DsaSignatureVerifier.java Test Results

This section provides test results from DsaSignatureVerifier.java on DSA digital signatures generated on a binary file. The verification will pass if the original document and the digital signature have not been modified.

Now let's see the verification result of the first DSA digital signature generated previously.

herong> java DsaSignatureVerifier \
   dsa_512.pub DsaSignatureGenerator.class dsa_512.sig

Public Key Info:
Algorithm = DSA

Signature Object Info:
Algorithm = SHA1withDSA
Provider = SUN version 12
Verify Processing Info:
Number of input bytes = 2859
Verification result = true

Cool. The signature verification passed. So nobody changed DsaSignatureGenerator.class or dsa_512.sig.

What will happen if DsaSignatureGenerator.class is changed? Let's create a modified version by adding characters to the end of the file:

herong> copy  DsaSignatureGenerator.class+con \
   DsaSignatureGenerator.modified

DsaSignatureGenerator.class
con
A^Z
        1 file(s) copied.

The DsaSignatureGenerator.java will tell us that the signature failed to pass the verification:

herong> java DsaSignatureVerifier dsa_512.pub \
   DsaSignatureGenerator.modified dsa_512.sig

Public Key Info:
Algorithm = DSA

Signature Object Info:
Algorithm = SHA1withDSA
Provider = SUN version 12
Verify Processing Info:
Number of input bytes = 529
Verification result = false

We can also verify the digital signature generated with the 1024-bit private key:

herong> java DsaSignatureVerifier \
   dsa_1024.pub DsaSignatureGenerator.class dsa_1024.sig

Public Key Info:
Algorithm = DSA

Signature Object Info:
Algorithm = SHA1withDSA
Provider = SUN version 12
Verify Processing Info:
Number of input bytes = 2859
Verification result = true

Perfect. The digital signature passed verification nicely.

Table of Contents

 About This Book

 Cryptography Terminology

 Cryptography Basic Concepts

 Introduction to AES (Advanced Encryption Standard)

 Introduction to DES Algorithm

 DES Algorithm - Illustrated with Java Programs

 DES Algorithm Java Implementation

 DES Algorithm - Java Implementation in JDK JCE

 DES Encryption Operation Modes

 DES in Stream Cipher Modes

 PHP Implementation of DES - mcrypt

 Blowfish - 8-Byte Block Cipher

 Secret Key Generation and Management

 Cipher - Secret Key Encryption and Decryption

 Introduction of RSA Algorithm

 RSA Implementation using java.math.BigInteger Class

 Introduction of DSA (Digital Signature Algorithm)

Java Default Implementation of DSA

 DsaKeyGenerator.java - Generating DSA Key Pair

 DSA 512-bit and 1024-bit Key Pair Examples

 DsaKeyChecker.java - Reading and Checking DSA Keys

 Example of DSA Key Parameters and Properties

 java.security.Signature - The Data Signing Class

 DsaSignatureGenerator.java - Generating DSA Digital Signature

 DsaSignatureGenerator.java Test Results

 DsaSignatureVerifier.java - Verifying DSA Digital Signature

DsaSignatureVerifier.java Test Results

 Private key and Public Key Pair Generation

 PKCS#8/X.509 Private/Public Encoding Standards

 Cipher - Public Key Encryption and Decryption

 MD5 Mesasge Digest Algorithm

 SHA1 Mesasge Digest Algorithm

 OpenSSL Introduction and Installation

 OpenSSL Generating and Managing RSA Keys

 OpenSSL Managing Certificates

 OpenSSL Generating and Signing CSR

 OpenSSL Validating Certificate Path

 "keytool" and "keystore" from JDK

 "OpenSSL" Signing CSR Generated by "keytool"

 Migrating Keys from "keystore" to "OpenSSL" Key Files

 Certificate X.509 Standard and DER/PEM Formats

 Migrating Keys from "OpenSSL" Key Files to "keystore"

 Using Certificates in IE

 Using Certificates in Google Chrome

 Using Certificates in Firefox

 Archived Tutorials

 References

 Full Version in PDF/EPUB