Use NotFoundException in more places

12 files changed, 141 insertions, 85 deletions

diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpDecryptVerify.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpDecryptVerify.java
index 4b6aaaa4d..7b022b694 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpDecryptVerify.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpDecryptVerify.java
@@ -238,19 +238,19 @@ public class PgpDecryptVerify {
 
                 PGPPublicKeyEncryptedData encData = (PGPPublicKeyEncryptedData) obj;
 
-                // get master key id for this encryption key id
                 long masterKeyId = 0;
+                PGPSecretKeyRing secretKeyRing = null;
                 try {
+                    // get master key id for this encryption key id
                     masterKeyId = ProviderHelper.getMasterKeyId(mContext,
                             KeyRings.buildUnifiedKeyRingsFindBySubkeyUri(Long.toString(encData.getKeyID()))
                     );
+                    // get actual keyring object based on master key id
+                    secretKeyRing = ProviderHelper.getPGPSecretKeyRing(mContext, masterKeyId);
                 } catch (ProviderHelper.NotFoundException e) {
-                    Log.e(Constants.TAG, "key not found!", e);
                     // continue with the next packet in the while loop
                     continue;
                 }
-                // get actual keyring object based on master key id
-                PGPSecretKeyRing secretKeyRing = ProviderHelper.getPGPSecretKeyRing(mContext, masterKeyId);
                 if (secretKeyRing == null) {
                     // continue with the next packet in the while loop
                     continue;
@@ -390,8 +390,14 @@ public class PgpDecryptVerify {
             PGPOnePassSignatureList sigList = (PGPOnePassSignatureList) dataChunk;
             for (int i = 0; i < sigList.size(); ++i) {
                 signature = sigList.get(i);
-                signatureKey = ProviderHelper
-                        .getPGPPublicKeyRingWithKeyId(mContext, signature.getKeyID()).getPublicKey();
+
+                // TODO: rework this code, seems wonky!
+                try {
+                    signatureKey = ProviderHelper
+                            .getPGPPublicKeyRingWithKeyId(mContext, signature.getKeyID()).getPublicKey();
+                } catch (ProviderHelper.NotFoundException e) {
+                    Log.d(Constants.TAG, "key not found!");
+                }
                 if (signatureKeyId == 0) {
                     signatureKeyId = signature.getKeyID();
                 }
@@ -401,10 +407,12 @@ public class PgpDecryptVerify {
                     signatureIndex = i;
                     signatureKeyId = signature.getKeyID();
                     String userId = null;
-                    PGPPublicKeyRing signKeyRing = ProviderHelper.getPGPPublicKeyRingWithKeyId(
-                            mContext, signatureKeyId);
-                    if (signKeyRing != null) {
+                    try {
+                        PGPPublicKeyRing signKeyRing = ProviderHelper.getPGPPublicKeyRingWithKeyId(
+                                mContext, signatureKeyId);
                         userId = PgpKeyHelper.getMainUserId(signKeyRing.getPublicKey());
+                    } catch (ProviderHelper.NotFoundException e) {
+                        Log.d(Constants.TAG, "key not found!");
                     }
                     signatureResult.setUserId(userId);
                     break;
@@ -598,7 +606,11 @@ public class PgpDecryptVerify {
             }
 
             // this one can't fail now (yay database constraints)
-            signatureKey = ProviderHelper.getPGPPublicKeyRing(mContext, (Long) data.get(KeyRings.MASTER_KEY_ID)).getPublicKey();
+            try {
+                signatureKey = ProviderHelper.getPGPPublicKeyRing(mContext, (Long) data.get(KeyRings.MASTER_KEY_ID)).getPublicKey();
+            } catch (ProviderHelper.NotFoundException e) {
+                Log.e(Constants.TAG, "key not found!", e);
+            }
             signatureResult.setUserId((String) data.get(KeyRings.USER_ID));
 
             break;
@@ -664,11 +676,13 @@ public class PgpDecryptVerify {
         long signatureKeyId = signature.getKeyID();
         boolean validKeyBinding = false;
 
-        PGPPublicKeyRing signKeyRing = ProviderHelper.getPGPPublicKeyRingWithKeyId(context,
-                signatureKeyId);
         PGPPublicKey mKey = null;
-        if (signKeyRing != null) {
+        try {
+            PGPPublicKeyRing signKeyRing = ProviderHelper.getPGPPublicKeyRingWithKeyId(context,
+                    signatureKeyId);
             mKey = signKeyRing.getPublicKey();
+        } catch (ProviderHelper.NotFoundException e) {
+            Log.d(Constants.TAG, "key not found");
         }
 
         if (signature.getKeyID() != mKey.getKeyID()) {
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpImportExport.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpImportExport.java
index 89a949922..854f065ec 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpImportExport.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpImportExport.java
@@ -194,11 +194,14 @@ public class PgpImportExport {
             arOutStream.setHeader("Version", PgpHelper.getFullVersion(mContext));
 
             updateProgress(progress * 100 / masterKeyIdsSize, 100);
-            PGPPublicKeyRing publicKeyRing =
-                    ProviderHelper.getPGPPublicKeyRing(mContext, pubKeyMasterId);
 
-            if (publicKeyRing != null) {
+            try {
+                PGPPublicKeyRing publicKeyRing = ProviderHelper.getPGPPublicKeyRing(mContext, pubKeyMasterId);
+
                 publicKeyRing.encode(arOutStream);
+            } catch (ProviderHelper.NotFoundException e) {
+                Log.e(Constants.TAG, "key not found!", e);
+                // TODO: inform user?
             }
 
             if (mKeychainServiceListener.hasServiceStopped()) {
@@ -217,12 +220,15 @@ public class PgpImportExport {
             arOutStream.setHeader("Version", PgpHelper.getFullVersion(mContext));
 
             updateProgress(progress * 100 / masterKeyIdsSize, 100);
-            PGPSecretKeyRing secretKeyRing =
-                    ProviderHelper.getPGPSecretKeyRing(mContext, secretKeyMasterId);
 
-            if (secretKeyRing != null) {
+            try {
+                PGPSecretKeyRing secretKeyRing = ProviderHelper.getPGPSecretKeyRing(mContext, secretKeyMasterId);
                 secretKeyRing.encode(arOutStream);
+            } catch (ProviderHelper.NotFoundException e) {
+                Log.e(Constants.TAG, "key not found!", e);
+                // TODO: inform user?
             }
+
             if (mKeychainServiceListener.hasServiceStopped()) {
                 arOutStream.close();
                 return null;
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyHelper.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyHelper.java
index d4311367f..cd00f000c 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyHelper.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpKeyHelper.java
@@ -201,9 +201,12 @@ public class PgpKeyHelper {
     }
 
     public static PGPPublicKey getEncryptPublicKey(Context context, long masterKeyId) {
-        PGPPublicKeyRing keyRing = ProviderHelper.getPGPPublicKeyRing(context, masterKeyId);
-        if (keyRing == null) {
-            Log.e(Constants.TAG, "keyRing is null!");
+        PGPPublicKeyRing keyRing = null;
+        try {
+            keyRing = ProviderHelper.getPGPPublicKeyRing(context, masterKeyId);
+        } catch (ProviderHelper.NotFoundException e) {
+            Log.e(Constants.TAG, "key not found!", e);
+            // TODO: throw exception here!
             return null;
         }
         Vector<PGPPublicKey> encryptKeys = getUsableEncryptKeys(keyRing);
@@ -215,8 +218,12 @@ public class PgpKeyHelper {
     }
 
     public static PGPSecretKey getCertificationKey(Context context, long masterKeyId) {
-        PGPSecretKeyRing keyRing = ProviderHelper.getPGPSecretKeyRing(context, masterKeyId);
-        if (keyRing == null) {
+        PGPSecretKeyRing keyRing = null;
+        try {
+            keyRing = ProviderHelper.getPGPSecretKeyRing(context, masterKeyId);
+        } catch (ProviderHelper.NotFoundException e) {
+            Log.e(Constants.TAG, "key not found!", e);
+            // TODO: throw exception here!
             return null;
         }
         Vector<PGPSecretKey> signingKeys = getUsableCertificationKeys(keyRing);
@@ -227,8 +234,12 @@ public class PgpKeyHelper {
     }
 
     public static PGPSecretKey getSigningKey(Context context, long masterKeyId) {
-        PGPSecretKeyRing keyRing = ProviderHelper.getPGPSecretKeyRing(context, masterKeyId);
-        if (keyRing == null) {
+        PGPSecretKeyRing keyRing = null;
+        try {
+            keyRing = ProviderHelper.getPGPSecretKeyRing(context, masterKeyId);
+        } catch (ProviderHelper.NotFoundException e) {
+            Log.e(Constants.TAG, "key not found!", e);
+            // TODO: throw exception here!
             return null;
         }
         Vector<PGPSecretKey> signingKeys = getUsableSigningKeys(keyRing);
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpSignEncrypt.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpSignEncrypt.java
index 653d8bce4..53444f739 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpSignEncrypt.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/pgp/PgpSignEncrypt.java
@@ -235,7 +235,11 @@ public class PgpSignEncrypt {
         PGPSecretKeyRing signingKeyRing = null;
         PGPPrivateKey signaturePrivateKey = null;
         if (enableSignature) {
-            signingKeyRing = ProviderHelper.getPGPSecretKeyRingWithKeyId(mContext, mSignatureKeyId);
+            try {
+                signingKeyRing = ProviderHelper.getPGPSecretKeyRingWithKeyId(mContext, mSignatureKeyId);
+            } catch (ProviderHelper.NotFoundException e) {
+                throw new PgpGeneralException(mContext.getString(R.string.error_signature_failed));
+            }
             signingKey = PgpKeyHelper.getSigningKey(mContext, mSignatureKeyId);
             if (signingKey == null) {
                 throw new PgpGeneralException(mContext.getString(R.string.error_signature_failed));
@@ -464,8 +468,12 @@ public class PgpSignEncrypt {
             throw new PgpGeneralException(mContext.getString(R.string.error_no_signature_key));
         }
 
-        PGPSecretKeyRing signingKeyRing =
-                ProviderHelper.getPGPSecretKeyRingWithKeyId(mContext, mSignatureKeyId);
+        PGPSecretKeyRing signingKeyRing;
+        try {
+            signingKeyRing = ProviderHelper.getPGPSecretKeyRingWithKeyId(mContext, mSignatureKeyId);
+        } catch (ProviderHelper.NotFoundException e) {
+            throw new PgpGeneralException(mContext.getString(R.string.error_signature_failed));
+        }
         PGPSecretKey signingKey = PgpKeyHelper.getSigningKey(mContext, mSignatureKeyId);
         if (signingKey == null) {
             throw new PgpGeneralException(mContext.getString(R.string.error_signature_failed));
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/provider/ProviderHelper.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/provider/ProviderHelper.java
index 6b6be49f1..28376096d 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/provider/ProviderHelper.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/provider/ProviderHelper.java
@@ -159,39 +159,35 @@ public class ProviderHelper {
 
         return result;
     }
-    public static PGPKeyRing getPGPKeyRing(Context context, Uri queryUri) {
+
+    public static PGPKeyRing getPGPKeyRing(Context context, Uri queryUri) throws NotFoundException {
         Map<Long, PGPKeyRing> result = getPGPKeyRings(context, queryUri);
-        if(result.isEmpty())
-            return null;
-        return result.values().iterator().next();
+        if(result.isEmpty()) {
+            throw new NotFoundException("PGPKeyRing object not found!");
+        } else {
+            return result.values().iterator().next();
+        }
     }
 
-    public static PGPPublicKeyRing getPGPPublicKeyRingWithKeyId(Context context, long keyId) {
+    public static PGPPublicKeyRing getPGPPublicKeyRingWithKeyId(Context context, long keyId)
+            throws NotFoundException {
         Uri uri = KeyRings.buildUnifiedKeyRingsFindBySubkeyUri(Long.toString(keyId));
-        long masterKeyId;
-        try {
-            masterKeyId = getMasterKeyId(context, uri);
-            return getPGPPublicKeyRing(context, masterKeyId);
-        } catch (NotFoundException e) {
-            return null;
-        }
+        long masterKeyId = getMasterKeyId(context, uri);
+        return getPGPPublicKeyRing(context, masterKeyId);
     }
-    public static PGPSecretKeyRing getPGPSecretKeyRingWithKeyId(Context context, long keyId) {
+
+    public static PGPSecretKeyRing getPGPSecretKeyRingWithKeyId(Context context, long keyId)
+            throws NotFoundException {
         Uri uri = KeyRings.buildUnifiedKeyRingsFindBySubkeyUri(Long.toString(keyId));
-        long masterKeyId;
-        try {
-            masterKeyId = getMasterKeyId(context, uri);
-            return getPGPSecretKeyRing(context, masterKeyId);
-        } catch (NotFoundException notFound) {
-            return null;
-        }
+        long masterKeyId = getMasterKeyId(context, uri);
+        return getPGPSecretKeyRing(context, masterKeyId);
     }
 
     /**
      * Retrieves the actual PGPPublicKeyRing object from the database blob based on the masterKeyId
      */
     public static PGPPublicKeyRing getPGPPublicKeyRing(Context context,
-                                                                    long masterKeyId) {
+                                                       long masterKeyId) throws NotFoundException {
         Uri queryUri = KeyRingData.buildPublicKeyRingUri(Long.toString(masterKeyId));
         return (PGPPublicKeyRing) getPGPKeyRing(context, queryUri);
     }
@@ -200,7 +196,7 @@ public class ProviderHelper {
      * Retrieves the actual PGPSecretKeyRing object from the database blob based on the maserKeyId
      */
     public static PGPSecretKeyRing getPGPSecretKeyRing(Context context,
-                                                                    long masterKeyId) {
+                                                       long masterKeyId) throws NotFoundException {
         Uri queryUri = KeyRingData.buildSecretKeyRingUri(Long.toString(masterKeyId));
         return (PGPSecretKeyRing) getPGPKeyRing(context, queryUri);
     }
@@ -214,7 +210,12 @@ public class ProviderHelper {
         long masterKeyId = masterKey.getKeyID();
 
         // IF there is a secret key, preserve it!
-        PGPSecretKeyRing secretRing = ProviderHelper.getPGPSecretKeyRing(context, masterKeyId);
+        PGPSecretKeyRing secretRing = null;
+        try {
+            secretRing = ProviderHelper.getPGPSecretKeyRing(context, masterKeyId);
+        } catch (NotFoundException e) {
+            Log.e(Constants.TAG, "key not found!");
+        }
 
         // delete old version of this keyRing, which also deletes all keys and userIds on cascade
         try {
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/service/PassphraseCacheService.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/service/PassphraseCacheService.java
index 8d2afe3b7..cbc71ce6a 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/service/PassphraseCacheService.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/service/PassphraseCacheService.java
@@ -33,7 +33,6 @@ import android.os.Message;
 import android.os.Messenger;
 import android.os.RemoteException;
 import android.support.v4.util.LongSparseArray;
-import android.util.Log;
 
 import org.spongycastle.openpgp.PGPException;
 import org.spongycastle.openpgp.PGPPrivateKey;
@@ -48,6 +47,7 @@ import org.sufficientlysecure.keychain.helper.Preferences;
 import org.sufficientlysecure.keychain.pgp.PgpKeyHelper;
 import org.sufficientlysecure.keychain.provider.KeychainContract;
 import org.sufficientlysecure.keychain.provider.ProviderHelper;
+import org.sufficientlysecure.keychain.util.Log;
 
 import java.util.Date;
 import java.util.Iterator;
@@ -231,6 +231,8 @@ public class PassphraseCacheService extends Service {
             }
         } catch (PGPException e) {
             // silently catch
+        } catch (ProviderHelper.NotFoundException e) {
+            Log.e(Constants.TAG, "key not found!", e);
         }
 
         return true;
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/CertifyKeyActivity.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/CertifyKeyActivity.java
index de8a9cd6d..e2e09f052 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/CertifyKeyActivity.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/CertifyKeyActivity.java
@@ -224,8 +224,9 @@ public class CertifyKeyActivity extends ActionBarActivity implements
      * handles the UI bits of the signing process on the UI thread
      */
     private void initiateSigning() {
-        PGPPublicKeyRing pubring = ProviderHelper.getPGPPublicKeyRing(this, mPubKeyId);
-        if (pubring != null) {
+        try {
+            PGPPublicKeyRing pubring = ProviderHelper.getPGPPublicKeyRing(this, mPubKeyId);
+
             // if we have already signed this key, dont bother doing it again
             boolean alreadySigned = false;
 
@@ -248,14 +249,14 @@ public class CertifyKeyActivity extends ActionBarActivity implements
                 String passphrase = PassphraseCacheService.getCachedPassphrase(this, mMasterKeyId);
                 if (passphrase == null) {
                     PassphraseDialogFragment.show(this, mMasterKeyId,
-                        new Handler() {
-                            @Override
-                            public void handleMessage(Message message) {
-                                if (message.what == PassphraseDialogFragment.MESSAGE_OKAY) {
-                                    startSigning();
+                            new Handler() {
+                                @Override
+                                public void handleMessage(Message message) {
+                                    if (message.what == PassphraseDialogFragment.MESSAGE_OKAY) {
+                                        startSigning();
+                                    }
                                 }
-                            }
-                        });
+                            });
                     // bail out; need to wait until the user has entered the passphrase before trying again
                     return;
                 } else {
@@ -268,6 +269,8 @@ public class CertifyKeyActivity extends ActionBarActivity implements
                 setResult(RESULT_CANCELED);
                 finish();
             }
+        } catch (ProviderHelper.NotFoundException e) {
+            Log.e(Constants.TAG, "key not found!", e);
         }
     }
 
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/EditKeyActivity.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/EditKeyActivity.java
index cfb7c56c2..4e21b172e 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/EditKeyActivity.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/EditKeyActivity.java
@@ -300,15 +300,16 @@ public class EditKeyActivity extends ActionBarActivity implements EditorListener
     private void finallyEdit(final long masterKeyId) {
         if (masterKeyId != 0) {
             PGPSecretKey masterKey = null;
-            mKeyRing = ProviderHelper.getPGPSecretKeyRing(this, masterKeyId);
-            if (mKeyRing != null) {
+            try {
+                mKeyRing = ProviderHelper.getPGPSecretKeyRing(this, masterKeyId);
+
                 masterKey = mKeyRing.getSecretKey();
                 mMasterCanSign = PgpKeyHelper.isCertificationKey(mKeyRing.getSecretKey());
                 for (PGPSecretKey key : new IterableIterator<PGPSecretKey>(mKeyRing.getSecretKeys())) {
                     mKeys.add(key);
                     mKeysUsages.add(-1); // get usage when view is created
                 }
-            } else {
+            } catch (ProviderHelper.NotFoundException e) {
                 Log.e(Constants.TAG, "Keyring not found with masterKeyId: " + masterKeyId);
                 AppMsg.makeText(this, R.string.error_no_secret_key_found, AppMsg.STYLE_ALERT).show();
                 // TODO
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/EncryptAsymmetricFragment.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/EncryptAsymmetricFragment.java
index 7fcb9a552..2ec4dd89e 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/EncryptAsymmetricFragment.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/EncryptAsymmetricFragment.java
@@ -146,17 +146,19 @@ public class EncryptAsymmetricFragment extends Fragment {
     private void preselectKeys(long preselectedSignatureKeyId, long[] preselectedEncryptionKeyIds) {
         if (preselectedSignatureKeyId != 0) {
             // TODO: don't use bouncy castle objects!
-            PGPSecretKeyRing keyRing = ProviderHelper.getPGPSecretKeyRingWithKeyId(getActivity(),
-                    preselectedSignatureKeyId);
-            PGPSecretKey masterKey;
-            if (keyRing != null) {
-                masterKey = keyRing.getSecretKey();
+            try {
+                PGPSecretKeyRing keyRing = ProviderHelper.getPGPSecretKeyRingWithKeyId(getActivity(),
+                        preselectedSignatureKeyId);
+
+                PGPSecretKey masterKey = keyRing.getSecretKey();
                 if (masterKey != null) {
                     Vector<PGPSecretKey> signKeys = PgpKeyHelper.getUsableSigningKeys(keyRing);
                     if (signKeys.size() > 0) {
                         setSignatureKeyId(masterKey.getKeyID());
                     }
                 }
+            } catch (ProviderHelper.NotFoundException e) {
+                Log.e(Constants.TAG, "key not found!", e);
             }
         }
 
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/ViewCertActivity.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/ViewCertActivity.java
index 92e171130..0dc36a792 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/ViewCertActivity.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/ViewCertActivity.java
@@ -145,14 +145,14 @@ public class ViewCertActivity extends ActionBarActivity
             }
 
             PGPSignature sig = PgpConversionHelper.BytesToPGPSignature(data.getBlob(INDEX_DATA));
-            PGPKeyRing signeeRing = ProviderHelper.getPGPKeyRing(this,
-                    KeychainContract.KeyRingData.buildPublicKeyRingUri(
-                            Long.toString(data.getLong(INDEX_MASTER_KEY_ID))));
-            PGPKeyRing signerRing = ProviderHelper.getPGPKeyRing(this,
-                    KeychainContract.KeyRingData.buildPublicKeyRingUri(
-                            Long.toString(sig.getKeyID())));
-
-            if (signerRing != null) {
+            try {
+                PGPKeyRing signeeRing = ProviderHelper.getPGPKeyRing(this,
+                        KeychainContract.KeyRingData.buildPublicKeyRingUri(
+                                Long.toString(data.getLong(INDEX_MASTER_KEY_ID))));
+                PGPKeyRing signerRing = ProviderHelper.getPGPKeyRing(this,
+                        KeychainContract.KeyRingData.buildPublicKeyRingUri(
+                                Long.toString(sig.getKeyID())));
+
                 try {
                     sig.init(new JcaPGPContentVerifierBuilderProvider().setProvider(
                             Constants.BOUNCY_CASTLE_PROVIDER_NAME), signeeRing.getPublicKey());
@@ -170,7 +170,7 @@ public class ViewCertActivity extends ActionBarActivity
                     mStatus.setText("error!");
                     mStatus.setTextColor(getResources().getColor(R.color.alert));
                 }
-            } else {
+            } catch (ProviderHelper.NotFoundException e) {
                 mStatus.setText("key unavailable");
                 mStatus.setTextColor(getResources().getColor(R.color.black));
             }
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/ViewKeyActivityJB.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/ViewKeyActivityJB.java
index 6dc0413bb..6f52ea916 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/ViewKeyActivityJB.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/ViewKeyActivityJB.java
@@ -93,6 +93,9 @@ public class ViewKeyActivityJB extends ViewKeyActivity implements CreateNdefMess
         } catch(IOException e) {
             Log.e(Constants.TAG, "Error parsing keyring", e);
             return null;
+        } catch (ProviderHelper.NotFoundException e) {
+            Log.e(Constants.TAG, "key not found!", e);
+            return null;
         }
     }
 
diff --git a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/dialog/PassphraseDialogFragment.java b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/dialog/PassphraseDialogFragment.java
index a3feab959..74bc73952 100644
--- a/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/dialog/PassphraseDialogFragment.java
+++ b/OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/dialog/PassphraseDialogFragment.java
@@ -139,9 +139,9 @@ public class PassphraseDialogFragment extends DialogFragment implements OnEditor
             secretKey = null;
             alert.setMessage(R.string.passphrase_for_symmetric_encryption);
         } else {
-            secretKey = ProviderHelper.getPGPSecretKeyRing(activity, secretKeyId).getSecretKey();
-
-            if (secretKey == null) {
+            try {
+                secretKey = ProviderHelper.getPGPSecretKeyRing(activity, secretKeyId).getSecretKey();
+            } catch (ProviderHelper.NotFoundException e) {
                 alert.setTitle(R.string.title_key_not_found);
                 alert.setMessage(getString(R.string.key_not_found, secretKeyId));
                 alert.setPositiveButton(android.R.string.ok, new OnClickListener() {
@@ -153,6 +153,7 @@ public class PassphraseDialogFragment extends DialogFragment implements OnEditor
                 mCanKB = false;
                 return alert.create();
             }
+
             String userId = PgpKeyHelper.getMainUserIdSafe(activity, secretKey);
 
             Log.d(Constants.TAG, "User id: '" + userId + "'");
@@ -194,9 +195,13 @@ public class PassphraseDialogFragment extends DialogFragment implements OnEditor
                                         sendMessageToHandler(MESSAGE_CANCEL);
                                         return;
                                     } else {
-                                        clickSecretKey = PgpKeyHelper.getKeyNum(ProviderHelper
-                                                .getPGPSecretKeyRingWithKeyId(activity, secretKeyId),
-                                                curKeyIndex);
+                                        try {
+                                            clickSecretKey = PgpKeyHelper.getKeyNum(ProviderHelper
+                                                    .getPGPSecretKeyRingWithKeyId(activity, secretKeyId),
+                                                    curKeyIndex);
+                                        } catch (ProviderHelper.NotFoundException e) {
+                                            Log.e(Constants.TAG, "key not found!", e);
+                                        }
                                         curKeyIndex++; // does post-increment work like C?
                                         continue;
                                     }