PyDES

一个简单的例子：

from pyDes import *
data = "Please encrypt my data"
k = des("DESCRYPT", CBC, "", 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) == data

PyDES 主页：http://twhiteman.netfirms.com/des.html

Installation

• Extract the files from the pyDes archive.
• Run the following command: python setup.py install

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.

ommon 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.