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

# Copyright (c) 2020 Detlev Offenbach <detlev@die-offenbachs.de>
#

"""
Module implementing a check for setting too permissive file permissions.
"""

#
# This is a modified version of the one found in the bandit package.
#
# Original Copyright 2014 Hewlett-Packard Development Company, L.P.
#
# SPDX-License-Identifier: Apache-2.0
#

import stat


def getChecks():
    """
    Public method to get a dictionary with checks handled by this module.
    
    @return dictionary containing checker lists containing checker function and
        list of codes
    @rtype dict
    """
    return {
        "Call": [
            (checkFilePermissions, ("S102",)),
        ],
    }


def checkFilePermissions(reportError, context, config):
    """
    Function to check for setting too permissive file permissions.
    
    @param reportError function to be used to report errors
    @type func
    @param context security context object
    @type SecurityContext
    @param config dictionary with configuration data
    @type dict
    """
    if 'chmod' in context.callFunctionName:
        if context.callArgsCount == 2:
            mode = context.getCallArgAtPosition(1)
            
            if (
                mode is not None and
                isinstance(mode, int) and
                (mode & stat.S_IWOTH or mode & stat.S_IXGRP)
            ):
                # world writable is an HIGH, group executable is a MEDIUM
                if mode & stat.S_IWOTH:
                    severity = "H"
                else:
                    severity = "M"
                
                filename = context.getCallArgAtPosition(0)
                if filename is None:
                    filename = 'NOT PARSED'
                
                reportError(
                    context.node.lineno - 1,
                    context.node.col_offset,
                    "S103",
                    severity,
                    "H",
                    oct(mode),
                    filename
                )
