Xojo Plugin

AES XTS Mode

See more Encryption Examples

Demonstrates the AES-XTS mode of operation.

Note: This example requires Chilkat v9.5.0.91 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.

// Here we have a sample from CAVS validatition data:

// COUNT = 301
// DataUnitLen = 200
// Key = 
// 394c97881abd989d29c703e48a72b397
// a7acf51b59649eeea9b33274d8541df4
// i = 4b15c684a152d485fe9937d39b168c29
// PT = 2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0
// CT = f3473802e38a3ffef4d4fb8e6aa266ebde553a64528a06463e

// Note: The above sample requires an AES-XTS implementation that fully supports ciphertext-stealing
// because the data to be encrypted is not an even multiple of the AES block size (i.e. not a multiple of 16 bytes).
// Chilkat fully supports AES-XTS with ciphertext stealing.
// (i.e. Chilkat implements XEX-based tweaked-codebook mode with ciphertext stealing (XTS))

Dim key As String
key = "394c97881abd989d29c703e48a72b397"
Dim tweakKey As String
tweakKey = "a7acf51b59649eeea9b33274d8541df4"
Dim dataUnit As String
dataUnit = "4b15c684a152d485fe9937d39b168c29"

Dim bd As New Chilkat.BinData
success = bd.AppendEncoded("2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0","hex")

Dim crypt As New Chilkat.Crypt2

crypt.CryptAlgorithm = "aes"
crypt.CipherMode = "xts"
crypt.KeyLength = 128

crypt.SetEncodedKey key,"hex"
crypt.XtsSetEncodedTweakKey tweakKey,"hex"
crypt.XtsSetEncodedTweakValue dataUnit,"hex"

// In-place encrypt the contents of bd.
success = crypt.EncryptBd(bd)

System.DebugLog("CT = " + bd.GetEncoded("hexlower"))

// Decrypt to revert back to the unencrypted content:
success = crypt.DecryptBd(bd)

System.DebugLog("PT = " + bd.GetEncoded("hexlower"))

// Output:
// CT = f3473802e38a3ffef4d4fb8e6aa266ebde553a64528a06463e
// PT = 2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0