steps towards symmetric file encryption

res/layout/encrypt_file.xml

@@ -49,6 +49,12 @@
 
     </LinearLayout>
 
+    <CheckBox
+        android:id="@+id/ascii_armour"
+        android:text="@string/ascii_armour"
+        android:layout_height="wrap_content"
+        android:layout_width="wrap_content"/>
+
     <TabHost
         android:id="@+id/tab_host"
         android:layout_weight="1"
@@ -66,6 +72,7 @@
             android:layout_height="fill_parent"
             android:paddingTop="65dip">
 
+<!-- -->
             <LinearLayout
                 android:id="@+id/tab_asymmetric"
                 android:layout_width="fill_parent"
@@ -132,17 +139,82 @@
                     android:layout_height="0dip"
                     android:layout_weight="1"/>
 
-           </LinearLayout>
-
-           <LinearLayout
+            </LinearLayout>
+ <!-- -->
+            <ScrollView
                 android:id="@+id/tab_symmetric"
                 android:layout_width="fill_parent"
                 android:layout_height="fill_parent"
-                android:orientation="vertical">
+                android:fillViewport="true">
+
+                <LinearLayout
+                    android:layout_width="fill_parent"
+                    android:layout_height="fill_parent"
+                    android:orientation="vertical"
+                    android:paddingTop="3dip">
+
+                    <TableLayout
+                        android:layout_height="fill_parent"
+                        android:layout_width="fill_parent"
+                        android:stretchColumns="1"
+                        android:layout_marginRight="?android:attr/scrollbarSize"
+                        android:paddingLeft="6dip">
+
+                        <TableRow
+                            android:layout_marginBottom="5dip">
+
+                            <TextView android:id="@+id/label_algorithm"
+                                      android:text="Algorithm:"
+                                      android:layout_height="wrap_content"
+                                      android:layout_width="wrap_content"
+                                      android:layout_gravity="center_vertical"
+                                      android:paddingRight="10dip"/>
+
+                            <Spinner
+                                android:id="@+id/algorithm"
+                                android:layout_width="fill_parent"
+                                android:layout_height="wrap_content"/>
+
+                        </TableRow>
+
+                        <TableRow>
+
+                            <TextView android:id="@+id/label_pass_phrase"
+                                      android:text="Pass phrase"
+                                      android:layout_height="wrap_content"
+                                      android:layout_width="wrap_content"
+                                      android:layout_gravity="center_vertical"
+                                      android:paddingRight="10dip"/>
+
+                            <EditText android:id="@+id/pass_phrase"
+                                      android:layout_height="wrap_content"
+                                      android:layout_width="fill_parent"
+                                      android:inputType="textPassword"/>
+
+                        </TableRow>
+
+                        <TableRow>
+
+                            <TextView android:id="@+id/label_pass_phrase_again"
+                                      android:text="Again:"
+                                      android:layout_height="wrap_content"
+                                      android:layout_width="wrap_content"
+                                      android:layout_gravity="center_vertical"
+                                      android:paddingRight="10dip"/>
+
+                            <EditText android:id="@+id/pass_phrase_again"
+                                      android:layout_height="wrap_content"
+                                      android:layout_width="fill_parent"
+                                      android:inputType="textPassword"/>
+
+                        </TableRow>
+
+                    </TableLayout>
 
 
+                </LinearLayout>
 
-           </LinearLayout>
+            </ScrollView>
 
         </FrameLayout>
 

res/values/strings.xml

@@ -83,5 +83,7 @@
     <string name="filemanager_title_save">Save As...</string>
     <string name="filemanager_btn_save">Save</string>
 
+    <string name="ascii_armour">ASCII armour</string>
+
 </resources>
 

src/org/thialfihar/android/apg/Apg.java

@@ -1147,11 +1147,17 @@ public class Apg {
                                boolean armored,
                                long encryptionKeyIds[], long signatureKeyId,
                                String signaturePassPhrase,
-                               ProgressDialogUpdater progress)
+                               ProgressDialogUpdater progress,
+                               int symmetricAlgorithm,
+                               String passPhrase)
             throws IOException, GeneralException, PGPException, NoSuchProviderException,
             NoSuchAlgorithmException, SignatureException {
         Security.addProvider(new BouncyCastleProvider());
 
+        if (encryptionKeyIds == null) {
+            encryptionKeyIds = new long[0];
+        }
+
         ArmoredOutputStream armorOut = null;
         OutputStream out = null;
         OutputStream encryptOut = null;
@@ -1166,8 +1172,8 @@ public class Apg {
         PGPSecretKeyRing signingKeyRing = null;
         PGPPrivateKey signaturePrivateKey = null;
 
-        if (encryptionKeyIds == null || encryptionKeyIds.length == 0) {
-            throw new GeneralException("no encryption key(s) given");
+        if (encryptionKeyIds.length == 0 && passPhrase == null) {
+            throw new GeneralException("no encryption key(s) or pass phrase given");
         }
 
         if (signatureKeyId != 0) {
@@ -1199,9 +1205,13 @@ public class Apg {
         progress.setProgress("preparing streams...", 20, 100);
         // encryptFile and compress input file content
         PGPEncryptedDataGenerator cPk =
-                new PGPEncryptedDataGenerator(PGPEncryptedData.AES_256, true, new SecureRandom(),
+                new PGPEncryptedDataGenerator(symmetricAlgorithm, true, new SecureRandom(),
                                               new BouncyCastleProvider());
 
+        if (encryptionKeyIds.length == 0) {
+            // symmetric encryption
+            cPk.addMethod(passPhrase.toCharArray());
+        }
         for (int i = 0; i < encryptionKeyIds.length; ++i) {
             PGPPublicKey key = getEncryptPublicKey(encryptionKeyIds[i]);
             if (key != null) {

src/org/thialfihar/android/apg/EncryptFileActivity.java

@@ -31,12 +31,14 @@ import java.util.Collections;
 import java.util.Vector;
 
 import org.bouncycastle2.bcpg.HashAlgorithmTags;
+import org.bouncycastle2.openpgp.PGPEncryptedData;
 import org.bouncycastle2.openpgp.PGPException;
 import org.bouncycastle2.openpgp.PGPPublicKeyRing;
 import org.bouncycastle2.openpgp.PGPSecretKey;
 import org.bouncycastle2.openpgp.PGPSecretKeyRing;
 import org.openintents.intents.FileManager;
 import org.thialfihar.android.apg.Apg.GeneralException;
+import org.thialfihar.android.apg.utils.Choice;
 
 import android.app.Dialog;
 import android.content.ActivityNotFoundException;
@@ -47,11 +49,13 @@ import android.os.Environment;
 import android.os.Message;
 import android.view.View;
 import android.view.View.OnClickListener;
+import android.widget.ArrayAdapter;
 import android.widget.Button;
 import android.widget.CheckBox;
 import android.widget.EditText;
 import android.widget.ImageButton;
 import android.widget.ListView;
+import android.widget.Spinner;
 import android.widget.TabHost;
 import android.widget.TextView;
 import android.widget.Toast;
@@ -68,17 +72,24 @@ public class EncryptFileActivity extends BaseActivity {
     private TextView mMainUserId = null;
     private TextView mMainUserIdRest = null;
     private ListView mPublicKeyList = null;
+    private Spinner mAlgorithm = null;
+    private EditText mPassPhrase = null;
+    private EditText mPassPhraseAgain = null;
+    private Button mAsciiArmour = null;
     private Button mEncryptButton = null;
 
     private long mEncryptionKeyIds[] = null;
     private String mInputFilename = null;
     private String mOutputFilename = null;
 
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.encrypt_file);
 
+        mAsciiArmour = (CheckBox) findViewById(R.id.ascii_armour);
+
         mTabHost = (TabHost) findViewById(R.id.tab_host);
         mTabHost.setup();
 
@@ -96,6 +107,8 @@ public class EncryptFileActivity extends BaseActivity {
 
         mTabHost.setCurrentTab(0);
 
+        // asymmetric tab
+
         Vector<PGPPublicKeyRing> keyRings =
                 (Vector<PGPPublicKeyRing>) Apg.getPublicKeyRings().clone();
         Collections.sort(keyRings, new Apg.PublicKeySorter());
@@ -130,6 +143,34 @@ public class EncryptFileActivity extends BaseActivity {
             }
         });
 
+        // symmetric tab
+
+        mAlgorithm = (Spinner) findViewById(R.id.algorithm);
+        Choice choices[] = {
+                new Choice(PGPEncryptedData.AES_128, "AES 128"),
+                new Choice(PGPEncryptedData.AES_192, "AES 192"),
+                new Choice(PGPEncryptedData.AES_256, "AES 256"),
+                new Choice(PGPEncryptedData.BLOWFISH, "Blowfish"),
+                new Choice(PGPEncryptedData.TWOFISH, "Twofish"),
+                new Choice(PGPEncryptedData.CAST5, "CAST5"),
+                new Choice(PGPEncryptedData.DES, "DES"),
+                new Choice(PGPEncryptedData.TRIPLE_DES, "Triple DES"),
+                new Choice(PGPEncryptedData.IDEA, "IDEA"),
+        };
+        ArrayAdapter<Choice> adapter =
+                new ArrayAdapter<Choice>(this, android.R.layout.simple_spinner_item, choices);
+        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
+        mAlgorithm.setAdapter(adapter);
+        for (int i = 0; i < choices.length; ++i) {
+            if (choices[i].getId() == PGPEncryptedData.AES_256) {
+                mAlgorithm.setSelection(i);
+                break;
+            }
+        }
+
+        mPassPhrase = (EditText) findViewById(R.id.pass_phrase);
+        mPassPhraseAgain = (EditText) findViewById(R.id.pass_phrase_again);
+
         mEncryptButton.setOnClickListener(new OnClickListener() {
             @Override
             public void onClick(View v) {
@@ -232,7 +273,20 @@ public class EncryptFileActivity extends BaseActivity {
                 return;
             }
         } else {
+            // symmetric encryption
+            String passPhrase = mPassPhrase.getText().toString();
+            String passPhraseAgain = mPassPhraseAgain.getText().toString();
+            if (!passPhrase.equals(passPhraseAgain)) {
+                Toast.makeText(this, "Pass phrases don't match.",
+                               Toast.LENGTH_SHORT).show();
+                return;
+            }
 
+            if (passPhrase.length() == 0) {
+                Toast.makeText(this, "Enter a pass phrase.",
+                               Toast.LENGTH_SHORT).show();
+                return;
+            }
         }
 
         askForOutputFilename();
@@ -274,14 +328,16 @@ public class EncryptFileActivity extends BaseActivity {
                 boolean encryptIt = mEncryptionKeyIds != null && mEncryptionKeyIds.length > 0;
 
                 if (encryptIt) {
-                    Apg.encrypt(in, out, true, mEncryptionKeyIds, getSecretKeyId(),
-                                Apg.getPassPhrase(), this);
-                } else {
-                    Apg.signText(in, out, getSecretKeyId(),
-                                 Apg.getPassPhrase(), HashAlgorithmTags.SHA256, this);
+                    Apg.encrypt(in, out, mAsciiArmour.isSelected(),
+                                mEncryptionKeyIds, getSecretKeyId(),
+                                Apg.getPassPhrase(), this,
+                                PGPEncryptedData.AES_256, null);
                 }
             } else {
-
+                Apg.encrypt(in, out, mAsciiArmour.isSelected(),
+                            null, 0, null, this,
+                            ((Choice) mAlgorithm.getSelectedItem()).getId(),
+                            mPassPhrase.getText().toString());
             }
 
             out.close();

src/org/thialfihar/android/apg/EncryptMessageActivity.java

@@ -25,6 +25,7 @@ import java.security.SignatureException;
 import java.util.Vector;
 
 import org.bouncycastle2.bcpg.HashAlgorithmTags;
+import org.bouncycastle2.openpgp.PGPEncryptedData;
 import org.bouncycastle2.openpgp.PGPException;
 import org.bouncycastle2.openpgp.PGPPublicKey;
 import org.bouncycastle2.openpgp.PGPPublicKeyRing;
@@ -200,7 +201,8 @@ public class EncryptMessageActivity extends BaseActivity {
 
             if (encryptIt) {
                 Apg.encrypt(in, out, true, mEncryptionKeyIds, getSecretKeyId(),
-                            Apg.getPassPhrase(), this);
+                            Apg.getPassPhrase(), this,
+                            PGPEncryptedData.AES_256, null);
             } else {
                 Apg.signText(in, out, getSecretKeyId(),
                              Apg.getPassPhrase(), HashAlgorithmTags.SHA256, this);

src/org/thialfihar/android/apg/ui/widget/KeyEditor.java

@@ -26,7 +26,6 @@ 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;