This error usually pops up when there’s a problem with an SSH key being used by libcrypto, a cryptography library often used for SSH connections.
Here’s a breakdown of common causes and how to troubleshoot them:
1. Key Format Issues
- Incorrect Line Endings: Make sure your private key file has Unix-style line endings (LF). Windows uses CRLF, which can cause problems. You can fix this with a text editor.
- Extra Characters or Whitespace: Ensure there are no extra characters, spaces, or lines before the “—–BEGIN OPENSSH PRIVATE KEY—–” or after the “—–END OPENSSH PRIVATE KEY—–” lines in your key file.
- Missing Newline: Sometimes, a missing newline character at the very end of the key file can trigger this. Add a newline if needed.
2. Key Permissions
- Too Open Permissions: The private key file should have restrictive permissions. Use
chmod 600 your_key_fileto set appropriate permissions.
3. SSH Agent Problems
- Agent Not Running: If you use an SSH agent (like
ssh-agent), ensure it’s running and your key is loaded into it. - Agent Crashed: If your agent crashed, restarting it might resolve the issue.
4. Key Type Mismatch
- Unsupported Key Type: The server you’re connecting to might not support the type of key you’re using. Try generating a different key type (e.g.,
ssh-keygen -t ed25519).
5. Corrupted Key
- Regenerate the Key: If you suspect your key is corrupted, generate a new one.
How to Troubleshoot
Check that the key file exists and is readable
Ensure the correct permissions (e.g.,
chmod 600).Verify the key format
Or for private keys in other formats:
If it says “unable to load key”, the file format might be wrong.
Convert between formats (PEM ↔ DER)
DER to PEM:
PEM to DER:
If encrypted, provide the passphrase
You’ll be prompted for the password.
