NAME
Crypt::MultiKey::SSHAgentClient - Interact with the user's SSH Agent
SYNOPSIS
my $agent= Crypt::MultiKey::SSHAgentClient->new;
my @keys= $agent->list_keys;
my $signature_bytes= $agent->sign($keys[0], $data_bytes);DESCRIPTION
You can ask OpenSSH to sign arbitrary data using ssh-keygen -Y, however this feature is an option when building OpenSSH and even some modern Linux distros haven't enabled it. So, this module makes a direct socket connection to your SSH agent! If that fails, it falls back to running the ssh-add(1) and ssh-keygen(1) commands.
CONSTRUCTORS
new
Create a new object. This object connects to the agent on demand, so creating the object might succeed but then throw an exception during list_keys if it can't connect and the ssh-add program isn't found or ssh-keygen doesn't support -Y.
ATTRIBUTES
ssh_auth_sock
Path of SSH agent socket. Defaults to $ENV{SSH_AUTH_SOCK}.
ssh_add_cmd
Path to ssh-add(1) command, defaulting to 'ssh-add' which lets the OS find it.
ssh_keygen_cmd
Path to ssh-keygen(1) command, defaulting to 'ssh-keygen' which lets the OS find it.
METHODS
list_keys
my @keys= $agent->list_keys;
# (
# { type => $algo,
# pubkey_base64 => $base64,
# comment => $text,
# },
# ...
# )Return a list of keys available in the agent. type, pubkey_base64, and comment are the exact strings seen in the output of ssh-add -L.
This list is cached for 0.1s to avoid spamming the connection if many PKeys are being checked.
sign
my $signature_bytes= $agent->sign($pubkey, $data_bytes, $namespace);The $pubkey can be either the base64 string of the public key, or the hashref for that key returned by list_keys. $data_bytes can be any scalar containing bytes. The $namespace defaults to "Crypt::MultiKey".
CONFIGURATION
You can specify the paths to the exeutables used by this module with the %Crypt::MultiKey::command_path global variable:
- ssh-add
-
$Crypt::MultiKey::command_path{'ssh-add'} - ssh-keygen
-
$Crypt::MultiKey::command_path{'ssh-keygen'}.
For security, these are not configurable from an environment variable.
VERSION
version 0.000_001
AUTHOR
Michael Conrad <mike@nrdvana.net>
COPYRIGHT AND LICENSE
This software is copyright (c) 2026 by Michael Conrad.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.