Xbase++

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.

Xbase++

LOCAL nSuccess
LOCAL cKey
LOCAL cTweakKey
LOCAL cDataUnit
LOCAL oBd
LOCAL oCrypt

nSuccess := 0

//  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))

cKey := "394c97881abd989d29c703e48a72b397"
cTweakKey := "a7acf51b59649eeea9b33274d8541df4"
cDataUnit := "4b15c684a152d485fe9937d39b168c29"

oBd := CreateObject("Chilkat.BinData")
oBd:AppendEncoded("2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0", "hex")

oCrypt := CreateObject("Chilkat.Crypt2")

oCrypt:CryptAlgorithm := "aes"
oCrypt:CipherMode := "xts"
oCrypt:KeyLength := 128

oCrypt:SetEncodedKey(cKey, "hex")
oCrypt:XtsSetEncodedTweakKey(cTweakKey, "hex")
oCrypt:XtsSetEncodedTweakValue(cDataUnit, "hex")

//  In-place encrypt the contents of bd.
nSuccess := oCrypt:EncryptBd(oBd)

? "CT = " + oBd:GetEncoded("hexlower")

//  Decrypt to revert back to the unencrypted content:
nSuccess := oCrypt:DecryptBd(oBd)

? "PT = " + oBd:GetEncoded("hexlower")

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

oBd:destroy()
oCrypt:destroy()