Code cleanup

src/main/java/toys/BlindOracleApplet.java

@@ -88,7 +88,7 @@ public static void install(byte[] bArray, short bOffset, byte bLength){
         // the JCRE calls the Applet.install method.
         if(bArray!=null && bArray.length > 0){
             // the line below works on the card, but not in the simulator
-            new BlindOracleApplet().register(bArray, (short) (bOffset + 1), bArray[bOffset]);;
+            new BlindOracleApplet().register(bArray, (short) (bOffset + 1), bArray[bOffset]);
         }else{
             // keep the simulator happy and register without arguments
             new BlindOracleApplet().register();

src/main/java/toys/Crypto.java

@@ -97,6 +97,6 @@ static public short pbkdf2(byte[] pass, short pOff, short pLen,
         }
         // get our memory back
         heap.free(len);
-        return (short)hash.getLength();
+        return hash.getLength();
     }
 }

src/main/java/toys/MemoryCardApplet.java

@@ -29,7 +29,7 @@ public static void install(byte[] bArray, short bOffset, byte bLength){
         // the JCRE calls the Applet.install method.
         if(bArray!=null && bArray.length > 0){
             // the line below works on the card, but not in the simulator
-            new MemoryCardApplet().register(bArray, (short) (bOffset + 1), bArray[bOffset]);;
+            new MemoryCardApplet().register(bArray, (short) (bOffset + 1), bArray[bOffset]);
         }else{
             // keep the simulator happy and register without arguments
             new MemoryCardApplet().register();

src/main/java/toys/PinCode.java

@@ -32,15 +32,15 @@ public PinCode(byte maxCounter, byte maxLen){
     }
     public boolean check(byte[] buf, short off, byte len){
         Crypto.hmacSha256.init(secret, (short)0, (short)secret.length);
-        short lenHmac = Crypto.hmacSha256.doFinal(buf, off, (short)len, hmacResult, (short)0);
+        short lenHmac = Crypto.hmacSha256.doFinal(buf, off, len, hmacResult, (short)0);
         boolean result = super.check(hmacResult, (short)0, (byte)lenHmac);
         // empty array
         Util.arrayFillNonAtomic(hmacResult, (short)0, (short)hmacResult.length, (byte)0x00);
         return result;
     }
     public void update(byte[] buf, short off, byte len){
         Crypto.hmacSha256.init(secret, (short)0, (short)secret.length);
-        short lenHmac = Crypto.hmacSha256.doFinal(buf, off, (short)len, hmacResult, (short)0);
+        short lenHmac = Crypto.hmacSha256.doFinal(buf, off, len, hmacResult, (short)0);
         super.update(hmacResult, (short)0, (byte)lenHmac);
         // empty array
         Util.arrayFillNonAtomic(hmacResult, (short)0, (short)hmacResult.length, (byte)0x00);

src/main/java/toys/SecureChannel.java

@@ -132,7 +132,7 @@ public short openChannelSS(byte[] hostPubkey, short hostPubkeyOff,
         // add card nonce
         Crypto.random.generateData(cardNonce, cardNonceOff, LENGTH_NONCE);
         Crypto.sha256.doFinal(cardNonce, cardNonceOff, LENGTH_NONCE, heap.buffer, off);
-        openChannel(heap.buffer, off, (short)Crypto.sha256.getLength());
+        openChannel(heap.buffer, off, Crypto.sha256.getLength());
         heap.free(len);
         return LENGTH_NONCE;
     }
@@ -163,7 +163,7 @@ public short openChannelES(byte[] hostPubkey, short hostPubkeyOff,
         // add card nonce
         Crypto.random.generateData(cardNonce, cardNonceOff, LENGTH_NONCE);
         Crypto.sha256.doFinal(cardNonce, cardNonceOff, LENGTH_NONCE, heap.buffer, off);
-        openChannel(heap.buffer, off, (short)Crypto.sha256.getLength());
+        openChannel(heap.buffer, off, Crypto.sha256.getLength());
         heap.free(len);
         return LENGTH_NONCE;
     }
@@ -194,7 +194,7 @@ public short openChannelEE(
         // calculating shared secret
         Crypto.sha256.reset();
         Crypto.sha256.doFinal(heap.buffer, off, ecdhLen, heap.buffer, off);
-        openChannel(heap.buffer, off, (short)Crypto.sha256.getLength());
+        openChannel(heap.buffer, off, Crypto.sha256.getLength());
         heap.free(len);
         // pubkey is just ECDH of private key with G
         return Secp256k1.getPublicKey( ephemeralPrivateKey, false,
@@ -284,7 +284,7 @@ public short authenticateData(byte[] data, short dataOffset, short dataLen,
     public short signData(byte[] data, short dataOffset, short dataLen, 
                           byte[] out, short outOffset)
     {
-        short len = (short)Crypto.sha256.getLength();
+        short len = Crypto.sha256.getLength();
         short off = heap.allocate(len);
 
         Crypto.sha256.reset();

src/main/java/toys/SingleUseKeyApplet.java

@@ -54,16 +54,14 @@ public SingleUseKeyApplet(){
     // ok, if you want to use it without secure communication 
     // - you should be able to, even though it might be an issue with MITM
     // if you don't - comment out this function
+    @SuppressWarnings("fallthrough")
     protected short processPlainMessage(byte[] buf, short len){
         // ugly copy-paste for now
         switch (buf[ISO7816.OFFSET_INS]){
             case INS_SINGLE_USE_KEY:
                 switch (buf[ISO7816.OFFSET_P1]){
                     case SUBCMD_SINGLE_USE_KEY_GENERATE:
                         generateRandomKey();
-                        // no need to break - we return compressed pubkey
-                        // but compiler complains, so
-                        return Secp256k1.serialize((ECPublicKey)singleUseKeyPair.getPublic(), true, buf, OFFSET_PLAIN_PAYLOAD);
                     case SUBCMD_SINGLE_USE_KEY_GET_PUBKEY:
                         // serialize pubkey in compressed form
                         return Secp256k1.serialize((ECPublicKey)singleUseKeyPair.getPublic(), true, buf, OFFSET_PLAIN_PAYLOAD);
@@ -89,6 +87,7 @@ protected short processSecureMessage(byte[] buf, short len){
         }
         return 0;
     }
+    @SuppressWarnings("fallthrough")
     protected short processSingleUseKeyCommand(byte[] buf, short len){
         if(isLocked()){
             ISOException.throwIt(ERR_CARD_LOCKED);
@@ -98,10 +97,6 @@ protected short processSingleUseKeyCommand(byte[] buf, short len){
         switch (subcmd){
             case SUBCMD_SINGLE_USE_KEY_GENERATE:
                 generateRandomKey();
-                // no need to break - we return compressed pubkey
-                // but compiler complains, so
-                lenOut += Secp256k1.serialize((ECPublicKey)singleUseKeyPair.getPublic(), true, buf, OFFSET_SECURE_PAYLOAD);
-                return lenOut;
             case SUBCMD_SINGLE_USE_KEY_GET_PUBKEY:
                 // serialize pubkey in compressed form
                 lenOut += Secp256k1.serialize((ECPublicKey)singleUseKeyPair.getPublic(), true, buf, OFFSET_SECURE_PAYLOAD);

src/main/java/toys/TeapotApplet.java

@@ -116,7 +116,7 @@ protected void StoreData(APDU apdu){
             ISOException.throwIt(ISO7816.SW_WRONG_LENGTH);
         }
         // copy content of the buffer to the data array
-        data.put(buf, (short)ISO7816.OFFSET_CDATA, len);
+        data.put(buf, ISO7816.OFFSET_CDATA, len);
         // send back data stored in flash
         SendData(apdu);
     }