1 files changed, 127 insertions, 0 deletions
diff --git a/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/engines/DESedeEngine.java b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/engines/DESedeEngine.java
new file mode 100644
index 000000000..e0c0fb85d
--- /dev/null
+++ b/libraries/spongycastle/core/src/main/java/org/spongycastle/crypto/engines/DESedeEngine.java
@@ -0,0 +1,127 @@
+package org.spongycastle.crypto.engines;
+
+import org.spongycastle.crypto.CipherParameters;
+import org.spongycastle.crypto.DataLengthException;
+import org.spongycastle.crypto.OutputLengthException;
+import org.spongycastle.crypto.params.KeyParameter;
+
+/**
+ * a class that provides a basic DESede (or Triple DES) engine.
+ */
+public class DESedeEngine
+    extends DESEngine
+{
+    protected static final int  BLOCK_SIZE = 8;
+
+    private int[]               workingKey1 = null;
+    private int[]               workingKey2 = null;
+    private int[]               workingKey3 = null;
+
+    private boolean             forEncryption;
+
+    /**
+     * standard constructor.
+     */
+    public DESedeEngine()
+    {
+    }
+
+    /**
+     * initialise a DESede cipher.
+     *
+     * @param encrypting whether or not we are for encryption.
+     * @param params the parameters required to set up the cipher.
+     * @exception IllegalArgumentException if the params argument is
+     * inappropriate.
+     */
+    public void init(
+        boolean           encrypting,
+        CipherParameters  params)
+    {
+        if (!(params instanceof KeyParameter))
+        {
+            throw new IllegalArgumentException("invalid parameter passed to DESede init - " + params.getClass().getName());
+        }
+
+        byte[] keyMaster = ((KeyParameter)params).getKey();
+
+        if (keyMaster.length != 24 && keyMaster.length != 16)
+        {
+            throw new IllegalArgumentException("key size must be 16 or 24 bytes.");
+        }
+
+        this.forEncryption = encrypting;
+
+        byte[] key1 = new byte[8];
+        System.arraycopy(keyMaster, 0, key1, 0, key1.length);
+        workingKey1 = generateWorkingKey(encrypting, key1);
+
+        byte[] key2 = new byte[8];
+        System.arraycopy(keyMaster, 8, key2, 0, key2.length);
+        workingKey2 = generateWorkingKey(!encrypting, key2);
+
+        if (keyMaster.length == 24)
+        {
+            byte[] key3 = new byte[8];
+            System.arraycopy(keyMaster, 16, key3, 0, key3.length);
+            workingKey3 = generateWorkingKey(encrypting, key3);
+        }
+        else    // 16 byte key
+        {
+            workingKey3 = workingKey1;
+        }
+    }
+
+    public String getAlgorithmName()
+    {
+        return "DESede";
+    }
+
+    public int getBlockSize()
+    {
+        return BLOCK_SIZE;
+    }
+
+    public int processBlock(
+        byte[] in,
+        int inOff,
+        byte[] out,
+        int outOff)
+    {
+        if (workingKey1 == null)
+        {
+            throw new IllegalStateException("DESede engine not initialised");
+        }
+
+        if ((inOff + BLOCK_SIZE) > in.length)
+        {
+            throw new DataLengthException("input buffer too short");
+        }
+
+        if ((outOff + BLOCK_SIZE) > out.length)
+        {
+            throw new OutputLengthException("output buffer too short");
+        }
+
+        byte[] temp = new byte[BLOCK_SIZE];
+
+        if (forEncryption)
+        {
+            desFunc(workingKey1, in, inOff, temp, 0);
+            desFunc(workingKey2, temp, 0, temp, 0);
+            desFunc(workingKey3, temp, 0, out, outOff);
+        }
+        else
+        {
+            desFunc(workingKey3, in, inOff, temp, 0);
+            desFunc(workingKey2, temp, 0, temp, 0);
+            desFunc(workingKey1, temp, 0, out, outOff);
+        }
+
+        return BLOCK_SIZE;
+    }
+
+    public void reset()
+    {
+    }
+}