Secure FTP connection intermittently fails

[raboof]

We use version 0.1.54 of jsch, which appears to contain a bug that is triggered since jdk 1.8.0_121.

We're impacted by this as shown by the test failures tracked in #361.

It looks like we'll either have to move away from jsch, wait for the bug to be fixed there, or help them fix it.

[raboof]

Hmm jsch seems quite dead, perhaps we should consider moving to another library anyway, for example https://github.com/hierynomus/sshj

[raboof]

Pinging past ftp module contributors: @svezfaz @juanjovazquez @argast @nktpro @eharik @rafacm @neowulf33 - this bug seems to be triggered quite a lot on recent openjdk versions, anyone up to taking a look?

[juanjovazquez]

@raboof I'll try to have a look into it ASAP. We should probably assess moving away from jsch.

[charego]

Have you seen this issue since changing libraries? Personally I have seen the exception with sshj.
hierynomus/sshj#354

[raboof]

@charlesrgould that's interesting, we haven't seen it since switching to sshj - but that doesn't mean it is gone of course, as it was intermittent to begin with. At least sshj is actively maintained so if there's anything to fix there's a chance of fixing it there :).

[hierynomus]

@raboof And you even know the maintainer ;) Happy to work with you to fix this.