如何解密来自python的加密字符串?

时间:2017-06-08 09:45:48

标签: ios swift python-2.7 aes pycrypto

我从python获得加密的base64字符串。格式为AES 256 CBC。但是当我尝试使用iOS Swift解密时,它将解密的字符串作为nil返回。

# coding=utf-8
import base64
from random import choice
from string import letters

try:
    from Crypto import Random
    from Crypto.Cipher import AES
except ImportError:
    import crypto
    import sys

    sys.modules['Crypto'] = crypto
    from crypto.Cipher import AES
    from crypto import Random


class AESCipher(object):
    def __init__(self, key):
        self.bs = 32
        self.key = key

    def encrypt(self, raw):
        _raw = raw
        raw = self._pad(raw)

        print raw, ';'
        print _raw, ';'

        iv = "".join([choice(letters[:26]) for i in xrange(16)])
        print " iv :", iv
        cipher = AES.new(self.key, AES.MODE_CBC, iv)
        return base64.b64encode(iv + cipher.encrypt(raw))

    def decrypt(self, enc):
        enc = base64.b64decode(enc)
        iv = enc[:AES.block_size]
        cipher = AES.new(self.key, AES.MODE_CBC, iv)
        return self._unpad(cipher.decrypt(enc[AES.block_size:])).decode('utf-8')

    def _pad(self, s):
        a = (self.bs - len(s) % self.bs)
        b = chr(self.bs - len(s) % self.bs)
        return s + a * b

    @staticmethod
    def _unpad(s):
        return s[:-ord(s[len(s) - 1:])]
def encrypt(k, t):
    o = AESCipher(k)
    return o.encrypt(t)


def decrypt(k, t):
    o = AESCipher(k)
    return o.decrypt(t)


def main():
    k = "qwertyuiopasdfghjklzxcvbnmqwerty"
    s1 = "Hello World!"

    d2 = encrypt(k, s1)

    print " Password :", k
    print "Encrypted :", d2
    print "    Plain :", decrypt(k, d2)

if __name__ == '__main__':
    main()

的iOS

我在这里使用AES256CBC Lib https://github.com/SwiftyBeaver/AES256CBC

let decrypted = AES256CBC.decryptString("Ymdqc3ZqdmZ1cXdsZG1sZenhgr4Xt0+ceARYRh1n40QkNDV/dyKbQjYLcbiXBBeO", password: "qwertyuiopasdfghjklzxcvbnmqwerty")

        print("decrypted: \(String(describing: decrypted))") // here I get nil

当python运行时,我得到这个日志

iv : bgjsvjvfuqwldmle
 Password : qwertyuiopasdfghjklzxcvbnmqwerty
Encrypted : Ymdqc3ZqdmZ1cXdsZG1sZenhgr4Xt0+ceARYRh1n40QkNDV/dyKbQjYLcbiXBBeO
    Plain : Hello World!

我不知道为什么python和iOS在AES中不一样。任何人解决这个问题请在下面给出答案。提前谢谢。

1 个答案:

答案 0 :(得分:0)

我认为你需要首先解码你的base64字符串。 也许这会起作用(只是谷歌搜索它,我不是iOS开发者,所以我很抱歉最终的错误)

let decodedData = NSData("Ymdqc3ZqdmZ1cXdsZG1sZenhgr4Xt0+ceARYRh1n40QkNDV/dyKbQjYLcbiXBBeO": base64String, options:NSDataBase64DecodingOptions.fromRaw(0)!)
let decodedString = NSString(data: decodedData, encoding: NSUTF8StringEncoding)
let decrypted = AES256CBC.decryptString(decodedString, password: "qwertyuiopasdfghjklzxcvbnmqwerty")
        print("decrypted: \(String(describing: decrypted))")

它也在documentation

中说明