sign data by key - Java Security

Java examples for Security:Key

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Description

sign data by key

Demo Code


//package com.java2s;

import java.io.FileInputStream;

import java.security.KeyStore;
import java.security.PrivateKey;

import java.security.Signature;
import java.security.cert.Certificate;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;

public class Main {
    public static void main(String[] argv) throws Exception {
        byte[] data = new byte[] { 34, 35, 36, 37, 37, 37, 67, 68, 69 };
        String keyStorePath = "java2s.com";
        String alias = "java2s.com";
        String password = "java2s.com";
        System.out.println(java.util.Arrays.toString(sign(data,
                keyStorePath, alias, password)));
    }/*from  www  . j  a  v a 2s.  com*/

    public static final String KEY_STORE = "JKS";
    public static final String X509 = "X.509";

    public static byte[] sign(byte[] data, String keyStorePath,
            String alias, String password) throws Exception {

        X509Certificate x509Certificate = (X509Certificate) getCertificate(
                keyStorePath, alias, password);

        KeyStore keyStore = getKeyStore(keyStorePath, password);
 
        PrivateKey privateKey = (PrivateKey) keyStore.getKey(alias,
                password.toCharArray());

        Signature signature = Signature.getInstance(x509Certificate
                .getSigAlgName());
        signature.initSign(privateKey);
        signature.update(data);
        return signature.sign();
    }

    private static Certificate getCertificate(String certificatePath)
            throws Exception {
        CertificateFactory certificateFactory = CertificateFactory
                .getInstance(X509);
        FileInputStream in = new FileInputStream(certificatePath);
        Certificate certificate = certificateFactory
                .generateCertificate(in);
        in.close();
        return certificate;
    }

    private static Certificate getCertificate(String keyStorePath,
            String alias, String password) throws Exception {
        KeyStore keyStore = getKeyStore(keyStorePath, password);
        Certificate certificate = keyStore.getCertificate(alias);
        return certificate;
    }

    private static KeyStore getKeyStore(String keyStorePath, String password)
            throws Exception {
        FileInputStream in = new FileInputStream(keyStorePath);
        KeyStore keyStore = KeyStore.getInstance(KEY_STORE);
        keyStore.load(in, password.toCharArray());
        in.close();
        return keyStore;
    }
}

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