Chilkat2-Python

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

See more Encryption Examples

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.

Chilkat2-Python

import sys
import chilkat2

success = False

# 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 = chilkat2.BinData()
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 = chilkat2.Crypt2()

# Specify the encryption to be used.
# First we'll do AES-128 CBC
crypt.CryptAlgorithm = "aes"
crypt.CipherMode = "cbc"
crypt.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.CryptAlgorithm = "chacha20"
crypt.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.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.")