From 78193007b209a4e40867f1096972f96e2794c0c9 Mon Sep 17 00:00:00 2001
From: Thialfihar <thialfihar@gmail.com>
Date: Thu, 22 Apr 2010 15:30:19 +0000
Subject: [PATCH] added file decryption, rewrote the various "Choice"
 derivations to us the Id structure as well

---
 AndroidManifest.xml                           |  11 +
 res/layout/decrypt_file.xml                   | 122 +++++++
 src/org/thialfihar/android/apg/Apg.java       |  34 +-
 .../android/apg/DecryptFileActivity.java      | 319 ++++++++++++++++++
 .../android/apg/DecryptMessageActivity.java   |  22 +-
 .../android/apg/EncryptFileActivity.java      |   6 +-
 src/org/thialfihar/android/apg/Id.java        |  15 +-
 .../thialfihar/android/apg/MainActivity.java  |   2 +-
 .../android/apg/ui/widget/KeyEditor.java      |  65 ++--
 .../android/apg/ui/widget/SectionView.java    |  35 +-
 10 files changed, 537 insertions(+), 94 deletions(-)
 create mode 100644 res/layout/decrypt_file.xml
 create mode 100644 src/org/thialfihar/android/apg/DecryptFileActivity.java

diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index e54d70dc1..b9dd47fd0 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -99,6 +99,17 @@
 
         </activity>
 
+        <activity
+            android:name=".DecryptFileActivity"
+            android:label="@string/title_decryptFile"
+            android:configChanges="keyboardHidden|orientation|keyboard">
+
+            <intent-filter>
+                <action android:name="org.thialfihar.android.apg.intent.DECRYPT_FILE" />
+            </intent-filter>
+
+        </activity>
+
         <activity
             android:name=".MailListActivity"
             android:label="@string/title_mailInbox"
diff --git a/res/layout/decrypt_file.xml b/res/layout/decrypt_file.xml
new file mode 100644
index 000000000..7ea44b2f5
--- /dev/null
+++ b/res/layout/decrypt_file.xml
@@ -0,0 +1,122 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2010 Thialfihar <thi@thialfihar.org>
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<LinearLayout
+    xmlns:android="http://schemas.android.com/apk/res/android"
+    android:layout_width="fill_parent"
+    android:layout_height="fill_parent"
+    android:orientation="vertical"
+    android:paddingTop="5dip">
+
+    <LinearLayout
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:orientation="horizontal"
+        android:paddingLeft="5dip"
+        android:paddingRight="5dip">
+
+        <TextView
+            android:id="@+id/label_filename"
+            android:textAppearance="?android:attr/textAppearanceMedium"
+            android:layout_width="50dip"
+            android:layout_height="wrap_content"
+            android:text="@string/label_file"/>
+
+        <EditText
+            android:id="@+id/filename"
+            android:layout_width="0dip"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"/>
+
+        <ImageButton
+            android:id="@+id/btn_browse"
+            android:src="@drawable/ic_launcher_folder_small"
+            android:layout_height="wrap_content"
+            android:layout_width="wrap_content"/>
+
+    </LinearLayout>
+
+    <LinearLayout
+        android:id="@+id/layout_signature"
+        android:orientation="horizontal"
+        android:layout_height="wrap_content"
+        android:layout_width="wrap_content">
+
+        <RelativeLayout
+            android:layout_height="wrap_content"
+            android:layout_width="wrap_content">
+
+            <ImageView
+                android:id="@+id/ic_signature"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:src="@drawable/signed_large"/>
+
+            <ImageView
+                android:id="@+id/ic_signature_status"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:src="@drawable/overlay_error"/>
+
+        </RelativeLayout>
+
+        <LinearLayout
+            android:orientation="vertical"
+            android:layout_height="wrap_content"
+            android:layout_width="wrap_content"
+            android:paddingLeft="5dip">
+
+            <TextView
+                android:id="@+id/main_user_id"
+                android:text="Main User Id"
+                android:textAppearance="?android:attr/textAppearanceMedium"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_gravity="left"/>
+
+            <TextView
+                android:id="@+id/main_user_id_rest"
+                android:text="Main User Id Rest"
+                android:textAppearance="?android:attr/textAppearanceSmall"
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:layout_gravity="left"/>
+
+        </LinearLayout>
+
+    </LinearLayout>
+
+    <LinearLayout
+        android:layout_width="fill_parent"
+        android:layout_height="0dip"
+        android:layout_weight="1"/>
+
+    <LinearLayout
+        android:orientation="horizontal"
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        style="@android:style/ButtonBar">
+
+        <Button
+            android:id="@+id/btn_decrypt"
+            android:text="@string/btn_decrypt"
+            android:layout_weight="1"
+            android:layout_width="0dip"
+            android:layout_height="wrap_content"/>
+
+    </LinearLayout>
+
+</LinearLayout>
diff --git a/src/org/thialfihar/android/apg/Apg.java b/src/org/thialfihar/android/apg/Apg.java
index dc7090ea6..80865ada3 100644
--- a/src/org/thialfihar/android/apg/Apg.java
+++ b/src/org/thialfihar/android/apg/Apg.java
@@ -275,14 +275,10 @@ public class Apg {
         return mPassPhrase;
     }
 
-    public static PGPSecretKey createKey(KeyEditor.AlgorithmChoice algorithmChoice, int keySize,
-                                         String passPhrase)
+    public static PGPSecretKey createKey(int algorithmChoice, int keySize, String passPhrase)
                   throws NoSuchAlgorithmException, PGPException, NoSuchProviderException,
                   GeneralException, InvalidAlgorithmParameterException {
 
-        if (algorithmChoice == null) {
-            throw new GeneralException("unknown algorithm choice");
-        }
         if (keySize < 512) {
             throw new GeneralException("key size must be at least 512bit");
         }
@@ -296,15 +292,15 @@ public class Apg {
         int algorithm = 0;
         KeyPairGenerator keyGen = null;
 
-        switch (algorithmChoice.getId()) {
-            case KeyEditor.AlgorithmChoice.DSA: {
+        switch (algorithmChoice) {
+            case Id.choice.algorithm.dsa: {
                 keyGen = KeyPairGenerator.getInstance("DSA", new BouncyCastleProvider());
                 keyGen.initialize(keySize, new SecureRandom());
                 algorithm = PGPPublicKey.DSA;
                 break;
             }
 
-            case KeyEditor.AlgorithmChoice.ELGAMAL: {
+            case Id.choice.algorithm.elgamal: {
                 if (keySize != 2048) {
                     throw new GeneralException("ElGamal currently requires 2048bit");
                 }
@@ -323,7 +319,7 @@ public class Apg {
                 break;
             }
 
-            case KeyEditor.AlgorithmChoice.RSA: {
+            case Id.choice.algorithm.rsa: {
                 keyGen = KeyPairGenerator.getInstance("RSA", new BouncyCastleProvider());
                 keyGen.initialize(keySize, new SecureRandom());
 
@@ -429,11 +425,11 @@ public class Apg {
 
         progress.setProgress("preparing master key...", 10, 100);
         KeyEditor keyEditor = (KeyEditor) keyEditors.getChildAt(0);
-        int usageId = keyEditor.getUsage().getId();
-        boolean canSign = (usageId == KeyEditor.UsageChoice.SIGN_ONLY ||
-                           usageId == KeyEditor.UsageChoice.SIGN_AND_ENCRYPT);
-        boolean canEncrypt = (usageId == KeyEditor.UsageChoice.ENCRYPT_ONLY ||
-                              usageId == KeyEditor.UsageChoice.SIGN_AND_ENCRYPT);
+        int usageId = keyEditor.getUsage();
+        boolean canSign = (usageId == Id.choice.usage.sign_only ||
+                           usageId == Id.choice.usage.sign_and_encrypt);
+        boolean canEncrypt = (usageId == Id.choice.usage.encrypt_only ||
+                              usageId == Id.choice.usage.sign_and_encrypt);
 
         String mainUserId = userIds.get(0);
 
@@ -517,11 +513,11 @@ public class Apg {
             unhashedPacketsGen = new PGPSignatureSubpacketGenerator();
 
             keyFlags = 0;
-            usageId = keyEditor.getUsage().getId();
-            canSign = (usageId == KeyEditor.UsageChoice.SIGN_ONLY ||
-                       usageId == KeyEditor.UsageChoice.SIGN_AND_ENCRYPT);
-            canEncrypt = (usageId == KeyEditor.UsageChoice.ENCRYPT_ONLY ||
-                          usageId == KeyEditor.UsageChoice.SIGN_AND_ENCRYPT);
+            usageId = keyEditor.getUsage();
+            canSign = (usageId == Id.choice.usage.sign_only ||
+                       usageId == Id.choice.usage.sign_and_encrypt);
+            canEncrypt = (usageId == Id.choice.usage.encrypt_only ||
+                          usageId == Id.choice.usage.sign_and_encrypt);
             if (canSign) {
                 keyFlags |= KeyFlags.SIGN_DATA;
             }
diff --git a/src/org/thialfihar/android/apg/DecryptFileActivity.java b/src/org/thialfihar/android/apg/DecryptFileActivity.java
new file mode 100644
index 000000000..47be98344
--- /dev/null
+++ b/src/org/thialfihar/android/apg/DecryptFileActivity.java
@@ -0,0 +1,319 @@
+/*
+ * Copyright (C) 2010 Thialfihar <thi@thialfihar.org>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.thialfihar.android.apg;
+
+import java.io.ByteArrayOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.security.Security;
+import java.security.SignatureException;
+
+import org.bouncycastle2.jce.provider.BouncyCastleProvider;
+import org.bouncycastle2.openpgp.PGPException;
+import org.openintents.intents.FileManager;
+
+import android.app.Dialog;
+import android.content.ActivityNotFoundException;
+import android.content.Intent;
+import android.net.Uri;
+import android.os.Bundle;
+import android.os.Message;
+import android.view.View;
+import android.view.View.OnClickListener;
+import android.widget.Button;
+import android.widget.EditText;
+import android.widget.ImageButton;
+import android.widget.ImageView;
+import android.widget.LinearLayout;
+import android.widget.TextView;
+import android.widget.Toast;
+
+public class DecryptFileActivity extends BaseActivity {
+    private EditText mFilename = null;
+    private ImageButton mBrowse = null;
+    private Button mDecryptButton = null;
+    private LinearLayout mSignatureLayout = null;
+    private ImageView mSignatureStatusImage = null;
+    private TextView mUserId = null;
+    private TextView mUserIdRest = null;
+
+    private String mInputFilename = null;
+    private String mOutputFilename = null;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        setContentView(R.layout.decrypt_file);
+
+        mFilename = (EditText) findViewById(R.id.filename);
+        mBrowse = (ImageButton) findViewById(R.id.btn_browse);
+        mBrowse.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                openFile();
+            }
+        });
+
+        mDecryptButton = (Button) findViewById(R.id.btn_decrypt);
+        mDecryptButton.setOnClickListener(new OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                decryptClicked();
+            }
+        });
+
+        mSignatureLayout = (LinearLayout) findViewById(R.id.layout_signature);
+        mSignatureStatusImage = (ImageView) findViewById(R.id.ic_signature_status);
+        mUserId = (TextView) findViewById(R.id.main_user_id);
+        mUserIdRest = (TextView) findViewById(R.id.main_user_id_rest);
+
+        mSignatureLayout.setVisibility(View.INVISIBLE);
+    }
+
+    private void openFile() {
+        String filename = mFilename.getText().toString();
+
+        Intent intent = new Intent(FileManager.ACTION_PICK_FILE);
+
+        intent.setData(Uri.parse("file://" + filename));
+
+        intent.putExtra(FileManager.EXTRA_TITLE, "Select file to decrypt...");
+        intent.putExtra(FileManager.EXTRA_BUTTON_TEXT, "Open");
+
+        try {
+            startActivityForResult(intent, Id.request.filename);
+        } catch (ActivityNotFoundException e) {
+            // No compatible file manager was found.
+            Toast.makeText(this, R.string.no_filemanager_installed, Toast.LENGTH_SHORT).show();
+        }
+    }
+
+    private void decryptClicked() {
+        String error = null;
+        String currentFilename = mFilename.getText().toString();
+        if (mInputFilename == null || !mInputFilename.equals(currentFilename)) {
+            mInputFilename = mFilename.getText().toString();
+            File file = new File(mInputFilename);
+            String filename = file.getName();
+            if (filename.endsWith(".asc") || filename.endsWith(".gpg")) {
+                filename = filename.substring(0, filename.length() - 4);
+            }
+            mOutputFilename = Constants.path.app_dir + "/" + filename;
+        }
+
+        if (mInputFilename.equals("")) {
+            Toast.makeText(this, "Select a file first.", Toast.LENGTH_SHORT).show();
+            return;
+        }
+
+        try {
+            InputStream in = new FileInputStream(mInputFilename);
+            setSecretKeyId(Apg.getDecryptionKeyId(in));
+            showDialog(Id.dialog.pass_phrase);
+        } catch (FileNotFoundException e) {
+            error = "file not found: " + e.getLocalizedMessage();
+        } catch (IOException e) {
+            error = e.getLocalizedMessage();
+        } catch (Apg.GeneralException e) {
+            error = e.getLocalizedMessage();
+        }
+        if (error != null) {
+            Toast.makeText(this, "Error: " + error, Toast.LENGTH_SHORT).show();
+        }
+    }
+
+    @Override
+    public void passPhraseCallback(String passPhrase) {
+        super.passPhraseCallback(passPhrase);
+        askForOutputFilename();
+    }
+
+    private void askForOutputFilename() {
+        showDialog(Id.dialog.output_filename);
+    }
+
+    private void decryptStart() {
+        showDialog(Id.dialog.decrypting);
+        startThread();
+    }
+
+    @Override
+    public void run() {
+        String error = null;
+        Security.addProvider(new BouncyCastleProvider());
+
+        Bundle data = new Bundle();
+        Message msg = new Message();
+
+        try {
+            InputStream in = new FileInputStream(mInputFilename);
+            ByteArrayOutputStream out = new ByteArrayOutputStream();
+
+            data = Apg.decrypt(in, out, Apg.getPassPhrase(), this);
+
+            out.close();
+            OutputStream fileOut = new FileOutputStream(mOutputFilename);
+            fileOut.write(out.toByteArray());
+            fileOut.close();
+        } catch (PGPException e) {
+            error = e.getMessage();
+        } catch (IOException e) {
+            error = e.getMessage();
+        } catch (SignatureException e) {
+            error = e.getMessage();
+            e.printStackTrace();
+        } catch (Apg.GeneralException e) {
+            error = e.getMessage();
+        }
+
+        data.putInt("type", Id.message.done);
+
+        if (error != null) {
+            data.putString("error", error);
+        }
+
+        msg.setData(data);
+        sendMessage(msg);
+    }
+
+    @Override
+    protected Dialog onCreateDialog(int id) {
+        switch (id) {
+            case Id.dialog.output_filename: {
+                return FileDialog.build(this, "Decrypt to file",
+                                        "Please specify which file to decrypt to.\n" +
+                                        "WARNING! File will be overwritten if it exists.",
+                                        mOutputFilename,
+                                        new FileDialog.OnClickListener() {
+
+                                            @Override
+                                            public void onOkClick(String filename) {
+                                                removeDialog(Id.dialog.output_filename);
+                                                mOutputFilename = filename;
+                                                decryptStart();
+                                            }
+
+                                            @Override
+                                            public void onCancelClick() {
+                                                removeDialog(Id.dialog.output_filename);
+                                            }
+                                        },
+                                        getString(R.string.filemanager_title_save),
+                                        getString(R.string.filemanager_btn_save),
+                                        Id.request.output_filename);
+            }
+
+            default: {
+                break;
+            }
+        }
+
+        return super.onCreateDialog(id);
+    }
+
+    @Override
+    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
+        switch (requestCode) {
+            case Id.request.filename: {
+                if (resultCode == RESULT_OK && data != null) {
+                    String filename = data.getDataString();
+                    if (filename != null) {
+                        // Get rid of URI prefix:
+                        if (filename.startsWith("file://")) {
+                            filename = filename.substring(7);
+                        }
+                        // replace %20 and so on
+                        filename = Uri.decode(filename);
+
+                        mFilename.setText(filename);
+                    }
+                }
+                return;
+            }
+
+            case Id.request.output_filename: {
+                if (resultCode == RESULT_OK && data != null) {
+                    String filename = data.getDataString();
+                    if (filename != null) {
+                        // Get rid of URI prefix:
+                        if (filename.startsWith("file://")) {
+                            filename = filename.substring(7);
+                        }
+                        // replace %20 and so on
+                        filename = Uri.decode(filename);
+
+                        FileDialog.setFilename(filename);
+                    }
+                }
+                return;
+            }
+
+            default: {
+                break;
+            }
+        }
+        super.onActivityResult(requestCode, resultCode, data);
+    }
+
+    @Override
+    public void doneCallback(Message msg) {
+        super.doneCallback(msg);
+        Bundle data = msg.getData();
+        removeDialog(Id.dialog.decrypting);
+
+        String error = data.getString("error");
+        if (error != null) {
+            Toast.makeText(DecryptFileActivity.this,
+                           "Error: " + data.getString("error"),
+                           Toast.LENGTH_SHORT).show();
+        } else {
+            Toast.makeText(DecryptFileActivity.this,
+                           "Successfully decrypted.",
+                           Toast.LENGTH_SHORT).show();
+        }
+
+        mSignatureLayout.setVisibility(View.INVISIBLE);
+        if (data.getBoolean("signature")) {
+            String userId = data.getString("signatureUserId");
+            long signatureKeyId = data.getLong("signatureKeyId");
+            mUserIdRest.setText("id: " + Long.toHexString(signatureKeyId & 0xffffffffL));
+            if (userId == null) {
+                userId = getResources().getString(R.string.unknown_user_id);
+            }
+            String chunks[] = userId.split(" <", 2);
+            userId = chunks[0];
+            if (chunks.length > 1) {
+                mUserIdRest.setText("<" + chunks[1]);
+            }
+            mUserId.setText(userId);
+
+            if (data.getBoolean("signatureSuccess")) {
+                mSignatureStatusImage.setImageResource(R.drawable.overlay_ok);
+            } else if (data.getBoolean("signatureUnknown")) {
+                mSignatureStatusImage.setImageResource(R.drawable.overlay_error);
+            } else {
+                mSignatureStatusImage.setImageResource(R.drawable.overlay_error);
+            }
+            mSignatureLayout.setVisibility(View.VISIBLE);
+        }
+    }
+}
diff --git a/src/org/thialfihar/android/apg/DecryptMessageActivity.java b/src/org/thialfihar/android/apg/DecryptMessageActivity.java
index fc2c68ba4..3f2a74987 100644
--- a/src/org/thialfihar/android/apg/DecryptMessageActivity.java
+++ b/src/org/thialfihar/android/apg/DecryptMessageActivity.java
@@ -147,9 +147,8 @@ public class DecryptMessageActivity extends BaseActivity {
 
         // else treat it as an encrypted message
         mSignedOnly = false;
-        ByteArrayInputStream in =
-                new ByteArrayInputStream(messageData.getBytes());
         try {
+            ByteArrayInputStream in = new ByteArrayInputStream(messageData.getBytes());
             setSecretKeyId(Apg.getDecryptionKeyId(in));
             showDialog(Id.dialog.pass_phrase);
         } catch (IOException e) {
@@ -198,15 +197,18 @@ public class DecryptMessageActivity extends BaseActivity {
 
         String messageData = mMessage.getText().toString();
 
-        ByteArrayInputStream in = new ByteArrayInputStream(messageData.getBytes());
-        ByteArrayOutputStream out = new ByteArrayOutputStream();
-
         try {
+            ByteArrayInputStream in = new ByteArrayInputStream(messageData.getBytes());
+            ByteArrayOutputStream out = new ByteArrayOutputStream();
+
             if (mSignedOnly) {
                 data = Apg.verifyText(in, out, this);
             } else {
                 data = Apg.decrypt(in, out, Apg.getPassPhrase(), this);
             }
+
+            out.close();
+            data.putString("decryptedMessage", Strings.fromUTF8ByteArray(out.toByteArray()));
         } catch (PGPException e) {
             error = e.getMessage();
         } catch (IOException e) {
@@ -222,8 +224,6 @@ public class DecryptMessageActivity extends BaseActivity {
 
         if (error != null) {
             data.putString("error", error);
-        } else {
-            data.putString("decryptedMessage", Strings.fromUTF8ByteArray(out.toByteArray()));
         }
 
         msg.setData(data);
@@ -258,13 +258,9 @@ public class DecryptMessageActivity extends BaseActivity {
             if (data.getBoolean("signature")) {
                 String userId = data.getString("signatureUserId");
                 mSignatureKeyId = data.getLong("signatureKeyId");
-                mUserIdRest.setText("id: " +
-                                    Long.toHexString(mSignatureKeyId & 0xffffffffL));
+                mUserIdRest.setText("id: " + Long.toHexString(mSignatureKeyId & 0xffffffffL));
                 if (userId == null) {
-                    userId =
-                            getResources()
-                                    .getString(
-                                               R.string.unknown_user_id);
+                    userId = getResources().getString(R.string.unknown_user_id);
                 }
                 String chunks[] = userId.split(" <", 2);
                 userId = chunks[0];
diff --git a/src/org/thialfihar/android/apg/EncryptFileActivity.java b/src/org/thialfihar/android/apg/EncryptFileActivity.java
index 461938a14..d32f1ccf6 100644
--- a/src/org/thialfihar/android/apg/EncryptFileActivity.java
+++ b/src/org/thialfihar/android/apg/EncryptFileActivity.java
@@ -16,6 +16,7 @@
 
 package org.thialfihar.android.apg;
 
+import java.io.ByteArrayOutputStream;
 import java.io.File;
 import java.io.FileInputStream;
 import java.io.FileNotFoundException;
@@ -267,7 +268,7 @@ public class EncryptFileActivity extends BaseActivity {
             }
 
             InputStream in = new FileInputStream(mInputFilename);
-            OutputStream out = new FileOutputStream(mOutputFilename);
+            ByteArrayOutputStream out = new ByteArrayOutputStream();
 
             if (mTabHost.getCurrentTabTag().equals(TAB_ASYMMETRIC)) {
                 boolean encryptIt = mEncryptionKeyIds != null && mEncryptionKeyIds.length > 0;
@@ -284,6 +285,9 @@ public class EncryptFileActivity extends BaseActivity {
             }
 
             out.close();
+            OutputStream fileOut = new FileOutputStream(mOutputFilename);
+            fileOut.write(out.toByteArray());
+            fileOut.close();
         } catch (FileNotFoundException e) {
             error = "file not found: " + e.getMessage();
         }
diff --git a/src/org/thialfihar/android/apg/Id.java b/src/org/thialfihar/android/apg/Id.java
index 92932a7d6..c96b4ccb7 100644
--- a/src/org/thialfihar/android/apg/Id.java
+++ b/src/org/thialfihar/android/apg/Id.java
@@ -80,5 +80,18 @@ public final class Id {
         public static final int public_key = 0x21070001;
         public static final int secret_key = 0x21070002;
     }
-}
 
+    public static final class choice {
+        public static final class algorithm {
+            public static final int dsa = 0x21070001;
+            public static final int elgamal = 0x21070002;
+            public static final int rsa = 0x21070003;
+        }
+
+        public static final class usage {
+            public static final int sign_only = 0x21070001;
+            public static final int encrypt_only = 0x21070002;
+            public static final int sign_and_encrypt = 0x21070003;
+        }
+    }
+}
diff --git a/src/org/thialfihar/android/apg/MainActivity.java b/src/org/thialfihar/android/apg/MainActivity.java
index b1c656207..d6b04ce92 100644
--- a/src/org/thialfihar/android/apg/MainActivity.java
+++ b/src/org/thialfihar/android/apg/MainActivity.java
@@ -360,7 +360,7 @@ public class MainActivity extends BaseActivity {
     }
 
     public void startDecryptFileActivity() {
-        //startActivity(new Intent(this, DecryptFileActivity.class));
+        startActivity(new Intent(this, DecryptFileActivity.class));
     }
 
     public void startMailListActivity(String account) {
diff --git a/src/org/thialfihar/android/apg/ui/widget/KeyEditor.java b/src/org/thialfihar/android/apg/ui/widget/KeyEditor.java
index 263f34675..15d6eb3ea 100644
--- a/src/org/thialfihar/android/apg/ui/widget/KeyEditor.java
+++ b/src/org/thialfihar/android/apg/ui/widget/KeyEditor.java
@@ -24,7 +24,9 @@ import java.util.Vector;
 
 import org.bouncycastle2.openpgp.PGPSecretKey;
 import org.thialfihar.android.apg.Apg;
+import org.thialfihar.android.apg.Id;
 import org.thialfihar.android.apg.R;
+import org.thialfihar.android.apg.R.id;
 import org.thialfihar.android.apg.utils.Choice;
 
 import android.app.DatePickerDialog;
@@ -65,26 +67,6 @@ public class KeyEditor extends LinearLayout implements Editor, OnClickListener {
                 }
             };
 
-    public static class AlgorithmChoice extends Choice {
-        public static final int DSA = 1;
-        public static final int ELGAMAL = 2;
-        public static final int RSA = 3;
-
-        public AlgorithmChoice(int id, String name) {
-            super(id, name);
-        }
-    }
-
-    public static class UsageChoice extends Choice {
-        public static final int SIGN_ONLY = 1;
-        public static final int ENCRYPT_ONLY = 2;
-        public static final int SIGN_AND_ENCRYPT = 3;
-
-        public UsageChoice(int id, String name) {
-            super(id, name);
-        }
-    }
-
     public KeyEditor(Context context) {
         super(context);
     }
@@ -103,18 +85,17 @@ public class KeyEditor extends LinearLayout implements Editor, OnClickListener {
         mCreationDate = (TextView) findViewById(R.id.creation);
         mExpiryDateButton = (Button) findViewById(R.id.expiry);
         mUsage = (Spinner) findViewById(R.id.usage);
-        KeyEditor.UsageChoice choices[] = {
-                new KeyEditor.UsageChoice(KeyEditor.UsageChoice.SIGN_ONLY,
-                                          getResources().getString(R.string.sign_only)),
-                new KeyEditor.UsageChoice(KeyEditor.UsageChoice.ENCRYPT_ONLY,
-                                          getResources().getString(R.string.encrypt_only)),
-                new KeyEditor.UsageChoice(KeyEditor.UsageChoice.SIGN_AND_ENCRYPT,
-                                          getResources().getString(R.string.sign_and_encrypt)),
+        Choice choices[] = {
+                new Choice(Id.choice.usage.sign_only,
+                           getResources().getString(R.string.sign_only)),
+                new Choice(Id.choice.usage.encrypt_only,
+                           getResources().getString(R.string.encrypt_only)),
+                new Choice(Id.choice.usage.sign_and_encrypt,
+                           getResources().getString(R.string.sign_and_encrypt)),
         };
-        ArrayAdapter<KeyEditor.UsageChoice> adapter =
-                new ArrayAdapter<KeyEditor.UsageChoice>(getContext(),
-                                                        android.R.layout.simple_spinner_item,
-                                                        choices);
+        ArrayAdapter<Choice> adapter =
+                new ArrayAdapter<Choice>(getContext(),
+                                         android.R.layout.simple_spinner_item, choices);
         adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
         mUsage.setAdapter(adapter);
 
@@ -169,18 +150,18 @@ public class KeyEditor extends LinearLayout implements Editor, OnClickListener {
         }
         mKeyId.setText(keyId1Str + " " + keyId2Str);
 
-        Vector<KeyEditor.UsageChoice> choices = new Vector<KeyEditor.UsageChoice>();
-        choices.add(new KeyEditor.UsageChoice(KeyEditor.UsageChoice.SIGN_ONLY,
-                                              getResources().getString(R.string.sign_only)));
+        Vector<Choice> choices = new Vector<Choice>();
+        choices.add(new Choice(Id.choice.usage.sign_only,
+                               getResources().getString(R.string.sign_only)));
         if (!mIsMasterKey) {
-            choices.add(new KeyEditor.UsageChoice(KeyEditor.UsageChoice.ENCRYPT_ONLY,
-                                                  getResources().getString(R.string.encrypt_only)));
+            choices.add(new Choice(Id.choice.usage.encrypt_only,
+                                   getResources().getString(R.string.encrypt_only)));
         }
-        choices.add(new KeyEditor.UsageChoice(KeyEditor.UsageChoice.SIGN_AND_ENCRYPT,
-                                              getResources().getString(R.string.sign_and_encrypt)));
+        choices.add(new Choice(Id.choice.usage.sign_and_encrypt,
+                               getResources().getString(R.string.sign_and_encrypt)));
 
-        ArrayAdapter<KeyEditor.UsageChoice> adapter =
-                new ArrayAdapter<KeyEditor.UsageChoice>(getContext(),
+        ArrayAdapter<Choice> adapter =
+                new ArrayAdapter<Choice>(getContext(),
                                                         android.R.layout.simple_spinner_item,
                                                         choices);
         adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
@@ -242,7 +223,7 @@ public class KeyEditor extends LinearLayout implements Editor, OnClickListener {
      return mExpiryDate;
     }
 
-    public UsageChoice getUsage() {
-        return (UsageChoice) mUsage.getSelectedItem();
+    public int getUsage() {
+        return ((Choice) mUsage.getSelectedItem()).getId();
     }
 }
diff --git a/src/org/thialfihar/android/apg/ui/widget/SectionView.java b/src/org/thialfihar/android/apg/ui/widget/SectionView.java
index b257da409..5a9f47702 100644
--- a/src/org/thialfihar/android/apg/ui/widget/SectionView.java
+++ b/src/org/thialfihar/android/apg/ui/widget/SectionView.java
@@ -25,8 +25,10 @@ import java.util.Vector;
 import org.bouncycastle2.openpgp.PGPException;
 import org.bouncycastle2.openpgp.PGPSecretKey;
 import org.thialfihar.android.apg.Apg;
+import org.thialfihar.android.apg.Id;
 import org.thialfihar.android.apg.R;
 import org.thialfihar.android.apg.ui.widget.Editor.EditorListener;
+import org.thialfihar.android.apg.utils.Choice;
 
 import android.app.AlertDialog;
 import android.app.ProgressDialog;
@@ -57,7 +59,7 @@ public class SectionView extends LinearLayout implements OnClickListener, Editor
     private TextView mTitle;
     private int mType = 0;
 
-    private KeyEditor.AlgorithmChoice mNewKeyAlgorithmChoice;
+    private Choice mNewKeyAlgorithmChoice;
     private int mNewKeySize;
 
     volatile private PGPSecretKey mNewKey;
@@ -181,24 +183,23 @@ public class SectionView extends LinearLayout implements OnClickListener, Editor
                 dialog.setTitle("Create Key");
 
                 final Spinner algorithm = (Spinner) view.findViewById(R.id.algorithm);
-                KeyEditor.AlgorithmChoice choices[] = {
-                        new KeyEditor.AlgorithmChoice(KeyEditor.AlgorithmChoice.DSA,
-                                                      getResources().getString(R.string.dsa)),
-                        /*new KeyEditor.AlgorithmChoice(KeyEditor.AlgorithmChoice.ELGAMAL,
-                                                      getResources().getString(R.string.elgamal)),*/
-                        new KeyEditor.AlgorithmChoice(KeyEditor.AlgorithmChoice.RSA,
-                                                      getResources().getString(R.string.rsa)),
+                Choice choices[] = {
+                        new Choice(Id.choice.algorithm.dsa,
+                                   getResources().getString(R.string.dsa)),
+                        /*new Choice(Id.choice.algorithm.elgamal,
+                                   getResources().getString(R.string.elgamal)),*/
+                        new Choice(Id.choice.algorithm.rsa,
+                                   getResources().getString(R.string.rsa)),
                 };
-                ArrayAdapter<KeyEditor.AlgorithmChoice> adapter =
-                        new ArrayAdapter<KeyEditor.AlgorithmChoice>(
-                                getContext(),
-                                android.R.layout.simple_spinner_item,
-                                choices);
+                ArrayAdapter<Choice> adapter =
+                        new ArrayAdapter<Choice>(getContext(),
+                                                 android.R.layout.simple_spinner_item,
+                                                 choices);
                 adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
                 algorithm.setAdapter(adapter);
                 // make RSA the default
                 for (int i = 0; i < choices.length; ++i) {
-                    if (choices[i].getId() == KeyEditor.AlgorithmChoice.RSA) {
+                    if (choices[i].getId() == Id.choice.algorithm.rsa) {
                         algorithm.setSelection(i);
                         break;
                     }
@@ -217,8 +218,7 @@ public class SectionView extends LinearLayout implements OnClickListener, Editor
                             mNewKeySize = 0;
                         }
 
-                        mNewKeyAlgorithmChoice =
-                                (KeyEditor.AlgorithmChoice) algorithm.getSelectedItem();
+                        mNewKeyAlgorithmChoice = (Choice) algorithm.getSelectedItem();
                         createKey();
                     }
                 });
@@ -294,7 +294,8 @@ public class SectionView extends LinearLayout implements OnClickListener, Editor
     public void run() {
         String error = null;
         try {
-            mNewKey = Apg.createKey(mNewKeyAlgorithmChoice, mNewKeySize, Apg.getPassPhrase());
+            mNewKey = Apg.createKey(mNewKeyAlgorithmChoice.getId(),
+                                    mNewKeySize, Apg.getPassPhrase());
         } catch (NoSuchProviderException e) {
             error = e.getMessage();
         } catch (NoSuchAlgorithmException e) {