(Unicode C++) JWE with Binary Data

Demonstrates how to create a JWE that contains a binary payload (such as a JPG image).

Note: This example requires Chilkat v9.5.0.66 or greater.

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#include <CkBinDataW.h>
#include <CkJweW.h>
#include <CkJsonObjectW.h>
#include <CkStringBuilderW.h>

void ChilkatSample(void)
    {
    // This requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // Note: This example requires Chilkat v9.5.0.66 or greater.

    bool success;

    // Load a JPG file that will be the JWE payload.
    CkBinDataW jpgBytes;
    success = jpgBytes.LoadFile(L"qa_data/jpg/starfish.jpg");
    // Make sure your app checks the success/failure of the call to LoadFile..
    wprintf(L"Original JPG size = %d\n",jpgBytes.get_NumBytes());

    CkJweW jwe;

    CkJsonObjectW jweProtHdr;
    jweProtHdr.AppendString(L"alg",L"A128KW");
    jweProtHdr.AppendString(L"enc",L"A128CBC-HS256");
    jwe.SetProtectedHeader(jweProtHdr);

    const wchar_t *aesWrappingKey = L"GawgguFyGrWKav7AX4VKUg";
    jwe.SetWrappingKey(0,aesWrappingKey,L"base64url");

    // Encrypt and return the JWE in sbJwe:
    CkStringBuilderW sbJwe;
    success = jwe.EncryptBd(jpgBytes,sbJwe);
    if (success != true) {
        wprintf(L"%s\n",jwe.lastErrorText());
        return;
    }

    // Show the JWE:
    wprintf(L"%s\n",sbJwe.getAsString());
    wprintf(L"size of JWE: %d\n",sbJwe.get_Length());

    // ---------------------------------------------------------
    // Decrypt to get the original JPG file..

    CkJweW jwe2;
    success = jwe2.LoadJweSb(sbJwe);
    if (success != true) {
        wprintf(L"%s\n",jwe2.lastErrorText());
        return;
    }

    // Set the AES wrap key.
    jwe2.SetWrappingKey(0,aesWrappingKey,L"base64url");

    // Decrypt.
    CkBinDataW jpgOriginal;
    success = jwe2.DecryptBd(0,jpgOriginal);
    if (success != true) {
        wprintf(L"%s\n",jwe2.lastErrorText());
        return;
    }

    wprintf(L"Decrypted JPG size = %d\n",jpgOriginal.get_NumBytes());

    // Save the decrypted JPG to a file.
    success = jpgOriginal.WriteFile(L"qa_output/jwe_decrypted_starfish.jpg");

    wprintf(L"success = %d\n",success);

    // The output of this program, when tested, was:
    // Original JPG size = 6229
    // eyJhbGciOiJBMTI4S1ciLCJlbmMiOiJBMTI4Q0JDLUhTMjU2In0.9YFz_wteV ... 7Et3hKhpxnKEXw
    // size of JWE: 8473
    // Decrypted JPG size = 6229
    // success = True
    }