SECURITY OF MERCURIAL-SERVER

mercurial-server relies entirely on sshd to grant access to remote users. As a

result, it runs no daemons, installs no setuid programs, and no part of it

runs as root except the install process: all programs run as the user hg. And

any attack on mercurial-server can only be started if the Bad Guys already

have a public key in ~hg/.ssh/authorized_keys, otherwise sshd will bar the

way. No matter what command the user tries to run on the remote system via

ssh, mercurial-server is run. 

It parses the command line the user asked for, and interprets and runs the

corresponding hg operation itself if access is allowed, so users can only read

and add to history within repositories; they cannot run any other hg command.

In addition, every push and pull is logged with a datestamp, changeset ID and

the key that performed the operation.

However, while the first paragraph holds no matter what bugs

mercurial-server contains, the second depends on the relevant code being

correct; though the entire codebase is short, mercurial-server is a fairly

new program and may harbour bugs. Backups are

essential!