Authenticate with OpenPGP keys
SSH-enabled classes in SecureBlackbox support authentication using OpenPGP as defined by RFC 4253.
Besides attaching the TElSSHPGPAuthHandler, you need to use an instance of TElSSHPGPKey instead of TElSSHKey for authentication. Load the private OpenPGP key using Import() method. Then use the key for authentication as described in the corresponding how-to article.
To validate the OpenPGP key sent by the other party in SSH communication, you use regular OnKeyValidate event of your SSH transport class. You need to check the class type of the key, passed in Key parameter of OnKeyValidate event, and if this is an TElSSHPGPKey, validate it accordingly.
Remember, that OpenPGP authentication is a very recent addition to SSH, and it's not supported by most third-party SSH clients and servers.