Sign a JWS with an HMAC Key

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.SetMacKey, which sets the symmetric MAC key for a signature. The key bytes are supplied in a named encoding such as hex or base64.

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

void ChilkatSample(void)
    {
    BOOL success;
    HCkJws jws;
    HCkJsonObject header;
    BOOL bIncludeBom;
    const char *base64Key;
    const char *jwsCompact;

    success = FALSE;

    jws = CkJws_Create();

    //  Protected header specifying HMAC-SHA256.
    header = CkJsonObject_Create();
    CkJsonObject_UpdateString(header,"alg","HS256");
    success = CkJws_SetProtectedHeader(jws,0,header);
    if (success == FALSE) {
        printf("%s\n",CkJws_lastErrorText(jws));
        CkJws_Dispose(jws);
        CkJsonObject_Dispose(header);
        return;
    }

    bIncludeBom = FALSE;
    success = CkJws_SetPayload(jws,"This is the content to sign.","utf-8",bIncludeBom);
    if (success == FALSE) {
        printf("%s\n",CkJws_lastErrorText(jws));
        CkJws_Dispose(jws);
        CkJsonObject_Dispose(header);
        return;
    }

    //  Set the symmetric MAC key for signature 0.  The key bytes are provided in the named encoding (here
    //  base64).  In production, obtain the key from a secure source rather than hard-coding it.
    base64Key = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU=";
    success = CkJws_SetMacKey(jws,0,base64Key,"base64");
    if (success == FALSE) {
        printf("%s\n",CkJws_lastErrorText(jws));
        CkJws_Dispose(jws);
        CkJsonObject_Dispose(header);
        return;
    }

    jwsCompact = CkJws_createJws(jws);
    if (CkJws_getLastMethodSuccess(jws) == FALSE) {
        printf("%s\n",CkJws_lastErrorText(jws));
        CkJws_Dispose(jws);
        CkJsonObject_Dispose(header);
        return;
    }

    printf("%s\n",jwsCompact);


    CkJws_Dispose(jws);
    CkJsonObject_Dispose(header);

    }