# acl.py - changeset access control for mercurial

#

# Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>

#

# This software may be used and distributed according to the terms of the

# GNU General Public License version 2, incorporated herein by reference.

#

# this hook allows to allow or deny access to parts of a repo when

# taking incoming changesets.

#

# authorization is against local user name on system where hook is

# run, not committer of original changeset (since that is easy to

# spoof).

#

# acl hook is best to use if you use hgsh to set up restricted shells

# for authenticated users to only push to / pull from.  not safe if

# user has interactive shell access, because they can disable hook.

# also not safe if remote users share one local account, because then

# no way to tell remote users apart.

#

# to use, configure acl extension in hgrc like this:

#

#   [extensions]

#   hgext.acl =

#

#   [hooks]

#   pretxnchangegroup.acl = python:hgext.acl.hook

#

#   [acl]

#   sources = serve        # check if source of incoming changes in this list

#                          # ("serve" == ssh or http, "push", "pull", "bundle")

#

# allow and deny lists have subtree pattern (default syntax is glob)

# on left, user names on right. deny list checked before allow list.

#

#   [acl.allow]

#   # if acl.allow not present, all users allowed by default

#   # empty acl.allow = no users allowed

#   docs/** = doc_writer

#   .hgtags = release_engineer

#

#   [acl.deny]

#   # if acl.deny not present, no users denied by default

#   # empty acl.deny = all users allowed

#   glob pattern = user4, user5

#   ** = user6

from mercurial.i18n import _

from mercurial import util, match

import getpass

def buildmatch(ui, repo, user, key):

    '''return tuple of (match function, list enabled).'''

    if not ui.has_section(key):

        ui.debug(_('acl: %s not enabled\n') % key)

        return None

    pats = [pat for pat, users in ui.configitems(key)

            if user in users.replace(',', ' ').split()]

    ui.debug(_('acl: %s enabled, %d entries for user %s\n') %

             (key, len(pats), user))

    if pats:

    return match.never(repo.root, '')

def hook(ui, repo, hooktype, node=None, source=None, **kwargs):

    if hooktype != 'pretxnchangegroup':

        raise util.Abort(_('config error - hook type "%s" cannot stop '

                           'incoming changesets') % hooktype)

    if source not in ui.config('acl', 'sources', 'serve').split():

        ui.debug(_('acl: changes have source "%s" - skipping\n') % source)

        return

    user = getpass.getuser()

    cfg = ui.config('acl', 'config')

    if cfg:

        ui.readconfig(cfg, sections = ['acl.allow', 'acl.deny'])

    allow = buildmatch(ui, repo, user, 'acl.allow')

    deny = buildmatch(ui, repo, user, 'acl.deny')

    for rev in xrange(repo[node], len(repo)):

        ctx = repo[rev]

        for f in ctx.files():

            if deny and deny(f):

                ui.debug(_('acl: user %s denied on %s\n') % (user, f))

                raise util.Abort(_('acl: access denied for changeset %s') % ctx)

            if allow and not allow(f):

                ui.debug(_('acl: user %s not allowed on %s\n') % (user, f))

                raise util.Abort(_('acl: access denied for changeset %s') % ctx)

        ui.debug(_('acl: allowing changeset %s\n') % ctx)