh.connect('hostname', username='user', password='password')
except AuthenticationException as e:
    print(f"Authentication failed: {e}")
except SSHException as e:
    print(f"SSH error occurred: {e}")
except Exception as e:
    print(f"An error occurred: {e}")

Key Points

Use specific exception classes from paramiko.ssh_exception for accurate error handling.
Avoid referencing non-existent attributes like open_failed_adminstratively_prohibited.
Implement broad exception handling for unforeseen errors.
Ensure correct import statements for exception classes.
Consult the paramiko documentation for up-to-date exception handling practices.

Best Practices for Paramiko Exception Handling

When working with paramiko, following best practices for exception handling can significantly improve the robustness of your application:

Catch specific exceptions before general ones.
Log or handle exceptions appropriately to provide useful feedback.
Keep exception handling code organized and readable.

What are the most common Paramiko exceptions?

The most common paramiko exceptions include SSHException, AuthenticationException, and SocketException. These are typically raised during connection establishment, authentication, and data transfer.

How do I handle connection timeouts in Paramiko?

To handle connection timeouts, you can set the timeout parameter when calling ssh.connect(). If a timeout occurs, paramiko raises a socket.timeout exception, which can be caught and handled accordingly.

By understanding and correctly handling exceptions in paramiko, you can develop more reliable and secure SSH clients and servers in Python.