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package com.example.usbtoken;
import java.security.PublicKey;
import java.security.Signature;
import java.util.Objects;
/**
 *
 * @author TuoiCM
 */
public class Notary {

    private String signatureAlgorithm;
    private static final String DEFAULT_SIGNATURE_ALGORITHM = "SHA1withRSA";

    public Notary(String signatureAlgorithm) {
        Objects.nonNull(signatureAlgorithm);
        this.signatureAlgorithm = signatureAlgorithm;
    }

    public Notary() {
        this(DEFAULT_SIGNATURE_ALGORITHM);
    }

    public boolean verifySignature(byte[] data, byte[] signature, PublicKey publicKey) {
        Objects.nonNull(publicKey);
        try {
            Signature sig = Signature.getInstance(this.signatureAlgorithm);
            sig.initVerify(publicKey);
            sig.update(data);
            return sig.verify(signature);
        } catch (Exception e) {
            throw new RuntimeException("Ups, something went wrong... ", e);
        }
    }
}