diff src/com/trilead/ssh2/crypto/cipher/BlockCipherFactory.java @ 0:0ce5cc452d02

initial version
author Carl Byington <carl@five-ten-sg.com>
date Thu, 22 May 2014 10:41:19 -0700
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/com/trilead/ssh2/crypto/cipher/BlockCipherFactory.java	Thu May 22 10:41:19 2014 -0700
@@ -0,0 +1,101 @@
+
+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<CipherEntry> ciphers = new Vector<CipherEntry>();
+
+    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 = 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 = 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;
+    }
+}