Logic App - SFTP SSH connector KeyExchangeFailed

sam57 16 Reputation points
2020-12-02T11:29:58.753+00:00

We are using the sFTP SSH connector to connect to an external FTP server. When trying to connect, we get the error "The connection was closed by the server: No common host key algorithms. (KeyExchangeFailed)". According to the Azure documentation, the connector uses the SSH.NET library. Both the library and the FTP server support the "ssh-ed25519" Host Key algorithm.

Furthermore, if I use the SSH.NET nuget package locally, it just works. Same SSH key, same username, same server address.

So my question is: what version of SSH.NET is being used, and what properties/settings? Because there is probably a difference in the usage of the library.
If I'm not mistaken the source of the sFTP-SSH connector is not publically available, is it?

Azure Logic Apps
Azure Logic Apps
An Azure service that automates the access and use of data across clouds without writing code.
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  1. ChaitanyaNaykodi-MSFT 24,681 Reputation points Microsoft Employee
    2020-12-07T21:43:23.883+00:00

    Hello @sam57 ,
    My sincere apologies for not conveying this before, somehow I missed it. The "ssh-ed25519" host key algorithm is not supported by the SFTP-SSH connector even though it is supported by the SSH.NET library. The algorithm's currently supported are mentioned here. Regarding the exact version SSH.NET used, I have reached out to the team internally and will update this thread as soon as I have a response. Thank you! Please let me know if there are any additional concerns.