Change-Id: Ie44950f7d2f2f94a0412efb6c274f6e1e31efcd6
Signed-off-by: Carsten Hammer <carsten.hammer@t-online.de>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Provide a mechanism for a subclass to provide its own set
of default identities from anywhere as an Iterable<KeyPair>.

The default implementation is functionally unchanged and uses
the known default identity files in the ~/.ssh directory. A subclass
can override the getDefaultKeys() function and return whatever keys
are appropriate.

Bug: 543152
Change-Id: I500d63146bc67e20e051f617790eb87c7cb500b6
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Change-Id: I143c242c0e3299323ae166a59947b1195539e6bf
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

Don't use the ~/.ssh directory as cache key for the key provider
but the configured paths of the default keys. Otherwise changes
in that list of paths are not picked up.

This is in particular a problem for EGit, where the user can modify
this list of keys interactively in the preferences. Without this
change, Eclipse needs to be restarted to pick up such changes.

Bug: 542845
Change-Id: I63432fb10729a90b3c5e14f13e39bf482aef811b
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Change-Id: I0fdf595cba93f5a5cdd0496cee07ac91db304532
Signed-off-by: Mincong Huang <mincong.h@gmail.com>

Change-Id: I6bed174c062a0785641dc8ad69151bf7e843cdcf
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

This continues what commit d9ac7ddf10
(Remove unnecessary modifiers from interfaces, 2018-11-15) started.

Change-Id: I89720985a5a986722a0dcb9b5e9bbc25996bd5b3

ProxyDataFactory had a parameter of type HostConfigEntry, but actually
it wasn't used anywhere. Remove it -- it was the last leaked type from
Apache MINA sshd.

Also use the logger provided by upstream SshClient instead of creating
a new Logger.

Bug: 520927
Change-Id: Iaa78bbb998a5e574fa091664b75c48a3b9cfb897
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Add tests for password and keyboard-interactive authentication.
Implement password authentication; the default provided by sshd
is non-interactive, which is not useful for JGit.

Make sure the CredentialsProvider gets reset on successive password
retrieval attempts. Otherwise it might always return the same non-
accepted password from a secure storage. (That one was discovered
by actually trying this via EGit; the JGit tests don't catch this.)

Change the default order of authentication mechanisms to prefer
password over keyboard-interactive. This is a mitigation for upstream
bug SSHD-866.[1]

Also include a fix for upstream bug SSHD-867.[2]

[1] https://issues.apache.org/jira/projects/SSHD/issues/SSHD-866
[2] https://issues.apache.org/jira/projects/SSHD/issues/SSHD-867

Bug: 520927
Change-Id: I423e548f06d3b51531016cf08938c8bd7acaa2a9
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

This is not about the ssh config ProxyCommand but about programmatic
support for HTTP and SOCKS5 proxies. Eclipse allows the user to
specify such proxies, and JSch at least contains code to connect
through proxies. So our Apache MINA sshd client also should be able
to do this.

Add interfaces and provide two implementations for HTTP and SOCKS5
proxies. Adapt the core code to be able to deal with proxy connections
at all. The built-in client-side support for this in sshd 2.0.0 is
woefully inadequate.

Tested manually by running proxies and then fetching various real-
world repositories via these proxies from different servers. Proxies
tested: ssh -D (SOCKS, anonymous), tinyproxy (HTTP, anonymous), and
3proxy (SOCKS & HTTP, username-password authentication). The GSS-API
authentication is untested since I have no Kerberos setup.

Bug: 520927
Change-Id: I1a5c34687d439b3ef8373c5d58e24004f93e63ae
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

We will get an API evolution problem if we expose as API classes and
interfaces that derive from upstream classes or interfaces. Upstream
interfaces also evolve quite erratically and evolution doesn't seem
to follow semantic versioning.

Introduce a new KeyPasswordProvider interface so that we don't have
to depend on the upstream FilePasswordProvider in our API. (We do
need _some_ abstraction for getting passwords for encrypted keys in
the API; EGit will need to provide its own implementation.)

Move some other upstream dependencies (HostConfigEntry, and various
previously protected methods in SshdSessionFactory) out of the API:
classes moved to internal space, and methods made private.

The only dependencies on upstream interfaces are thus in a few method
parameter types. Those cannot be avoided, but should also not pose
problems.

Bug: 520927
Change-Id: Idc9c6b0f237f29f46343c0fe15179242f2007bec
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

sshd only asks exactly once for the password. C.f. upstream issue
SSHD-850.[1] So we have to work around this limitation for now.
Once we move to sshd > 2.1.0, this can be simplified somewhat.

[1] https://issues.apache.org/jira/browse/SSHD-850

Bug: 520927
Change-Id: Id65650228486c5ed30affa9c62eac982e01ae207
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

By default sshd will use its default built-in list, which matches
the one of openssh (as far as the algorithms exist in sshd at all).
But it doesn't handle HostKeyAlgorithms from the ssh config at all.

Implement this as in openssh, including the '+' and '-' modifiers
and reordering the default if there are known host keys for a
server already.

Add tests for the reordering.

Also use a more robust reader for the known hosts file. The default
aborts on the first error.

Bug: 520927
Change-Id: Ib1684440bfe2e96140536aa1a93c4bd4a0d35916
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Set the internal property on the session as defined in the ssh config.

Note that NumberOfPasswordPrompts in openssh applies independently to
both user logins in keyboard-interactive authentication _and_ to
passphrases for identity files (encrypted keys). Apache MINA sshd uses
the setting only for keyboard-interactive authentication, but not for
identity file passphrase prompts. For identity files, it asks exactly
once. This has been reported as issue SSHD-850 upstream.[1]

[1] https://issues.apache.org/jira/browse/SSHD-850

Bug: 520927
Change-Id: I390ffe9e1c52b96d3e8e28fd8edbdc73dde9edb4
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

sshd does support gssapi-with-mic on the server side, but has no
built-in client-side support for this authentication mechanism.

Add our own implementation for it, following RFC 4462.[1] To avoid
needlessly re-trying mechanisms that aren't even configured on the
client, we disable mechanisms that fail on the very first attempt
to use them.

Since we have no real Kerberos5 test setup, this cannot be fully
tested in CI. The disabling of the authentication mechanism and
that it is skipped when not successful _is_ tested.

[1] https://www.ietf.org/rfc/rfc4462.txt

Bug: 520927
Change-Id: I5d0cdb14103588a57c52f927df541b589ab88d88
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Tests that it works with unknown authentications in the list, and
fails if there are no common authentications between server and
client. The latter also tests that the ssh config setting is taken
into account at all.

And promptly the JGit sshd client didn't. Add a fix for this. It's
a tiny bit hacky: Apache MINA looks up a custom property set on a
hierarchy of "PropertyResolver"s starting with the session. On the
session itself this property can never be set since it's read
already in the session constructor before anyone had any chance
to set it. The next element in the resolver hierarchy is the sshd
SshClient, and so we set that property there. Since we use one
SshClient and one ClientSession per JGit SshdSession, this is OK.

Bug: 520927
Change-Id: I62446fc1fffde125a8965c030240f0918ae234b7
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Add a new ssh client implementation based on Apach MINA sshd 2.0.0.

This implementation uses JGit's own config file parser and host entry
resolver. Code inspection of the Apache MINA implementation revealed
a few bugs or idiosyncrasies that immediately would re-introduce bugs
already fixed in the past in JGit.

Apache MINA sshd is not without quirks either, and I had to configure
and override more than I had expected. But at least it was all doable
in clean ways.

Apache MINA boasts support for Bouncy Castle, so in theory this should
open the way to using more ssh key algorithms, such as ed25519.

The implementation is in a separate bundle and is still not used in
the core org.eclipse.jgit bundle. The tests re-use the ssh tests from
the core test bundle.

Bug: 520927
Change-Id: Ib35e73c35799140fe050d1ff4fb18d0d3596580e
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>