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.
2,829 questions
{count} votes

1 answer

Sort by: Most helpful
  1. ChaitanyaNaykodi-MSFT 22,311 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.