Example usage for java.security Signature initSign

Introduction

In this page you can find the example usage for java.security Signature initSign.

Prototype

public final void initSign(PrivateKey privateKey) throws InvalidKeyException 

Source Link

Document

Initialize this object for signing.

Usage

From source file:Main.java

public static void main(String[] args) throws Exception {
    KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");
    kpg.initialize(1024);/*from w ww .ja  v a2s . c  om*/
    KeyPair keyPair = kpg.genKeyPair();

    byte[] data = "test".getBytes("UTF8");

    Signature sig = Signature.getInstance("MD5WithRSA");
    sig.initSign(keyPair.getPrivate());
    sig.update(data);
    byte[] signatureBytes = sig.sign();
    System.out.println("Singature:" + new BASE64Encoder().encode(signatureBytes));

    sig.initVerify(keyPair.getPublic());
    sig.update(data);

    System.out.println(sig.verify(signatureBytes));
}

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From source file:Main.java

public static void main(String[] argv) throws Exception {
    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
    keyGen.initialize(1024);//  w  ww . ja  v a  2  s . c  o  m
    KeyPair keypair = keyGen.genKeyPair();
    DSAPrivateKey privateKey = (DSAPrivateKey) keypair.getPrivate();
    DSAPublicKey publicKey = (DSAPublicKey) keypair.getPublic();

    DSAParams dsaParams = privateKey.getParams();
    BigInteger p = dsaParams.getP();
    BigInteger q = dsaParams.getQ();
    BigInteger g = dsaParams.getG();
    BigInteger x = privateKey.getX();
    BigInteger y = publicKey.getY();

    // Create the DSA key factory
    KeyFactory keyFactory = KeyFactory.getInstance("DSA");
    // Create the DSA private key
    KeySpec privateKeySpec = new DSAPrivateKeySpec(x, p, q, g);
    PrivateKey privateKey1 = keyFactory.generatePrivate(privateKeySpec);

    byte[] buffer = new byte[1024];

    Signature sig = Signature.getInstance(privateKey1.getAlgorithm());
    sig.initSign(privateKey1);
    sig.update(buffer, 0, buffer.length);
}

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From source file:MainClass.java

public static void main(String[] args) throws Exception {
    Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());

    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("RSA", "BC");
    keyGen.initialize(512, new SecureRandom());
    KeyPair keyPair = keyGen.generateKeyPair();

    Signature signature = Signature.getInstance("SHA256withRSA", "BC");
    signature.initSign(keyPair.getPrivate());

    byte[] message = "abc".getBytes();
    signature.update(message);/*from w  w  w .  jav  a2s  .  com*/

    byte[] sigBytes = signature.sign();
    Cipher cipher = Cipher.getInstance("RSA/None/PKCS1Padding", "BC");
    cipher.init(Cipher.DECRYPT_MODE, keyPair.getPublic());

    byte[] decSig = cipher.doFinal(sigBytes);
    ASN1InputStream aIn = new ASN1InputStream(decSig);
    ASN1Sequence seq = (ASN1Sequence) aIn.readObject();

    System.out.println(ASN1Dump.dumpAsString(seq));

    MessageDigest hash = MessageDigest.getInstance("SHA-256", "BC");
    hash.update(message);

    ASN1OctetString sigHash = (ASN1OctetString) seq.getObjectAt(1);
    System.out.println(MessageDigest.isEqual(hash.digest(), sigHash.getOctets()));
}

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From source file:signature.SignLicense.java

public static void main(String[] args) throws Exception {

    if (args.length != 2) {
        System.out.println("Usage: SignLicense licenseFile privateKey");
        System.exit(1);/*from   w ww .ja va2  s.  co m*/
    }

    Properties license = new Properties();
    license.load(new FileInputStream(args[0]));

    PrivateKey privateKey = Utils.readPrivateKeyFromFile(args[1]);
    Signature signature = Signature.getInstance("SHA1withDSA", "SUN");
    signature.initSign(privateKey);

    String[] propKeys = license.keySet().toArray(new String[0]);
    Arrays.sort(propKeys);
    for (String propKey : propKeys) {
        if (!"Signature".equals(propKey)) {
            String propValue = license.getProperty(propKey);
            signature.update(propValue.getBytes("UTF-8"));
        }
    }

    byte[] sig = signature.sign();
    license.setProperty("Signature", new String(Base64.encodeBase64(sig)));
    license.store(new FileOutputStream(args[0]), null);
}

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From source file:com.threerings.getdown.tools.AppletParamSigner.java

public static void main(String[] args) {
    try {//w w  w .j  a  va2 s .  c om
        if (args.length != 7) {
            System.err
                    .println("AppletParamSigner keystore storepass alias keypass " + "appbase appname imgpath");
            System.exit(255);
        }

        String keystore = args[0];
        String storepass = args[1];
        String alias = args[2];
        String keypass = args[3];
        String appbase = args[4];
        String appname = args[5];
        String imgpath = args[6];
        String params = appbase + appname + imgpath;

        KeyStore store = KeyStore.getInstance("JKS");
        store.load(new BufferedInputStream(new FileInputStream(keystore)), storepass.toCharArray());
        PrivateKey key = (PrivateKey) store.getKey(alias, keypass.toCharArray());
        Signature sig = Signature.getInstance("SHA1withRSA");
        sig.initSign(key);
        sig.update(params.getBytes());
        String signed = new String(Base64.encodeBase64(sig.sign()));
        System.out.println("<param name=\"appbase\" value=\"" + appbase + "\" />");
        System.out.println("<param name=\"appname\" value=\"" + appname + "\" />");
        System.out.println("<param name=\"bgimage\" value=\"" + imgpath + "\" />");
        System.out.println("<param name=\"signature\" value=\"" + signed + "\" />");

    } catch (Exception e) {
        System.err.println("Failed to produce signature.");
        e.printStackTrace();
    }
}

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From source file:Main.java

public static void main(String[] argv) throws Exception {
    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
    keyGen.initialize(1024);/*  w  w  w . java2s  . c  om*/
    KeyPair keypair = keyGen.genKeyPair();
    DSAPrivateKey privateKey = (DSAPrivateKey) keypair.getPrivate();
    DSAPublicKey publicKey = (DSAPublicKey) keypair.getPublic();

    DSAParams dsaParams = privateKey.getParams();
    BigInteger p = dsaParams.getP();
    BigInteger q = dsaParams.getQ();
    BigInteger g = dsaParams.getG();
    BigInteger x = privateKey.getX();
    BigInteger y = publicKey.getY();

    KeyFactory keyFactory = KeyFactory.getInstance("DSA");
    KeySpec publicKeySpec = new DSAPublicKeySpec(y, p, q, g);
    PublicKey publicKey1 = keyFactory.generatePublic(publicKeySpec);
    KeySpec privateKeySpec = new DSAPrivateKeySpec(x, p, q, g);
    PrivateKey privateKey1 = keyFactory.generatePrivate(privateKeySpec);

    byte[] buffer = new byte[1024];

    Signature sig = Signature.getInstance(privateKey1.getAlgorithm());
    sig.initSign(privateKey1);
    sig.update(buffer, 0, buffer.length);

    byte[] signature = sig.sign();

    sig = Signature.getInstance(publicKey1.getAlgorithm());
    sig.initVerify(publicKey1);
    sig.update(buffer, 0, buffer.length);
    sig.verify(signature);

}

---

From source file:SignatureTest.java

public static void main(String[] args) {
    try {//from   w  ww .java 2 s . c  o m
        if (args[0].equals("-genkeypair")) {
            KeyPairGenerator pairgen = KeyPairGenerator.getInstance("DSA");
            SecureRandom random = new SecureRandom();
            pairgen.initialize(KEYSIZE, random);
            KeyPair keyPair = pairgen.generateKeyPair();
            ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(args[1]));
            out.writeObject(keyPair.getPublic());
            out.close();
            out = new ObjectOutputStream(new FileOutputStream(args[2]));
            out.writeObject(keyPair.getPrivate());
            out.close();
        } else if (args[0].equals("-sign")) {
            ObjectInputStream keyIn = new ObjectInputStream(new FileInputStream(args[3]));
            PrivateKey privkey = (PrivateKey) keyIn.readObject();
            keyIn.close();

            Signature signalg = Signature.getInstance("DSA");
            signalg.initSign(privkey);

            File infile = new File(args[1]);
            InputStream in = new FileInputStream(infile);
            int length = (int) infile.length();
            byte[] message = new byte[length];
            in.read(message, 0, length);
            in.close();

            signalg.update(message);
            byte[] signature = signalg.sign();

            DataOutputStream out = new DataOutputStream(new FileOutputStream(args[2]));
            int signlength = signature.length;
            out.writeInt(signlength);
            out.write(signature, 0, signlength);
            out.write(message, 0, length);
            out.close();
        } else if (args[0].equals("-verify")) {
            ObjectInputStream keyIn = new ObjectInputStream(new FileInputStream(args[2]));
            PublicKey pubkey = (PublicKey) keyIn.readObject();
            keyIn.close();

            Signature verifyalg = Signature.getInstance("DSA");
            verifyalg.initVerify(pubkey);

            File infile = new File(args[1]);
            DataInputStream in = new DataInputStream(new FileInputStream(infile));
            int signlength = in.readInt();
            byte[] signature = new byte[signlength];
            in.read(signature, 0, signlength);

            int length = (int) infile.length() - signlength - 4;
            byte[] message = new byte[length];
            in.read(message, 0, length);
            in.close();

            verifyalg.update(message);
            if (!verifyalg.verify(signature))
                System.out.print("not ");
            System.out.println("verified");
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

---

From source file:GenSig.java

public static void main(String[] args) {

    /* Generate a DSA signature */

    if (args.length != 1) {
        System.out.println("Usage: GenSig nameOfFileToSign");
    } else/*w w w  . j ava2  s.  c  o m*/
        try {

            /* Generate a key pair */

            KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA", "SUN");
            SecureRandom random = SecureRandom.getInstance("SHA1PRNG", "SUN");

            keyGen.initialize(1024, random);

            KeyPair pair = keyGen.generateKeyPair();
            PrivateKey priv = pair.getPrivate();
            PublicKey pub = pair.getPublic();

            /*
             * Create a Signature object and initialize it with the private
             * key
             */

            Signature dsa = Signature.getInstance("SHA1withDSA", "SUN");

            dsa.initSign(priv);

            /* Update and sign the data */

            FileInputStream fis = new FileInputStream(args[0]);
            BufferedInputStream bufin = new BufferedInputStream(fis);
            byte[] buffer = new byte[1024];
            int len;
            while (bufin.available() != 0) {
                len = bufin.read(buffer);
                dsa.update(buffer, 0, len);
            }
            ;

            bufin.close();

            /*
             * Now that all the data to be signed has been read in, generate
             * a signature for it
             */

            byte[] realSig = dsa.sign();

            /* Save the signature in a file */
            FileOutputStream sigfos = new FileOutputStream("sig");
            sigfos.write(realSig);

            sigfos.close();

            /* Save the public key in a file */
            byte[] key = pub.getEncoded();
            FileOutputStream keyfos = new FileOutputStream("suepk");
            keyfos.write(key);

            keyfos.close();

        } catch (Exception e) {
            System.err.println("Caught exception " + e.toString());
        }

}

---

From source file:testSig.java

public static void main(String[] args) {

    /* Test generating and verifying a DSA signature */

    try {//from   ww w. j a  v a 2s .  c  o  m

        /* generate a key pair */

        KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
        keyGen.initialize(1024, new SecureRandom());
        KeyPair pair = keyGen.generateKeyPair();

        /*
         * create a Signature object to use for signing and verifying
         */

        Signature dsa = Signature.getInstance("SHA/DSA");

        /* initialize the Signature object for signing */

        PrivateKey priv = pair.getPrivate();

        dsa.initSign(priv);

        /* Update and sign the data */

        FileInputStream fis = new FileInputStream(args[0]);
        byte b;
        while (fis.available() != 0) {
            b = (byte) fis.read();
            dsa.update(b);
        }
        ;

        fis.close();

        /*
         * Now that all the data to be signed has been read in, sign it
         */
        byte[] sig = dsa.sign();

        /* Verify the signature */

        /* Initialize the Signature object for verification */
        PublicKey pub = pair.getPublic();
        dsa.initVerify(pub);

        /* Update and verify the data */

        fis = new FileInputStream(args[0]);
        while (fis.available() != 0) {
            b = (byte) fis.read();
            dsa.update(b);
        }
        ;

        fis.close();

        boolean verifies = dsa.verify(sig);

        System.out.println("signature verifies: " + verifies);

    } catch (Exception e) {
        System.err.println("Caught exception " + e.toString());
    }

}

---

From source file:MainClass.java

public static byte[] signData(byte[] data, PrivateKey key) throws Exception {
    Signature signer = Signature.getInstance("SHA1withDSA");
    signer.initSign(key);
    signer.update(data);//from  ww  w. j  ava  2  s .  co m
    return (signer.sign());
}

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