Credentials API

[Therzok]

I've thought about this a bit, but shouldn't the Credentials implementations provide their credentials as callbacks and not as normal properties?

What I've been thinking is like making the Credentials similar to an interactive prompt. Calling Username.get would end up calling the callback set to get the username.

Moreover, it would be easier to pack them in a Func<GitCredentialType, Tuple<string, string>>.

[rhuijben]

+1, but I think this will require changes in libgit2 as well. The current http and ssh implementations are not really friendly for implementations that want to do more than caching credentials: they don't retry on failed credentials... and don't really tell which kind of credentials you should supply. (E.g. ssh will just ask for all credential types, even those not supported by the server. Libssh2 provides a list of what is supported and so does a HTTP 401 response)

[carlosmn]

The HTTP transport should retry as long as it gets a 401 (or at least that's the idea). SSH itself doesn't let you retry unless you explicitly choose the keyboard-interactive method AFAICT (i.e. if you fail to auth with 'password', the connection is closed).

The lack of accurate reporting from the ssh transport wrt possible credentials in definitely a bug; this transport makes a bunch of assumptions that we're slowly getting rid of.

[carlosmn]

So it turns out my understanding of ssh was just wrong. I've started work on making it less silly.

Regarding the libgit2sharp layer, I fully agree it should support a callback. This callback would have to return one of the supported Credential-inheriting objects, since we do need to end up allocating the C structure.