[GUACAMOLE-745] Add support for OpenSSH private key format

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Done
• Fix Version/s: 1.5.0
• Component/s: guacd, SSH
• Environment: Docker official images 1.0.0
• Assignee: Unassigned
• Reporter: Julien Nicoulaud
• Created: 01/Mar/19 20:52
• Updated: 30/Jun/22 23:47
• Resolved: 12/Jan/22 20:20

Description

Since OpenSSH 7.8, ssh-keygen does not generate keys in PEM format by default anymore: https://www.openssh.com/txt/release-7.8

Attempting to use keys in the new format in Guacamole does not work, and does not print any helpful error message even in debug mode:

guacd_1      | guacd[296]: DEBUG:        Attempting private key import (WITHOUT passphrase)
guacd_1      | guacd[296]: DEBUG:        Initial import failed: (null)
guacd_1      | guacd[296]: DEBUG:        Re-attempting private key import (WITH passphrase)
guacd_1      | guacd[296]: ERROR:        Auth key import failed: (null)

It would be nice if keys in OpenSSH new format were supported. At least a more helpful error message should be printed (like "unrecognized key format").

Issue Links

• causes: GUACAMOLE-1504 SSH public key authentication fails with "Unable to extract public key from private key"
• fixes: GUACAMOLE-1553 Make Error - Presumably OpenSSL 3?
• fixes: GUACAMOLE-746 Add support for ED25519 SSH keys
• supercedes: GUACAMOLE-945 Migrate SSH support (back) to libssh