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.

func chilkatTest() {
    var success: Bool = false

    let jws = CkoJws()!

    //  Load the JWS compact serialization.
    var jwsCompact: String? = "eyJhbGciOiJIUzI1NiJ9.VGhpcyBpcyB0aGUgY29udGVudCB0byBzaWduLg.<signature>"
    success = jws.load(jwsStr: jwsCompact)
    if success == false {
        print("\(jws.lastErrorText!)")
        return
    }

    //  Provide the key for signature 0 (here an HMAC key).
    var base64Key: String? = "YWJjZGVmZ2hpamtsbW5vcHFyc3R1dnd4eXowMTIzNDU="
    success = jws.setMacKey(index: 0, key: base64Key, encoding: "base64")
    if success == false {
        print("\(jws.lastErrorText!)")
        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.
    var v: Int = jws.validate(index: 0).intValue
    if v < 0 {
        print("\(jws.lastErrorText!)")
        return
    }

    if v != 1 {
        print("The signature is not valid.")
        return
    }

    print("The signature is valid.")

}