Error Connecting SFTP via SSH Failed to Get Reply from Pageant

Help & Support
1

I'm having trouble connecting to an SFTP server with a private key. The private key works with Pageant when connecting through Putty but does not work with Directory Opus with the PPK file specified or through Pageant. I tried to generate the key with the "Version 2" parameter and used an old version of puttygen to generate the key. This is a local server with no internet access, so I can adjust any encryption settings as needed.

The logs show the message "Failed to get Reply from Pageant" and then "Server refused our key". I've seen several other threads and tried all of the comments that were suggested. I'm assuming it is some type of incompatibility with the key and the server but I'm out of options. Does anyone have any other suggestions?

Here is the complete log:

Server version: SSH-2.0-OpenSSH_8.9p1 Ubuntu-3ubuntu0.6
Using SSH protocol version 2
We claim version: SSH-2.0-PuTTY_Directory_Opus
Server supports delayed compression; will try this later
Doing ECDH key exchange with curve Curve25519 and hash SHA-256
Server also has ecdsa-sha2-nistp256 host key, but we don't know it
Host key fingerprint is:
ssh-ed25519 256 xx:xx:xx:xx:xx:xx
Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Reading key file "D:\.config\.ssh\private_old.ppk"
Pageant is running. Requesting keys.
Failed to get reply from Pageant
Using username "joe".
Offered public key
Server refused our key
Server refused our key
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connection closed
2

Which version of Pageant is it? And is it 32 or 64-bit? (Not sure if that matters, but it might.)

Also, make sure neither Opus nor Pageant are running elevated (UAC).

3

Great, thank you. The elevation issue solved the Pageant error. Both DOpus and pageant are 64bit. The pageant version is Release 0.78.

It now accepts the certificate from Pageant but I'm still receiving the error "Server refused our key". This key is confirmed to work with Putty and OpenSSH.
Based on some other threads, I understand it's possible the ssh libraries in DOpus are incompatible with the latest versions of OpenSSH server. Any other ideas or configurations I can make on the server side to make this work?

Here is the latest log:

Initialised AES-256 SDCTR client->server encryption
Initialised HMAC-SHA-256 client->server MAC algorithm
Initialised AES-256 SDCTR server->client encryption
Initialised HMAC-SHA-256 server->client MAC algorithm
Reading key file "D:\.config\.ssh\private_old.ppk"
Pageant is running. Requesting keys.
Pageant has 1 SSH-2 keys
Pageant key #0 matches configured key file
Using username "joe".
Trying Pageant key #0
Server refused our key
Disconnected: Unable to authenticate
SSH: Unable to authenticate
Connection closed
4

That might mean the key or server requires an algorithm which Opus doesn't support yet, although you usually get a different error message for that.

(If it is that, we plan to completely overhaul SFTP support as the first large piece of work after we ship version 13, which should address it. Didn't want to do it for the initial release as it would have pushed back release of all the other new stuff.)

This page has some suggestions, including how to make the server generate a detailed log of what happens during authentication:

5

@Leo It was due to the use of the older version ssh in directory opus using the SHA-1 hash algorithm. A VERY INSECURE workaround is to add this line to sshd_config :

PubkeyAcceptedKeyTypes +ssh-rsa