#==================================================================

    # SET DEFAULTS GLOBAL, REPOS, REPOSITORY GROUPS

    #==================================================================

    # default global permissions taken from the default user

    default_global_perms = UserToPerm.query() \

        .filter(UserToPerm.user_id == default_user_id) \

        .options(joinedload(UserToPerm.permission))

    for perm in default_global_perms:

        permissions[GLOBAL].add(perm.permission.permission_name)

    # defaults for repositories, taken from default user

    for perm in default_repo_perms:

        r_k = perm.UserRepoToPerm.repository.repo_name

        if perm.Repository.owner_id == user_id:

            p = 'repository.admin'

        elif perm.Repository.private:

            p = 'repository.none'

        else:

            p = perm.Permission.permission_name

        permissions[RK][r_k] = p

    # defaults for repository groups taken from default user permission

    # on given group

    for perm in default_repo_groups_perms:

        rg_k = perm.UserRepoGroupToPerm.group.group_name

        p = perm.Permission.permission_name

        permissions[GK][rg_k] = p

    # defaults for user groups taken from default user permission

    # on given user group

    for perm in default_user_group_perms:

        u_k = perm.UserUserGroupToPerm.user_group.users_group_name

        p = perm.Permission.permission_name

        permissions[UK][u_k] = p

    #======================================================================

    # !! Augment GLOBALS with user permissions if any found !!

    #======================================================================

    # USER GROUPS comes first

    # user group global permissions

    user_perms_from_users_groups = Session().query(UserGroupToPerm) \

        .options(joinedload(UserGroupToPerm.permission)) \

        .join((UserGroupMember, UserGroupToPerm.users_group_id ==

               UserGroupMember.users_group_id)) \

        .filter(UserGroupMember.user_id == user_id) \

        .join((UserGroup, UserGroupMember.users_group_id ==

               UserGroup.users_group_id)) \

        .filter(UserGroup.users_group_active == True) \

        .order_by(UserGroupToPerm.users_group_id) \

        .all()

    # need to group here by groups since user can be in more than

    # one group

    _grouped = [[x, list(y)] for x, y in

                itertools.groupby(user_perms_from_users_groups,

                                  lambda x:x.users_group)]

    for gr, perms in _grouped:

        for perm in perms:

            permissions[GLOBAL].add(perm.permission.permission_name)

    # user specific global permissions

    user_perms = Session().query(UserToPerm) \

            .options(joinedload(UserToPerm.permission)) \

            .filter(UserToPerm.user_id == user_id).all()

    for perm in user_perms:

        permissions[GLOBAL].add(perm.permission.permission_name)

    # for each kind of global permissions, only keep the one with heighest weight

    kind_max_perm = {}

    for perm in sorted(permissions[GLOBAL], key=lambda n: PERM_WEIGHTS[n]):

        kind = perm.rsplit('.', 1)[0]

        kind_max_perm[kind] = perm

    permissions[GLOBAL] = set(kind_max_perm.values())

    ## END GLOBAL PERMISSIONS

    #======================================================================

    # !! PERMISSIONS FOR REPOSITORIES !!

    #======================================================================

    #======================================================================

    # check if user is part of user groups for this repository and

    # fill in his permission from it.

    #======================================================================

    # user group for repositories permissions

    user_repo_perms_from_users_groups = \

     Session().query(UserGroupRepoToPerm, Permission, Repository,) \

        .join((Repository, UserGroupRepoToPerm.repository_id ==

               Repository.repo_id)) \

        .join((Permission, UserGroupRepoToPerm.permission_id ==

               Permission.permission_id)) \

        .join((UserGroup, UserGroupRepoToPerm.users_group_id ==

               UserGroup.users_group_id)) \

        .filter(UserGroup.users_group_active == True) \

        .join((UserGroupMember, UserGroupRepoToPerm.users_group_id ==

               UserGroupMember.users_group_id)) \

        .filter(UserGroupMember.user_id == user_id) \

        .all()

    for perm in user_repo_perms_from_users_groups:

        bump_permission(RK,

            perm.UserGroupRepoToPerm.repository.repo_name,

            perm.Permission.permission_name)

    # user permissions for repositories

    user_repo_perms = Permission.get_default_perms(user_id)

    for perm in user_repo_perms:

        bump_permission(RK,

            perm.UserRepoToPerm.repository.repo_name,

            perm.Permission.permission_name)

    #======================================================================

    # !! PERMISSIONS FOR REPOSITORY GROUPS !!

    #======================================================================

    #======================================================================

    # check if user is part of user groups for this repository groups and

    # fill in his permission from it.

    #======================================================================

    # user group for repo groups permissions

    user_repo_group_perms_from_users_groups = \

     Session().query(UserGroupRepoGroupToPerm, Permission, RepoGroup) \

     .join((RepoGroup, UserGroupRepoGroupToPerm.group_id == RepoGroup.group_id)) \

     .join((Permission, UserGroupRepoGroupToPerm.permission_id

            == Permission.permission_id)) \

     .join((UserGroup, UserGroupRepoGroupToPerm.users_group_id ==

            UserGroup.users_group_id)) \

     .filter(UserGroup.users_group_active == True) \

     .join((UserGroupMember, UserGroupRepoGroupToPerm.users_group_id

            == UserGroupMember.users_group_id)) \

     .filter(UserGroupMember.user_id == user_id) \

     .all()

    for perm in user_repo_group_perms_from_users_groups:

        bump_permission(GK,

            perm.UserGroupRepoGroupToPerm.group.group_name,

            perm.Permission.permission_name)

    # user explicit permissions for repository groups

    user_repo_groups_perms = Permission.get_default_group_perms(user_id)

    for perm in user_repo_groups_perms:

        bump_permission(GK,

            perm.UserRepoGroupToPerm.group.group_name,

            perm.Permission.permission_name)

    #======================================================================

    # !! PERMISSIONS FOR USER GROUPS !!

    #======================================================================

    # user group for user group permissions

    user_group_user_groups_perms = \

     Session().query(UserGroupUserGroupToPerm, Permission, UserGroup) \

     .join((UserGroup, UserGroupUserGroupToPerm.target_user_group_id

            == UserGroup.users_group_id)) \

     .join((Permission, UserGroupUserGroupToPerm.permission_id

            == Permission.permission_id)) \

     .join((UserGroupMember, UserGroupUserGroupToPerm.user_group_id

            == UserGroupMember.users_group_id)) \

     .filter(UserGroupMember.user_id == user_id) \

     .join((UserGroup, UserGroupMember.users_group_id ==

            UserGroup.users_group_id), aliased=True, from_joinpoint=True) \

     .filter(UserGroup.users_group_active == True) \

     .all()

    for perm in user_group_user_groups_perms:

        bump_permission(UK,

            perm.UserGroupUserGroupToPerm.target_user_group.users_group_name,

            perm.Permission.permission_name)

    # user explicit permission for user groups

    user_user_groups_perms = Permission.get_default_user_group_perms(user_id)

    for perm in user_user_groups_perms:

        bump_permission(UK,

            perm.UserUserGroupToPerm.user_group.users_group_name,

            perm.Permission.permission_name)

    return permissions

class AuthUser(object):

    """

    Represents a Kallithea user, including various authentication and

    authorization information. Typically used to store the current user,

    but is also used as a generic user information data structure in

    parts of the code, e.g. user management.

    Constructed from a database `User` object, a user ID or cookie dict,

    it looks up the user (if needed) and copies all attributes to itself,

    adding various non-persistent data. If lookup fails but anonymous

    access to Kallithea is enabled, the default user is loaded instead.

    However, `AuthUser` does refuse to load a user that is not `active`.

    Note that Kallithea distinguishes between the default user (an actual

    user in the database with username "default") and "no user" (no actual

    User object, AuthUser filled with blank values and username "None").

    If the default user is active, that will always be used instead of

    "no user". On the other hand, if the default user is disabled (and

    there is no login information), we instead get "no user"; this should

    only happen on the login page (as all other requests are redirected).

    `is_default_user` specifically checks if the AuthUser is the user named

    "default". Use `is_anonymous` to check for both "default" and "no user".

    """

    def __init__(self, user_id=None, dbuser=None, authenticating_api_key=None,

            is_external_auth=False):

        self.is_external_auth = is_external_auth

        self.authenticating_api_key = authenticating_api_key

        # These attributes will be overridden by fill_data, below, unless the

        # requested user cannot be found and the default anonymous user is

        # not enabled.

        self.user_id = None

        self.username = None

        self.api_key = None

        self.name = ''

        self.lastname = ''

        self.email = ''

        self.admin = False

        # Look up database user, if necessary.

        if user_id is not None:

            log.debug('Auth User lookup by USER ID %s', user_id)

            dbuser = UserModel().get(user_id)

        else:

            # Note: dbuser is allowed to be None.

            log.debug('Auth User lookup by database user %s', dbuser)

        is_user_loaded = self._fill_data(dbuser)

        # If user cannot be found, try falling back to anonymous.

        if is_user_loaded:

            assert dbuser is not None

            self.is_default_user = dbuser.is_default_user

        else:

            default_user = User.get_default_user(cache=True)

            is_user_loaded = self._fill_data(default_user)

            self.is_default_user = is_user_loaded

        self.is_anonymous = not is_user_loaded or self.is_default_user

        if not self.username:

            self.username = 'None'

        log.debug('Auth User is now %s', self)

    def _fill_data(self, dbuser):

        """

        Copies database fields from a `db.User` to this `AuthUser`. Does

        not copy `api_keys` and `permissions` attributes.

        Checks that `dbuser` is `active` (and not None) before copying;

        returns True on success.

        """

        if dbuser is not None and dbuser.active:

            log.debug('filling %s data', dbuser)

            for k, v in dbuser.get_dict().iteritems():

                assert k not in ['api_keys', 'permissions']

                setattr(self, k, v)

            return True

        return False

    @LazyProperty

    def permissions(self):

        return self.__get_perms(user=self, cache=False)

    def has_repository_permission_level(self, repo_name, level, purpose=None):

        required_perms = {

            'read': ['repository.read', 'repository.write', 'repository.admin'],

            'write': ['repository.write', 'repository.admin'],

            'admin': ['repository.admin'],

        }[level]

        actual_perm = self.permissions['repositories'].get(repo_name)

        ok = actual_perm in required_perms

        log.debug('Checking if user %r can %r repo %r (%s): %s (has %r)',

            self.username, level, repo_name, purpose, ok, actual_perm)

        return ok

    def has_repository_group_permission_level(self, repo_group_name, level, purpose=None):

        required_perms = {

            'read': ['group.read', 'group.write', 'group.admin'],

            'write': ['group.write', 'group.admin'],

            'admin': ['group.admin'],

        }[level]

        actual_perm = self.permissions['repositories_groups'].get(repo_group_name)

        ok = actual_perm in required_perms

        log.debug('Checking if user %r can %r repo group %r (%s): %s (has %r)',

            self.username, level, repo_group_name, purpose, ok, actual_perm)

        return ok

    def has_user_group_permission_level(self, user_group_name, level, purpose=None):

        required_perms = {

            'read': ['usergroup.read', 'usergroup.write', 'usergroup.admin'],

            'write': ['usergroup.write', 'usergroup.admin'],

            'admin': ['usergroup.admin'],

        }[level]

        actual_perm = self.permissions['user_groups'].get(user_group_name)

        ok = actual_perm in required_perms

        log.debug('Checking if user %r can %r user group %r (%s): %s (has %r)',

            self.username, level, user_group_name, purpose, ok, actual_perm)

        return ok

    @property

    def api_keys(self):

        return self._get_api_keys()

    def __get_perms(self, user, cache=False):

        """

        Fills user permission attribute with permissions taken from database

        works for permissions given for repositories, and for permissions that

        are granted to groups

        :param user: `AuthUser` instance

        """

        user_id = user.user_id

        user_is_admin = user.is_admin

        log.debug('Getting PERMISSION tree')

        compute = conditional_cache('short_term', 'cache_desc',

                                    condition=cache, func=_cached_perms_data)

        return compute(user_id, user_is_admin)

    def _get_api_keys(self):

        api_keys = [self.api_key]

        for api_key in UserApiKeys.query() \

                .filter_by(user_id=self.user_id, is_expired=False):

            api_keys.append(api_key.api_key)

        return api_keys

    @property

    def is_admin(self):

        return self.admin

    @property

    def repositories_admin(self):

        """

        Returns list of repositories you're an admin of

        """

        return [x[0] for x in self.permissions['repositories'].iteritems()

                if x[1] == 'repository.admin']

    @property

    def repository_groups_admin(self):

        """

        Returns list of repository groups you're an admin of

        """

        return [x[0] for x in self.permissions['repositories_groups'].iteritems()

                if x[1] == 'group.admin']

    @property

    def user_groups_admin(self):

        """

        Returns list of user groups you're an admin of

        """

        return [x[0] for x in self.permissions['user_groups'].iteritems()

                if x[1] == 'usergroup.admin']

    @staticmethod

    def check_ip_allowed(user, ip_addr):

        """

        Check if the given IP address (a `str`) is allowed for the given

        user (an `AuthUser` or `db.User`).

        """

        allowed_ips = AuthUser.get_allowed_ips(user.user_id, cache=True)

        if check_ip_access(source_ip=ip_addr, allowed_ips=allowed_ips):

            log.debug('IP:%s is in range of %s', ip_addr, allowed_ips)

            return True

        else:

            log.info('Access for IP:%s forbidden, '

                     'not in %s' % (ip_addr, allowed_ips))

            return False

    def __repr__(self):

    def to_cookie(self):

        """ Serializes this login session to a cookie `dict`. """

        return {

            'user_id': self.user_id,

            'is_external_auth': self.is_external_auth,

        }

    @staticmethod

    def from_cookie(cookie):

        """

        Deserializes an `AuthUser` from a cookie `dict`.

        """

        au = AuthUser(

            user_id=cookie.get('user_id'),

            is_external_auth=cookie.get('is_external_auth', False),

        )

        return au

    @classmethod

    def get_allowed_ips(cls, user_id, cache=False):

        _set = set()

        default_ips = UserIpMap.query().filter(UserIpMap.user_id ==

                                        User.get_default_user(cache=True).user_id)

        if cache:

            default_ips = default_ips.options(FromCache("sql_cache_short",

                                              "get_user_ips_default"))

        for ip in default_ips:

            try:

                _set.add(ip.ip_addr)

            except ObjectDeletedError:

                # since we use heavy caching sometimes it happens that we get

                # deleted objects here, we just skip them

                pass

        user_ips = UserIpMap.query().filter(UserIpMap.user_id == user_id)

        if cache:

            user_ips = user_ips.options(FromCache("sql_cache_short",

                                                  "get_user_ips_%s" % user_id))

        for ip in user_ips:

            try:

                _set.add(ip.ip_addr)

            except ObjectDeletedError:

                # since we use heavy caching sometimes it happens that we get

                # deleted objects here, we just skip them

                pass

        return _set or set(['0.0.0.0/0', '::/0'])

def set_available_permissions(config):

    """

    This function will propagate globals with all available defined

    permission given in db. We don't want to check each time from db for new

    permissions since adding a new permission also requires application restart

    ie. to decorate new views with the newly created permission

    :param config: current config instance

    """

    log.info('getting information about all available permissions')

    try:

        all_perms = Session().query(Permission).all()

        config['available_permissions'] = [x.permission_name for x in all_perms]

    finally:

        Session.remove()

#==============================================================================

# CHECK DECORATORS

#==============================================================================

def _redirect_to_login(message=None):

    """Return an exception that must be raised. It will redirect to the login

    page which will redirect back to the current URL after authentication.

    The optional message will be shown in a flash message."""

    from kallithea.lib import helpers as h

    if message:

        h.flash(message, category='warning')

    p = request.path_qs

    log.debug('Redirecting to login page, origin: %s', p)

    return HTTPFound(location=url('login_home', came_from=p))

# Use as decorator

class LoginRequired(object):

    """Client must be logged in as a valid User, or we'll redirect to the login

    page.

    If the "default" user is enabled and allow_default_user is true, that is

    considered valid too.

    Also checks that IP address is allowed.

    """

    def __init__(self, allow_default_user=False):

        self.allow_default_user = allow_default_user

    def __call__(self, func):

        return decorator(self.__wrapper, func)

    def __wrapper(self, func, *fargs, **fkwargs):

        controller = fargs[0]

        user = request.authuser

        loc = "%s:%s" % (controller.__class__.__name__, func.__name__)

        log.debug('Checking access for user %s @ %s', user, loc)

        # Check if we used an API key to authenticate.

        if user.authenticating_api_key is not None:

            log.info('user %s authenticated with API key ****%s @ %s',

                     user, user.authenticating_api_key[-4:], loc)

            return func(*fargs, **fkwargs)

        # CSRF protection: Whenever a request has ambient authority (whether

        # through a session cookie or its origin IP address), it must include

        # the correct token, unless the HTTP method is GET or HEAD (and thus

        # guaranteed to be side effect free. In practice, the only situation

        # where we allow side effects without ambient authority is when the

        # authority comes from an API key; and that is handled above.

        if request.method not in ['GET', 'HEAD']:

            token = request.POST.get(secure_form.token_key)

            if not token or token != secure_form.authentication_token():

                log.error('CSRF check failed')

                raise HTTPForbidden()

        # regular user authentication

        if user.is_default_user:

            if self.allow_default_user:

                log.info('default user @ %s', loc)

                return func(*fargs, **fkwargs)

            log.info('default user is not accepted here @ %s', loc)

        elif user.is_anonymous: # default user is disabled and no proper authentication

            log.warning('user is anonymous and NOT authenticated with regular auth @ %s', loc)

        else: # regular authentication

            log.info('user %s authenticated with regular auth @ %s', user, loc)

            return func(*fargs, **fkwargs)

        raise _redirect_to_login()

# Use as decorator

class NotAnonymous(object):

    """Ensures that client is not logged in as the "default" user, and

    redirects to the login page otherwise. Must be used together with

    LoginRequired."""

    def __call__(self, func):

        return decorator(self.__wrapper, func)

    def __wrapper(self, func, *fargs, **fkwargs):

        cls = fargs[0]

        user = request.authuser

        log.debug('Checking that user %s is not anonymous @%s', user.username, cls)

        if user.is_default_user:

            raise _redirect_to_login(_('You need to be a registered user to '

                                       'perform this action'))

        else:

            return func(*fargs, **fkwargs)

class _PermsDecorator(object):

    """Base class for controller decorators with multiple permissions"""

    def __init__(self, *required_perms):

        self.required_perms = required_perms # usually very short - a list is thus fine

    def __call__(self, func):

        return decorator(self.__wrapper, func)

    def __wrapper(self, func, *fargs, **fkwargs):

        cls = fargs[0]

        user = request.authuser

        log.debug('checking %s permissions %s for %s %s',

          self.__class__.__name__, self.required_perms, cls, user)

        if self.check_permissions(user):

            log.debug('Permission granted for %s %s', cls, user)

            return func(*fargs, **fkwargs)

        else:

            log.info('Permission denied for %s %s', cls, user)

            if user.is_default_user:

                raise _redirect_to_login(_('You need to be signed in to view this page'))

            else:

                raise HTTPForbidden()

    def check_permissions(self, user):

        raise NotImplementedError()

class HasPermissionAnyDecorator(_PermsDecorator):

    """

    Checks the user has any of the given global permissions.

    """

    def check_permissions(self, user):

        global_permissions = user.permissions['global'] # usually very short

        return any(p in global_permissions for p in self.required_perms)

class _PermDecorator(_PermsDecorator):

    """Base class for controller decorators with a single permission"""

    def __init__(self, required_perm):

        _PermsDecorator.__init__(self, [required_perm])

        self.required_perm = required_perm

# -*- coding: utf-8 -*-

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""

kallithea.lib.base

~~~~~~~~~~~~~~~~~~

The base Controller API

Provides the BaseController class for subclassing. And usage in different

controllers

This file was forked by the Kallithea project in July 2014.

Original author and date, and relevant copyright and licensing information is below:

:created_on: Oct 06, 2010

:author: marcink

:copyright: (c) 2013 RhodeCode GmbH, and others.

:license: GPLv3, see LICENSE.md for more details.

"""

import datetime

import decorator

import logging

import time

import traceback

import warnings

import webob.exc

import paste.httpexceptions

import paste.auth.basic

import paste.httpheaders

from webhelpers.pylonslib import secure_form

from tg import config, tmpl_context as c, request, response, session, render_template

from tg import TGController

from tg.i18n import ugettext as _

from kallithea import __version__, BACKENDS

from kallithea.config.routing import url

from kallithea.lib.utils2 import str2bool, safe_unicode, AttributeDict, \

    safe_str, safe_int

from kallithea.lib import auth_modules

from kallithea.lib.auth import AuthUser, HasPermissionAnyMiddleware

from kallithea.lib.compat import json

from kallithea.lib.utils import get_repo_slug

from kallithea.lib.exceptions import UserCreationError

from kallithea.lib.vcs.exceptions import RepositoryError, EmptyRepositoryError, ChangesetDoesNotExistError

from kallithea.model import meta

from kallithea.model.db import PullRequest, Repository, Ui, User, Setting

from kallithea.model.scm import ScmModel

log = logging.getLogger(__name__)

def render(template_path):

    return render_template({'url': url}, 'mako', template_path)

def _filter_proxy(ip):

    """

    HEADERS can have multiple ips inside the left-most being the original

    client, and each successive proxy that passed the request adding the IP

    address where it received the request from.

    :param ip:

    """

    if ',' in ip:

        _ips = ip.split(',')

        _first_ip = _ips[0].strip()

        log.debug('Got multiple IPs %s, using %s', ','.join(_ips), _first_ip)

        return _first_ip

    return ip

def _get_ip_addr(environ):

    proxy_key = 'HTTP_X_REAL_IP'

    proxy_key2 = 'HTTP_X_FORWARDED_FOR'

    def_key = 'REMOTE_ADDR'

    ip = environ.get(proxy_key)

    if ip:

        return _filter_proxy(ip)

    ip = environ.get(proxy_key2)

    if ip:

        return _filter_proxy(ip)

    ip = environ.get(def_key, '0.0.0.0')

    return _filter_proxy(ip)

def _get_access_path(environ):

    path = environ.get('PATH_INFO')

    org_req = environ.get('tg.original_request')

    if org_req:

        path = org_req.environ.get('PATH_INFO')

    return path

def log_in_user(user, remember, is_external_auth):

    """

    Log a `User` in and update session and cookies. If `remember` is True,

    the session cookie is set to expire in a year; otherwise, it expires at

    the end of the browser session.

    Returns populated `AuthUser` object.

    """

    user.update_lastlogin()

    meta.Session().commit()

    auth_user = AuthUser(dbuser=user,

                         is_external_auth=is_external_auth)

    # It should not be possible to explicitly log in as the default user.

    assert not auth_user.is_default_user

    # Start new session to prevent session fixation attacks.

    session.invalidate()

    session['authuser'] = cookie = auth_user.to_cookie()

    # If they want to be remembered, update the cookie.

    # NOTE: Assumes that beaker defaults to browser session cookie.

    if remember:

        t = datetime.datetime.now() + datetime.timedelta(days=365)

        session._set_cookie_expires(t)

    session.save()

    log.info('user %s is now authenticated and stored in '

             'session, session attrs %s', user.username, cookie)

    # dumps session attrs back to cookie

    session._update_cookie_out()

    return auth_user

class BasicAuth(paste.auth.basic.AuthBasicAuthenticator):

    def __init__(self, realm, authfunc, auth_http_code=None):

        self.realm = realm

        self.authfunc = authfunc

        self._rc_auth_http_code = auth_http_code

    def build_authentication(self, environ):

        head = paste.httpheaders.WWW_AUTHENTICATE.tuples('Basic realm="%s"' % self.realm)

        # Consume the whole body before sending a response

        try:

            request_body_size = int(environ.get('CONTENT_LENGTH', 0))

        except (ValueError):

            request_body_size = 0

        environ['wsgi.input'].read(request_body_size)

        if self._rc_auth_http_code and self._rc_auth_http_code == '403':

            # return 403 if alternative http return code is specified in

            # Kallithea config

            return paste.httpexceptions.HTTPForbidden(headers=head)

        return paste.httpexceptions.HTTPUnauthorized(headers=head)

    def authenticate(self, environ):

        authorization = paste.httpheaders.AUTHORIZATION(environ)

        if not authorization:

            return self.build_authentication(environ)

        (authmeth, auth) = authorization.split(' ', 1)

        if 'basic' != authmeth.lower():

            return self.build_authentication(environ)

        auth = auth.strip().decode('base64')

        _parts = auth.split(':', 1)

        if len(_parts) == 2:

            username, password = _parts

            if self.authfunc(username, password, environ) is not None:

                return username

        return self.build_authentication(environ)

    __call__ = authenticate

class BaseVCSController(object):

    """Base controller for handling Mercurial/Git protocol requests

    (coming from a VCS client, and not a browser).

    """

    def __init__(self, application, config):

        self.application = application

        self.config = config

        # base path of repo locations

        self.basepath = self.config['base_path']

        # authenticate this VCS request using the authentication modules

        self.authenticate = BasicAuth('', auth_modules.authenticate,

                                      config.get('auth_ret_code'))

    def _authorize(self, environ, start_response, action, repo_name, ip_addr):

        """Authenticate and authorize user.

        Since we're dealing with a VCS client and not a browser, we only

        support HTTP basic authentication, either directly via raw header

        inspection, or by using container authentication to delegate the

        authentication to the web server.

        Returns (user, None) on successful authentication and authorization.

        Returns (None, wsgi_app) to send the wsgi_app response to the client.

        """

        # Check if anonymous access is allowed.

        default_user = User.get_default_user(cache=True)

        is_default_user_allowed = (default_user.active and

            self._check_permission(action, default_user, repo_name, ip_addr))

        if is_default_user_allowed:

            return default_user, None

        if not default_user.active:

            log.debug('Anonymous access is disabled')

        else:

            log.debug('Not authorized to access this '

                      'repository as anonymous user')

        username = None

        #==============================================================

        # DEFAULT PERM FAILED OR ANONYMOUS ACCESS IS DISABLED SO WE

        # NEED TO AUTHENTICATE AND ASK FOR AUTH USER PERMISSIONS

        #==============================================================

        # try to auth based on environ, container auth methods

        log.debug('Running PRE-AUTH for container based authentication')

        pre_auth = auth_modules.authenticate('', '', environ)

        if pre_auth is not None and pre_auth.get('username'):

            username = pre_auth['username']

        log.debug('PRE-AUTH got %s as username', username)

        # If not authenticated by the container, running basic auth

        if not username:

            self.authenticate.realm = safe_str(self.config['realm'])

            result = self.authenticate(environ)

            if isinstance(result, str):

                paste.httpheaders.AUTH_TYPE.update(environ, 'basic')

                paste.httpheaders.REMOTE_USER.update(environ, result)

                username = result

            else:

                return None, result.wsgi_application

        #==============================================================

        # CHECK PERMISSIONS FOR THIS REQUEST USING GIVEN USERNAME

        #==============================================================

        try:

            user = User.get_by_username_or_email(username)

            if user is None or not user.active:

                return None, webob.exc.HTTPForbidden()

        except Exception:

            log.error(traceback.format_exc())

            return None, webob.exc.HTTPInternalServerError()

        # check permissions for this repository

        perm = self._check_permission(action, user, repo_name, ip_addr)

        if not perm:

            return None, webob.exc.HTTPForbidden()

        return user, None

    def _handle_request(self, environ, start_response):

        raise NotImplementedError()