Resolving "SFTP Error: No Hostkey Alg" in Engine Yard

Information

Error Message: "SFTP error: no hostkey alg"

Cause: This error occurs when the SSH client does not support the host key algorithms required by the remote SFTP server. It may be due to an outdated OpenSSH version or unsupported key types.

Resolution Steps:

1. Update OpenSSH:
   • For Gentoo-based instances, run:

     sudo echo =net-misc/openssh-5.9_p1-r1 >> /etc/portage/package.keywords/local
     sudo emerge -av =net-misc/openssh-5.9_p1-r1
     sudo /etc/init.d/ssh restart

   • Retry the SFTP connection.
2. Specify Host Key Algorithms:
   • Modify your SSH configuration file (`~/.ssh/config`) to include:

     Host <sftp_server>
         HostKeyAlgorithms +ssh-rsa
         PubkeyAcceptedKeyTypes +ssh-rsa
         IdentityFile /home/deploy/.ssh/id_rsa
         User <username>

   • Alternatively, use the command line:

     sftp -oHostKeyAlgorithms=+ssh-rsa -oPubkeyAcceptedKeyTypes=+ssh-rsa -i /home/deploy/.ssh/id_rsa <username>@<sftp_server>

3. Use an Alternative SSH Client:
   • Try using PuTTY or another GUI SSH client to determine if the issue is client-side.
   • Convert your key using PuTTYgen if necessary.

Verification:

• Ensure the SFTP connection is successful without errors.
• If issues persist, verify the SSH configuration and permissions, and consider using alternative clients or configurations.