from os.path import isfile
from pysqlcipher import dbapi2 as sqlite
import hashlib
import sys
import time
import logging
import re

SCRIPTNAME = "fmd_wechatdecipher.py"
logging.basicConfig(filename='EnMicroMsg-decrypted.log', format="%(asctime)s %(levelname)s: %(message)s", datefmt="%d-%b-%Y %I:%M:%S %p", level=logging.DEBUG)

def decrypt( key ):
        logging.info( "Connecting database..." )
        conn = sqlite.connect( "EnMicroMsg.db" )
        c = conn.cursor()                
        c.execute( "PRAGMA key = '" + key + "';" )
        c.execute( "PRAGMA cipher_use_hmac = OFF;" )
        c.execute( "PRAGMA cipher_page_size = 1024;" )
        c.execute( "PRAGMA kdf_iter = 4000;" )
        try:
                logging.info( "Decrypting..." )
                c.execute( "ATTACH DATABASE 'EnMicroMsg-decrypted.db' AS wechatdecrypted KEY '';" )
                c.execute( "SELECT sqlcipher_export( 'wechatdecrypted' );" )
                c.execute( "DETACH DATABASE wechatdecrypted;" )
                logging.info( "Detaching database..." )
                c.close()
                status = 1
        except:
                c.close()
                status = 0
        return status
        
        
def generate_key():
        imei = input( "IMEI: " )
        logging.info( "IMEI: " + str( imei ))
        uin = get_uin()
        logging.info( "UIN: " + str( uin ))
        logging.info( "Generating key..." )        
        key = hashlib.md5( str( imei ) + str( uin )).hexdigest()[ 0:7 ]
        logging.info( "Key: " + key )
        return key
        

def db_hash():
        f = open( 'EnMicroMsg-decrypted.db', 'rb' ).read()
        logging.info( "Generating hash values..." )        
        if len( f ) > 0:
                db_md5 = hashlib.md5( f ).hexdigest()
                logging.info( "EnMicroMsg-decrypted.db MD5: " + db_md5 )
                db_sha1 = hashlib.sha1( f ).hexdigest()
                logging.info( "EnMicroMsg-decrypted.db SHA1: " + db_sha1 )
                return
                

def get_uin():
        f = open( 'system_config_prefs.xml', 'r' ).read()
        uin = re.findall( 'name="default_uin" value="([\-?[0-9]+)"', f )
        return uin[ 0 ] if uin else 0


def main():        
        if not ( isfile( "EnMicroMsg.db" ) and isfile( "system_config_prefs.xml" )):
                print "##########"
                print "'EnMicroMsg.db' or 'system_config_prefs.xml' not found!"
                print "Script exiting..."
                print "##########"
                sys.exit()
                
        logging.info( "Script starting..." )
        key = generate_key()
        status = decrypt( key )
        if status == 1:
                db_hash()
                print "##########"
                print "Decryption successful!"
                print "Decrypted file: EnMicroMsg-decrypted.db"
                print "Log file: EnMicroMsg-decrypted.log"
                print "##########"
                logging.info( "Decryption successful!" )
                logging.info( "Decrypted filename: EnMicroMsg-decrypted.db" )
        else:
                print "##########"
                print "Decryption failed!"
                print "Make sure you input correct IMEI number!"
                print "Log file: EnMicroMsg-decrypted.log"
                print "##########"
                logging.info( "Decryption failed!" )
                logging.warning( "Make sure you input correct IMEI number!" )
        logging.info( "Script exiting..." )


main()