Unicode C

Create a JWS into a StringBuilder

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.CreateJwsSb, which creates a JWS and writes it into a StringBuilder.

Background. JWS (JSON Web Signature) integrity-protects a payload with a signature or MAC. The header alg names the algorithm; this example uses HMAC-SHA256 (HS256) with a symmetric MAC key.

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Unicode C

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

void ChilkatSample(void)
    {
    BOOL success;
    HCkJwsW jws;
    HCkJsonObjectW header;
    BOOL bIncludeBom;
    const wchar_t *base64Key;
    HCkStringBuilderW sbJws;

    success = FALSE;

    jws = CkJwsW_Create();

    //  Set the protected header for signer 0, specifying the signature algorithm (alg).
    header = CkJsonObjectW_Create();
    CkJsonObjectW_UpdateString(header,L"alg",L"HS256");
    success = CkJwsW_SetProtectedHeader(jws,0,header);
    if (success == FALSE) {
        wprintf(L"%s\n",CkJwsW_lastErrorText(jws));
        CkJwsW_Dispose(jws);
        CkJsonObjectW_Dispose(header);
        return;
    }

    //  Set the payload to be signed.
    bIncludeBom = FALSE;
    success = CkJwsW_SetPayload(jws,L"This is the content to sign.",L"utf-8",bIncludeBom);
    if (success == FALSE) {
        wprintf(L"%s\n",CkJwsW_lastErrorText(jws));
        CkJwsW_Dispose(jws);
        CkJsonObjectW_Dispose(header);
        return;
    }

    //  Provide the HMAC key (base64) for signer 0.  In production, obtain the key from a secure source
    //  rather than hard-coding it.
    base64Key = L"YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU=";
    success = CkJwsW_SetMacKey(jws,0,base64Key,L"base64");
    if (success == FALSE) {
        wprintf(L"%s\n",CkJwsW_lastErrorText(jws));
        CkJwsW_Dispose(jws);
        CkJsonObjectW_Dispose(header);
        return;
    }

    //  Create the JWS and write it into a StringBuilder.
    sbJws = CkStringBuilderW_Create();
    success = CkJwsW_CreateJwsSb(jws,sbJws);
    if (success == FALSE) {
        wprintf(L"%s\n",CkJwsW_lastErrorText(jws));
        CkJwsW_Dispose(jws);
        CkJsonObjectW_Dispose(header);
        CkStringBuilderW_Dispose(sbJws);
        return;
    }

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


    CkJwsW_Dispose(jws);
    CkJsonObjectW_Dispose(header);
    CkStringBuilderW_Dispose(sbJws);

    }