Unicode C++

AES Encrypt and Decrypt a File

_LANGUAGE_ demonstrates how to AES encrypt a file of any size, and then decrypt. Unicode C++

#include <CkCrypt2W.h>

void ChilkatSample(void)
    {
    bool success = false;

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

    CkCrypt2W crypt;

    crypt.put_CryptAlgorithm(L"aes");

    //  CipherMode may be "ecb" or "cbc"
    crypt.put_CipherMode(L"cbc");

    //  KeyLength may be 128, 192, 256
    crypt.put_KeyLength(256);

    //  The padding scheme determines the contents of the bytes
    //  that are added to pad the result to a multiple of the
    //  encryption algorithm's block size.  AES has a block
    //  size of 16 bytes, so encrypted output is always
    //  a multiple of 16.
    crypt.put_PaddingScheme(0);

    //  An initialization vector is required if using CBC mode.
    //  ECB mode does not use an IV.
    //  The length of the IV is equal to the algorithm's block size.
    //  It is NOT equal to the length of the key.
    const wchar_t *ivHex = L"000102030405060708090A0B0C0D0E0F";
    crypt.SetEncodedIV(ivHex,L"hex");

    //  The secret key must equal the size of the key.  For
    //  256-bit encryption, the binary secret key is 32 bytes.
    //  For 128-bit encryption, the binary secret key is 16 bytes.
    const wchar_t *keyHex = L"000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F";
    crypt.SetEncodedKey(keyHex,L"hex");

    //  Encrypt a file, producing the .aes as output.
    //  The input file is unchanged, the output .aes contains the encrypted
    //  contents of the input file.

    //  Note: The .aes output file has no file format.  It is simply a stream
    //  of bytes that resembles random binary data.
    const wchar_t *inFile = L"/Users/chilkat/testData/pdf/sample.pdf";
    const wchar_t *outFile = L"/Users/chilkat/testData/p7m/sample.pdf.aes";
    success = crypt.CkEncryptFile(inFile,outFile);
    if (success != true) {
        wprintf(L"%s\n",crypt.lastErrorText());
        return;
    }

    //  For demonstration purposes, a different instance of the object will be used
    //  for decryption.
    CkCrypt2W decrypt;

    //  All settings must match to be able to decrypt:
    decrypt.put_CryptAlgorithm(L"aes");
    decrypt.put_CipherMode(L"cbc");
    decrypt.put_KeyLength(256);
    decrypt.put_PaddingScheme(0);
    decrypt.SetEncodedIV(ivHex,L"hex");
    decrypt.SetEncodedKey(keyHex,L"hex");

    //  Decrypt the .aes
    inFile = L"/Users/chilkat/testData/p7m/sample.pdf.aes";
    outFile = L"/Users/chilkat/testData/pdf/recovered.pdf";
    success = decrypt.CkDecryptFile(inFile,outFile);
    if (success == false) {
        wprintf(L"%s\n",decrypt.lastErrorText());
        return;
    }

    wprintf(L"Success!\n");
    }