is_external_auth=False):

        self.is_authenticated = False

        self.is_external_auth = is_external_auth

        self.authenticating_api_key = authenticating_api_key

        user_model = UserModel()

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

        # 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

        self.inherit_default_permissions = 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 = user_model.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 not is_user_loaded:

            is_user_loaded = self._fill_data(self._default_user)

        self.is_default_user = (self.user_id == self._default_user.user_id)

        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, 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: `AuthUser` instance

        :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_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,

            inherit_from_default=user.inherit_default_permissions)

        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] auth:%s')>" \

            % (self.user_id, self.username, (self.is_authenticated or self.is_default_user))

    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),

        )

        au.is_authenticated = True

        return au

    @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 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(h.literal(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, and if using API key instead

    of regular cookie authentication, checks that API key access is allowed

    (based on `api_access` parameter and the API view whitelist).

    """

    def __init__(self, api_access=False, allow_default_user=False):

        self.api_access = api_access

        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)

        if not AuthUser.check_ip_allowed(user, request.ip_addr):

            raise _redirect_to_login(_('IP %s not allowed') % request.ip_addr)

        # Check if we used an API key to authenticate.

        api_key = user.authenticating_api_key

        if api_key is not None:

            # Check that controller is enabled for API key usage.

            if not self.api_access and not allowed_api_access(loc, api_key=api_key):

                # controller does not allow API access

                log.warning('API access to %s is not allowed', loc)

                raise HTTPForbidden()

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

                     user, 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_authenticated:

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

            return func(*fargs, **fkwargs)

        elif 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)

        else:

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

        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:

            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

class HasRepoPermissionLevelDecorator(_PermDecorator):

    """

    Checks the user has at least the specified permission level for the requested repository.

    """

    def check_permissions(self, user):

        repo_name = get_repo_slug(request)

        return user.has_repository_permission_level(repo_name, self.required_perm)

class HasRepoGroupPermissionLevelDecorator(_PermDecorator):

    """

    Checks the user has any of given permissions for the requested repository group.

    """

    def check_permissions(self, user):

        repo_group_name = get_repo_group_slug(request)

        return user.has_repository_group_permission_level(repo_group_name, self.required_perm)

class HasUserGroupPermissionLevelDecorator(_PermDecorator):

    """

    Checks for access permission for any of given predicates for specific

    user group. In order to fulfill the request any of predicates must be meet

    """

    def check_permissions(self, user):

        user_group_name = get_user_group_slug(request)

        return user.has_user_group_permission_level(user_group_name, self.required_perm)

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

# CHECK FUNCTIONS

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

class _PermsFunction(object):

    """Base function for other check functions with multiple permissions"""

    def __init__(self, *required_perms):

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

    def __nonzero__(self):

        """ Defend against accidentally forgetting to call the object

            and instead evaluating it directly in a boolean context,

            which could have security implications.

        """

        raise AssertionError(self.__class__.__name__ + ' is not a bool and must be called!')

    def __call__(self, *a, **b):

        raise NotImplementedError()

class HasPermissionAny(_PermsFunction):

    def __call__(self, purpose=None):

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

        ok = any(p in global_permissions for p in self.required_perms)

        log.debug('Check %s for global %s (%s): %s' %

            (request.user.username, self.required_perms, purpose, ok))

        return ok

class _PermFunction(_PermsFunction):

    """Base function for other check functions with a single permission"""

    def __init__(self, required_perm):

        _PermsFunction.__init__(self, [required_perm])

        self.required_perm = required_perm

class HasRepoPermissionLevel(_PermFunction):

    def __call__(self, repo_name, purpose=None):

        return request.user.has_repository_permission_level(repo_name, self.required_perm, purpose)

class HasRepoGroupPermissionLevel(_PermFunction):

    def __call__(self, group_name, purpose=None):

        return request.user.has_repository_group_permission_level(group_name, self.required_perm, purpose)

class HasUserGroupPermissionLevel(_PermFunction):

    def __call__(self, user_group_name, purpose=None):

        return request.user.has_user_group_permission_level(user_group_name, self.required_perm, purpose)

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

# SPECIAL VERSION TO HANDLE MIDDLEWARE AUTH

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

class HasPermissionAnyMiddleware(object):

    def __init__(self, *perms):

        self.required_perms = set(perms)

    def __call__(self, user, repo_name, purpose=None):

        # repo_name MUST be unicode, since we handle keys in ok

        # dict by unicode

        repo_name = safe_unicode(repo_name)

        user = AuthUser(user.user_id)

        try:

            ok = user.permissions['repositories'][repo_name] in self.required_perms

        except KeyError:

            ok = False

        log.debug('Middleware check %s for %s for repo %s (%s): %s' % (user.username, self.required_perms, repo_name, purpose, ok))

        return ok

def check_ip_access(source_ip, allowed_ips=None):

    """

    Checks if source_ip is a subnet of any of allowed_ips.

    :param source_ip:

    :param allowed_ips: list of allowed ips together with mask

    """

    from kallithea.lib import ipaddr

    log.debug('checking if ip:%s is subnet of %s', source_ip, allowed_ips)

    if isinstance(allowed_ips, (tuple, list, set)):

        for ip in allowed_ips:

            if ipaddr.IPAddress(source_ip) in ipaddr.IPNetwork(ip):

                log.debug('IP %s is network %s',

                          ipaddr.IPAddress(source_ip), ipaddr.IPNetwork(ip))

                return True

    return False