Where are authorized keys stored in Linux?
In the realm of Linux, managing SSH keys is a crucial aspect of ensuring secure remote access and authentication. One of the most frequently asked questions in this context is where the authorized keys are stored. The storage location for these keys varies depending on the distribution and configuration of the Linux system, but there are some common paths to consider.
Standard Location for Authorized Keys
The most common location for storing authorized keys is within the user’s home directory. Specifically, the authorized_keys file is typically found in the .ssh subdirectory of the user’s home directory. This path is as follows:
“`
~/.ssh/authorized_keys
“`
Here, the tilde (~) represents the user’s home directory, which can be accessed by typing `cd ~` in the terminal. The .ssh directory is a hidden directory, meaning it is not visible in standard directory listings unless you use the `-a` or `–all` option with the `ls` command.
Understanding the authorized_keys File
The authorized_keys file contains the public keys of the users who are authorized to log in to the system via SSH. Each line in this file represents a different public key, formatted as follows:
“`
ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDOfs4gj8JX…
“`
This line indicates that the key is of type `ssh-rsa`, followed by the actual key data. The key data itself is a long string of alphanumeric characters, which is unique to each public key.
Additional Storage Locations
While the standard location for authorized keys is within the user’s home directory, there are other scenarios where keys may be stored in different locations. For example:
1. System-Wide Configuration: In some cases, the system administrator may configure SSH keys for all users on the system. In such cases, the authorized_keys file can be found in `/etc/ssh/authorized_keys`.
2. Root User: The root user has special privileges and may have its own set of authorized keys. These keys are stored in the same location as for other users, but under the root user’s home directory:
“`
/root/.ssh/authorized_keys
“`
Conclusion
In conclusion, the standard location for storing authorized keys in Linux is within the user’s home directory, specifically in the .ssh subdirectory. However, it’s important to note that there may be other storage locations depending on the system configuration and the user’s role. Understanding these locations can help you manage and troubleshoot SSH key-related issues more effectively.
