本文实例讲述了Python3对称加密算法AES、DES3。分享给大家供大家参考，具体如下：
python3.6此库安装方式，需要pip3 install pycryptodome。
如有site-packages中存在crypto、pycrypto，在pip之前，需要pip3 uninstall crypto、pip3 uninstall pycrypto，否则无法安装成功。
C:/WINDOWS/system32>pip3 install pycryptodome
Collecting pycryptodome
Downloading https://files.pythonhosted.org/packages/0f/5d/a429a53eacae3e13143248c3868c76985bcd0d75858bd4c25b574e51bd4d/pycryptodome-3.6.3-cp36-cp36m-win_amd64.whl (7.9MB)
100% |████████████████████████████████| 7.9MB 111kB/s
Installing collected packages: pycryptodome
Successfully installed pycryptodome-3.6.3
这里顺带说一下pycrypto，这个库已经有很久没有人维护了，如果需要安装此库，需要先安装 VC++ build tools
然后将 ~/BuildTools/VC/Tools/MSVC/14.15.26726/include 目录下的 stdint.h 拷贝到 C:/Program Files (x86)/Windows Kits/10/Include/10.0.17134.0/ucrt 下。（Win10 需管理员权限）
接着将同目录下的 inttypes.h 中的 #include <stdint.h> （第十四行），改成 #include "stdint.h"。
然后使用 pip3 install pycrypto，就能直接安装了。
注：如果不是业务需要，请尽可能使用 pycryptodome。
AES：
import Crypto.Cipher.AESimport Crypto.Randomimport base64import binasciidef auto_fill(x): if len(x) <= 32: while len(x) not in [16, 24, 32]: x += " " return x.encode() else: raise "密钥长度不能大于32位！"key = "asd"content = "abcdefg1234567"x = Crypto.Cipher.AES.new(auto_fill(key), Crypto.Cipher.AES.MODE_ECB)a = base64.encodebytes(x.encrypt(auto_fill(content)))b = x.decrypt(base64.decodebytes(a))print(a)print(b)a = binascii.b2a_base64(x.encrypt(auto_fill(content)))b = x.decrypt(binascii.a2b_base64(a))print(a)print(b)key = "dsa"iv = Crypto.Random.new().read(16) # 向量，必须为16字节content = "1234567abcdefg"y = Crypto.Cipher.AES.new(auto_fill(key), Crypto.Cipher.AES.MODE_CBC, iv)c = binascii.b2a_base64(y.encrypt(auto_fill(content)))z = Crypto.Cipher.AES.new(auto_fill(key), Crypto.Cipher.AES.MODE_CBC, iv)d = z.decrypt(binascii.a2b_base64(c))print(c)print(d)
运行结果：
b'jr/EIUp32kLHc3ypZZ1cyg==/n'
b'abcdefg1234567 '
b'jr/EIUp32kLHc3ypZZ1cyg==/n'
b'abcdefg1234567 '
b'j+Ul9KQd0HnuiHW3z9tD7A==/n'
b'1234567abcdefg '
DES3：
import Crypto.Cipher.DES3import base64import binasciidef auto_fill(x): if len(x) > 24: raise "密钥长度不能大于等于24位！" else: while len(x) < 16: x += " " return x.encode()key = "asd"content = "abcdefg1234567"x = Crypto.Cipher.DES3.new(auto_fill(key), Crypto.Cipher.DES3.MODE_ECB)a = base64.encodebytes(x.encrypt(auto_fill(content)))print(a)b = x.decrypt(base64.decodebytes(a))print(b)a = binascii.b2a_base64(x.encrypt(auto_fill(content)))b = x.decrypt(binascii.a2b_base64(a))print(a)print(b)
运行结果：
b'/ee3NFKeNqEk/qMNd1mjog==/n'
b'abcdefg1234567 '
b'/ee3NFKeNqEk/qMNd1mjog==/n'
b'abcdefg1234567 '
附：AES的工厂模式封装Cipher_AES.py（封装Crypto.Cipher.AES）
'''Created on 2018年7月7日@author: ray'''import Crypto.Cipher.AESimport Crypto.Randomimport base64import binasciiclass Cipher_AES: pad_default = lambda x, y: x + (y - len(x) % y) * " ".encode("utf-8") unpad_default = lambda x: x.rstrip() pad_user_defined = lambda x, y, z: x + (y - len(x) % y) * z.encode("utf-8") unpad_user_defined = lambda x, z: x.rstrip(z) pad_pkcs5 = lambda x, y: x + (y - len(x) % y) * chr(y - len(x) % y).encode("utf-8") unpad_pkcs5 = lambda x: x[:-ord(x[-1])] def __init__(self, key="abcdefgh12345678", iv=Crypto.Random.new().read(Crypto.Cipher.AES.block_size)): self.__key = key self.__iv = iv def set_key(self, key): self.__key = key def get_key(self): return self.__key def set_iv(self, iv): self.__iv = iv def get_iv(self): return self.__iv def Cipher_MODE_ECB(self): self.__x = Crypto.Cipher.AES.new(self.__key.encode("utf-8"), Crypto.Cipher.AES.MODE_ECB) def Cipher_MODE_CBC(self): self.__x = Crypto.Cipher.AES.new(self.__key.encode("utf-8"), Crypto.Cipher.AES.MODE_CBC, self.__iv.encode("utf-8")) def encrypt(self, text, cipher_method, pad_method="", code_method=""): if cipher_method.upper() == "MODE_ECB": self.Cipher_MODE_ECB() elif cipher_method.upper() == "MODE_CBC": self.Cipher_MODE_CBC() cipher_text = b"".join([self.__x.encrypt(i) for i in self.text_verify(text.encode("utf-8"), pad_method)]) if code_method.lower() == "base64": return base64.encodebytes(cipher_text).decode("utf-8").rstrip() elif code_method.lower() == "hex": return binascii.b2a_hex(cipher_text).decode("utf-8").rstrip() else: return cipher_text.decode("utf-8").rstrip() def decrypt(self, cipher_text, cipher_method, pad_method="", code_method=""): if cipher_method.upper() == "MODE_ECB": self.Cipher_MODE_ECB() elif cipher_method.upper() == "MODE_CBC": self.Cipher_MODE_CBC() if code_method.lower() == "base64": cipher_text = base64.decodebytes(cipher_text.encode("utf-8")) elif code_method.lower() == "hex": cipher_text = binascii.a2b_hex(cipher_text.encode("utf-8")) else: cipher_text = cipher_text.encode("utf-8") return self.unpad_method(self.__x.decrypt(cipher_text).decode("utf-8"), pad_method) def text_verify(self, text, method): while len(text) > len(self.__key): text_slice = text[:len(self.__key)] text = text[len(self.__key):] yield text_slice else: if len(text) == len(self.__key): yield text else: yield self.pad_method(text, method) def pad_method(self, text, method): if method == "": return Cipher_AES.pad_default(text, len(self.__key)) elif method == "PKCS5Padding": return Cipher_AES.pad_pkcs5(text, len(self.__key)) else: return Cipher_AES.pad_user_defined(text, len(self.__key), method) def unpad_method(self, text, method): if method == "": return Cipher_AES.unpad_default(text) elif method == "PKCS5Padding": return Cipher_AES.unpad_pkcs5(text) else: return Cipher_AES.unpad_user_defined(text, method) 使用方法：
加密：Cipher_AES(key [, iv]).encrypt(text, cipher_method [, pad_method [, code_method]])
解密：Cipher_AES(key [, iv]).decrypt(cipher_text, cipher_method [, pad_method [, code_method]])
key：密钥（长度必须为16、24、32）
iv：向量（长度与密钥一致，ECB模式不需要）
text：明文（需要加密的内容）
cipher_text：密文（需要解密的内容）
cipher_method：加密方法，目前只有"MODE_ECB"、"MODE_CBC"两种
pad_method：填充方式，解决 Java 问题选用"PKCS5Padding"
code_method：编码方式，目前只有"base64"、"hex"两种
来段调用封装类 Cipher_AES 的 demo_Cipher_AES.py，方便大家理解：
import Cipher_AESkey = "qwedsazxc123321a"iv = key[::-1]text = "我爱小姐姐，可小姐姐不爱我 - -"cipher_method = "MODE_CBC"pad_method = "PKCS5Padding"code_method = "base64"cipher_text = Cipher_AES(key, iv).encrypt(text, cipher_method, pad_method, code_method)print(cipher_text)text = Cipher_AES(key, iv).decrypt(cipher_text, cipher_method, pad_method, code_method)print(text)'''运行结果：uxhf+MoSko4xa+jGOyzJvYH9n5NvrCwEHbwm/A977CmGqzg+fYE0GeL5/M5v9O1o我爱小姐姐，可小姐姐不爱我 - -'''
希望本文所述对大家Python程序设计有所帮助。
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