#!/usr/local/bin/python2.7

"""
$Id: charencode.py 3555 2011-04-04 08:18:26Z stamparm $

Copyright (c) 2006-2010 sqlmap developers (http://sqlmap.sourceforge.net/)
See the file 'doc/COPYING' for copying permission
"""

import string

from lib.core.enums import PRIORITY
from lib.core.exception import sqlmapUnsupportedFeatureException

__priority__ = PRIORITY.LOWEST

def tamper(payload):
    """
    Urlencodes all characters in a given payload (not processing already encoded)
    Example: 'SELECT FIELD FROM%20TABLE' becomes '%53%45%4c%45%43%54%20%46%49%45%4c%44%20%46%52%4f%4d%20%54%41%42%4c%45'
    """

    retVal = payload

    if payload:
        retVal = ""
        i = 0

        while i < len(payload):
            if payload[i] == '%' and (i < len(payload) - 2) and payload[i+1] in string.hexdigits and payload[i+2] in string.hexdigits:
                retVal += payload[i:i+3]
                i += 3
            else:
                retVal += '%%%X' % ord(payload[i])
                i += 1

    return retVal
