Unicode C

Set a Per-Recipient JWE Header

See more JSON Web Encryption (JWE) Examples

Demonstrates Jwe.SetRecipientHeader, which sets the per-recipient unprotected header for a recipient index.

Background. Per-recipient headers carry recipient-specific values such as a key id (kid), and are used with the JSON serialization forms that support multiple recipients.

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Unicode C

#include <C_CkJweW.h>
#include <C_CkJsonObjectW.h>
#include <C_CkStringBuilderW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkJweW jwe;
    HCkJsonObjectW header;
    const wchar_t *base64Key;
    HCkJsonObjectW recipHeader;
    HCkStringBuilderW sbContent;
    HCkStringBuilderW sbJwe;

    success = FALSE;

    jwe = CkJweW_Create();

    //  Protected header: AES key-wrap with AES-256-GCM content encryption.
    header = CkJsonObjectW_Create();
    CkJsonObjectW_UpdateString(header,L"alg",L"A256KW");
    CkJsonObjectW_UpdateString(header,L"enc",L"A256GCM");
    success = CkJweW_SetProtectedHeader(jwe,header);
    if (success == FALSE) {
        wprintf(L"%s\n",CkJweW_lastErrorText(jwe));
        CkJweW_Dispose(jwe);
        CkJsonObjectW_Dispose(header);
        return;
    }

    //  The 256-bit key-wrapping key (base64) for recipient index 0.  In production, obtain the key from a
    //  secure source rather than hard-coding it.
    base64Key = L"YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU=";
    success = CkJweW_SetWrappingKey(jwe,0,base64Key,L"base64");
    if (success == FALSE) {
        wprintf(L"%s\n",CkJweW_lastErrorText(jwe));
        CkJweW_Dispose(jwe);
        CkJsonObjectW_Dispose(header);
        return;
    }

    //  Set the per-recipient unprotected header for recipient 0, for example a key id used to identify
    //  which key a recipient should use.
    recipHeader = CkJsonObjectW_Create();
    CkJsonObjectW_UpdateString(recipHeader,L"kid",L"recipient-key-1");
    success = CkJweW_SetRecipientHeader(jwe,0,recipHeader);
    if (success == FALSE) {
        wprintf(L"%s\n",CkJweW_lastErrorText(jwe));
        CkJweW_Dispose(jwe);
        CkJsonObjectW_Dispose(header);
        CkJsonObjectW_Dispose(recipHeader);
        return;
    }

    sbContent = CkStringBuilderW_Create();
    CkStringBuilderW_Append(sbContent,L"This is the secret content.");
    sbJwe = CkStringBuilderW_Create();
    success = CkJweW_EncryptSb(jwe,sbContent,L"utf-8",sbJwe);
    if (success == FALSE) {
        wprintf(L"%s\n",CkJweW_lastErrorText(jwe));
        CkJweW_Dispose(jwe);
        CkJsonObjectW_Dispose(header);
        CkJsonObjectW_Dispose(recipHeader);
        CkStringBuilderW_Dispose(sbContent);
        CkStringBuilderW_Dispose(sbJwe);
        return;
    }

    wprintf(L"%s\n",CkStringBuilderW_getAsString(sbJwe));


    CkJweW_Dispose(jwe);
    CkJsonObjectW_Dispose(header);
    CkJsonObjectW_Dispose(recipHeader);
    CkStringBuilderW_Dispose(sbContent);
    CkStringBuilderW_Dispose(sbJwe);

    }