53 lines
1.7 KiB
Python
53 lines
1.7 KiB
Python
# -*- coding: utf-8 -*-
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from __future__ import absolute_import, unicode_literals
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import struct
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import socket
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import base64
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from wechatpy.utils import to_text, to_binary, random_string, byte2int
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from wechatpy.crypto.pkcs7 import PKCS7Encoder
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try:
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from wechatpy.crypto.cryptography import WeChatCipher
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except ImportError:
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try:
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from wechatpy.crypto.pycrypto import WeChatCipher
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except ImportError:
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raise Exception('You must install either cryptography or PyCrypto!')
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class BasePrpCrypto(object):
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def __init__(self, key):
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self.cipher = WeChatCipher(key)
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def get_random_string(self):
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return random_string(16)
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def _encrypt(self, text, _id):
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text = to_binary(text)
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tmp_list = []
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tmp_list.append(to_binary(self.get_random_string()))
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length = struct.pack(b'I', socket.htonl(len(text)))
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tmp_list.append(length)
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tmp_list.append(text)
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tmp_list.append(to_binary(_id))
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text = b''.join(tmp_list)
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text = PKCS7Encoder.encode(text)
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ciphertext = to_binary(self.cipher.encrypt(text))
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return base64.b64encode(ciphertext)
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def _decrypt(self, text, _id, exception=None):
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text = to_binary(text)
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plain_text = self.cipher.decrypt(base64.b64decode(text))
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padding = byte2int(plain_text[-1])
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content = plain_text[16:-padding]
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xml_length = socket.ntohl(struct.unpack(b'I', content[:4])[0])
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xml_content = to_text(content[4:xml_length + 4])
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from_id = to_text(content[xml_length + 4:])
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if from_id != _id:
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exception = exception or Exception
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raise exception()
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return xml_content
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