C#

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.

C#

bool 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.
Chilkat.BinData jpgBytes = new Chilkat.BinData();
success = jpgBytes.LoadFile("qa_data/jpg/starfish.jpg");
if (success != true) {
    Debug.WriteLine("Failed to load JPG file.");
    return;
}

//  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.)
Debug.WriteLine(jpgBytes.GetEncoded("base64_mime"));

//  Sample base64_mime JPG data:

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

Chilkat.Crypt2 crypt = 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;

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

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) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

//  Examine the JPG bytes again.  The bytes should be different because they are encrypted:
Debug.WriteLine(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) {
    Debug.WriteLine(crypt.LastErrorText);
    return;
}

Debug.WriteLine(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");

Debug.WriteLine("Success.");