SSH Host Keys unavailable with NT Authentication
When using the Windows NT/SAM or Windows ADSI Authentication connectors in Titan FTP Server 2019 or Cornerstone MFT Server 2019, you may notice that the Public Host Key feature of SFTP/SSH is not available for use.
User Authentication Settings
SSH/SFTP Settings
This scenario will occur when the "Impersonate NT User After Login" option on the NT/SAM Authentication connector is enabled.

The reason for this is that in order for Titan/Cornerstone to be able to Impersonate the Windows NT/AD user context after login, Titan/Cornerstone needs to log in to the Windows NT/AD server to acquire an impersonation token which allows Titan/Cornerstone to operate under the context of the user. Since Windows NT/AD logins require both a username and a password, the server needs to acquire that information from the SFTP client user during login. This means that Password authentication must be used by the SFTP client to receive the credentials to pass along to the NT server for login. Since Password authentication is required, Host Key authentication cannot be enabled as Windows NT will not accept an SSH Host Key in lieu of the Windows Password.
Administrators will want to keep this in mind when designing their authentication strategy. If Public Host Key access from SFTP clients will be a requirement, even if it's just for one user, then the Impersonate NT User After Login option cannot be used.
Related Articles
How To: Setup Key Authentication for SFTP in Titan
Question How do I setup key authentication for SFTP in Titan. Reasoning I have a requirement from end users that need to add an extra layer of security by connecting to Titan via SFTP with key authentication. Answer You have the option in Titan to ...
How To: Create a SFTP Key in Titan Nextgen
Related To Titan Nextgen Builds 1.x Question How do I create a SFTP keys in Titan Nextgen? Reasoning I would like to be able to create a SFTP host keys for secure SFTP encrypted connections. Answer You have the option in Titan Nextgen to create ...
Cornerstone SSH Host Keys
Cornerstone MFT Server can use Secure File Transfer Protocol (SFTP), a Host Key Authentication method which adds Secure Shell (SSH) protection to your data transfers. This is Public Key Infrastructure (PKI), which is the use of a key pair made up of ...
Titan SSH Host Keys
Titan FTP Server can use Secure File Transfer Protocol (SFTP), a Host Key Authentication method which adds Secure Shell (SSH) protection to your data transfers. This is Public Key Infrastructure (PKI), which is the use of a key pair made up of a ...
How To: Create a server with Windows NT/SAM authentication in Titan Nextgen
Related To Titan Nextgen Builds 1.x and above. Question How can I configure a server to utilize windows NT/SAM as the authentication server in Titan Nextgen? Reasoning I would like to be able to integrate my current local windows users so I can give ...