Validate a JWS Signature

See more JSON Web Signatures (JWS) Examples

Demonstrates Jws.Validate, which validates exactly one signature, identified by a zero-based index, using the key configured at that same index.

#include <CkJws.h>

void ChilkatSample(void)
    {
    bool success = false;

    CkJws jws;

    //  Load the JWS compact serialization.
    const char *jwsCompact = "eyJhbGciOiJIUzI1NiJ9.VGhpcyBpcyB0aGUgY29udGVudCB0byBzaWduLg.<signature>";
    success = jws.LoadJws(jwsCompact);
    if (success == false) {
        std::cout << jws.lastErrorText() << "\r\n";
        return;
    }

    //  Provide the key for signature 0 (here an HMAC key).
    const char *base64Key = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU=";
    success = jws.SetMacKey(0,base64Key,"base64");
    if (success == false) {
        std::cout << jws.lastErrorText() << "\r\n";
        return;
    }

    //  Validate the signature identified by the zero-based index, using the key configured at that index.
    //  Validate returns 1 when the signature or MAC is cryptographically valid, 0 when it is not, or a
    //  negative value on error.
    int v = jws.Validate(0);
    if (v < 0) {
        std::cout << jws.lastErrorText() << "\r\n";
        return;
    }

    if (v != 1) {
        std::cout << "The signature is not valid." << "\r\n";
        return;
    }

    std::cout << "The signature is valid." << "\r\n";
    }