checkSPF.py

#!/usr/bin/python3.4
# -*-coding:Utf-8 -*

import subprocess as sp
import re
import ipaddress



def checkSpf(mailHeaders):
    """Check if Ip from SPF received is in dig querry"""
    receivedSpf = mailHeaders['Received-SPF']
    if receivedSpf:
        spfResult = dict()
        if re.search('Softfail', receivedSpf):
            spfResult['spfResult'] = 'Softfail'
            return spfResult
        elif re.search('Fail', receivedSpf):
            spfResult['spfResult'] = 'Fail'
            return spfResult
        elif re.search('Neutral',receivedSpf):
            spfResult['spfResult'] = 'Neutral'
            return spfResult
        elif re.search('Permerror', receivedSpf):
            spfResult['spfResult'] = 'Permerror'
            return spfResult
        elif re.search('TempError', receivedSpf):
            spfResult['spfResult'] = 'Temperror'
            return spfResult
        elif re.search('None', receivedSpf):
            spfResult['spfResult'] = 'None'
            return spfResult
        elif re.search('Pass', receivedSpf):
            spfResult['spfResult'] = 'Pass'
            try:
                senderDomain = re.search('(\@[^\s]*)', receivedSpf).group(1)
            except AttributeError:
                # Domain not found in the original string
                senderDomain = '' # apply your error handling
            try:
                senderDomain = senderDomain.split('@')
            except AttributeError:
                senderDomain = '' #apply your error handling
                senderDomain = senderDomain[1].split(';')
            try:
                senderIp = re.search('(\client-ip=[^\s]*)',receivedSpf).group(1)
            except AttributeError:
                senderIp = '' # apply your error handling
                senderIp = senderIp.split('client-ip=')
                senderIp = senderIp[1].split(';')
            try:
                senderIp = ipaddress.ip_address(senderIp[0])
            except:
                senderIp = ''
            #print(senderIp[0])
            try:
                digResult = sp.check_output(["dig", "+short","TXT",senderDomain[0]]).decode("ascii")
            except sp.CalledProcessError:
                return spfResult
            #ipNetworks = re.findall(r'(([0-9]{1,3}.){3}.([0-9]{1,3}))(\/\d\d)?',digResult)
            ipNetworks = re.findall( r'(([0-9]+(?:\.[0-9]+){3})+/+[0-9]{2})|([0-9]+(?:\.[0-9]+){3})', digResult)
            print(ipNetworks)
            if ipNetworks != None:
                results = [t[0] for t in ipNetworks]
                #print(len(results))
                for i, val in enumerate(results):
                    try:
                        network = val
                    except:
                        network = ''
                        #print(network)
                    if not network:
                        spfResult['spfResult'] = 'Pass'
                        return spfResult
                    else:
                        try:
                            network = ipaddress.ip_network(network)
                            if senderIp in ipaddress.ip_network(network):
                                spfResult['spfTrue'] = 'True'
                                return spfResult
                            else:
                                if i == len(results):
                                    spfResult['spfTrue'] = 'False'
                                    return spfResult
                        except ValueError:
                            network = ipaddress.IPv6Interface(network)
                            if senderIp in network.network:
                                spfResult['spfTrue'] = 'True'
                                return spfResult
                            else:
                                if i== len(results):
                                    spfResult['spfTrue'] = 'False'
                                    return spfResult
        else:
            return spfResult