OpenSSH 8.4 has introduced simple environment variable substitution
for some keys. Implement that feature in our ssh config file parser,
too.

Bug: 572103
Change-Id: I360f2c5510eea4ec3329aeedf3d29dfefc9163f0
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

OpenSSH has changed some things in ssh config files. Update our parser
to implement some of these changes:

* ignore trailing comments on a line
* rename PubkeyAcceptedKeyTypes to PubkeyAcceptedAlgorithms

Note that for the rename, openSSH still accepts both names. We do the
same, translating names whenever we get or set values.

Change-Id: Icccca060e6a4350a7acf05ff9e260f2c8c60ee1a
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Motivation: JSch serves as 'default' implementations of the SSH
transport. If a client application does not use it then there is no need
to pull in this dependency.

Move the classes depending on JSch to an OSGi fragment extending the
org.eclipse.jgit bundle and keep them in the same package as before
since moving them to another package would break API. Defer moving them
to a separate package to the next major release.

Add a new feature org.eclipse.jgit.ssh.jsch feature to enable
installation. With that users can now decide which of the ssh client
integrations (JCraft JSch or Apache Mina SSHD) they want to install.
We will remove the JCraft JSch integration in a later step due to the
reasons discussed in bug 520927.

Bug: 553625
Change-Id: I5979c8a9dbbe878a2e8ac0fbfde7230059d74dc2
Also-by: Michael Dardis <git@md-5.net>
Signed-off-by: Michael Dardis <git@md-5.net>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Signed-off-by: David Ostrovsky <david@ostrovsky.org>

This is the format given by the Eclipse legal doc generator [1].

[1] https://www.eclipse.org/projects/tools/documentation.php?id=technology.jgit

Bug: 548298
Change-Id: I8d8cabc998ba1b083e3f0906a8d558d391ffb6c4
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

- use FS.DETECTED instead of db.getFS() since the ssh config is
typically in a different place than the repository, the same is used in
OpenSshConfig
- reduce unnecessary repeated writes by introducing wait for one tick of
the file time resolution

Change-Id: Ifac915e97ff420ec5cf8e2f162e351f9f51b6b14
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

This enables higher file timestamp resolution on filesystems like ext4,
Mac APFS (1ns) or NTFS (100ns) providing high timestamp resolution on
filesystem level.

Note:
- on some OSes Java 8,9 truncate milliseconds, see
https://bugs.openjdk.java.net/browse/JDK-8177809, fixed in Java 10
- UnixFileAttributes truncates timestamp resolution to microseconds when
converting the internal representation to FileTime exposed in the API,
see https://bugs.openjdk.java.net/browse/JDK-8181493
- WindowsFileAttributes also provides only microsecond resolution

Change-Id: I25ffff31a3c6f725fc345d4ddc2f26da3b88f6f2
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Move the bulk of the basic parsing and host entry handling into a
new class OpenSshConfigFile that has no dependencies on any concrete
ssh implementation. Make the existing OpenSshConfig use the new
parser.

Introduce a new class SshConstants collecting all the various ssh-
related string literals. Also use TreeMaps with a case-insensitive
key comparator instead of converting keys to uppercase. Add a test
to verify that keys are matched case-insensitively.

Most of the parsing code was simply moved, except that the new
parser supports looking up entries given host name, port, and user
name, and can thus handle more %-substitutions correctly. This
feature is not yet used and cannot be used with JSch since JSch
only has a ConfigRepository.getConfig(String) interface.

The split is still worth the trouble as it opens the way to using
another ssh client altogether. Apache MINA sshd, for instance,
resolves host entries giving host name, port, and user name.

(Apache MINA has a built-in ssh config handling, but that has
problems, too: its pattern matching is case-insensitive, and its
merging of host entries if several match is not the same as in
OpenSsh. But with this refactoring, it will be possible to plug in
OpenSshConfigFile into an Apache MINA sshd  client without dragging
along JSch.)

One test case that doesn't make sense anymore has been removed. It
tested that repeatedly querying for a host entry returned the same
object. That is no longer true since the caching has been moved to
a deeper level.

Bug: 520927
Change-Id: I6381d52b29099595e6eaf8b05c786aeeaefbf9cc
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Add a simple ssh git server based on Apache MINA sshd, and use it
in new tests that verify ssh operations and in particular a number
of bugs that had cropped up over time in JSch.

The git server supports fetching only, and sftp access.

The tests are all in an abstract base class; the concrete JschSshTest
class only provides ssh-specific test setup. So the same tests could
be run easily also with some other ssh client.

Bug: 520927
Change-Id: Ide6687b717fb497a29fc83f22b07390a26dfce1d
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Change-Id: I3b748620f067582afef20f144feebe40d0332be2
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

Change-Id: Id924f79c8b2c720297ebc49bf9c5d4ddd6d52547
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>

Change-Id: I63ad25e1ebd94081c8848f4d21044cf9041f971d
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

Jsch caches keys (aka identities) specified in ~/.ssh/config via
IndentityFile only for the current Jsch Session. This results in
multiple password prompts for successive sessions.

Do the handling of IdentityFile exclusively in JGit, as it was before
4.9. JGit uses different Jsch instances per host and caches the
IdentityFile there, allowing it to be re-used in different sessions
for the same host.

* Add comments to explain this.
* Move the JschBugFixingConfig from OpenSshConfig to
  JschConfigSessionFactory to have all these Jsch work-arounds
  in one place.
* Make that config hide the IdentityFile config from Jsch to avoid
  that Jsch overrides the JGit behavior.

Bug: 529173
Change-Id: Ib36c34a2921ba736adeb64de71323c2b91151613
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Jsch 0.1.54 passes on the values from ~/.ssh/config for
"ServerAliveInterval" and "ConnectTimeout" as read from
the config file to java.net.Socket.setSoTimeout(). That
method expects milliseconds, but the values in the config
file are seconds!

The missing conversion in Jsch means that the timeout is
set way too low, and if the server doesn't respond within
that very short time frame, Jsch kills the connection and
then throws an exception with a message such as "session is
down" or "timeout in waiting for rekeying process".

As a work-around, do the conversion to milliseconds in the
Jsch-facing Config interface of OpenSshConfig. That way Jsch
already gets these values as milliseconds.

Bug: 526867
Change-Id: Ibc9b93f7722fffe10f3e770dfe7fdabfb3b97e74
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Do tilde replacement for values from the ssh config file that are
file names in all cases to make sure that they are already replaced
when Jsch tries to get the values.

Previously, OpenSshConfig did tilde replacement only for the
IdentityFile in the JGit-facing "Host" interface and left the
replacement in the Jsch-facing "Config" interface to Jsch.

But on Windows the JGit notion of what should be used to replace the
tilde differs from Jsch's replacement. Jsch always replaces the tilde
by the value of the system property "user.home", whereas JGit also
considers some environment variables like %HOME%. This can lead to
rather surprising failures as in the case of bug 526175 where
%HOME% != user.home.

Prior to commit 9d24470 (i.e.,prior to JGit 4.9.0) this problem never
occurred because Jsch was completely unaware of the ssh config file
and all host and IdentityFile handling happened exclusively in JGit.

Bug: 526175
Change-Id: I1511699664ffea07cb58ed751cfdb79b15e3a99e
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Except for %p and %r and partially %C, we can do token substitutions
as defined by OpenSSH inside the config file parser. %p and %r can
be replaced only if specified in the config; if not, it would be the
caller's responsibility to replace them with values obtained from the
URI to connect to.

Jsch doesn't know about token substitutions at all. By doing the
replacements as good as we can in the config file parser, we can
make Jsch support most of these tokens.

%i is not handled at all as Java has no concept of a "user ID".

Includes unit tests.

Bug: 496170
Change-Id: If9d324090707de5d50c740b0d4455aefa8db46ee
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>

Ensure the Jsch instance used knows about ~/.ssh/config. This
enables Jsch to honor more user configurations (see
com.jcraft.jsch.Session.applyConfig()), in particular also the
UserKnownHostsFile configuration, or additional identities given
via multiple IdentityFile entries.

Turn JGit's OpenSshConfig into a full parser that can be a
Jsch-compliant ConfigRepository. This avoids a few bugs
in Jsch's OpenSSHConfig and keeps the JGit-facing interface
unchanged. At the same time we can supply a JGit OpenSshConfig
instance as a ConfigRepository to Jsch. And since they'll both
work from the same object, we can also be sure that the parsing
behavior is identical.

The parser does not handle the "Match" and "Include" keys, and it
doesn't do %-token substitutions (yet).

Note that Jsch doesn't handle multi-valued UserKnownHostFile
entries as known by modern OpenSSH.[1]

[1] http://man.openbsd.org/OpenBSD-current/man5/ssh_config.5

Additional tests for new features are provided in OpenSshConfigTest.

Bug: 490939
Change-Id: Ic683bd412fa8c5632142aebba4a07fad4c64c637
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Set missingOverrideAnnotation=warning in Eclipse compiler preferences
which enables the warning:

  The method <method> of type <type> should be tagged with @Override
  since it actually overrides a superclass method

Justification for this warning is described in:

  http://stackoverflow.com/a/94411/381622

Enabling this causes in excess of 1000 warnings across the entire
code-base. They are very easy to fix automatically with Eclipse's
"Quick Fix" tool.

Fix all of them except 2 which cause compilation failure when the
project is built with mvn; add TODO comments on those for further
investigation.

Change-Id: I5772061041fd361fe93137fd8b0ad356e748a29c
Signed-off-by: David Pursehouse <david.pursehouse@gmail.com>

Connecting to an SshSession may fail due to different reasons. Jsch for 
example often throws an com.jcraft.jsch.JschException: verify: false.[1]
The issue is still not fixed in JSch 0.1.51.
 
In such a case it is worth retrying to connect. The number of connection
attempts can be configured using ssh_config parameter
"ConnectionAttempts" [2].

Don't retry if the user canceled authentication.

[1] http://sourceforge.net/p/jsch/bugs/58/
[2] http://linux.die.net/man/5/ssh_config

Bug: 437656
Change-Id: I6dd2a3786b7d3f15f5a46821d8edac987a57e381
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Change-Id: Iedb54eb9d8396bc3ae66d8754c1527fd9ca655f9

This include replacing assertTrue(!..) with assertFalse()

Change-Id: Idecd8018641454e10127d82ea3ddda3f671489ef

Change-Id: I5a6ef686c444fb1e46c9f784bad01165471ef372
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

java.io.File.mkdir() and mkdirs() report failure as an exceptional
return value false. Fix the code which silently ignored this
exceptional return value.

Change-Id: I41244f4b9d66176e68e2c07e2329cf08492f8619
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>

Eclipse has some problem re-running single JUnit tests if
the tests are in Junit 3 format, but the JUnit 4 launcher
is used. This was quite unnecessary and the move was not
completed. We still have no JUnit4 test.

This completes the extermination of JUnit3. Most of the
work was global searce/replace using regular expression,
followed by numerous invocarions of quick-fix and organize
imports and verification that we had the same number of
tests before and after.

- Annotations were introduced.
- All references to JUnit3 classes removed
- Half-good replacement for getting the test name. This was
  needed to make the TestRngs work. The initialization of
  TestRngs was also made lazily since we can not longer find
  out the test name in runtime in the @Before methods.
- Renamed test classes to end with Test, with the exception
  of TestTranslateBundle, which fails from Maven
- Moved JGitTestUtil to the junit support bundle

Change-Id: Iddcd3da6ca927a7be773a9c63ebf8bb2147e2d13
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

Per CQ 3448 this is the initial contribution of the JGit project
to eclipse.org.  It is derived from the historical JGit repository
at commit 3a2dd9921c.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>