NeoRSAKey: call Cipher.init() only once

Don't write to the EEPROM everytime a security operation is executed.

Signed-off-by: Michael Walle <[email protected]>

src/cc/walle/neopgp/NeoRSAKey.java

@@ -3,6 +3,7 @@
 
 import javacard.framework.ISO7816;
 import javacard.framework.ISOException;
+import javacard.framework.JCSystem;
 import javacard.framework.Util;
 import javacard.security.KeyBuilder;
 import javacard.security.KeyPair;
@@ -22,7 +23,8 @@ public class NeoRSAKey extends NeoKey {
 
  private short modulusSize;
  private short publicExponentSize;
- private Cipher cipher;
+ private Cipher encryptCipher;
+ private Cipher decryptCipher;
 
  public NeoRSAKey(byte keyRef, short size) {
  super(keyRef);
@@ -32,7 +34,8 @@ public NeoRSAKey(byte keyRef, short size) {
  publicKey = (RSAPublicKey)KeyBuilder.buildKey(KeyBuilder.TYPE_RSA_PUBLIC, size, false);
  privateKey = (RSAPrivateCrtKey)KeyBuilder.buildKey(KeyBuilder.TYPE_RSA_CRT_PRIVATE, size, false);
  keyPair = new KeyPair(publicKey, privateKey);
- cipher = Cipher.getInstance(Cipher.ALG_RSA_PKCS1, false);
+ encryptCipher = Cipher.getInstance(Cipher.ALG_RSA_PKCS1, false);
+ decryptCipher = Cipher.getInstance(Cipher.ALG_RSA_PKCS1, false);
  }
 
  public short getAlgorithmAttributes(byte[] buf, short off) {
@@ -44,6 +47,20 @@ public short getAlgorithmAttributes(byte[] buf, short off) {
  return off;
  }
 
+ public void generate() {
+ boolean needTransaction = JCSystem.getTransactionDepth() == 0;
+
+ if (needTransaction)
+ JCSystem.beginTransaction();
+
+ super.generate();
+ encryptCipher.init(privateKey, Cipher.MODE_ENCRYPT);
+ decryptCipher.init(privateKey, Cipher.MODE_DECRYPT);
+
+ if (needTransaction)
+ JCSystem.commitTransaction();
+ }
+
  public short getPublicKey(byte[] buf, short off) {
  short lengthOffset1, lengthOffset2;
 
@@ -81,23 +98,17 @@ public short sign(byte[] buf, short off, short len) {
  return 0;
  }
 
- cipher.init(privateKey, Cipher.MODE_ENCRYPT);
- off = cipher.doFinal(buf, off, len, buf, (short)0);
- return off;
+ return encryptCipher.doFinal(buf, off, len, buf, (short)0);
  }
 
  public short decipher(byte[] buf, short off, short len) {
  if (buf[off] != NeoPGPApplet.PSO_PAD_RSA)
  ISOException.throwIt(ISO7816.SW_WRONG_DATA);
 
- cipher.init(privateKey, Cipher.MODE_DECRYPT);
- off = cipher.doFinal(buf, (short)(off + 1), (short)(len - 1), buf, (short)0);
- return off;
+ return decryptCipher.doFinal(buf, (short)(off + 1), (short)(len - 1), buf, (short)0);
  }
 
  public short authenticate(byte[] buf, short off, short len) {
- cipher.init(privateKey, Cipher.MODE_ENCRYPT);
- off = cipher.doFinal(buf, off, len, buf, (short)0);
- return off;
+ return encryptCipher.doFinal(buf, off, len, buf, (short)0);
  }
 }