From 28b4d52dc728ff9016890ff3630d1237f1f2650b Mon Sep 17 00:00:00 2001
From: Eugene Crosser <crosser@average.org>
Date: Fri, 3 May 2013 13:37:05 +0400
Subject: [PATCH] make errro handling via exception

---
 src/org/average/nfcauthcr/Check.java  |  9 ++++++--
 src/org/average/nfcauthcr/Enroll.java |  2 +-
 src/org/average/nfcauthcr/YkNeo.java  | 31 +++++++++------------------
 3 files changed, 18 insertions(+), 24 deletions(-)

diff --git a/src/org/average/nfcauthcr/Check.java b/src/org/average/nfcauthcr/Check.java
index c3738f7..1fc5cea 100644
--- a/src/org/average/nfcauthcr/Check.java
+++ b/src/org/average/nfcauthcr/Check.java
@@ -14,6 +14,7 @@ import android.util.Log;
 import android.widget.Toast;
 
 import org.average.nfcauthcr.YkNeo;
+import org.average.nfcauthcr.CRException;
 
 public class Check extends Activity {
 
@@ -61,12 +62,16 @@ public class Check extends Activity {
 		Tag tag = intent.getParcelableExtra(NfcAdapter.EXTRA_TAG);
 		if (tag == null) return;
 		IsoDep isoTag = IsoDep.get(tag);
-		byte[] response = YkNeo.doChallengeYubiKey(
+		try {
+			byte[] response = YkNeo.doChallengeYubiKey(
 						isoTag, slot, challenge);
-		if (response != null) {
 			Intent data = getIntent();
 			data.putExtra("response", response);
 			setResult(RESULT_OK, data);
+		} catch (CRException e) {
+			Log.v(TAG, e.getMessage());
+			Toast.makeText(this, e.getMessage(),
+					Toast.LENGTH_LONG).show();
 		}
 		finish();
 	}
diff --git a/src/org/average/nfcauthcr/Enroll.java b/src/org/average/nfcauthcr/Enroll.java
index 9f9d535..5b125fa 100644
--- a/src/org/average/nfcauthcr/Enroll.java
+++ b/src/org/average/nfcauthcr/Enroll.java
@@ -127,7 +127,7 @@ public class Enroll extends Activity {
 		rng.nextBytes(challenge);
 		Log.v(TAG, "Random challenge: " + hex(challenge));
 		Log.v(TAG, "Launching challenging activity");
-		Intent crIntent = new Intent(this, NFCAuthCRCheck.class);
+		Intent crIntent = new Intent(this, Check.class);
 		crIntent.putExtra("slot", slot);
 		crIntent.putExtra("challenge", challenge);
 		this.startActivityForResult(crIntent, 0);
diff --git a/src/org/average/nfcauthcr/YkNeo.java b/src/org/average/nfcauthcr/YkNeo.java
index a291eab..1537459 100644
--- a/src/org/average/nfcauthcr/YkNeo.java
+++ b/src/org/average/nfcauthcr/YkNeo.java
@@ -7,7 +7,8 @@ import android.nfc.NfcAdapter;
 import android.nfc.Tag;
 import android.nfc.TagLostException;
 import android.nfc.tech.IsoDep;
-//import android.util.Log;
+
+import org.average.nfcauthcr.CRException;
 
 public class YkNeo {
 
@@ -23,18 +24,16 @@ public class YkNeo {
 	private static final byte SLOT_CHAL_HMAC2 = 0x38;
 
 	public static final byte[] doChallengeYubiKey(IsoDep isoTag, int slot,
-						byte[] challenge) {
+						byte[] challenge)
+				throws CRException {
 		try {
 			isoTag.connect();
 			byte[] resp = isoTag.transceive(selectApdu);
 			int length = resp.length;
-			//Log.v(TAG, "response to select length is " + length);
 			if (resp[length - 2] != (byte)0x90 ||
 			    resp[length - 1] != 0x00) {
-				//Log.v(TAG, "Wrong response to select");
-				//Toast.makeText(this, R.string.tag_error,
-				//		Toast.LENGTH_LONG).show();
-				return null;
+				throw new CRException(
+				"NFC Error code in the response to select");
 			}
 			byte[] crApdu = new byte[69];
 			crApdu[0] = 0x00; // CLA
@@ -52,24 +51,14 @@ public class YkNeo {
 			length = resp.length;
 			if (resp[length - 2] != (byte)0x90 ||
 			    resp[length - 1] != 0x00) {
-				//Log.v(TAG, "Wrong response to challenge");
-				//Toast.makeText(this, R.string.tag_error,
-				//		Toast.LENGTH_LONG).show();
-				return null;
+				throw new CRException(
+				"NFC Error code in the response to CR");
 			}
-			//Log.v(TAG, "response to challenge length is " + length);
 			return Arrays.copyOf(resp, length-2);
 		} catch (TagLostException e) {
-			//Log.v(TAG, e.getMessage());
-			//Toast.makeText(this,
-			//	R.string.tag_lost, Toast.LENGTH_LONG).show();
+			throw new CRException("NFC connection lost", e);
 		} catch (IOException e) {
-			//Log.v(TAG, e.getMessage());
-			//Toast.makeText(this,
-			//	getText(R.string.tag_error) +
-			//	e.getMessage(),
-			//	Toast.LENGTH_LONG).show();
+			throw new CRException("NFC I/O error", e);
 		}
-		return null;
 	}
 }
-- 
2.39.2