(CkPython) Example for both AES-128 and ChaCha20 to Encrypt Binary Data

Demonstrates the use of the new EncryptBd and DecryptBd methods introduced in Chilkat v9.5.0.67 to encrypt/decrypt binary bytes.

Note: This example requires Chilkat v9.5.0.67 or greater.

Chilkat Python Downloads install with pip pip3 install chilkat or download... Python Module for Windows, MacOS, Linux, Alpine Linux, Solaris

import sys
import chilkat

# This example assumes the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

# Load a small JPG file to be encrypted/decrypted.
jpgBytes = chilkat.CkBinData()
success = jpgBytes.LoadFile("qa_data/jpg/starfish.jpg")
if (success != True):
    print("Failed to load JPG file.")
    sys.exit()

# Show the unencrypted JPG bytes in Base64 format.
# (The "base64_mime" encoding was added in Chilkat v9.5.0.67.
# The "base64" encoding emits a single line of base64, whereas
# "base64_mime" will emit multi-line base64 as it would appear
# in MIME.)
print(jpgBytes.getEncoded("base64_mime"))

# Sample base64_mime JPG data:

# 	/9j/4AAQSkZJRgABAgEASABIAAD/7Q18UGhvdG9zaG9wIDMuMAA4QklNA+0AAAAAABAASAAAAAEA
# 	AQBIAAAAAQABOEJJTQPzAAAAAAAIAAAAAAAAAAE4QklNBAoAAAAAAAEAADhCSU0nEAAAAAAACgAB
# 	AAAAAAAAAAI4QklNA/UAAAAAAEgAL2ZmAAEAbGZmAAYAAAAAAAEAL2ZmAAEAoZmaAAYAAAAAAAEA
# 	MgAAAAEAWgAAAAYAAAAAAAEANQAAAAEALQAAAAYAAAAAAAE4QklNBBQAAAAAAAQAAAABOEJJTQQM
# 	...

crypt = chilkat.CkCrypt2()

# Specify the encryption to be used.
# First we'll do AES-128 CBC
crypt.put_CryptAlgorithm("aes")
crypt.put_CipherMode("cbc")
crypt.put_KeyLength(128)

ivHex = "000102030405060708090A0B0C0D0E0F"
crypt.SetEncodedIV(ivHex,"hex")

keyHex = "000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F"
crypt.SetEncodedKey(keyHex,"hex")

# Do the in-place 128-bit AES CBC encryption.
# The contents of jpgBytes are replaced with the encrypted bytes.
success = crypt.EncryptBd(jpgBytes)
if (success != True):
    print(crypt.lastErrorText())
    sys.exit()

# Examine the JPG bytes again.  The bytes should be different because they are encrypted:
print(jpgBytes.getEncoded("base64_mime"))

# Sample base64_mime encrypted JPG data:

# 	sbz0babt1WCkQf5xKMdg/baZAcUBO5GVUUDF2BjVqmd+HrqKN+t6hAcqakL/bdo0q9hYmow0Tp1e
# 	AQ9V9DOiifQUZqWVkR+kL/c45bq8JGFDvgNl0djPt+yYhV789IB/fPH0upx+/ad++WNOlv1IxGMr
# 	Y1x1oERU/IsiEzafUJdI4kZ6FQo2IPGMF/Rm1h79I7hP1yYUFxvJyz+PzaySAUH1nLsNHyDVY5VY
# 	O90aH3steRSYbz8C8UF9wQ3qqEIXQNnnixvoNDnmHyY39VoVBI5F6rnPwYDfAk2t8tmuryFqvwAu
# 	...

# Decrypt to restore back to the original:
success = crypt.DecryptBd(jpgBytes)
if (success != True):
    print(crypt.lastErrorText())
    sys.exit()

print(jpgBytes.getEncoded("base64_mime"))

# 	/9j/4AAQSkZJRgABAgEASABIAAD/7Q18UGhvdG9zaG9wIDMuMAA4QklNA+0AAAAAABAASAAAAAEA
# 	AQBIAAAAAQABOEJJTQPzAAAAAAAIAAAAAAAAAAE4QklNBAoAAAAAAAEAADhCSU0nEAAAAAAACgAB
# 	AAAAAAAAAAI4QklNA/UAAAAAAEgAL2ZmAAEAbGZmAAYAAAAAAAEAL2ZmAAEAoZmaAAYAAAAAAAEA
# 	MgAAAAEAWgAAAAYAAAAAAAEANQAAAAEALQAAAAYAAAAAAAE4QklNBBQAAAAAAAQAAAABOEJJTQQM
# 	...

# ----------------------------------------------------------------------------------
# To do chacha20 encryption, just change the settings:

crypt.put_CryptAlgorithm("chacha20")
crypt.put_KeyLength(256)
# The initial count is the initial block counter for the chacha20 algorithm.
# It can be any integer, but must be set to the same when decrypting.
crypt.put_InitialCount(22)

success = crypt.EncryptBd(jpgBytes)
# jpgBytes now contains chacha20 encrypted bytes.

success = crypt.DecryptBd(jpgBytes)
# jpgBytes is now restored back to the original unencrypted by bytes.

# Save the bytes to a file..
success = jpgBytes.WriteFile("qa_output/starfish.jpg")

print("Success.")