When setting up automated SSH connections between servers, using public key authentication is the standard approach. The process involves generating a key pair (public and private) and placing the public key on the remote server you want to access.

Based on your system information (SunSSH 1.1), SSH keys are typically stored in:

/etc/ssh/  # System-wide configuration and host keys
~/.ssh/    # User-specific keys

To locate existing keys:

# List all SSH keys in user directory
ls -la ~/.ssh/

# Check for system keys
sudo ls -la /etc/ssh/

If you already have a key pair (likely id_rsa and id_rsa.pub), you can export the public key with:

# Display public key content
cat ~/.ssh/id_rsa.pub

# Or copy to clipboard (Linux/Mac)
xclip -sel clip < ~/.ssh/id_rsa.pub

If no keys exist, generate a new pair:

ssh-keygen -t rsa -b 4096
# Follow prompts (press Enter for defaults)

The standard method using ssh-copy-id:

ssh-copy-id -i ~/.ssh/id_rsa.pub user@remote_server

Manual method if ssh-copy-id isn't available:

cat ~/.ssh/id_rsa.pub | ssh user@remote_server "mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys"

For SunSSH specifically, check these configuration files:

# Main configuration
/etc/ssh/sshd_config

# Alternative locations
/etc/opt/ssh/sshd_config
/opt/ssh/etc/sshd_config

Key configuration parameters to verify:

PubkeyAuthentication yes
AuthorizedKeysFile .ssh/authorized_keys

If authentication fails:

# Check permissions (critical!)
chmod 700 ~/.ssh
chmod 600 ~/.ssh/authorized_keys

# Enable verbose SSH output
ssh -v user@remote_server

For SunSSH-specific debugging:

/usr/sbin/sshd -d -p 2222  # Start debug mode on alternate port

---

When working with SunSSH (common in Solaris environments), the default key locations are:

# System-wide keys (for SSH daemon)
/etc/ssh/ssh_host_rsa_key.pub
/etc/ssh/ssh_host_dsa_key.pub

# User-specific keys
~/.ssh/id_rsa.pub
~/.ssh/id_dsa.pub

First check what keys are available in your user directory:

bash-2.05# ls -la ~/.ssh/
total 16
drwx------   2 user     group        512 Jul 12 10:15 .
drwxr-xr-x  31 user     group       1024 Jul 12 10:15 ..
-rw-r--r--   1 user     group        566 Jul 12 10:15 id_rsa.pub
-rw-------   1 user     group       1675 Jul 12 10:15 id_rsa

To display your public key for transfer:

bash-2.05# cat ~/.ssh/id_rsa.pub
ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA... user@hostname

If no key exists, generate a new pair:

bash-2.05# ssh-keygen -t rsa -b 2048
Generating public/private rsa key pair.
Enter file in which to save the key (/home/user/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/user/.ssh/id_rsa.
Your public key has been saved in /home/user/.ssh/id_rsa.pub.

Use ssh-copy-id if available, or manually append to authorized_keys:

bash-2.05# cat ~/.ssh/id_rsa.pub | ssh user@remote "mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys"

Test the connection after key transfer:

bash-2.05# ssh -v user@remote
...
debug1: Authentications that can continue: publickey,password
debug1: Next authentication method: publickey
debug1: Offering public key: /home/user/.ssh/id_rsa
debug1: Server accepts key: pkalg ssh-rsa blen 277
...

For Solaris' SunSSH implementation, ensure proper permissions:

bash-2.05# chmod 700 ~/.ssh
bash-2.05# chmod 600 ~/.ssh/authorized_keys

If using older SunSSH versions, you might need to modify the sshd_config:

# Ensure these settings exist in /etc/ssh/sshd_config
PubkeyAuthentication yes
AuthorizedKeysFile .ssh/authorized_keys

If authentication fails, check these logs:

bash-2.05# tail -f /var/log/authlog

Common error messages and solutions:

# "Permission denied (publickey)"
- Verify the public key was correctly appended to authorized_keys
- Check file permissions (should be 600 for authorized_keys)

# "Agent admitted failure to sign using the key"
- Try ssh-add ~/.ssh/id_rsa to add the key to the agent