| |
| package com.trilead.ssh2.crypto.cipher; |
| |
| import java.util.Vector; |
| |
| /** |
| * BlockCipherFactory. |
| * |
| * @author Christian Plattner, plattner@trilead.com |
| * @version $Id: BlockCipherFactory.java,v 1.2 2008/04/01 12:38:09 cplattne Exp $ |
| */ |
| public class BlockCipherFactory |
| { |
| static class CipherEntry |
| { |
| String type; |
| int blocksize; |
| int keysize; |
| String cipherClass; |
| |
| public CipherEntry(String type, int blockSize, int keySize, String cipherClass) |
| { |
| this.type = type; |
| this.blocksize = blockSize; |
| this.keysize = keySize; |
| this.cipherClass = cipherClass; |
| } |
| } |
| |
| static Vector ciphers = new Vector(); |
| |
| static |
| { |
| /* Higher Priority First */ |
| |
| ciphers.addElement(new CipherEntry("aes256-ctr", 16, 32, "com.trilead.ssh2.crypto.cipher.AES")); |
| ciphers.addElement(new CipherEntry("aes192-ctr", 16, 24, "com.trilead.ssh2.crypto.cipher.AES")); |
| ciphers.addElement(new CipherEntry("aes128-ctr", 16, 16, "com.trilead.ssh2.crypto.cipher.AES")); |
| ciphers.addElement(new CipherEntry("blowfish-ctr", 8, 16, "com.trilead.ssh2.crypto.cipher.BlowFish")); |
| |
| ciphers.addElement(new CipherEntry("aes256-cbc", 16, 32, "com.trilead.ssh2.crypto.cipher.AES")); |
| ciphers.addElement(new CipherEntry("aes192-cbc", 16, 24, "com.trilead.ssh2.crypto.cipher.AES")); |
| ciphers.addElement(new CipherEntry("aes128-cbc", 16, 16, "com.trilead.ssh2.crypto.cipher.AES")); |
| ciphers.addElement(new CipherEntry("blowfish-cbc", 8, 16, "com.trilead.ssh2.crypto.cipher.BlowFish")); |
| |
| ciphers.addElement(new CipherEntry("3des-ctr", 8, 24, "com.trilead.ssh2.crypto.cipher.DESede")); |
| ciphers.addElement(new CipherEntry("3des-cbc", 8, 24, "com.trilead.ssh2.crypto.cipher.DESede")); |
| } |
| |
| public static String[] getDefaultCipherList() |
| { |
| String list[] = new String[ciphers.size()]; |
| for (int i = 0; i < ciphers.size(); i++) |
| { |
| CipherEntry ce = (CipherEntry) ciphers.elementAt(i); |
| list[i] = new String(ce.type); |
| } |
| return list; |
| } |
| |
| public static void checkCipherList(String[] cipherCandidates) |
| { |
| for (int i = 0; i < cipherCandidates.length; i++) |
| getEntry(cipherCandidates[i]); |
| } |
| |
| public static BlockCipher createCipher(String type, boolean encrypt, byte[] key, byte[] iv) |
| { |
| try |
| { |
| CipherEntry ce = getEntry(type); |
| Class cc = Class.forName(ce.cipherClass); |
| BlockCipher bc = (BlockCipher) cc.newInstance(); |
| |
| if (type.endsWith("-cbc")) |
| { |
| bc.init(encrypt, key); |
| return new CBCMode(bc, iv, encrypt); |
| } |
| else if (type.endsWith("-ctr")) |
| { |
| bc.init(true, key); |
| return new CTRMode(bc, iv, encrypt); |
| } |
| throw new IllegalArgumentException("Cannot instantiate " + type); |
| } |
| catch (Exception e) |
| { |
| throw new IllegalArgumentException("Cannot instantiate " + type); |
| } |
| } |
| |
| private static CipherEntry getEntry(String type) |
| { |
| for (int i = 0; i < ciphers.size(); i++) |
| { |
| CipherEntry ce = (CipherEntry) ciphers.elementAt(i); |
| if (ce.type.equals(type)) |
| return ce; |
| } |
| throw new IllegalArgumentException("Unkown algorithm " + type); |
| } |
| |
| public static int getBlockSize(String type) |
| { |
| CipherEntry ce = getEntry(type); |
| return ce.blocksize; |
| } |
| |
| public static int getKeySize(String type) |
| { |
| CipherEntry ce = getEntry(type); |
| return ce.keysize; |
| } |
| } |