Failed to exchange the keys

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NomisGari
Posts: 1
Joined: Fri Jul 29, 2022 7:55 am

Failed to exchange the keys

Post by NomisGari »

Hello WingFTP-Community,

actually I'm running a SFTP-Server behind some Citrix Netscaler. Theres a virtual server account on the Netscaler set up for this server which holds the public IP and should transfer the traffic to the host server.

Scanning the public IP shows, that the adress is reachable and Port 22 for SFTP is open.

After I installed WingFTP the domain log showed up with:

Connected from "Internal IP from virtual server account" (local address "IP host server", port 22)
[02] Fri, 29 Jul 2022 09:33:56 (0000002) Failed to exchange the keys.
[02] Fri, 29 Jul 2022 09:33:56 (0000002) Closed session, disconnected from "Internal IP from virtual server account"
[02] Fri, 29 Jul 2022 09:34:08 (0000001) Failed to exchange the keys.
.
.
.
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Our network admin just adjusted one setting and afterwards the connectione worked. Now "without any change" the same
message appears again and a connection is not possible.

Is there something special how WingFTP communicates or do someone have an idea what's the technical background of this message?

Kind regards

Simon
FTP
Site Admin
Posts: 2072
Joined: Tue Sep 29, 2009 6:09 am

Re: Failed to exchange the keys

Post by FTP »

Normally this issue is caused by the SFTP client, so please use a popular SFTP client software, and also have a look at this KB article: https://bbs.wftpserver.com/viewtopic.php?t=3547
seattle
Posts: 28
Joined: Tue Nov 07, 2017 7:31 pm

Re: Failed to exchange the keys

Post by seattle »

is it possible to add "diffie-hellman-group16-sha256" to acceptable algorithms?
What other changes would be needed if adding the above?
FTP
Site Admin
Posts: 2072
Joined: Tue Sep 29, 2009 6:09 am

Re: Failed to exchange the keys

Post by FTP »

WingFTP doesn't support this algorithm, and here are all the supported algorithms:

Code: Select all

curve25519-sha256
curve25519-sha256@libssh.org
ecdh-sha2-nistp256,ecdh-sha2-nistp384
ecdh-sha2-nistp521
diffie-hellman-group14-sha1
diffie-hellman-group1-sha1
diffie-hellman-group-exchange-sha1
diffie-hellman-group-exchange-sha256
diffie-hellman-group16-sha512
diffie-hellman-group18-sha512
seattle
Posts: 28
Joined: Tue Nov 07, 2017 7:31 pm

Re: Failed to exchange the keys

Post by seattle »

adding diffie-hellman-group1-sha1 to the list worked fine,
our client is working on updating their connection software so they can use the more modern version.
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