util: add utility method to check for bad ssh urls (SEC)
Our use of SSH has an exploit that will parse the first part of an url
blindly as a hostname. Prior to this set of security patches, a url
with '-oProxyCommand' could run arbitrary code on a user's machine. In
addition, at least on Windows, a pipe '|' can be abused to execute
arbitrary commands in a similar fashion.
We defend against this by checking ssh:// URLs and looking for a
hostname that starts with a - or contains a |.
When this happens, let's throw a big abort into the user's face so
that they can inspect what's going on.
$ cat > engine.py << EOF
>
> from mercurial import templater
>
> class mytemplater(object):
> def __init__(self, loader, filters, defaults, aliases):
> self.loader = loader
>
> def process(self, t, map):
> tmpl = self.loader(t)
> for k, v in map.iteritems():
> if k in ('templ', 'ctx', 'repo', 'revcache', 'cache'):
> continue
> if hasattr(v, '__call__'):
> v = v(**map)
> v = templater.stringify(v)
> tmpl = tmpl.replace('{{%s}}' % k, v)
> yield tmpl
>
> templater.engines['my'] = mytemplater
> EOF
$ hg init test
$ echo '[extensions]' > test/.hg/hgrc
$ echo "engine = `pwd`/engine.py" >> test/.hg/hgrc
$ cd test
$ cat > mymap << EOF
> changeset = my:changeset.txt
> EOF
$ cat > changeset.txt << EOF
> {{rev}} {{node}} {{author}}
> EOF
$ hg ci -Ama
adding changeset.txt
adding mymap
$ hg log --style=./mymap
0 97e5f848f0936960273bbf75be6388cd0350a32b test
$ cat > changeset.txt << EOF
> {{p1rev}} {{p1node}} {{p2rev}} {{p2node}}
> EOF
$ hg ci -Ama
$ hg log --style=./mymap
0 97e5f848f0936960273bbf75be6388cd0350a32b -1 0000000000000000000000000000000000000000
-1 0000000000000000000000000000000000000000 -1 0000000000000000000000000000000000000000
invalid engine type:
$ echo 'changeset = unknown:changeset.txt' > unknownenginemap
$ hg log --style=./unknownenginemap
abort: invalid template engine: unknown
[255]
$ cd ..