Java Source Code testDES.java import import import import import import import
java.io.*; java.security.*; java.math.*; cryptix.util.core.BI; cryptix.util.core.ArrayUtil; cryptix.util.core.Hex; cryptix.provider.key.*;
class testDES { public static void main (String[] args) { try { FileOutputStream outFile1 = new FileOutputStream("DES.out"); // Note: PrintStream is deprecated, but still works fine in jdk1.1.7b PrintStream output1 = new PrintStream(outFile1); // convert a string to a DES key and print out the result RawSecretKey key2 = new RawSecretKey("DES",Hex.fromString("3812A419C63BE771")); RawKey rkey = (RawKey) key2; byte[] yval = rkey.getEncoded(); BigInteger Bkey = new BigInteger(yval); String w = cryptix.util.core.BI.dumpString(Bkey); output1.println("The Encryption Key = " + w); // use the DES key to encrypt a string Cipher des=Cipher.getInstance("DES/ECB/NONE","Cryptix"); des.initEncrypt(key2); byte[] ciphertext = des.crypt(Hex.fromString("01010101010101010102030405060708090A0B0C0D0E0F10111 2131415161718")); // print out length and representation of ciphertext output1.print("\n"); output1.println("ciphertext.length = " + ciphertext.length); BigInteger Bciph = new BigInteger(ciphertext); w = cryptix.util.core.BI.dumpString(Bciph); output1.println("Ciphertext for DES encryption = " + w); // decrypt ciphertext des.initDecrypt(key2); ciphertext = des.crypt(ciphertext); output1.print("\n"); output1.println("plaintext.length = " + ciphertext.length); // print out representation of decrypted ciphertext Bciph = new BigInteger(ciphertext);
w = cryptix.util.core.BI.dumpString(Bciph); output1.println("Plaintext for DES encryption = " + w); output1.println(" "); output1.close(); } catch (Exception e) { System.err.println("Caught exception " + e.toString()); } }}
Sample Program Output DES.out The Encryption Key = Multi-Precision Integer 62 bits long... sign: Positive magnitude: 3812A419C63BE771 ciphertext.length = 32 Ciphertext for DES encryption = Multi-Precision Integer 254 bits long... sign: Positive magnitude: 3A2EAD12F475D82C 1FC97BB9A6D955E1 EA5541946BB4F2E6 F29555A6E8F1FB3C plaintext.length = 32 Plaintext for DES encryption = Multi-Precision Integer 249 bits long... sign: Positive magnitude: 0101010101010101 0102030405060708 090A0B0C0D0E0F10 1112131415161718
RSA
import import import import import import import
java.math.BigInteger; java.security.KeyFactory; java.security.Security; java.security.interfaces.RSAPrivateKey; java.security.interfaces.RSAPublicKey; java.security.spec.RSAPrivateKeySpec; java.security.spec.RSAPublicKeySpec;
import javax.crypto.Cipher; public class MainClass {
public static void main(String[] args) throws Exception { Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvid er()); byte[] input = new byte[] { (byte) 0xbe, (byte) 0xef }; Cipher cipher = Cipher.getInstance("RSA/None/NoPadding", "BC"); KeyFactory keyFactory = KeyFactory.getInstance("RSA", "BC"); RSAPublicKeySpec pubKeySpec = new RSAPublicKeySpec(new BigInteger( "12345678", 16), new BigInteger("11", 16)); RSAPrivateKeySpec privKeySpec = new RSAPrivateKeySpec(new BigInteger( "12345678", 16), new BigInteger("12345678", 16)); RSAPublicKey pubKey = (RSAPublicKey) keyFactory.generatePublic(pubKeySpec ); RSAPrivateKey privKey = (RSAPrivateKey) keyFactory.generatePrivate(privKe ySpec); cipher.init(Cipher.ENCRYPT_MODE, pubKey); byte[] cipherText = cipher.doFinal(input); System.out.println("cipher: " + new String(cipherText)); cipher.init(Cipher.DECRYPT_MODE, privKey); byte[] plainText = cipher.doFinal(cipherText); System.out.println("plain : " + new String(plainText)); } }
aes
import import import import
java.security.*; javax.crypto.*; javax.crypto.spec.*; java.io.*;
/** * This program generates a AES key, retrieves its raw bytes, and * then reinstantiates a AES key from the key bytes. * The reinstantiated key is used to initialize a AES cipher for * encryption and decryption. */ public class AES { /** * Turns array of bytes into string * * @param buf Array of bytes to convert to hex string * @return Generated hex string */ public static String asHex (byte buf[]) { StringBuffer strbuf = new StringBuffer(buf.length * 2); int i;
for (i = 0; i < buf.length; i++) { if (((int) buf[i] & 0xff) < 0x10) strbuf.append("0"); strbuf.append(Long.toString((int) buf[i] & 0xff, 16)); } return strbuf.toString(); } public static void main(String[] args) throws Exception { String message="This is just an example"; // Get the KeyGenerator KeyGenerator kgen = KeyGenerator.getInstance("AES"); kgen.init(128); // 192 and 256 bits may not be available // Generate the secret key specs. SecretKey skey = kgen.generateKey(); byte[] raw = skey.getEncoded(); SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES"); // Instantiate the cipher Cipher cipher = Cipher.getInstance("AES"); cipher.init(Cipher.ENCRYPT_MODE, skeySpec); byte[] encrypted = cipher.doFinal((args.length == 0 ? "This is just an example" : args[0]).getBytes()); System.out.println("encrypted string: " + asHex(encrypted)); cipher.init(Cipher.DECRYPT_MODE, skeySpec); byte[] original = cipher.doFinal(encrypted); String originalString = new String(original); System.out.println("Original string: " + originalString + " " + asHex(original)); } }
Sha import import import import import
java.io.BufferedReader; java.io.IOException; java.io.InputStreamReader; java.io.UnsupportedEncodingException; java.security.NoSuchAlgorithmException;
public class Ex01 { public static void main(String[] args) throws IOException { BufferedReader userInput = new BufferedReader (new InputStreamReader(System.in)); System.out.println("Enter string:"); String rawString = userInput.readLine(); try { System.out.println("SHA1 hash of string: " + AeSimpleSHA1.SHA1(rawString)); } catch (NoSuchAlgorithmException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (UnsupportedEncodingException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }
Implementing the Diffie-Hellman key exchange import import import import import
java.math.BigInteger; java.security.KeyFactory; java.security.KeyPair; java.security.KeyPairGenerator; java.security.SecureRandom;
import javax.crypto.spec.DHParameterSpec; import javax.crypto.spec.DHPublicKeySpec; public class MainClass { public final static int pValue = 47; public final static int gValue = 71; public final static int XaValue = 9; public final static int XbValue = 14; public static void main(String[] args) throws Exception { BigInteger p = new BigInteger(Integer.toString(pValue)); BigInteger g = new BigInteger(Integer.toString(gValue)); BigInteger Xa = new BigInteger(Integer.toString(XaValue)); BigInteger Xb = new BigInteger(Integer.toString(XbValue));
createKey(); int bitLength = 512; // 512 bits SecureRandom rnd = new SecureRandom(); p = BigInteger.probablePrime(bitLength, rnd); g = BigInteger.probablePrime(bitLength, rnd); createSpecificKey(p, g); } public static void createKey() throws Exception { KeyPairGenerator kpg = KeyPairGenerator.getInstance("DiffieHellman"); kpg.initialize(512); KeyPair kp = kpg.generateKeyPair(); KeyFactory kfactory = KeyFactory.getInstance("DiffieHellman"); DHPublicKeySpec kspec = (DHPublicKeySpec) kfactory.getKeySpec(kp.getPublic(), DHPublicKeySpec.class); } public static void createSpecificKey(BigInteger p, BigInteger g) throws Exception { KeyPairGenerator kpg = KeyPairGenerator.getInstance("DiffieHellman"); DHParameterSpec param = new DHParameterSpec(p, g); kpg.initialize(param); KeyPair kp = kpg.generateKeyPair(); KeyFactory kfactory = KeyFactory.getInstance("DiffieHellman"); DHPublicKeySpec kspec = (DHPublicKeySpec) kfactory.getKeySpec(kp.getPublic(), DHPublicKeySpec.class); } }
