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：
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import crypto.cipher.aes
import crypto.random
import base64
import binascii
def 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)
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运行结果：
b'jr/eiup32klhc3ypzz1cyg==\n'
b'abcdefg1234567 '
b'jr/eiup32klhc3ypzz1cyg==\n'
b'abcdefg1234567 '
b'j+ul9kqd0hnuihw3z9td7a==\n'
b'1234567abcdefg '
des3：
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import crypto.cipher.des3
import base64
import binascii
def 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)
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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）
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'''
created on 2018年7月7日
@author: ray
'''
import crypto.cipher.aes
import crypto.random
import base64
import binascii
class 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)
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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：
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import cipher_aes
key = "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 - -
'''
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希望本文所述对大家python程序设计有所帮助。
原文链接：https://blog.csdn.net/qq_42486920/article/details/80850974