info > ssh-keysign(8)

man perldoc info pydoc3 ri search

🔐 SSH-KEYSIGN(8)

📖 NAME

ssh-keysign — OpenSSH helper for host-based authentication

🚀 Quick Reference

Use Case	Command / Config	Description
🔑 Enable host-based authentication	EnableSSHKeysign yes in /etc/ssh/ssh_config	Allows ssh-keysign to be invoked by ssh(1) for host-based authentication
⚙️ Automatic invocation	ssh-keysign (invoked by ssh)	ssh-keysign is called automatically by ssh(1) when host-based authentication is configured; no direct user invocation needed
🔐 Required host key files	/etc/ssh/ssh_host_*_key	Private keys (DSA, ECDSA, Ed25519, RSA) must be owned by root and readable only by root; ssh-keysign must be set-uid root

📝 SYNOPSIS

ssh-keysign

📚 DESCRIPTION

ssh-keysign is used by ssh(1) to access the local host keys and generate the digital signature required during host-based authentication.

ssh-keysign is disabled by default and can only be enabled in the global client configuration file /etc/ssh/ssh_config by setting EnableSSHKeysign to "yes".

ssh-keysign is not intended to be invoked by the user, but from ssh(1). See ssh(1) and sshd(8) for more information about host-based authentication.

📁 FILES

• /etc/ssh/ssh_config — Controls whether ssh-keysign is enabled.
• /etc/ssh/ssh_host_dsa_key
/etc/ssh/ssh_host_ecdsa_key
/etc/ssh/ssh_host_ed25519_key
/etc/ssh/ssh_host_rsa_key
  — These files contain the private parts of the host keys used to generate the digital signature. They should be owned by root, readable only by root, and not accessible to others. Since they are readable only by root, ssh-keysign must be set-uid root if host-based authentication is used.
• /etc/ssh/ssh_host_dsa_key-cert.pub
/etc/ssh/ssh_host_ecdsa_key-cert.pub
/etc/ssh/ssh_host_ed25519_key-cert.pub
/etc/ssh/ssh_host_rsa_key-cert.pub
  — If these files exist they are assumed to contain public certificate information corresponding with the private keys above.

🔗 SEE ALSO

• ssh(1)
• ssh-keygen(1)
• ssh_config(5)
• sshd(8)

📜 HISTORY

ssh-keysign first appeared in OpenBSD 3.2.

👤 AUTHORS

Markus Friedl <markus AT openbsd.org>

BSD — November 30, 2019

🔐 SSH-KEYSIGN(8) 📖 NAME 🚀 Quick Reference 📝 SYNOPSIS 📚 DESCRIPTION 📁 FILES 🔗 SEE ALSO 📜 HISTORY 👤 AUTHORS