Java Tutorial/Security/Digital Signature Algorithm

Материал из Java эксперт
Перейти к: навигация, поиск

Create the DSA key factory from a Set of Digital Signature Algorithm (DSA) Parameters

   <source lang="java">

import java.math.BigInteger; import java.security.KeyFactory; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.PrivateKey; import java.security.PublicKey; import java.security.interfaces.DSAParams; import java.security.interfaces.DSAPrivateKey; import java.security.interfaces.DSAPublicKey; import java.security.spec.DSAPrivateKeySpec; import java.security.spec.DSAPublicKeySpec; import java.security.spec.KeySpec; public class Main { 

 public static void main(String[] argv) throws Exception {
   KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
   keyGen.initialize(1024);
   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");
 }

}</source>





Create the DSA private key from a Set of Digital Signature Algorithm (DSA) Parameters

   <source lang="java">

import java.math.BigInteger; import java.security.KeyFactory; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.PrivateKey; import java.security.PublicKey; import java.security.interfaces.DSAParams; import java.security.interfaces.DSAPrivateKey; import java.security.interfaces.DSAPublicKey; import java.security.spec.DSAPrivateKeySpec; import java.security.spec.DSAPublicKeySpec; import java.security.spec.KeySpec; public class Main { 

 public static void main(String[] argv) throws Exception {
   KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
   keyGen.initialize(1024);
   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 privateKeySpec = new DSAPrivateKeySpec(x, p, q, g);
   PrivateKey privateKey1 = keyFactory.generatePrivate(privateKeySpec);
 }

}</source>





Create the DSA public key from a Set of Digital Signature Algorithm (DSA) Parameters

   <source lang="java">

import java.math.BigInteger; import java.security.KeyFactory; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.PrivateKey; import java.security.PublicKey; import java.security.interfaces.DSAParams; import java.security.interfaces.DSAPrivateKey; import java.security.interfaces.DSAPublicKey; import java.security.spec.DSAPrivateKeySpec; import java.security.spec.DSAPublicKeySpec; import java.security.spec.KeySpec; public class Main { 

 public static void main(String[] argv) throws Exception {
   KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
   keyGen.initialize(1024);
   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);
 }

}</source>





Creating a Signature

   <source lang="java">

import java.math.BigInteger; import java.security.KeyFactory; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.PrivateKey; import java.security.Signature; import java.security.interfaces.DSAParams; import java.security.interfaces.DSAPrivateKey; import java.security.interfaces.DSAPublicKey; import java.security.spec.DSAPrivateKeySpec; import java.security.spec.KeySpec; public class Main { 

 public static void main(String[] argv) throws Exception {
   KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
   keyGen.initialize(1024);
   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);
 }

}</source>





Digital Signature Algorithm Demo

   <source lang="java">

import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.SecureRandom; import java.security.Security; import java.security.Signature; public class MainClass { 

 public static void main(String[] args) throws Exception {
   Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
   KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA", "BC");
   keyGen.initialize(512, new SecureRandom());
   KeyPair keyPair = keyGen.generateKeyPair();
   Signature signature = Signature.getInstance("DSA", "BC");
   signature.initSign(keyPair.getPrivate(), new SecureRandom());
   byte[] message = "abc".getBytes();
   signature.update(message);
   byte[] sigBytes = signature.sign();
   signature.initVerify(keyPair.getPublic());
   signature.update(message);
   System.out.println(signature.verify(sigBytes));
 }

}</source>





DSA Key Translator

   <source lang="java">

import java.security.KeyFactory; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.NoSuchAlgorithmException; import java.security.PrivateKey; import java.security.PublicKey; import java.security.spec.DSAPrivateKeySpec; import java.security.spec.DSAPublicKeySpec; import java.security.spec.InvalidKeySpecException; public class MainClass { 

 public static void main(String[] args) throws NoSuchAlgorithmException, InvalidKeySpecException {
   KeyPairGenerator kpg = KeyPairGenerator.getInstance("DSA");
   kpg.initialize(512);
   KeyPair keys = kpg.genKeyPair();
   PrivateKey priKey = keys.getPrivate();
   PublicKey pubKey = keys.getPublic();
   KeyFactory kf = KeyFactory.getInstance("DSA");
   DSAPrivateKeySpec dsaPriKeySpec = (DSAPrivateKeySpec) kf.getKeySpec(priKey,
       DSAPrivateKeySpec.class);
   DSAPublicKeySpec dsaPubKeySpec = (DSAPublicKeySpec) kf.getKeySpec(pubKey,
       DSAPublicKeySpec.class);
   System.out.println("\nDSA Private Key");
   System.out.println("\nx = " + dsaPriKeySpec.getX());
   System.out.println("\nDSA Public Key");
   System.out.println("\ng = " + dsaPubKeySpec.getG());
   System.out.println("\np = " + dsaPubKeySpec.getP());
   System.out.println("\nq = " + dsaPubKeySpec.getQ());
   System.out.println("\ny = " + dsaPubKeySpec.getY());
 }

} /* DSA Private Key x = 776400661570001590971791637592968309673321751461 DSA Public Key g = 5421644057436475141609648488325705128047428394380474376834667300766108262613900542681289080713724597310673074119355136085795982097390670890367185141189796 p = 13232376895198612407547930718267435757728527029623408872245156039757713029036368719146452186041204237350521785240337048752071462798273003935646236777459223 q = 857393771208094202104259627990318636601332086981 y = 9079896982621092847112483863863391775338648287464668946120962630349123906761002084264031103470728516533966483834610830067548970604189069706612392762346323

  • /</source>





DSA with Elliptic Curve

   <source lang="java">

import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.SecureRandom; import java.security.Security; import java.security.Signature; import java.security.spec.ECGenParameterSpec; public class MainClass { 

 public static void main(String[] args) throws Exception {
   Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
   KeyPairGenerator keyGen = KeyPairGenerator.getInstance("ECDSA", "BC");
   ECGenParameterSpec ecSpec = new ECGenParameterSpec("prime192v1");
   keyGen.initialize(ecSpec, new SecureRandom());
   KeyPair keyPair = keyGen.generateKeyPair();
   Signature signature = Signature.getInstance("ECDSA", "BC");
   signature.initSign(keyPair.getPrivate(), new SecureRandom());
   byte[] message = "abc".getBytes();
   signature.update(message);
   byte[] sigBytes = signature.sign();
   signature.initVerify(keyPair.getPublic());
   signature.update(message);
   System.out.println(signature.verify(sigBytes));
 }

}</source>





Export DSAPrivateKeySpec

   <source lang="java">

import java.io.FileOutputStream; import java.io.ObjectOutputStream; import java.security.KeyFactory; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.SecureRandom; import java.security.spec.DSAPrivateKeySpec; public class MainClass { 

 public static void main(String args[]) throws Exception {
   KeyPairGenerator kpg = KeyPairGenerator.getInstance("DSA");
   kpg.initialize(512, new SecureRandom());
   KeyPair kp = kpg.generateKeyPair();
   Class spec = Class.forName("java.security.spec.DSAPrivateKeySpec");
   KeyFactory kf = KeyFactory.getInstance("DSA");
   DSAPrivateKeySpec ks = (DSAPrivateKeySpec) kf.getKeySpec(kp.getPrivate(), spec);
   FileOutputStream fos = new FileOutputStream("exportedKey");
   ObjectOutputStream oos = new ObjectOutputStream(fos);
   oos.writeObject(ks.getX());
   oos.writeObject(ks.getP());
   oos.writeObject(ks.getQ());
   oos.writeObject(ks.getG());
 }

}</source>





Getting the Digital Signature Algorithm (DSA) Parameters of a Key Pair

   <source lang="java">

import java.math.BigInteger; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.interfaces.DSAParams; import java.security.interfaces.DSAPrivateKey; import java.security.interfaces.DSAPublicKey; public class Main { 

 public static void main(String[] argv) throws Exception {
   KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
   keyGen.initialize(1024);
   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();
 }

}</source>





Signed Object

   <source lang="java">

import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.Signature; import java.security.SignedObject; import java.util.Vector; public class MainClass { 

 public static void main(String[] args) throws Exception {
   String alg = "DSA";
   KeyPairGenerator kg = KeyPairGenerator.getInstance(alg);
   KeyPair keyPair = kg.genKeyPair();
   Vector v = new Vector();
   v.add("This is a test!");
   Signature sign = Signature.getInstance(alg);
   SignedObject so = new SignedObject(v, keyPair.getPrivate(), sign);
   System.out.println(so.verify(keyPair.getPublic(), sign));
 }

}</source>





Signing a Java Object

   <source lang="java">

import java.io.Serializable; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.PrivateKey; import java.security.PublicKey; import java.security.Signature; import java.security.SignedObject; public class Main { 

 public static void main(String[] argv) throws Exception {
   KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
   keyGen.initialize(1024);
   KeyPair keypair = keyGen.genKeyPair();
   PrivateKey privateKey = keypair.getPrivate();
   PublicKey publicKey = keypair.getPublic();
   Serializable o = new MyClass();
   Signature sig = Signature.getInstance(privateKey.getAlgorithm());
   SignedObject so = new SignedObject(o, privateKey, sig);
   
   sig = Signature.getInstance(publicKey.getAlgorithm());
   boolean b = so.verify(publicKey, sig);
   o = (MyClass) so.getObject();
 }

} class MyClass implements Serializable { 

 String s = "my string";
 int i = 123;

}</source>





Use DSAPrivateKeySpec

   <source lang="java">

import java.io.FileInputStream; import java.io.ObjectInputStream; import java.math.BigInteger; import java.security.KeyFactory; import java.security.PrivateKey; import java.security.spec.DSAPrivateKeySpec; public class MainClass { 

 public static void main(String args[]) throws Exception {
   FileInputStream fis = new FileInputStream("exportedKey");
   ObjectInputStream ois = new ObjectInputStream(fis);
   DSAPrivateKeySpec ks = new DSAPrivateKeySpec((BigInteger) ois.readObject(), (BigInteger) ois
       .readObject(), (BigInteger) ois.readObject(), (BigInteger) ois.readObject());
   KeyFactory kf = KeyFactory.getInstance("DSA");
   PrivateKey pk = kf.generatePrivate(ks);
   System.out.println("Got private key");
 }

}</source>





Use DSA to Sign

   <source lang="java">

import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.PrivateKey; import java.security.PublicKey; import java.security.Signature; public class MainClass { 

 public static void main(String[] args) throws Exception {
   String alg = "DSA";
   KeyPairGenerator kg = KeyPairGenerator.getInstance(alg);
   KeyPair keyPair = kg.genKeyPair();
   byte[] signature = performSigning("test", alg, keyPair);
   performVerification(args[0], alg, signature, keyPair.getPublic());
 }
 static byte[] performSigning(String s, String alg, KeyPair keyPair) throws Exception {
   Signature sign = Signature.getInstance(alg);
   PrivateKey privateKey = keyPair.getPrivate();
   PublicKey publicKey = keyPair.getPublic();
   sign.initSign(privateKey);
   sign.update(s.getBytes());
   return sign.sign();
 }
 static void performVerification(String s, String alg, byte[] signature, PublicKey publicKey)
     throws Exception {
   Signature sign = Signature.getInstance(alg);
   sign.initVerify(publicKey);
   sign.update(s.getBytes());
   System.out.println(sign.verify(signature));
 }

}</source>





Verifies the signature for the given buffer of bytes using the public key.

   <source lang="java">

import java.math.BigInteger; import java.security.KeyFactory; import java.security.KeyPair; import java.security.KeyPairGenerator; import java.security.PrivateKey; import java.security.PublicKey; import java.security.Signature; import java.security.interfaces.DSAParams; import java.security.interfaces.DSAPrivateKey; import java.security.interfaces.DSAPublicKey; import java.security.spec.DSAPrivateKeySpec; import java.security.spec.DSAPublicKeySpec; import java.security.spec.KeySpec; public class Main { 

 public static void main(String[] argv) throws Exception {
   KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
   keyGen.initialize(1024);
   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);
 }

}</source>


Источник — «http://jexp.ru/index.php?title=Java_Tutorial/Security/Digital_Signature_Algorithm&oldid=4296»