Metadata-Version: 2.1
Name: Padding
Version: 0.5
Summary: Padding methods for password based encryption
Home-page: http://pypi.python.org/pypi/Padding
Author: Peio Popov
Author-email: peio@peio.org
License: Public Domain
Keywords: padding,CMS,CMS Padding,Bit Padding,Null Padding,Random Padding,PKCS,RFC 5652,PKCS#5,PKCS#7,RFC 1423
Platform: UNKNOWN
Classifier: Development Status :: 5 - Production/Stable
Classifier: Environment :: Console
Classifier: Intended Audience :: Education
Classifier: License :: Public Domain
Classifier: Natural Language :: English
Classifier: Operating System :: OS Independent
Classifier: Programming Language :: Python
Classifier: Topic :: Security :: Cryptography
License-File: LICENSE.txt


Padding - Padding methods for password based encryption
---------------------------------------------

Append and remove padding to/from a string. 

I. Functions:
appendPadding(str, blocksize=AES_blocksize, mode='CMS'):
 Pad (append padding to) string for use with symmetric encryption algorithm
    Input: (string) str - String to be padded
           (int)    blocksize - block size of the encryption algorithm. Usually 8 or 16 bytes
           (string) mode - padding scheme one in (CMS, Bit, ZeroLen, Null, Space, Random)
    Return:(string) Padded string according to chosen padding mode

removePadding(str, blocksize=AES_blocksize, mode='CMS'):
  Remove padding from string 
  Input: (str) str - String to be padded
         (int) blocksize - block size of the algorithm. Usually 8 or 16 bytes
         (string) mode - padding scheme one in (CMS, Bit, ZeroLen, Null, Space, Random)
  Return:(string) Decrypted string without padding

II. Blocksizes:
DES (Triple DES), CAST5 and Blowfish have block size of 64 bits = 8 bytes
DES_blocksize = 8 
CAST5_blocksize = 8
Blowfish_blocksize = 8

AES has fixed block size of 128 bits = 16 bytes and this is the default blocksize
AES_blocksize = 16

III. Mode:
MODES ={
(0,'CMS')     : 'Pad with bytes all of the same value as the number of padding bytes. Default mode used in Cryptographic Message Syntax (CMS as defined in RFC 5652, PKCS#5, PKCS#7 and RFC 1423 PEM)',
(1,'Bit')     : 'BitPadding: Pad with 0x80 (10000000) followed by zero (null) bytes. Described in ANSI X.923 and ISO/IEC 9797-1',
(2,'ZeroLen') : 'Pad with zeroes except make the last byte equal to the number (length) of padding bytes',
(3,'Null')    : 'Pad with null bytes. Only for encrypting of text data.',
(4,'Space')   : 'Pad with spaces. Only for encrypting of text data.',
(5,'Random')  : 'ISO 10126 Padding (withdrawn in 2007): Pad with random bytes + last byte equal to the number of padding bytes'         
       }

CMS mode is the default one

Examples in the README.txt file


