Python使用Crypto库实现加密解密的示例详解

一：crypto库安装

pycrypto，pycryptodome是crypto第三方库，pycrypto已经停止更新三年了，所以不建议安装这个库；pycryptodome是pycrypto的延伸版本，用法和pycrypto 是一模一样的；所以只需要安装pycryptodome就可以了

pip install pycryptodome

二：python使用crypto

1：crypto的加密解密组件des.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-
 
from Crypto.Cipher import DES
from binascii import b2a_hex, a2b_hex
class MyDESCrypt: #自己实现的DES加密类
    def __init__(self, key = ''):
        #密钥长度必须为64位，也就是8个字节
        if key is not '':
            self.key = key.encode('utf-8')
        else:
            self.key = '12345678'.encode('utf-8')
        self.mode = DES.MODE_CBC
    # 加密函数，如果text不足16位就用空格补足为16位，
    # 如果大于16当时不是16的倍数，那就补足为16的倍数。
    def encrypt(self,text):
        try:
            text = text.encode('utf-8')
            cryptor = DES.new(self.key, self.mode, self.key)
            # 这里密钥key 长度必须为16（DES-128）,
            # 24（DES-192）,或者32 （DES-256）Bytes 长度
            # 目前DES-128 足够目前使用
            length = 16   #lenth可以设置为8的倍数
            count = len(text)
            if count < length:
                add = (length - count)
                # \0 backspace
                # text = text + ('\0' * add)
                text = text + ('\0' * add).encode('utf-8')
            elif count > length:
                add = (length - (count % length))
                # text = text + ('\0' * add)
                text = text + ('\0' * add).encode('utf-8')
            self.ciphertext = cryptor.encrypt(text)
            # 因为DES加密时候得到的字符串不一定是ascii字符集的，输出到终端或者保存时候可能存在问题
            # 所以这里统一把加密后的字符串转化为16进制字符串
            return b2a_hex(self.ciphertext)
        except:
            return ""
    # 解密后，去掉补足的空格用strip() 去掉
    def decrypt(self, text):
        try:
            cryptor = DES.new(self.key, self.mode, self.key)
            plain_text = cryptor.decrypt(a2b_hex(text))
            # return plain_text.rstrip('\0')
            return bytes.decode(plain_text).rstrip('\0')
        except:
            return ""

2：crypto组件使用

from . import des
msg = "password is 961223"
key = "12345678"  #key值可传可不传
des1 = des.MyDESCrypt()
#加密
cipherTxt = des1.encrypt(msg)  #返回值为bytes型
print(cipherTxt)
#解密
decTxt = des1.decrypt(cipherTxt);  #返回值为str型
print(decTxt)

知识补充

下面是小编为大家整理的一些Python利用pycrypto进行加密解密的示例，希望对大家有所帮助

AES-ECB加解密

下面是采用 ECB并以pkcs7填充的加密与解密方法

import base64

from Crypto.Cipher import AES
from Crypto.Util.Padding import pad, unpad


def aes_encrypt(secret_key, data):
    """加密数据
    :param secret_key: 加密秘钥
    :param data: 需要加密数据
    """
    data = bytes(data, encoding="utf-8")
    # 填充数据采用pkcs7
    data = pad(data, block_size=16, style="pkcs7")
    # 创建加密器
    cipher = AES.new(key=secret_key.encode("utf-8"), mode=AES.MODE_ECB)
    # 对数据进行加密
    encrypted_data = cipher.encrypt(data)
    # 对数据进行base64编码
    encrypted_data = base64.b64encode(encrypted_data)
    return encrypted_data.decode()


def aes_decrypt(secret_key, data):
    """解密数据
    """
    data = base64.b64decode(data)
    cipher = AES.new(key=secret_key.encode("utf-8"), mode=AES.MODE_ECB)
    decrypt_data = cipher.decrypt(data)
    decrypt_data = unpad(decrypt_data, 16, style="pkcs7")
    return decrypt_data.decode("utf-8")


if __name__ == '__main__':
    key = "22a1d4c4263e83d7f8c33a321eb19ae7"
    data = "asdASD73j8H9k6C1asvhBOK0PXOzJM7dsqXysssW"
    print("原始数据：%s" % data)
    r = aes_encrypt(key, data)
    print("加密数据：%s" % r)
    r = aes_decrypt("22a1d4c4263e83d7f8c33a321eb19ae7", r)
    print("解密数据：%s" % r)

执行结果如下

AES-GCM加解密

import base64
import random
import string

from Crypto.Cipher import AES


def encrypt_aes_gcm(key, data, associated_data=None, nonce=None):
    """
    AES-GCM加密
    :param key: 密钥。16, 24 or 32字符长度的字符串
    :param data: 待加密字符串
    :param associated_data: 附加数据，一般为None
    :param nonce: 随机值，和MD5的“加盐”有些类似，目的是防止同样的明文块，始终加密成同样的密文块
    :return:
    """
    key = key.encode('utf-8')
    data = data.encode('utf-8')
    # 假如先后端约定随机值为16位长度的字符串
    nonce = nonce or "1234567812345678"
    nonce = nonce.encode("utf-8")

    # 生成加密器
    cipher = AES.new(key, AES.MODE_GCM, nonce=nonce)
    if associated_data is not None:
        cipher.update(associated_data.encode())

    # 加密数据
    cipher_data, auth_tag = cipher.encrypt_and_digest(data)

    # 拼接数据
    join_data = nonce + cipher_data + auth_tag      # 拼接数据为：前16位为nonce，后16位为验签值

    # 返回base64编码数据
    return base64.b64encode(join_data).decode('utf-8')


def decrypt_aes_gcm(key, cipher_data, associated_data=None):
    """
    AES-GCM解密
    :param cipher_data: encrypt_aes_gcm 方法返回的数据
    :return:
    """
    key = key.encode('utf-8')

    # 进行base64解码
    debase64_cipher_data = base64.b64decode(cipher_data)

    # 分割数据
    nonce = debase64_cipher_data[:16]
    cipher_data = debase64_cipher_data[16:-16]
    auth_tag = debase64_cipher_data[-16:]

    cipher = AES.new(key, AES.MODE_GCM, nonce=nonce)
    if associated_data is not None:
        cipher.update(associated_data.encode())

    # 解密数据
    plaintext = cipher.decrypt_and_verify(cipher_data, auth_tag)
    return plaintext.decode()


if __name__ == '__main__':
    aes_key = 'DnKRYZbvVzdhPlF10rtcxmi5Cj36AbCd'
    associated_data = "1234567812345678"
    nonce = ''.join(random.sample(string.ascii_letters + string.digits, 16))
    data = '{"lang":"zh-CN","pageNumber":1,"pageSize":10,"cycleId":"1522973936269266945"}'
    print("原始数据：" + data)

    cipher_data = encrypt_aes_gcm(aes_key, data, associated_data=associated_data, nonce=nonce)
    print("加密数据：" + cipher_data)

    de_data = decrypt_aes_gcm(aes_key, cipher_data, associated_data)
    print("解密数据：" + de_data)

执行结果如下：

使用RAS实现非对称加解密

# -*- coding: utf-8 -*-

from Crypto import Random
from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_v1_5
import base64


def get_key():
    """生成公私钥"""
    # 生成rsa算法实例
    rsa = RSA.generate(1024, Random.new().read)
    # 生成公钥私钥
    private_pem = rsa.exportKey()
    public_pem = rsa.publickey().exportKey()

    return {
        "public_key": public_pem.decode(),
        "private_key": private_pem.decode()
    }


def rsa_encrypt(data, public_key):
    """公钥加密"""
    # 加载公钥
    rsakey = RSA.importKey(public_key)
    # 生成密码器
    cipher = PKCS1_v1_5.new(rsakey)
    # 加密数据。注意，在python3中加密的数据必须是bytes类型的数据，不能是str类型的数据
    encrypt_data = cipher.encrypt(data.encode(encoding="utf-8"))
    # # 对数据进行base64编码
    encrypt_data = base64.b64encode(encrypt_data)
    # 公钥每次加密的结果不一样。原因是每次padding的数据不一样
    return encrypt_data.decode()


def rsa_decrypt(cipher_data, private_key):
    """私钥解密"""
    # 加载私钥
    rsakey = RSA.importKey(private_key)
    # 生成密码器
    cipher = PKCS1_v1_5.new(rsakey)
    # 将密文解密成明文，返回的是一个bytes类型数据，需要自己转换成str
    decrypt_data = cipher.decrypt(base64.b64decode(cipher_data), "解密失败")
    return decrypt_data.decode()


if __name__ == '__main__':
    # k = get_key()
    # public_key = k.get("public_key")
    # private_key = k.get("private_key")
    #
    # print(public_key)
    # print(private_key)

    public_key = """-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDKF7UTc5K61xMUKrCtld0dYJf/
KjT5P+R3H8n8my8aEYqUaWQjO3CkQGsLN//5Tbs8g5Of4vAkqytoleWxSQxFGO7T
YuOQ7UtvRhKqTKvX8PvDnKX7ebKzw3zIXt1QDRbc2bJTqVAbPDdT1DNvyocQdCMC
BtPA2algMRs4Zq0qpwIDAQAB
-----END PUBLIC KEY-----
    """
    private_key = """-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----
    """

    data = "hello python!"
    cipher_data = rsa_encrypt(data, public_key)
    print(cipher_data)

    decrypt_data = rsa_decrypt(cipher_data, private_key)
    print(decrypt_data)