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 <CkJwsW.h>
#include <CkPublicKeyW.h>

void ChilkatSample(void)
    {
    bool success = false;

    CkJwsW jws;

    //  Load the JWS compact serialization.
    const wchar_t *jwsCompact = L"eyJhbGciOiJIUzI1NiJ9.VGhpcyBpcyB0aGUgY29udGVudCB0byBzaWduLg.<signature>";
    success = jws.LoadJws(jwsCompact);
    if (success == false) {
        wprintf(L"%s\n",jws.lastErrorText());
        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.
    CkPublicKeyW pubKey;
    success = pubKey.LoadFromFile(L"qa_data/signer_pubkey.pem");
    if (success == false) {
        wprintf(L"%s\n",pubKey.lastErrorText());
        return;
    }

    success = jws.SetPublicKey(0,pubKey);
    if (success == false) {
        wprintf(L"%s\n",jws.lastErrorText());
        return;
    }

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

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

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