JDK Tutorials - Herong's Tutorial Examples - Version 6.02, by Dr. Herong Yang
JceSecretCipher.java - Secret Key Encryption Sample Program
This section provides a tutorial example on how to write a secret key encryption and description program using the javax.crypto.Cipher class.
The following sample program shows you how to do encryption and decryption with a secret key using the javax.crypto.Cipher class:
/* JceSecretCipher.java - Copyright (c) 2014, HerongYang.com, All Rights Reserved. */ import java.io.*; import java.security.spec.*; import javax.crypto.*; import javax.crypto.spec.*; class JceSecretCipher { public static void main(String[] a) { if (a.length<5) { System.out.println("Usage:"); System.out.println("java JceSecretCipher algorithm mode keyFile" +" input output"); return; } String algorithm = a[0]; String mode = a[1]; String keyFile = a[2]; String input = a[3]; String output = a[4]; try { SecretKey ky = readKey(keyFile,algorithm); secretCipher(algorithm, mode, ky, input, output); } catch (Exception e) { System.out.println("Exception: "+e); return; } } private static SecretKey readKey(String input, String algorithm) throws Exception { String fl = input; FileInputStream fis = new FileInputStream(fl); int kl = fis.available(); byte[] kb = new byte[kl]; fis.read(kb); fis.close(); KeySpec ks = null; SecretKey ky = null; SecretKeyFactory kf = null; if (algorithm.equalsIgnoreCase("DES")) { ks = new DESKeySpec(kb); kf = SecretKeyFactory.getInstance("DES"); ky = kf.generateSecret(ks); } else if (algorithm.equalsIgnoreCase("DESede")) { ks = new DESedeKeySpec(kb); kf = SecretKeyFactory.getInstance("DESede"); ky = kf.generateSecret(ks); } else { ks = new SecretKeySpec(kb,algorithm); ky = new SecretKeySpec(kb,algorithm); } System.out.println(); System.out.println("KeySpec Object Info: "); System.out.println("Saved File = "+fl); System.out.println("Length = "+kb.length); System.out.println("toString = "+ks.toString()); System.out.println(); System.out.println("SecretKey Object Info: "); System.out.println("Algorithm = "+ky.getAlgorithm()); System.out.println("toString = "+ky.toString()); return ky; } private static void secretCipher(String algorithm, String mode, SecretKey ky, String input, String output) throws Exception { Cipher cf = Cipher.getInstance(algorithm); if (mode.equalsIgnoreCase("encrypt")) cf.init(Cipher.ENCRYPT_MODE,ky); else if (mode.equalsIgnoreCase("decrypt")) cf.init(Cipher.DECRYPT_MODE,ky); else throw new Exception("Invalid mode: "+mode); System.out.println(); System.out.println("Cipher Object Info: "); System.out.println("Block Size = "+cf.getBlockSize()); System.out.println("Algorithm = "+cf.getAlgorithm()); System.out.println("Provider = "+cf.getProvider()); System.out.println("toString = "+cf.toString()); FileInputStream fis = new FileInputStream(input); FileOutputStream fos = new FileOutputStream(output); int bufSize = 1024; byte[] buf = new byte[bufSize]; int n = fis.read(buf,0,bufSize); int fisSize = 0; int fosSize = 0; while (n!=-1) { fisSize += n; byte[] out = cf.update(buf,0,n); fosSize += out.length; fos.write(out); n = fis.read(buf,0,bufSize); } byte[] out = cf.doFinal(); fosSize += out.length; fos.write(out); fis.close(); fos.close(); System.out.println(); System.out.println("Cipher Process Info: "); System.out.println("Input Size = "+fisSize); System.out.println("Output Size = "+fosSize); } }
Note that:
See the next section for test result of this sample program.
Last update: 2014.
Table of Contents
Downloading and Installing JDK 1.8.0 on Windows
Downloading and Installing JDK 1.7.0 on Windows
Downloading and Installing JDK 1.6.2 on Windows
Date, Time and Calendar Classes
Date and Time Object and String Conversion
Number Object and Numeric String Conversion
Locales, Localization Methods and Resource Bundles
Calling and Importing Classes Defined in Unnamed Packages
HashSet, Vector, HashMap and Collection Classes
Character Set Encoding Classes and Methods
Encoding Conversion Programs for Encoded Text Files
Datagram Network Communication
DOM (Document Object Model) - API for XML Files
DTD (Document Type Definition) - XML Validation
XSD (XML Schema Definition) - XML Validation
XSL (Extensible Stylesheet Language)
Message Digest Algorithm Implementations in JDK
Private key and Public Key Pair Generation
PKCS#8/X.509 Private/Public Encoding Standards
Digital Signature Algorithm and Sample Program
"keytool" Commands and "keystore" Files
KeyStore and Certificate Classes
Secret Key Generation and Management
►Cipher - Secret Key Encryption and Decryption
javax.crypto.Cipher - The Secret Key Encryption Class
►JceSecretCipher.java - Secret Key Encryption Sample Program
Blowfish and DES Secret Key Encryption Tests
JcePublicCipher.java - Private and Public Key Encryption
DSA Public Key Encryption Tests
RSA Public Key Encryption Tests
The SSL (Secure Socket Layer) Protocol
SSL Socket Communication Testing Programs