(DataFlex) AES XTS Mode where Tweak Value is Data Unit Number

Demonstrates the AES-XTS mode of operation where the tweak value is specified as a data unit number.

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

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

Use ChilkatAx-9.5.0-win32.pkg

Procedure Test
    Boolean iSuccess
    String sKey
    String sTweakKey
    String sDataUnit
    Variant vBd
    Handle hoBd
    Handle hoCrypt
    String sTemp1
    Integer iTemp1

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

    // IEEE 1619 test vector 10
    Move "2718281828459045235360287471352662497757247093699959574966967627" To sKey
    Move "3141592653589793238462643383279502884197169399375105820974944592" To sTweakKey
    // The data unit number is 255
    // We'll specify this numerically by calling XtsSetDataUnitNumber with 255, 0 (see below)
    Move "00000000000000ff" To sDataUnit

    Get Create (RefClass(cComChilkatBinData)) To hoBd
    If (Not(IsComObjectCreated(hoBd))) Begin
        Send CreateComObject of hoBd
    End

    Get ComAppendEncoded Of hoBd "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f" "hex" To iSuccess
    Get ComAppendEncoded Of hoBd "202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f" "hex" To iSuccess
    Get ComAppendEncoded Of hoBd "404142434445464748494a4b4c4d4e4f505152535455565758595a5b5c5d5e5f" "hex" To iSuccess
    Get ComAppendEncoded Of hoBd "606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f" "hex" To iSuccess
    Get ComAppendEncoded Of hoBd "808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9f" "hex" To iSuccess
    Get ComAppendEncoded Of hoBd "a0a1a2a3a4a5a6a7a8a9aaabacadaeafb0b1b2b3b4b5b6b7b8b9babbbcbdbebf" "hex" To iSuccess
    Get ComAppendEncoded Of hoBd "c0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedf" "hex" To iSuccess
    Get ComAppendEncoded Of hoBd "e0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff" "hex" To iSuccess
    Get ComAppendEncoded Of hoBd "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d1e1f" "hex" To iSuccess
    Get ComAppendEncoded Of hoBd "202122232425262728292a2b2c2d2e2f303132333435363738393a3b3c3d3e3f" "hex" To iSuccess
    Get ComAppendEncoded Of hoBd "404142434445464748494a4b4c4d4e4f505152535455565758595a5b5c5d5e5f" "hex" To iSuccess
    Get ComAppendEncoded Of hoBd "606162636465666768696a6b6c6d6e6f707172737475767778797a7b7c7d7e7f" "hex" To iSuccess
    Get ComAppendEncoded Of hoBd "808182838485868788898a8b8c8d8e8f909192939495969798999a9b9c9d9e9f" "hex" To iSuccess
    Get ComAppendEncoded Of hoBd "a0a1a2a3a4a5a6a7a8a9aaabacadaeafb0b1b2b3b4b5b6b7b8b9babbbcbdbebf" "hex" To iSuccess
    Get ComAppendEncoded Of hoBd "c0c1c2c3c4c5c6c7c8c9cacbcccdcecfd0d1d2d3d4d5d6d7d8d9dadbdcdddedf" "hex" To iSuccess
    Get ComAppendEncoded Of hoBd "e0e1e2e3e4e5e6e7e8e9eaebecedeeeff0f1f2f3f4f5f6f7f8f9fafbfcfdfeff" "hex" To iSuccess

    Get ComNumBytes Of hoBd To iTemp1
    Showln "Size of plain-text: " iTemp1

    // This is the expected ciphertext:
    // cipherText =             "1c3b3a102f770386e4836c99e370cf9bea00803f5e482357a4ae12d414a3e63b"
    //                        + "5d31e276f8fe4a8d66b317f9ac683f44680a86ac35adfc3345befecb4bb188fd"
    //                        + "5776926c49a3095eb108fd1098baec70aaa66999a72a82f27d848b21d4a741b0"
    //                        + "c5cd4d5fff9dac89aeba122961d03a757123e9870f8acf1000020887891429ca"
    //                        + "2a3e7a7d7df7b10355165c8b9a6d0a7de8b062c4500dc4cd120c0f7418dae3d0"
    //                        + "b5781c34803fa75421c790dfe1de1834f280d7667b327f6c8cd7557e12ac3a0f"
    //                        + "93ec05c52e0493ef31a12d3d9260f79a289d6a379bc70c50841473d1a8cc81ec"
    //                        + "583e9645e07b8d9670655ba5bbcfecc6dc3966380ad8fecb17b6ba02469a020a"
    //                        + "84e18e8f84252070c13e9f1f289be54fbc481457778f616015e1327a02b140f1"
    //                        + "505eb309326d68378f8374595c849d84f4c333ec4423885143cb47bd71c5edae"
    //                        + "9be69a2ffeceb1bec9de244fbe15992b11b77c040f12bd8f6a975a44a0f90c29"
    //                        + "a9abc3d4d893927284c58754cce294529f8614dcd2aba991925fedc4ae74ffac"
    //                        + "6e333b93eb4aff0479da9a410e4450e0dd7ae4c6e2910900575da401fc07059f"
    //                        + "645e8b7e9bfdef33943054ff84011493c27b3429eaedb4ed5376441a77ed4385"
    //                        + "1ad77f16f541dfd269d50d6a5f14fb0aab1cbb4c1550be97f7ab4066193c4caa"
    //                        + "773dad38014bd2092fa755c824bb5e54c4f36ffda9fcea70b9c6e693e148c151";

    Get Create (RefClass(cComChilkatCrypt2)) To hoCrypt
    If (Not(IsComObjectCreated(hoCrypt))) Begin
        Send CreateComObject of hoCrypt
    End

    Set ComCryptAlgorithm Of hoCrypt To "aes"
    Set ComCipherMode Of hoCrypt To "xts"
    Set ComKeyLength Of hoCrypt To 256

    Send ComSetEncodedKey To hoCrypt sKey "hex"
    Send ComXtsSetEncodedTweakKey To hoCrypt sTweakKey "hex"

    // Here we set the tweak value as a data unit number (a 64-bit integer passed in 2 32-bit values)
    Send ComXtsSetDataUnitNumber To hoCrypt 255 0

    // In-place encrypt the contents of bd.
    Get pvComObject of hoBd to vBd
    Get ComEncryptBd Of hoCrypt vBd To iSuccess

    Get ComGetEncoded Of hoBd "hexlower" To sTemp1
    Showln "CT = " sTemp1

    // Decrypt to revert back to the unencrypted content:
    Get pvComObject of hoBd to vBd
    Get ComDecryptBd Of hoCrypt vBd To iSuccess

    Get ComGetEncoded Of hoBd "hexlower" To sTemp1
    Showln "PT = " sTemp1


End_Procedure