python基于pyDes库实现des加密的方法

本文实例讲述了python基于pyDes库实现des加密的方法。分享给大家供大家参考，具体如下：

下载及简介地址：https://twhiteman.netfirms.com/des.html

如需要在python中使用des加密，可以直接使用pyDes库加密，该库提供了CBC和ECB两种加密方式。

1、Windows下安装

下载后pyDes-x.x.x.zip并解压后，里面有setup.py文件，使用命令 setup.py --help可查看详细使用。

你可以使用命令python setup.py install命令安装，也可以直接将压缩包内的pyDes.py拷贝到本地的python lib库下直接开始使用

2、 使用

使用参数如下（拷贝自上述提供的地址）：

Class initialization
--------------------
pyDes.des(key, [mode], [IV], [pad], [padmode])
pyDes.triple_des(key, [mode], [IV], [pad], [padmode])
key     -> Bytes containing the encryption key. 8 bytes for DES, 16 or 24 bytes
    for Triple DES
mode    -> Optional argument for encryption type, can be either
    pyDes.ECB (Electronic Code Book) or pyDes.CBC (Cypher Block Chaining)
IV      -> Optional Initial Value bytes, must be supplied if using CBC mode.
    Length must be 8 bytes.
pad     -> Optional argument, set the pad character (PAD_NORMAL) to use during
    all encrypt/decrpt operations done with this instance.
padmode -> Optional argument, set the padding mode (PAD_NORMAL or PAD_PKCS5)
    to use during all encrypt/decrpt operations done with this instance.
I recommend to use PAD_PKCS5 padding, as then you never need to worry about any
padding issues, as the padding can be removed unambiguously upon decrypting
data that was encrypted using PAD_PKCS5 padmode.

Common methods
--------------
encrypt(data, [pad], [padmode])
decrypt(data, [pad], [padmode])
data    -> Bytes to be encrypted/decrypted
pad     -> Optional argument. Only when using padmode of PAD_NORMAL. For
    encryption, adds this characters to the end of the data block when
    data is not a multiple of 8 bytes. For decryption, will remove the
    trailing characters that match this pad character from the last 8
    bytes of the unencrypted data block.
padmode -> Optional argument, set the padding mode, must be one of PAD_NORMAL
    or PAD_PKCS5). Defaults to PAD_NORMAL

Example：

from pyDes import *
# For Python3, you'll need to use bytes, i.e.:
#  data = b"Please encrypt my data"
#  k = des(b"DESCRYPT", CBC, b"\0\0\0\0\0\0\0\0", pad=None, padmode=PAD_PKCS5)
data = "Please encrypt my data"
k = des("DESCRYPT", CBC, "\0\0\0\0\0\0\0\0", pad=None, padmode=PAD_PKCS5)
d = k.encrypt(data)
print "Encrypted: %r" % d
print "Decrypted: %r" % k.decrypt(d)
assert k.decrypt(d, padmode=PAD_PKCS5) == dat

以下是本人使用的例子,使用CBC加密的方式：

import base64
from pyDes import *
Des_Key = "BHC#@*UM" # Key
Des_IV = "\x22\x33\x35\x81\xBC\x38\x5A\xE7" # 自定IV向量
def DesEncrypt(str):
  k = des(Des_Key, CBC, Des_IV, pad=None, padmode=PAD_PKCS5)
  EncryptStr = k.encrypt(str)
  return base64.b64encode(EncryptStr) #转base64编码返回