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

    try:

        return bcrypt.checkpw(safe_bytes(password), ascii_bytes(hashed))

    except ValueError as e:

        # bcrypt will throw ValueError 'Invalid hashed_password salt' on all password errors

        log.error('error from bcrypt checking password: %s', e)

        return False

    log.error('check_password failed - no method found for hash length %s', len(hashed))

    return False

PERM_WEIGHTS = Permission.PERM_WEIGHTS

def bump_permission(permissions, key, new_perm):

    """Add a new permission for key to permissions.

    Assuming the permissions are comparable, set the new permission if it

    has higher weight, else drop it and keep the old permission.

    """

    cur_perm = permissions[key]

    new_perm_val = PERM_WEIGHTS[new_perm]

    cur_perm_val = PERM_WEIGHTS[cur_perm]

    if new_perm_val > cur_perm_val:

        permissions[key] = new_perm

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. It's up to other parts of

    the code to check e.g. if a supplied password is correct, and if so, trust

    the AuthUser object as an authenticated user.

    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

        # Look up database user, if necessary.

        if user_id is not None:

            assert dbuser is None

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

            dbuser = UserModel().get(user_id)

            assert dbuser is not None

        else:

            assert dbuser is not None

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

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

        self.is_anonymous = dbuser.is_default_user

        if dbuser.is_default_user and not dbuser.active:

            self.username = 'None'

            self.is_default_user = False

        else:

            # copy non-confidential database fields from a `db.User` to this `AuthUser`.

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

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

                setattr(self, k, v)

            self.is_default_user = dbuser.is_default_user

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

    @LazyProperty

    def global_permissions(self):

        log.debug('Getting global permissions for %s', self)

        if self.is_admin:

            return set(['hg.admin'])

        global_permissions = set()

        # default global permissions from the default user

        default_global_perms = UserToPerm.query() \

            .filter(UserToPerm.user_id == kallithea.DEFAULT_USER_ID) \

            .options(joinedload(UserToPerm.permission))

        for perm in default_global_perms:

            global_permissions.add(perm.permission.permission_name)

        # 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 == self.user_id) \

            .join((UserGroup, UserGroupMember.users_group_id ==

                   UserGroup.users_group_id)) \

                Session().query(UserGroupRepoGroupToPerm) \

                .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 == self.user_id) \

                .options(joinedload(UserGroupRepoGroupToPerm.permission)) \

                .all()

            for perm in user_repo_group_perms_from_users_groups:

                bump_permission(repository_group_permissions,

                    perm.group.group_name,

                    perm.permission.permission_name)

            # user explicit permissions for repository groups

            user_repo_groups_perms = Permission.get_default_group_perms(self.user_id)

            for perm in user_repo_groups_perms:

                bump_permission(repository_group_permissions,

                    perm.group.group_name,

                    perm.permission.permission_name)

        return repository_group_permissions

    @LazyProperty

    def permissions(self):

        """dict with all 4 kind of permissions - mainly for backwards compatibility"""

        return {

            'global': self.global_permissions,

            'repositories': self.repository_permissions,

            'repositories_groups': self.repository_group_permissions,

            'user_groups': self.user_group_permissions,

        }

    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.repository_permissions.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'],