[isabelle-dev] NEWS: Isabelle/Scala SSH connections use OpenSSH executables
makarius at sketis.net
Thu Sep 15 11:59:13 CEST 2022
*** System ***
* Isabelle/Scala SSH connections now use regular OpenSSH executables
from the local system: ssh, scp, sftp; the old ssh-java component has
been discontinued. This has various practical consequences:
- Authentication and configuration works accurately via the official
.ssh/known_hosts and .ssh/config files.
- Host connections are usually shared (via multiplexed channels), to
reduce the overhead for multiple commands. This also works for SSH
connections for rsync (e.g. "isabelle sync"). Windows/Cygwin does
not support multiplexing: the functionality should be the same, but
slower, with a new connection for each command.
- Multiple hops via "bastion hosts" can be easily configured in
.ssh/config via ProxyJump declarations. The former Isabelle/Scala
parameters for proxy_host etc. have been discontinued: minor
This refers to Isabelle/361cfb8e3648.
The change is motivated by a recent update of the OpenSSH server in Cygwin,
which locked out the ssh-java/jsch client for unknown reasons. Since jsch is
somewhat old and hardly maintained, I sat down to study the man pages for ssh
and ssh_config carefully. The result is formalized src/Pure/General/ssh.scala
Now we can have Windows heaps for the release ...
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