Validate a JWS with a Public Key

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.SetPublicKey, which sets the public key used to validate a signature of a loaded JWS.

The file path is relative to the application's current working directory. An absolute path may also be used. Supply the path appropriate to your own environment.

#include <C_CkJwsW.h>
#include <C_CkPublicKeyW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkJwsW jws;
    const wchar_t *jwsCompact;
    HCkPublicKeyW pubKey;
    int v;

    success = FALSE;

    jws = CkJwsW_Create();

    //  Load the JWS compact serialization.
    jwsCompact = L"eyJhbGciOiJIUzI1NiJ9.VGhpcyBpcyB0aGUgY29udGVudCB0byBzaWduLg.<signature>";
    success = CkJwsW_LoadJws(jws,jwsCompact);
    if (success == FALSE) {
        wprintf(L"%s\n",CkJwsW_lastErrorText(jws));
        CkJwsW_Dispose(jws);
        return;
    }

    //  The file path is relative to the application's current working directory.  An absolute path
    //  may also be used.  Supply the path appropriate to your own environment.
    //  Load the signer's public key and set it for validating signature 0.
    pubKey = CkPublicKeyW_Create();
    success = CkPublicKeyW_LoadFromFile(pubKey,L"qa_data/signer_pubkey.pem");
    if (success == FALSE) {
        wprintf(L"%s\n",CkPublicKeyW_lastErrorText(pubKey));
        CkJwsW_Dispose(jws);
        CkPublicKeyW_Dispose(pubKey);
        return;
    }

    success = CkJwsW_SetPublicKey(jws,0,pubKey);
    if (success == FALSE) {
        wprintf(L"%s\n",CkJwsW_lastErrorText(jws));
        CkJwsW_Dispose(jws);
        CkPublicKeyW_Dispose(pubKey);
        return;
    }

    //  Validate the signature.  Validate returns 1 when valid, 0 when not, or a negative value on error.
    v = CkJwsW_Validate(jws,0);
    if (v < 0) {
        wprintf(L"%s\n",CkJwsW_lastErrorText(jws));
        CkJwsW_Dispose(jws);
        CkPublicKeyW_Dispose(pubKey);
        return;
    }

    if (v != 1) {
        wprintf(L"The signature is not valid.\n");
        CkJwsW_Dispose(jws);
        CkPublicKeyW_Dispose(pubKey);
        return;
    }

    wprintf(L"The signature is valid.\n");


    CkJwsW_Dispose(jws);
    CkPublicKeyW_Dispose(pubKey);

    }