We run a server where FTP is disabled - SFTP only - and even then, access is only possible with a public/private keypair. In Security Center, SSH Password login is disabled.

Our process is usually this:

- User generates a keypair.
- We go to cPanel for an account, then Manage Keys.
- Import user's public key and authorize it.

User can then SFTP to the account. But recently, this process stopped working. User gets "permission denied" as soon as the SFTP client tries to connect, without even being prompted to enter the key's password (we've tried in several different SFTP clients).

The user *can* however log in via SSH if we enable shell access for them. So keypair SSH is working but SFTP is not.

The system is:
WHM 11.23.2 cPanel 11.23.6-R27698
CENTOS Enterprise 5 x86_64 on standard - WHM X v3.1.0

Thanks for any advice.