Sorry about the delay. I have been working on testing the client and handling exceptions (essentially dogfooding the SFTP client to myself via our implementation).
Previously, I started handling the state of the SSH.NET client, but that seems redundant. Now instead whenever I do an operation, I use it in a TryFunction and from there, read the Dotnet exception and expose that to the client via an Enum.
@JesperSchulz could I get a review of the code that I have written?

I want to keep the debugging page - since the connections can be finicky.

Here is a list of the objects and their intended functionality:

• codeunit SFTP Client: The codeunit to use for others
• codeunit SFTP Client Implementation: Internal functions. Holds the ISFTPClient
• interface ISFTPClient: Abstract client - determines the functions available for the SFTP Client Implementation to call
• interface ISFTPFile: Abstract SFTP file.
• codeunit DotnetSFTPClient: The SSH.NET file
• codeunit DotnetSFTPFile: The SSH.NET file
• page SFTP Client Debug: A debug page
• enum SFTP Exception Type: An enum to expose via SFTP Operation Response. Makes error handling easier
• page SFTP Folder Content: A page to show contents of a folder
• table SFTP Folder Content: A temporary table to hold contents of a folder
• codeunit SFTP Operation Response: A codeunit to respond to every request from the SFTP Client

I have included mock implementations of SFTP Client and SFTP File.
These are used in the SFTP Client Test to mock the functionality of the client without actually connecting to a remote host.

Currently I'm quite happy with the implementation. It does as I expect.

For future work, I would like to add HostKey fingerprinting which would add the ability for the user to check if the server had the correct hostkey. However, I can live without it for now.

One thing I may need is the functionality to disable SFTP connections.
You know for when you create a Sandbox environment and Business Central disables HTTP requests in the extensions settings.
Do you have any suggestions on what would be a good solution here? Maybe an event I can subscribe to to test? A subscription may also be the wrong tool since the boolean flag specifically states HTTP-requests?

Sorry about the delay. I have been working on testing the client and handling exceptions (essentially dogfooding the SFTP client to myself via our implementation). Previously, I started handling the state of the SSH.NET client, but that seems redundant. Now instead whenever I do an operation, I use it in a TryFunction and from there, read the Dotnet exception and expose that to the client via an Enum. @JesperSchulz could I get a review of the code that I have written?

I want to keep the debugging page - since the connections can be finicky.

Here is a list of the objects and their intended functionality:

• codeunit SFTP Client: The codeunit to use for others
• codeunit SFTP Client Implementation: Internal functions. Holds the ISFTPClient
• interface ISFTPClient: Abstract client - determines the functions available for the SFTP Client Implementation to call
• interface ISFTPFile: Abstract SFTP file.
• codeunit DotnetSFTPClient: The SSH.NET file
• codeunit DotnetSFTPFile: The SSH.NET file
• page SFTP Client Debug: A debug page
• enum SFTP Exception Type: An enum to expose via SFTP Operation Response. Makes error handling easier
• page SFTP Folder Content: A page to show contents of a folder
• table SFTP Folder Content: A temporary table to hold contents of a folder
• codeunit SFTP Operation Response: A codeunit to respond to every request from the SFTP Client

I have included mock implementations of SFTP Client and SFTP File. These are used in the SFTP Client Test to mock the functionality of the client without actually connecting to a remote host.

Currently I'm quite happy with the implementation. It does as I expect.

For future work, I would like to add HostKey fingerprinting which would add the ability for the user to check if the server had the correct hostkey. However, I can live without it for now.

One thing I may need is the functionality to disable SFTP connections. You know for when you create a Sandbox environment and Business Central disables HTTP requests in the extensions settings. Do you have any suggestions on what would be a good solution here? Maybe an event I can subscribe to to test? A subscription may also be the wrong tool since the boolean flag specifically states HTTP-requests?

Yes, I'll get to this soon! Promise. We're a bit low on capacity these weeks due to events, but from mid next week, we should be back to normal operations! Hang in there 😊