(MFC) AES XTS Mode

Demonstrates the AES-XTS mode of operation.

Note: This example requires Chilkat v9.5.0.91 or greater.

Chilkat C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkBinData.h>
#include <CkCrypt2.h>

void ChilkatSample(void)
    {
    CkString strOut;

    // This example assumes the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    bool success;

    // 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))

    const char *key = "394c97881abd989d29c703e48a72b397";
    const char *tweakKey = "a7acf51b59649eeea9b33274d8541df4";
    const char *dataUnit = "4b15c684a152d485fe9937d39b168c29";

    CkBinData bd;
    bd.AppendEncoded("2f3b9dcfbae729583b1d1ffdd16bb6fe2757329435662a78f0","hex");

    CkCrypt2 crypt;

    crypt.put_CryptAlgorithm("aes");
    crypt.put_CipherMode("xts");
    crypt.put_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);

    strOut.append("CT = ");
    strOut.append(bd.getEncoded("hexlower"));
    strOut.append("\r\n");

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

    strOut.append("PT = ");
    strOut.append(bd.getEncoded("hexlower"));
    strOut.append("\r\n");

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


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }