Source code for webnotes.utils.encrypt
"""
XTEA Block Encryption Algorithm
Author: Paul Chakravarti (paul_dot_chakravarti_at_gmail_dot_com)
License: Public Domain
"""
[docs]def get_key():
# Encryption key is datetime of creation of DocType, DocType"
import webnotes
return webnotes.conn.sql("select creation from tabDocType where name='DocType'")[0][0].strftime('%Y%m%d%H%M%s')[:16]
[docs]def encrypt(data, encryption_key = None):
if not encryption_key:
encryption_key = get_key()
return crypt(encryption_key, data).encode('hex')
[docs]def decrypt(data, encryption_key = None):
if not encryption_key:
encryption_key = get_key()
return crypt(encryption_key, data.decode('hex'))
[docs]def crypt(key,data,iv='\00\00\00\00\00\00\00\00',n=32):
def keygen(key,iv,n):
while True:
iv = xtea_encrypt(key,iv,n)
for k in iv:
yield ord(k)
xor = [ chr(x^y) for (x,y) in zip(map(ord,data),keygen(key,iv,n)) ]
return "".join(xor)
[docs]def xtea_encrypt(key,block,n=32,endian="!"):
import struct
v0,v1 = struct.unpack(endian+"2L",block)
k = struct.unpack(endian+"4L",key)
sum,delta,mask = 0L,0x9e3779b9L,0xffffffffL
for round in range(n):
v0 = (v0 + (((v1<<4 ^ v1>>5) + v1) ^ (sum + k[sum & 3]))) & mask
sum = (sum + delta) & mask
v1 = (v1 + (((v0<<4 ^ v0>>5) + v0) ^ (sum + k[sum>>11 & 3]))) & mask
return struct.pack(endian+"2L",v0,v1)
[docs]def xtea_decrypt(key,block,n=32,endian="!"):
import struct
v0,v1 = struct.unpack(endian+"2L",block)
k = struct.unpack(endian+"4L",key)
delta,mask = 0x9e3779b9L,0xffffffffL
sum = (delta * n) & mask
for round in range(n):
v1 = (v1 - (((v0<<4 ^ v0>>5) + v0) ^ (sum + k[sum>>11 & 3]))) & mask
sum = (sum - delta) & mask
v0 = (v0 - (((v1<<4 ^ v1>>5) + v1) ^ (sum + k[sum & 3]))) & mask
return struct.pack(endian+"2L",v0,v1)
