# -*- 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.auth

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

authentication and permission libraries

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: Apr 4, 2010

:author: marcink

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

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

"""

from __future__ import with_statement

import time

import random

import logging

import traceback

import hashlib

import itertools

import collections

from tempfile import _RandomNameSequence

from decorator import decorator

from pylons import url, request

from pylons.controllers.util import abort, redirect

from pylons.i18n.translation import _

from webhelpers.pylonslib import secure_form

from sqlalchemy import or_

from sqlalchemy.orm.exc import ObjectDeletedError

from sqlalchemy.orm import joinedload

from kallithea import __platform__, is_windows, is_unix

from kallithea.lib.vcs.utils.lazy import LazyProperty

from kallithea.model import meta

from kallithea.model.meta import Session

from kallithea.model.user import UserModel

from kallithea.model.db import User, Repository, Permission, \

    UserToPerm, UserGroupRepoToPerm, UserGroupToPerm, UserGroupMember, \

    RepoGroup, UserGroupRepoGroupToPerm, UserIpMap, UserGroupUserGroupToPerm, \

    UserGroup, UserApiKeys

from kallithea.lib.utils2 import safe_unicode, aslist

from kallithea.lib.utils import get_repo_slug, get_repo_group_slug, \

    get_user_group_slug, conditional_cache

from kallithea.lib.caching_query import FromCache

log = logging.getLogger(__name__)

class PasswordGenerator(object):

    """

    This is a simple class for generating password from different sets of

    characters

    usage::

        passwd_gen = PasswordGenerator()

        #print 8-letter password containing only big and small letters

            of alphabet

        passwd_gen.gen_password(8, passwd_gen.ALPHABETS_BIG_SMALL)

    """

    ALPHABETS_NUM = r'''1234567890'''

    ALPHABETS_SMALL = r'''qwertyuiopasdfghjklzxcvbnm'''

    ALPHABETS_BIG = r'''QWERTYUIOPASDFGHJKLZXCVBNM'''

    ALPHABETS_SPECIAL = r'''`-=[]\;',./~!@#$%^&*()_+{}|:"<>?'''

    ALPHABETS_FULL = ALPHABETS_BIG + ALPHABETS_SMALL \

        + ALPHABETS_NUM + ALPHABETS_SPECIAL

    ALPHABETS_ALPHANUM = ALPHABETS_BIG + ALPHABETS_SMALL + ALPHABETS_NUM

    ALPHABETS_BIG_SMALL = ALPHABETS_BIG + ALPHABETS_SMALL

    ALPHABETS_ALPHANUM_BIG = ALPHABETS_BIG + ALPHABETS_NUM

    ALPHABETS_ALPHANUM_SMALL = ALPHABETS_SMALL + ALPHABETS_NUM

    def __init__(self, passwd=''):

        self.passwd = passwd

    def gen_password(self, length, type_=None):

        if type_ is None:

            type_ = self.ALPHABETS_FULL

        self.passwd = ''.join([random.choice(type_) for _ in xrange(length)])

        return self.passwd

class KallitheaCrypto(object):

    @classmethod

    def hash_string(cls, str_):

        """

        Cryptographic function used for password hashing based on pybcrypt

        or pycrypto in windows

        :param password: password to hash

        """

        if is_windows:

            from hashlib import sha256

            return sha256(str_).hexdigest()

        elif is_unix:

            import bcrypt

            return bcrypt.hashpw(str_, bcrypt.gensalt(10))

        else:

            raise Exception('Unknown or unsupported platform %s' \

                            % __platform__)

    @classmethod

    def hash_check(cls, password, hashed):

        """

        Checks matching password with it's hashed value, runs different

        implementation based on platform it runs on

        :param password: password

        :param hashed: password in hashed form

        """

        if is_windows:

            from hashlib import sha256

            return sha256(password).hexdigest() == hashed

        elif is_unix:

            import bcrypt

            return bcrypt.hashpw(password, hashed) == hashed

        else:

            raise Exception('Unknown or unsupported platform %s' \

                            % __platform__)

def get_crypt_password(password):

    return KallitheaCrypto.hash_string(password)

def check_password(password, hashed):

    return KallitheaCrypto.hash_check(password, hashed)

def generate_api_key(str_, salt=None):

    """

    Generates API KEY from given string

    :param str_:

    :param salt:

    """

    if salt is None:

        salt = _RandomNameSequence().next()

    return hashlib.sha1(str_ + salt).hexdigest()

class CookieStoreWrapper(object):

    def __init__(self, cookie_store):

        self.cookie_store = cookie_store

    def __repr__(self):

        return 'CookieStore<%s>' % (self.cookie_store)

    def get(self, key, other=None):

        if isinstance(self.cookie_store, dict):

            return self.cookie_store.get(key, other)

        elif isinstance(self.cookie_store, AuthUser):

            return self.cookie_store.__dict__.get(key, other)

def _cached_perms_data(user_id, user_is_admin, user_inherit_default_permissions,

                       explicit, algo):

    RK = 'repositories'

    GK = 'repositories_groups'

    UK = 'user_groups'

    GLOBAL = 'global'

    PERM_WEIGHTS = Permission.PERM_WEIGHTS

    permissions = {RK: {}, GK: {}, UK: {}, GLOBAL: set()}

    def _choose_perm(new_perm, cur_perm):

        new_perm_val = PERM_WEIGHTS[new_perm]

        cur_perm_val = PERM_WEIGHTS[cur_perm]

        if algo == 'higherwin':

            if new_perm_val > cur_perm_val:

                return new_perm

            return cur_perm

        elif algo == 'lowerwin':

            if new_perm_val < cur_perm_val:

                return new_perm

            return cur_perm

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

    # fetch default permissions

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

    default_user = User.get_by_username('default', cache=True)

    default_user_id = default_user.user_id

    default_repo_perms = Permission.get_default_perms(default_user_id)

    default_repo_groups_perms = Permission.get_default_group_perms(default_user_id)

    default_user_group_perms = Permission.get_default_user_group_perms(default_user_id)

    if user_is_admin:

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

        # admin user have all default rights for repositories

        # and groups set to admin

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

        permissions[GLOBAL].add('hg.admin')

        permissions[GLOBAL].add('hg.create.write_on_repogroup.true')

        # repositories

        for perm in default_repo_perms:

            r_k = perm.UserRepoToPerm.repository.repo_name

            p = 'repository.admin'

            permissions[RK][r_k] = p

        # repository groups

        for perm in default_repo_groups_perms:

            rg_k = perm.UserRepoGroupToPerm.group.group_name

            p = 'group.admin'

            permissions[GK][rg_k] = p

        # user groups

        for perm in default_user_group_perms:

            u_k = perm.UserUserGroupToPerm.user_group.users_group_name

            p = 'usergroup.admin'

            permissions[UK][u_k] = p

        return permissions

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

    # SET DEFAULTS GLOBAL, REPOS, REPOSITORY GROUPS

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

    uid = user_id

    # 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.private and not (perm.Repository.user_id == uid):

            # disable defaults for private repos,

            p = 'repository.none'

        elif perm.Repository.user_id == uid:

            # set admin if owner

            p = 'repository.admin'

        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

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

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

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

    # those can be configured from groups or users explicitly

    _configurable = set([

        'hg.fork.none', 'hg.fork.repository',

        'hg.create.none', 'hg.create.repository',

        'hg.usergroup.create.false', 'hg.usergroup.create.true'

    ])

    # 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 == uid)\

        .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:

        # since user can be in multiple groups iterate over them and

        # select the lowest permissions first (more explicit)

        ##TODO: do this^^

        if not gr.inherit_default_permissions:

            # NEED TO IGNORE all configurable permissions and

            # replace them with explicitly set

            permissions[GLOBAL] = permissions[GLOBAL]\

                                            .difference(_configurable)

        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 == uid).all()

    if not user_inherit_default_permissions:

        # NEED TO IGNORE all configurable permissions and

        # replace them with explicitly set

        permissions[GLOBAL] = permissions[GLOBAL]\

                                        .difference(_configurable)

        for perm in user_perms:

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

    ## END GLOBAL PERMISSIONS

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

    # !! PERMISSIONS FOR REPOSITORIES !!

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

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

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

    # fill in his permission from it. _choose_perm decides of which

    # permission should be selected based on selected method

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

    # 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((UserGroupMember, UserGroupRepoToPerm.users_group_id ==

               UserGroupMember.users_group_id))\

        .filter(UserGroupMember.user_id == uid)\

        .all()

    multiple_counter = collections.defaultdict(int)

    for perm in user_repo_perms_from_users_groups:

        r_k = perm.UserGroupRepoToPerm.repository.repo_name

        multiple_counter[r_k] += 1

        p = perm.Permission.permission_name

        cur_perm = permissions[RK][r_k]

        if perm.Repository.user_id == uid:

            # set admin if owner

            p = 'repository.admin'

        else:

            if multiple_counter[r_k] > 1:

                p = _choose_perm(p, cur_perm)

        permissions[RK][r_k] = p

    # user explicit permissions for repositories, overrides any specified

    # by the group permission

    user_repo_perms = Permission.get_default_perms(uid)

    for perm in user_repo_perms:

        r_k = perm.UserRepoToPerm.repository.repo_name

        cur_perm = permissions[RK][r_k]

        # set admin if owner

        if perm.Repository.user_id == uid:

            p = 'repository.admin'

        else:

            p = perm.Permission.permission_name

            if not explicit:

                p = _choose_perm(p, cur_perm)

        permissions[RK][r_k] = p

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

    # !! PERMISSIONS FOR REPOSITORY GROUPS !!

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

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

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

    # fill in his permission from it. _choose_perm decides of which

    # permission should be selected based on selected method

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

    # 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((UserGroupMember, UserGroupRepoGroupToPerm.users_group_id

            == UserGroupMember.users_group_id))\

     .filter(UserGroupMember.user_id == uid)\

     .all()

    multiple_counter = collections.defaultdict(int)

    for perm in user_repo_group_perms_from_users_groups:

        g_k = perm.UserGroupRepoGroupToPerm.group.group_name

        multiple_counter[g_k] += 1

        p = perm.Permission.permission_name

        cur_perm = permissions[GK][g_k]

        if multiple_counter[g_k] > 1:

            p = _choose_perm(p, cur_perm)

        permissions[GK][g_k] = p

    # user explicit permissions for repository groups

    user_repo_groups_perms = Permission.get_default_group_perms(uid)

    for perm in user_repo_groups_perms:

        rg_k = perm.UserRepoGroupToPerm.group.group_name

        p = perm.Permission.permission_name

        cur_perm = permissions[GK][rg_k]

        if not explicit:

            p = _choose_perm(p, cur_perm)

        permissions[GK][rg_k] = p

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

    # !! 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 == uid)\

     .all()

    multiple_counter = collections.defaultdict(int)

    for perm in user_group_user_groups_perms:

        g_k = perm.UserGroupUserGroupToPerm.target_user_group.users_group_name

        multiple_counter[g_k] += 1

        p = perm.Permission.permission_name

        cur_perm = permissions[UK][g_k]

        if multiple_counter[g_k] > 1:

            p = _choose_perm(p, cur_perm)

        permissions[UK][g_k] = p

    #user explicit permission for user groups

    user_user_groups_perms = Permission.get_default_user_group_perms(uid)

    for perm in user_user_groups_perms:

        u_k = perm.UserUserGroupToPerm.user_group.users_group_name

        p = perm.Permission.permission_name

        cur_perm = permissions[UK][u_k]

        if not explicit:

            p = _choose_perm(p, cur_perm)

        permissions[UK][u_k] = p

    return permissions

def allowed_api_access(controller_name, whitelist=None, api_key=None):

    """

    Check if given controller_name is in whitelist API access

    """

    if not whitelist:

        from kallithea import CONFIG

        whitelist = aslist(CONFIG.get('api_access_controllers_whitelist'),

                           sep=',')

        log.debug('whitelist of API access is: %s' % (whitelist))

    api_access_valid = controller_name in whitelist

    if api_access_valid:

        log.debug('controller:%s is in API whitelist' % (controller_name))

    else:

        msg = 'controller: %s is *NOT* in API whitelist' % (controller_name)

        if api_key:

            #if we use API key and don't have access it's a warning

            log.warning(msg)

        else:

            log.debug(msg)

    return api_access_valid

class AuthUser(object):

    """

    A simple object that handles all attributes of user in Kallithea

    It does lookup based on API key,given user, or user present in session

    Then it fills all required information for such user. It also checks if

    anonymous access is enabled and if so, it returns default user as logged in

    """

    def __init__(self, user_id=None, api_key=None, username=None, ip_addr=None):

        self.user_id = user_id

        self._api_key = api_key

        self.api_key = None

        self.username = username

        self.ip_addr = ip_addr

        self.name = ''

        self.lastname = ''

        self.email = ''

        self.is_authenticated = False

        self.admin = False

        self.inherit_default_permissions = False

        self.propagate_data()

        self._instance = None

    @LazyProperty

    def permissions(self):

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

    @property

    def api_keys(self):

        return self.get_api_keys()

    def propagate_data(self):

        user_model = UserModel()

        self.anonymous_user = User.get_default_user(cache=True)

        is_user_loaded = False

        # lookup by userid

        if self.user_id is not None and self.user_id != self.anonymous_user.user_id:

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

            is_user_loaded = user_model.fill_data(self, user_id=self.user_id)

        # try go get user by api key

        elif self._api_key and self._api_key != self.anonymous_user.api_key:

            log.debug('Auth User lookup by API KEY %s' % self._api_key)

            is_user_loaded = user_model.fill_data(self, api_key=self._api_key)

        # lookup by username

        elif self.username:

            log.debug('Auth User lookup by USER NAME %s' % self.username)

            is_user_loaded = user_model.fill_data(self, username=self.username)

        else:

            log.debug('No data in %s that could been used to log in' % self)

        if not is_user_loaded:

            # if we cannot authenticate user try anonymous

            if self.anonymous_user.active:

                user_model.fill_data(self, user_id=self.anonymous_user.user_id)

                # then we set this user is logged in

                self.is_authenticated = True

            else:

                self.user_id = None

                self.username = None

                self.is_authenticated = False

        if not self.username:

            self.username = 'None'

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

    def get_perms(self, user, explicit=True, algo='higherwin', 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: instance of User object from database

        :param explicit: In case there are permissions both for user and a group

            that user is part of, explicit flag will define if user will

            explicitly override permissions from group, if it's False it will

            make decision based on the algo

        :param algo: algorithm to decide what permission should be choose if

            it's multiple defined, eg user in two different groups. It also

            decides if explicit flag is turned off how to specify the permission

            for case when user is in a group + have defined separate permission

        """

        user_id = user.user_id

        user_is_admin = user.is_admin

        user_inherit_default_permissions = user.inherit_default_permissions

        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,

                       user_inherit_default_permissions, explicit, algo)

    def get_api_keys(self):

        api_keys = [self.api_key]

        for api_key in UserApiKeys.query()\

                .filter(UserApiKeys.user_id == self.user_id)\

                .filter(or_(UserApiKeys.expires == -1,

                            UserApiKeys.expires >= time.time())).all():

            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']

    @property

    def ip_allowed(self):

        """

        Checks if ip_addr used in constructor is allowed from defined list of

        allowed ip_addresses for user

        :returns: boolean, True if ip is in allowed ip range

        """

        # check IP

        inherit = self.inherit_default_permissions

        return AuthUser.check_ip_allowed(self.user_id, self.ip_addr,

                                         inherit_from_default=inherit)

    @classmethod

    def check_ip_allowed(cls, user_id, ip_addr, inherit_from_default):

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

                        inherit_from_default=inherit_from_default)

        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):

        return "<AuthUser('id:%s[%s] ip:%s auth:%s')>"\

            % (self.user_id, self.username, self.ip_addr, self.is_authenticated)

    def set_authenticated(self, authenticated=True):

        if self.user_id != self.anonymous_user.user_id:

            self.is_authenticated = authenticated

    def get_cookie_store(self):

        return {'username': self.username,

                'user_id': self.user_id,

                'is_authenticated': self.is_authenticated}

    @classmethod

    def from_cookie_store(cls, cookie_store):

        """

        Creates AuthUser from a cookie store

        :param cls:

        :param cookie_store:

        """

        user_id = cookie_store.get('user_id')

        username = cookie_store.get('username')

        api_key = cookie_store.get('api_key')

        return AuthUser(user_id, api_key, username)

    @classmethod

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

        _set = set()

        if inherit_from_default:

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

                                            User.get_default_user(cache=True))

            if cache:

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

                                                  "get_user_ips_default"))

            # populate from default user

            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 pylons 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 pylons config instance

    """

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

    try:

        sa = meta.Session

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

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

    finally:

        meta.Session.remove()

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

# CHECK DECORATORS

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

def redirect_to_login(message=None):

    from kallithea.lib import helpers as h

    p = url.current()

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

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

    return redirect(url('login_home', came_from=p))

class LoginRequired(object):

    """

    Must be logged in to execute this function else

    redirect to login page

    :param api_access: if enabled this checks only for valid auth token

        and grants access based on valid token

    """

    def __init__(self, api_access=False):

        self.api_access = api_access

    def __call__(self, func):

        return decorator(self.__wrapper, func)

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

        cls = fargs[0]

        user = cls.authuser

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

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

        # check if our IP is allowed

        if not user.ip_allowed:

            return redirect_to_login(_('IP %s not allowed' % (user.ip_addr)))

            else:

        # CSRF protection - POSTs with session auth must contain correct token

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

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

                log.error('CSRF check failed')

                return abort(403)

        log.debug('Checking if %s is authenticated @ %s' % (user.username, loc))

        reason = 'RegularAuth' if user.is_authenticated else 'APIAuth'

            log.info('user %s authenticating with:%s IS authenticated on func %s '

                     % (user, reason, loc)

            )

            return func(*fargs, **fkwargs)

        else:

            log.warning('user %s authenticating with:%s NOT authenticated on func: %s: '

            )

            return redirect_to_login()

class NotAnonymous(object):

    """

    Must be logged in to execute this function else

    redirect to login page"""

    def __call__(self, func):

        return decorator(self.__wrapper, func)

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

        cls = fargs[0]

        self.user = cls.authuser

        log.debug('Checking if user is not anonymous @%s' % cls)

        anonymous = self.user.username == User.DEFAULT_USER

        if anonymous:

            return 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"""

    def __init__(self, *required_perms):

        self.required_perms = set(required_perms)

        self.user_perms = None

    def __call__(self, func):

        return decorator(self.__wrapper, func)

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

        cls = fargs[0]

        self.user = cls.authuser

        self.user_perms = self.user.permissions

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

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

        if self.check_permissions():

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

            return func(*fargs, **fkwargs)

        else:

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

            anonymous = self.user.username == User.DEFAULT_USER

            if anonymous:

                return redirect_to_login(_('You need to be signed in to view this page'))

            else:

                # redirect with forbidden ret code

                return abort(403)

    def check_permissions(self):

        """Dummy function for overriding"""

        raise Exception('You have to write this function in child class')

class HasPermissionAllDecorator(PermsDecorator):

    """

    Checks for access permission for all given predicates. All of them

    have to be meet in order to fulfill the request

    """