Swift Requires Chilkat v11.0.0+

Validate JWS Using RSASSA-PKCS1-v1_5 SHA-256

See more JSON Web Signatures (JWS) Examples

Validates a JSON Web Signature (JWS) that uses RSASSA-PKCS1-v1_5 SHA-256. Swift

func chilkatTest() {
    var success: Bool = false

    //  This requires the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    //  This example takes a JSON signature in compact serialization format,
    //  and uses an RSA public key to validate and recover the protected header and payload.

    //  We only need a public key for signature validation.  This is the RSA public key
    //  that is used:

    //       {"kty":"RSA", 
    //        "n":"ofgWCuLjybRlzo0tZWJjNiuSfb4p4fAkd_wWJcyQoTbji9k0l8W26mPddx
    //             HmfHQp-Vaw-4qPCJrcS2mJPMEzP1Pt0Bm4d4QlL-yRT-SFd2lZS-pCgNMs
    //             D1W_YpRPEwOWvG6b32690r2jZ47soMZo9wGzjb_7OMg0LOL-bSf63kpaSH
    //             SXndS5z5rexMdbBYUsLA9e-KXBdQOS-UTo7WTBEMa2R2CapHg665xsmtdV
    //             MTBQY4uDZlxvb3qCo5ZwKh9kG4LT6_I5IhlJH7aGhyxXFvUK-DWNmoudF8
    //             NAco9_h9iaGNj8q2ethFkMLs91kzk2PAcDTW9gb54h4FRWyuXpoQ", 
    //        "e":"AQAB"
    //       }

    let sbPubKey = CkoStringBuilder()!
    sbPubKey.append(value: "{\"kty\":\"RSA\",")
    sbPubKey.append(value: "\"n\":\"ofgWCuLjybRlzo0tZWJjNiuSfb4p4fAkd_wWJcyQoTbji9k0l8W26mPddx")
    sbPubKey.append(value: "HmfHQp-Vaw-4qPCJrcS2mJPMEzP1Pt0Bm4d4QlL-yRT-SFd2lZS-pCgNMs")
    sbPubKey.append(value: "D1W_YpRPEwOWvG6b32690r2jZ47soMZo9wGzjb_7OMg0LOL-bSf63kpaSH")
    sbPubKey.append(value: "SXndS5z5rexMdbBYUsLA9e-KXBdQOS-UTo7WTBEMa2R2CapHg665xsmtdV")
    sbPubKey.append(value: "MTBQY4uDZlxvb3qCo5ZwKh9kG4LT6_I5IhlJH7aGhyxXFvUK-DWNmoudF8")
    sbPubKey.append(value: "NAco9_h9iaGNj8q2ethFkMLs91kzk2PAcDTW9gb54h4FRWyuXpoQ\",")
    sbPubKey.append(value: "\"e\":\"AQAB\"")
    sbPubKey.append(value: "}")

    let pubKey = CkoPublicKey()!
    success = pubKey.load(fromString: sbPubKey.getAsString())
    if success == false {
        print("\(pubKey.lastErrorText!)")
        return
    }

    let jws = CkoJws()!

    //  Set the RSA public key:
    var signatureIndex: Int = 0
    jws.setPublicKey(index: signatureIndex, pubKey: pubKey)

    //  Load the JWS.
    let sbJws = CkoStringBuilder()!
    sbJws.append(value: "eyJhbGciOiJSUzI1NiJ9")
    sbJws.append(value: ".")
    sbJws.append(value: "eyJpc3MiOiJqb2UiLA0KICJleHAiOjEzMDA4MTkzODAsDQogImh0dHA6Ly9leGFt")
    sbJws.append(value: "cGxlLmNvbS9pc19yb290Ijp0cnVlfQ")
    sbJws.append(value: ".")
    sbJws.append(value: "cC4hiUPoj9Eetdgtv3hF80EGrhuB__dzERat0XF9g2VtQgr9PJbu3XOiZj5RZmh7")
    sbJws.append(value: "AAuHIm4Bh-0Qc_lF5YKt_O8W2Fp5jujGbds9uJdbF9CUAr7t1dnZcAcQjbKBYNX4")
    sbJws.append(value: "BAynRFdiuB--f_nZLgrnbyTyWzO75vRK5h6xBArLIARNPvkSjtQBMHlb1L07Qe7K")
    sbJws.append(value: "0GarZRmB_eSN9383LcOLn6_dO--xi12jzDwusC-eOkHWEsqtFZESc6BfI7noOPqv")
    sbJws.append(value: "hJ1phCnvWh6IeYI2w9QOYEUipUTI8np6LbgGY9Fs98rqVt5AXLIhWkWywlVmtVrB")
    sbJws.append(value: "p0igcN_IoypGlUPQGe77Rw")

    success = jws.loadSb(sbJws: sbJws)
    if success == false {
        print("\(jws.lastErrorText!)")
        return
    }

    //  Validate the 1st (and only) signature at index 0..
    var v: Int = jws.validate(index: signatureIndex).intValue
    if v < 0 {
        //  Perhaps Chilkat was not unlocked or the trial expired..
        print("Method call failed for some other reason.")
        print("\(jws.lastErrorText!)")
        return
    }

    if v == 0 {
        print("Invalid signature.  The RSA key was incorrect, the JWS was invalid, or both.")
        return
    }

    //  If we get here, the signature was validated..
    print("Signature validated.")
    print("--")

    //  Recover the original content:
    print("Recovered content:")
    print("\(jws.getPayload(charset: "utf-8")!)")
    print("--")

    //  Examine the protected header:

    let joseHeader = CkoJsonObject()!
    success = jws.getProtectedH(index: signatureIndex, json: joseHeader)
    if success == false {
        print("\(jws.lastErrorText!)")
        return
    }

    joseHeader.emitCompact = false

    print("Protected (JOSE) header:")
    print("\(joseHeader.emit()!)")

    //  Output:

    //  	Signature validated.
    //  	--
    //  	Recovered content:
    //  	{"iss":"joe", 
    //  	 "exp":1300819380,
    //  	 "http://example.com/is_root":true}
    //  	--
    //  	Protected (JOSE) header:
    //  	{ 
    //  	  "alg": "RS256"
    //  	}

}