Tag Archives: SSH

Verifying SSH configuration with a scan

Managing a number of Linux servers and keeping them secure can be a challenge. Certain tools can make the life of an admin a lot easier. To ensure an ssh daemon complies with a desired security configuration the admin can use a scanner … Continue reading

Posted in Linux Administration, Security | Tagged , , , | Comments Off on Verifying SSH configuration with a scan

Debug SSH Connection issue in key exchange

Securing a server means hardening the SSH server settings, but doing so can also cause issues with ssh clients. Finding the cipher or algorithm causing a failled connection can be tricky. Depending on the client used, the error message might be very … Continue reading

Posted in Linux Administration, Security | Tagged , , , , | Comments Off on Debug SSH Connection issue in key exchange

Harden SSH server settings

Many Linux Administrators use ssh on a daily basis. Many of the ssh servers are in their default configuration. Not changing the default configuration puts the security of the server at risk. That is why it is important to follow a few … Continue reading

Posted in Linux Administration, Security | Tagged , , , | Comments Off on Harden SSH server settings

Manage SSH-keys with the SSH-agent

Many webservices generate ssh keys to access their service. With the amount of services the number of SSH keys grows. To avoid dealing with the keys in the command line and the ssh_config(5), you can simply add the ssh-key to the … Continue reading

Posted in Linux Administration, Security | Tagged , , | Comments Off on Manage SSH-keys with the SSH-agent

Restrict SSH access to port forwarding to one specific port

Allowing access to an unprotected service on a server is always a problem. Sometimes the easiest way is to not expose this service to the network but allow access via ssh port-forwarding, but how to limit the SSH account to … Continue reading

Posted in Linux Administration, Security | Tagged , | Comments Off on Restrict SSH access to port forwarding to one specific port

Generate public SSH key from private SSH key

A lost SSH public-key or a web service generates an SSH key but does not provide the public-key part to you. What to do now? There is a solution for this situation. Continue reading

Posted in Linux Administration, Security | Tagged , | Comments Off on Generate public SSH key from private SSH key

Managing shell commands and processes

Not every command you might execute only runs for a couple of seconds. When you have a long running command a couple of problems can come with it. When the ssh connection is not stable, the command might be interrupted, … Continue reading

Posted in Linux Administration | Tagged , , | Comments Off on Managing shell commands and processes

Gitosis Arguments to command look dangerous

Dealing with non-English languages, you might come across a couple of issues caused by special characters. Even gitosis has its limitations in this area. One of the error messages caused by special characters is: “Arguments to command look dangerous”. When a … Continue reading

Posted in Linux Administration, Version control system | Tagged , , | Comments Off on Gitosis Arguments to command look dangerous

Gitosis Unsafe SSH username in keyfile

While configuring and using Gitosis you will probably see the following error sooner or later. This error will appear immediately when changed configuration is pushed to the gitosis-admin repository. With this error, the reported user keys are not provisioned properly … Continue reading

Posted in Linux Administration, Version control system | Tagged , , | Comments Off on Gitosis Unsafe SSH username in keyfile

Use ssh comfortably with command history and auto-complete

When using ssh on a daily basis you type a lot, given you are probably entering a lot of hostnames and command-line options. But on your local Linux or OS X powered computer you have a lot of powerful tools to make your life easier. I would like to show a couple of easy tricks to make your life easier while working with ssh. Continue reading

Posted in Linux Administration | Tagged , , | Comments Off on Use ssh comfortably with command history and auto-complete