Xojo Plugin

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.

Xojo Plugin

Dim success As Boolean
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.
Dim jpgBytes As New Chilkat.BinData
success = jpgBytes.LoadFile("qa_data/jpg/starfish.jpg")
If (success <> True) Then
    System.DebugLog("Failed to load JPG file.")
    Return
End If

// 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.)
System.DebugLog(jpgBytes.GetEncoded("base64_mime"))

// Sample base64_mime JPG data:

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

Dim crypt As New Chilkat.Crypt2

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

Dim ivHex As String
ivHex = "000102030405060708090A0B0C0D0E0F"
crypt.SetEncodedIV ivHex,"hex"

Dim keyHex As String
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) Then
    System.DebugLog(crypt.LastErrorText)
    Return
End If

// Examine the JPG bytes again.  The bytes should be different because they are encrypted:
System.DebugLog(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) Then
    System.DebugLog(crypt.LastErrorText)
    Return
End If

System.DebugLog(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")

System.DebugLog("Success.")