Changeset - 245b4e3abf39
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Søren Løvborg - 9 years ago 2017-01-02 20:35:25
sorenl@unity3d.com
auth: add AuthUser.is_anonymous, along with some exposition

This reveals the name of the NotAnonymous decorator to be misleading,
an unfortunate detail only documented here, but which must be properly
resolved in a later changeset.

Note that NotAnonymous behaves as advertised as long as it is used
together with LoginRequired, which is always the case in the current
code, so there's no actual security issue here, the code is just weird,
hard to read and fragile.

---

Some thoughts on cleaning this up in a future changeset: As it turns
out, every controller (except the login page!) should be LoginRequired
decorated (since it doesn't actually block anonymous users, as long as
anonymous access is enabled in the Kallithea config). Thus the most
obvious solution would be to move the LoginRequired functionality into
BaseController (with an override for LoginController), and delete the
decorator entirely. However, LoginRequired does one other thing: it
carries information about whether API access is enabled for individual
controller methods ("@LoginRequired(api_key=True)"), and also performs
the check for this, something which is not easily moved into the base
controller class, since the base controller doesn't know which method is
about to be called. Possibly that can be determined by poking Pylons,
but such code is likely to break with the upcoming TurboGears 2 move.
Thus such cleanup is probably better revisited after the switch to TG2.
1 file changed with 24 insertions and 11 deletions:
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kallithea/lib/auth.py
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@@ -366,230 +366,243 @@ def _cached_perms_data(user_id, user_is_
 
        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(user_id)
 
    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 == user_id) \
 
     .join((UserGroup, UserGroupMember.users_group_id ==
 
            UserGroup.users_group_id), aliased=True, from_joinpoint=True) \
 
     .filter(UserGroup.users_group_active == True) \
 
     .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(user_id)
 
    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):
 
    """
 
    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.
 

	
 
    `AuthUser` does not by itself authenticate users and the constructor
 
    sets the `is_authenticated` field to False. It's up to other parts
 
    of the code to check e.g. if a supplied password is correct, and if
 
    so, set `is_authenticated` to True.
 

	
 
    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,
 
            is_external_auth=False):
 

	
 
        self.is_authenticated = False
 
        self.is_external_auth = is_external_auth
 

	
 
        user_model = UserModel()
 
        self.anonymous_user = User.get_default_user(cache=True)
 
        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.anonymous_user)
 
            is_user_loaded =  self._fill_data(self._default_user)
 

	
 
        self.is_default_user = (self.user_id == self.anonymous_user.user_id)
 
        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)
 

	
 
    @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(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']
 

	
 
    @staticmethod
 
    def check_ip_allowed(user, ip_addr):
 
@@ -609,256 +622,256 @@ class AuthUser(object):
 

	
 
    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:
 
        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):
 
    """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))
 

	
 

	
 
class LoginRequired(object):
 
    """
 
    Must be logged in to execute this function else
 
    redirect to login page
 
    """Client must be logged in as a valid User (but the "default" user,
 
    if enabled, is considered valid), or we'll redirect to the login page.
 

	
 
    :param api_access: if enabled this checks only for valid auth token
 
        and grants access based on valid token
 
    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):
 
        self.api_access = api_access
 

	
 
    def __call__(self, func):
 
        return decorator(self.__wrapper, func)
 

	
 
    def __wrapper(self, func, *fargs, **fkwargs):
 
        controller = fargs[0]
 
        user = controller.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, controller.ip_addr):
 
            raise _redirect_to_login(_('IP %s not allowed') % controller.ip_addr)
 

	
 
        # check if we used an API key and it's a valid one
 
        api_key = request.GET.get('api_key')
 
        if api_key is not None:
 
            # explicit controller is enabled or API is in our whitelist
 
            if self.api_access or allowed_api_access(loc, api_key=api_key):
 
                if api_key in user.api_keys:
 
                    log.info('user %s authenticated with API key ****%s @ %s',
 
                             user, api_key[-4:], loc)
 
                    return func(*fargs, **fkwargs)
 
                else:
 
                    log.warning('API key ****%s is NOT valid', api_key[-4:])
 
                    raise _redirect_to_login(_('Invalid API key'))
 
            else:
 
                # controller does not allow API access
 
                log.warning('API access to %s is not allowed', loc)
 
                raise HTTPForbidden()
 

	
 
        # 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 or user.is_default_user:
 
            log.info('user %s authenticated with regular auth @ %s', user, loc)
 
            return func(*fargs, **fkwargs)
 
        else:
 
            log.warning('user %s NOT authenticated with regular auth @ %s', user, loc)
 
            raise _redirect_to_login()
 

	
 
class NotAnonymous(object):
 
    """
 
    Must be logged in to execute this function else
 
    redirect to login page"""
 
    """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]
 
        self.user = cls.authuser
 

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

	
 
        if self.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"""
 

	
 
    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)
 
            if self.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):
 
        """Dummy function for overriding"""
 
        raise Exception('You have to write this function in child class')
 

	
 

	
 
class HasPermissionAnyDecorator(PermsDecorator):
 
    """
 
    Checks for access permission for any of given predicates. In order to
 
    fulfill the request any of predicates must be meet
 
    """
 

	
 
    def check_permissions(self):
 
        if self.required_perms.intersection(self.user_perms.get('global')):
 
            return True
 
        return False
 

	
 

	
 
class HasRepoPermissionAnyDecorator(PermsDecorator):
 
    """
 
    Checks for access permission for any of given predicates for specific
 
    repository. In order to fulfill the request any of predicates must be meet
 
    """
 

	
 
    def check_permissions(self):
 
        repo_name = get_repo_slug(request)
 
        try:
 
            user_perms = set([self.user_perms['repositories'][repo_name]])
 
        except KeyError:
 
            return False
 

	
 
        if self.required_perms.intersection(user_perms):
 
            return True
 
        return False
 

	
 

	
 
class HasRepoGroupPermissionAnyDecorator(PermsDecorator):
 
    """
 
    Checks for access permission for any of given predicates for specific
 
    repository group. In order to fulfill the request any of predicates must be meet
 
    """
 

	
 
    def check_permissions(self):
 
        group_name = get_repo_group_slug(request)
 
        try:
 
            user_perms = set([self.user_perms['repositories_groups'][group_name]])
 
        except KeyError:
 
            return False
 

	
 
        if self.required_perms.intersection(user_perms):
 
            return True
 
        return False
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