Get a JWS Protected Header

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.GetProtectedH, which copies the decoded protected header of a signature into a JsonObject.

Background. The protected header is integrity-protected by the signature. Inspecting it (for example the alg value) is useful before deciding how to validate.

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#include <C_CkJws.h>
#include <C_CkJsonObject.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkJws jws;
    const char *jwsCompact;
    HCkJsonObject json;

    success = FALSE;

    jws = CkJws_Create();

    //  Load the JWS compact serialization.
    jwsCompact = "eyJhbGciOiJIUzI1NiJ9.VGhpcyBpcyB0aGUgY29udGVudCB0byBzaWduLg.<signature>";
    success = CkJws_LoadJws(jws,jwsCompact);
    if (success == FALSE) {
        printf("%s\n",CkJws_lastErrorText(jws));
        CkJws_Dispose(jws);
        return;
    }

    //  Copy the decoded protected header of signature 0 into a JsonObject.
    json = CkJsonObject_Create();
    success = CkJws_GetProtectedH(jws,0,json);
    if (success == FALSE) {
        printf("%s\n",CkJws_lastErrorText(jws));
        CkJws_Dispose(jws);
        CkJsonObject_Dispose(json);
        return;
    }

    CkJsonObject_putEmitCompact(json,FALSE);
    printf("%s\n",CkJsonObject_emit(json));


    CkJws_Dispose(jws);
    CkJsonObject_Dispose(json);

    }