SSH Telebit: Can't Connect Server - Public Key Troubleshooting Guide
This guide covers the common issues encountered while connecting to a server using SSH Telebit with public key authentication within a local network. The primary focus is to provide a global context of the topic, and it is assumed that the reader has a basic understanding of SSH and public key authentication.
Introduction to SSH and Telebit
SSH (Secure Shell) is a cryptographic network protocol used for secure data communication, remote command execution, and other notable secure network services between two networked computers. Telebit is a service that simplifies SSH access via a unique URL.
Understanding Public Key Authentication
Public key authentication is a method of identifying oneself to a remote login server using a pair of cryptographic keys rather than a password. One of these keys, a private key, is kept secret on the client machine. The other, a public key, is shared with the server.
Issue: Can't Connect Server with Public Key (SSH Telebit)
When attempting to connect using SSH Telebit, the terminal might display an error similar to the following:
OpenSSH_9.2p1, LibreSSL 3.3.6
debug1: Reading configuration data /Users/user/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Connecting to silent-dragon-85.telebit.io port 22.
debug1: Connection established.
debug1: identity file /Users/user/.ssh/id_rsa type 0
debug1: identity file /Users/user/.ssh/id_rsa-cert type -1
debug1: identity file /Users/user/.ssh/id_ed25519 type 3
debug1: identity file /Users/user/.ssh/id_ed25519-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_9.2
debug1: Remote protocol version 2.0, remote software version EndpointSSH-2.3.1-Release
debug1: no match: EndpointSSH-2.3.1-Release
debug1: Authenticating to silent-dragon-85.telebit.io:22 as 'sshusername'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: [email protected]
debug1: kex: host key algorithm: rsa-sha2-512
debug1: kex: server->client cipher: aes128-ctr MAC: hmac-sha2-256 compression: none
debug1: kex: client->server cipher: aes128-ctr MAC: hmac-sha2-256 compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ssh-rsa SHA256:
debug1: Host 'silent-dragon-85.telebit.io' is known and matches the RSA host key.
debug1: Found key in /Users/user/.ssh/known_hosts:1
debug1: rekey out after 4294967296 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /Users/user/.ssh/id_rsa
debug1: Offering public key: RSA SHA256:
debug1: Authentications that can continue: publickey
debug1: Trying private key: /Users/user/.ssh/id_ed25519
debug1: Offering public key: ED25519 SHA256:
debug1: Authentications that can continue: publickey
debug1: No more authentication methods to try.
[email protected]: Permission denied (publickey).
The issue described here is the SSH client can't authenticate with the server (silent-dragon-85.telebit.io) using public key authentication.
Troubleshooting Steps
1. Verify SSH Configuration (/etc/ssh/ssh_config and ~/.ssh/config)
Ensure that your SSH client configuration files do not have any settings that could interfere with the connection.
2. Check Public Key File Permissions (~/.ssh/id_rsa, ~/.ssh/id_ed25519)
Make sure that your private key files have correct permissions. The recommended settings are:
chmod 600 ~/.ssh/id_rsa
chmod 600 ~/.ssh/id_ed25519
3. Verify Public Key Added to Server (~/.ssh/authorized_keys)
Ensure that the corresponding public key has been added to the server's ~/.ssh/authorized_keys file.
A correctly formatted entry looks like this:
SHA256: sshusername@client
4. Ensure Correct Username and Server Address
Double-check that you have provided the correct username and server address, including the Telebit hostname and port: [email protected].
- SSH Telebit allows secure communication via unique URLs.
- Public key authentication is an alternative to password-based authentication.
- Common issues include incorrect config files, permission settings, missing authorized public keys.