cryptlib.py

import os
import sys

import config, Config
Config.config.disable_sslcompression = False

import CryptMessage
from lib import pyelliptic
from lib.pybitcointools import bitcoin as btctools

import base64

def encrypt(text, publickey):
	encrypted = CryptMessage.encrypt(text, CryptMessage.toOpensslPublickey(publickey))
	return encrypted

def decrypt(encrypted, privatekey):
	back = CryptMessage.getEcc(privatekey).decrypt(encrypted)
	return back.decode("utf8")

# Encrypt a text using the publickey
# Return: Encrypted text and AES key using base64 encoding
def eciesEncrypt(text, publickey):
	aes_key, encrypted = encrypt(text.encode("utf8"), publickey.decode("base64"))
	return (base64.b64encode(encrypted), base64.b64encode(aes_key))

# Decrypt a text using privatekey
# Return: Decrypted text
def eciesDecrypt(encrypted_text, privatekey):
	try:
		return decrypt(encrypted_text.decode("base64"), privatekey)
	except Exception as err:
		return None

# Encrypt a text using AES
# Return: Iv, AES key, Encrypted text
def aesEncrypt(text, key=None, iv=None):
	if key:
		key = key.decode("base64")
	else:
		key = os.urandom(32)
	if iv:  # Generate new AES key if not definied
		iv = iv.decode("base64")
	else:
		iv = pyelliptic.Cipher.gen_IV('aes-256-cbc')
	if text:
		encrypted = pyelliptic.Cipher(key, iv, 1, ciphername='aes-256-cbc').ciphering(text.encode("utf8"))
	else:
		encrypted = ""
	return (base64.b64encode(key), base64.b64encode(iv), base64.b64encode(encrypted))

# Decrypt a text using AES
# Return: Decrypted text
def aesDecrypt(iv, encrypted_text, key):
	encrypted_text = encrypted_text.decode("base64")
	iv = iv.decode("base64")
	text = None
	ctx = pyelliptic.Cipher(key.decode("base64"), iv, 0, ciphername='aes-256-cbc')
	try:
		decrypted = ctx.ciphering(encrypted_text)
		if decrypted and decrypted.decode("utf8"):  # Valid text decoded
			return decrypted
	except Exception, err:
		pass
	return None

# Transform private key to public key
def private_to_public(private):
	public = btctools.encode_pubkey(btctools.privtopub(private), "bin_compressed")
	public = base64.b64encode(public)
	return public