python加密与解密，加签与验签

在与第三方服务对接时，加密与解密，加签与验签是这个过程当中的关键一步

• 通常状况下，对接服务中会有两对公私钥。使用对方公钥进行加密，使用本身私钥进行加签。传回来的数据，使用本身的私钥解密，使用对方的公钥验签。

import base64
from Crypto.PublicKey import RSA
from Crypto.Hash import SHA
from Crypto.Cipher import PKCS1_v1_5
from Crypto.Signature import PKCS1_v1_5 as SIGN_PKCS

PUB_KEY = RSA.importKey(open('rsa_public_key.pem','r').read())
PRI_KEY = RSA.importKey(open('rsa_private_key.pem','r').read())

加密

def split_data(l, n):
    for i in range(0, len(l), n):
        yield l[i: i+n]
        
def encrypt(params):
    raw = params.encode('utf-8')
    cipher = PKCS1_v1_5.new(PUB_KEY)
    ＃ 加密超长字节117个字节一加密
    content = b''.join([cipher.encrypt(x) for x in chunks(raw, 117)])
    return base64.b64encode(content)

解密

def decrypt(data):
    raw = data.encode('utf-8')
    decrypt = PKCS1_v1_5.new(PRI_KEY).decrypt
    # 解密超长字符128一解密
    content = b''.join(decrypt(x, object()) for x in chunks(raw, 128))
    return content.decode()

加签

def signer(data):
    signstr = data.encode('utf-8')
    sign = SIGN_PKCS.new(PRI_KEY).sign(SHA.new(signstr))
    return base64.b64encode(sign)

验签

def verify_sign(unsign, raw_sign):
    """
     unsign: 签名
     raw_sign: 待验证签名
    """
    assert SIGN_PKCS.new(PUB_KEY).verify(SHA.new(unsign.encode('utf-8')), raw_sign)