Commit Graph

2 Commits

Author SHA1 Message Date
Thomas Wolf ffc1f9b026 sshd: implement ssh config PubkeyAcceptedAlgorithms
Apache MINA sshd 2.6.0 appears to use only the first appropriate
public key signature algorithm for a particular key. See [1]. For
RSA keys, that is rsa-sha2-512. This breaks authentication at servers
that only know the older (and deprecated) ssh-rsa algorithm.

With PubkeyAcceptedAlgorithms, users can re-order algorithms in
the ssh config file per host, if needed. Setting

  PubkeyAcceptedAlgorithms ^ssh-rsa

will put "ssh-rsa" at the front of the list of algorithms, and then
authentication at such servers with RSA keys works again.

[1] https://issues.apache.org/jira/browse/SSHD-1105

Bug: 572056
Change-Id: I86c3b93f05960c68936e80642965815926bb2532
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
2021-03-19 17:27:03 +01:00
Thomas Wolf 488d95571f Apache MINA sshd client
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>
2018-11-13 10:49:26 -08:00