pad and unpad byte array

Demonstrates using the pad and unpad methods of CkByteArray.

Download Chilkat Python Library

import chilkat


data = chilkat.CkByteData()
data.append('\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09',10)

#  These are the padding options for the "pad" method:
#  0 = Each padding byte is the pad count (16 extra added if size is already a multiple of 16)
#  1 = Random bytes except the last is the pad count (16 extra added if size is already multiple of 16)
#  2 = Pad with random data. (If already a multiple of 16, no padding is added).
#  3 = Pad with NULLs. (If already a multiple of 16, no padding is added).
#  4 = Pad with SPACE chars(0x20). (If already a multiple of 16, no padding is added).

#  We'll pad to a block size of 16 bytes.
blockSize = 16

paddingScheme = 0

#  Pad, display the padded byte data, unpad, then re-display
data.pad(blockSize,paddingScheme)
print data.getEncoded("hex")
data.unpad(16,paddingScheme)
print data.getEncoded("hex")
print "----"

paddingScheme = 1
#  Pad, display the padded byte data, unpad, then re-display
data.pad(blockSize,paddingScheme)
print data.getEncoded("hex")
data.unpad(16,paddingScheme)
print data.getEncoded("hex")
print "----"

#  There is no unpadding with schemes 2,3, and 4
data2 = chilkat.CkByteData()
data2.append('\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09',10)
paddingScheme = 2
#  Pad and display the padded byte data
data2.pad(blockSize,paddingScheme)
print data2.getEncoded("hex")
print "----"

#  There is no unpadding with schemes 2,3, and 4
data3 = chilkat.CkByteData()
data3.append('\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09',10)
paddingScheme = 3
#  Pad and display the padded byte data
data3.pad(blockSize,paddingScheme)
print data3.getEncoded("hex")
print "----"

#  There is no unpadding with schemes 2,3, and 4
data4 = chilkat.CkByteData()
data4.append('\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09',10)
paddingScheme = 4
#  Pad and display the padded byte data
data4.pad(blockSize,paddingScheme)
print data4.getEncoded("hex")
print "----"