Add module with support for (patched) Trilead SSH2 (SVNKit fork)

[charles-dyfis-net]

This is, perhaps, more a request for comments than a patch submitted as ready for merge. That said, it has been tested end-to-end against the version of Trilead SSH2 at http://svn.svnkit.com/repos/3rdparty/com.trilead.ssh2/trunk/ with the patch given in the diff applied.

Is there interest in merging this? If so, what work would be required to make it acceptable?

[ymnk]

If possible, we want to include your contributions in the next release. Unfortunately, we are not familiar with Trilead ssh2, so it is helpful if there is an example like https://github.com/ymnk/jsch-agent-proxy/blob/master/examples/src/main/java/com/jcraft/agentproxy/examples/SshjWithAgentProxy.java to try it.

[charles-dyfis-net]

I'm going to try to get the corresponding patch merged to the Trilead tree (rather, SVNKit's fork thereof, which appears to be the only actively maintained one). Once that's done, I'll update the code here with any necessary changes, including an end-to-end example.

[ymnk]

I have been checking following issues,

http://youtrack.jetbrains.com/issue/IDEA-52034
http://issues.tmatesoft.com/issue/SVNKIT-178
http://issues.tmatesoft.com/issue/SVNKIT-375

but it seems there have been no responses and progresses.

[charles-dyfis-net]

I've heard back from TMateSoftware indicating that they intend to review the patches to Trilead SSH2 and SVNKit soon -- over the weekend if possible. The patch to IDEA is on hold until my employer's in-house legal staff has had a chance to review the contributor agreement JetBrains requires; it is separately tracked at JetBrains/intellij-community#79.

[charles-dyfis-net]

As implied by the commit message for 2368be8, the Trilead SSH2 patch is now merged into the SVNKit repo, and published as part of 1.0.0-build217.

[ymnk]

I have succeeded to run an example TrileadWithAgentProxy, but needed to add some dependencies to "examples/pom.xml" for executing "cd examples && mvn compile"

[ymnk]

I have not understood the reason why following two modules are required,

jsch-agent-proxy-svnkit-trilead-ssh2
jsch-agent-proxy-svnkit-trilead-ssh2-thick

Is it difficult to merge those into one module?

[charles-dyfis-net]

The -thick one is a separate module because it provides less control over dependencies -- the typical design of jsch-agent-proxy allows someone to only incorporate dependencies for communicating with SSH agent if only targeting UNIX, or to only incorporate dependencies for Pageant if only targeting Windows.

The advantage it provides is ease-of-use, and I expect that its behavior is desirable in a majority of cases, but I didn't want to deviate from convention by making it mandatory.

[ymnk]

Ok, I understand your motivation. I think -thick module may be useful for an example program, but for the real use-case it may not. For example, on Windows platform, NCUSocketFactory must be used for ssh-agent of cygwin environment. Anyway, I'll only add jsch-agent-proxy-svnkit-trilead-ssh2 module.

[charles-dyfis-net]

Do you really want every user of your software to need to have this real-world knowledge, and be separately responsible for which platforms their software works on?

I agree that jsch-agent-proxy-svnkit-trilead-ssh2-thick is not a particularly good idea (as it doesn't benefit folks using any library other than Trilead SSH2), but having some piece of code which pulls in all the dependencies and tries every appropriate method to find a working agent is going to lead to greater uniformity of platform support amongst jsch-agent-proxy users.

[ymnk]

The branch https://github.com/ymnk/jsch-agent-proxy/tree/issue9/support_for_trileadssh2 has been merged into master.