Cryptography Tutorials - Herong's Tutorial Examples

∟Java Default Implementation of DSA

∟DsaSignatureGenerator.java Test Results

This section provides test results from DsaSignatureGenerator.java on a binary file with different DSA private keys. DSA digital signature size is 46 bytes when generated with the Java SHA1withDSA algorithm.

Want to see some test output from DsaSignatureGenerator.java? Here is the first test on the DsaSignatureGenerator.class binary file with the DSA 512-bit private key generated in the previous tutorial: 

herong> javac DsaSignatureGenerator.java

herong> java DsaSignatureGenerator \
   dsa_512.pri DsaSignatureGenerator.class dsa_512.sig

Private Key Info:
Algorithm = DSA

Signature Object Info:
Algorithm = SHA1withDSA
Provider = SUN version 12

Sign Processing Info:
Number of input bytes = 2859
Number of output bytes = 46

herong> java HexWriter dsa_512.sig dsa_512.hex
Number of input bytes: 46

herong> more dsa_512.hex
302C02141F5BD5A1B756874480D223B7
1CB18A85D8BEE09C02147C9B3CAD3317
A757F8C9CFC51A7925437BA17D0D

My DsaSignatureGenerator.java program seems to be working. A 46-byte digital signature is generated from the DsaSignatureGenerator.class file with a 512-bit DSA private key using the SHA-1 hashing algorithm.

What happens if I run the program again with the input message and the same private key? Is the digital signature going to be different? 

herong> java DsaSignatureGenerator \
   dsa_512.pri DsaSignatureGenerator.class dsa_512x.sig

Private Key Info:
Algorithm = DSA

Signature Object Info:
Algorithm = SHA1withDSA
Provider = SUN version 12

Sign Processing Info:
Number of input bytes = 2859
Number of output bytes = 46

herong> java HexWriter dsa_512x.sig dsa_512x.hex
Number of input bytes: 46

herong> more dsa_512x.hex
302C021459E171244C1A1C23EFE33B72
4464DF8971C436A4021473F09A1EB7DA
D1224C6ACE291DDE1B965C735E4E

The output shows that a different digital signature is generated. This proves that a random number, "k", is used in the DSA signature generation process. A different new digital signature will be generated each time the same input message and same private key is used.

Here is the second test with the 1024-bit private key on the same binary file, DsaSignatureGenerator.class: 

herong> java DsaSignatureGenerator \
   dsa_1024.pri DsaSignatureGenerator.class dsa_1024.sig

Private Key Info:
Algorithm = DSA

Signature Object Info:
Algorithm = SHA1withDSA
Provider = SUN version 12

Sign Processing Info:
Number of input bytes = 2859
Number of output bytes = 46

herong> java HexWriter dsa_1024.sig dsa_1024.hex
Number of input bytes: 46

herong> more dsa_1024.hex
302C02147182608511EA79A038806F0A
6206D7D086DCD27B02145496D01B967A
73B9E60626B0523502A4C12697AE

Of course, we are getting a different digital signature. But it has the same length: 46 bytes.

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