Verifies the signature for the given buffer of bytes using the public key. : Digital Signature Algorithm « Security « Java Tutorial

Java Tutorial
1. Language
2. Data Type
3. Operators
4. Statement Control
5. Class Definition
6. Development
7. Reflection
8. Regular Expressions
9. Collections
10. Thread
11. File
12. Generics
13. I18N
14. Swing
15. Swing Event
16. 2D Graphics
17. SWT
18. SWT 2D Graphics
19. Network
20. Database
21. Hibernate
22. JPA
23. JSP
24. JSTL
25. Servlet
26. Web Services SOA
27. EJB3
28. Spring
29. PDF
30. Email
31. J2ME
32. J2EE Application
33. XML
34. Design Pattern
35. Log
36. Security
37. Apache Common
38. Ant
39. JUnit
Java
Java Source Code / Java Documentation
Java Open Source
Jar File Download
Java Articles
Java Products
Java by API
Photoshop Tutorials
Maya Tutorials
Flash Tutorials
3ds-Max Tutorials
Illustrator Tutorials
GIMP Tutorials
C# / C Sharp
C# / CSharp Tutorial
C# / CSharp Open Source
ASP.Net
ASP.NET Tutorial
JavaScript DHTML
JavaScript Tutorial
JavaScript Reference
HTML / CSS
HTML CSS Reference
C / ANSI-C
C Tutorial
C++
C++ Tutorial
Ruby
PHP
Python
Python Tutorial
Python Open Source
SQL Server / T-SQL
SQL Server / T-SQL Tutorial
Oracle PL / SQL
Oracle PL/SQL Tutorial
PostgreSQL
SQL / MySQL
MySQL Tutorial
VB.Net
VB.Net Tutorial
Flash / Flex / ActionScript
VBA / Excel / Access / Word
XML
XML Tutorial
Microsoft Office PowerPoint 2007 Tutorial
Microsoft Office Excel 2007 Tutorial
Microsoft Office Word 2007 Tutorial
Java Tutorial » Security » Digital Signature Algorithm 
36. 16. 4. Verifies the signature for the given buffer of bytes using the public key.
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[] argvthrows Exception {
    KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
    keyGen.initialize(1024);
    KeyPair keypair = keyGen.genKeyPair();
    DSAPrivateKey privateKey = (DSAPrivateKeykeypair.getPrivate();
    DSAPublicKey publicKey = (DSAPublicKeykeypair.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);

  }
}
36. 16. Digital Signature Algorithm
36. 16. 1. Use DSA to Sign
36. 16. 2. Signed Object
36. 16. 3. Creating a Signature
36. 16. 4. Verifies the signature for the given buffer of bytes using the public key.
36. 16. 5. Digital Signature Algorithm Demo
36. 16. 6. DSA with Elliptic Curve
36. 16. 7. DSA Key Translator
36. 16. 8. Use DSAPrivateKeySpec
36. 16. 9. Getting the Digital Signature Algorithm (DSA) Parameters of a Key Pair
36. 16. 10. Create the DSA key factory from a Set of Digital Signature Algorithm (DSA) Parameters
36. 16. 11. Create the DSA private key from a Set of Digital Signature Algorithm (DSA) Parameters
36. 16. 12. Create the DSA public key from a Set of Digital Signature Algorithm (DSA) Parameters
36. 16. 13. Export DSAPrivateKeySpec
36. 16. 14. Signing a Java Object
www.java2java.com | Contact Us
Copyright 2009 - 12 Demo Source and Support. All rights reserved.
All other trademarks are property of their respective owners.