-implementation of "--send-key"

-implementation of "--sign-key"
-partial implementation of exchanging/verifying keys via QR Code

AndroidManifest.xml

@@ -183,6 +183,11 @@
             android:label="@string/title_keyServerQuery"
             android:configChanges="keyboardHidden|orientation|keyboard"/>
 
+        <activity
+            android:name=".SendKeyActivity"
+            android:label="@string/title_sendKey"
+            android:configChanges="keyboardHidden|orientation|keyboard"/>
+
         <activity
             android:name=".PreferencesActivity"
             android:label="@string/title_preferences"
@@ -193,6 +198,17 @@
             android:label="@string/title_keyServerPreference"
             android:configChanges="keyboardHidden|orientation|keyboard"/>
 
+        <activity
+            android:name=".SignKeyActivity"
+            android:label="@string/title_signKey"
+            android:configChanges="keyboardHidden|orientation|keyboard"/>
+            
+        <activity
+            android:name=".ImportFromQRCodeActivity"
+            android:label="@string/title_importFromQRCode"
+            android:configChanges="keyboardHidden|orientation|keyboard"/>
+
+
         <service android:name=".Service" />
 
         <provider

pom.xml

@@ -27,7 +27,12 @@
 			<artifactId>scprov-jdk15</artifactId>
 			<version>1.46.99.4-UNOFFICIAL-ROBERTO-RELEASE-SNAPSHOT</version>
 			<type>jar</type>
-			<scope>provided</scope>
+		</dependency>
+		<dependency>
+			<groupId>com.google.zxing</groupId>
+			<artifactId>android-integration</artifactId>
+			<version>1.6-SNAPSHOT</version>
+			<type>jar</type>
 		</dependency>
 	</dependencies>
 	<build>

res/layout/key_server_export_layout.xml

@@ -0,0 +1,42 @@
+<?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">
+
+    <LinearLayout
+        android:layout_width="fill_parent"
+        android:layout_height="wrap_content"
+        android:orientation="horizontal">
+
+	    <Spinner
+	        android:id="@+id/keyServer"
+            android:layout_width="0dip"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"/>
+
+        <Button
+            android:id="@+id/btn_export_to_server"
+            android:text="@string/btn_export_to_server"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"/>
+
+    </LinearLayout>
+
+</LinearLayout>

res/layout/sign_key_layout.xml

@@ -0,0 +1,40 @@
+<?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">
+
+	<LinearLayout android:layout_width="fill_parent"
+		android:layout_height="wrap_content" android:orientation="horizontal">
+	</LinearLayout>
+	
+	<LinearLayout android:layout_width="fill_parent"
+		android:layout_height="wrap_content" android:orientation="horizontal">
+
+		<TextView android:id="@+id/textView1" android:layout_height="wrap_content"
+			android:text="@string/label_sendKey" android:textAppearance="?android:attr/textAppearanceMedium"
+			android:layout_width="wrap_content"></TextView>
+		<CheckBox android:text="" android:id="@+id/sendKey"
+			android:layout_width="wrap_content" android:layout_height="wrap_content"
+			android:checked="true"></CheckBox>
+	</LinearLayout>
+
+	<LinearLayout android:layout_width="fill_parent"
+		android:layout_height="wrap_content" android:orientation="horizontal">
+
+		<Spinner android:id="@+id/keyServer" android:layout_width="wrap_content"
+			android:layout_height="wrap_content" android:layout_weight="1" />
+	</LinearLayout>
+
+	<Button android:layout_height="wrap_content"
+		android:layout_width="wrap_content" android:text="@string/btn_sign"
+		android:id="@+id/sign"></Button>
+
+</LinearLayout>

res/values/strings.xml

@@ -42,7 +42,10 @@
     <string name="title_keyNotFound">Key Not Found</string>
     <string name="title_help">Getting Started</string>
     <string name="title_keyServerQuery">Query Key Server</string>
+    <string name="title_sendKey">Export to Key Server</string>
     <string name="title_unknownSignatureKey">Unknown Signature Key</string>
+    <string name="title_importFromQRCode">Import from QR Code</string>
+    <string name="title_signKey">Sign Key</string>
 
     <!-- section_lowerCase: capitalized words, no punctuation -->
     <string name="section_userIds">User IDs</string>
@@ -74,6 +77,7 @@
     <string name="btn_changePassPhrase">Change Pass Phrase</string>
     <string name="btn_setPassPhrase">Set Pass Phrase</string>
     <string name="btn_search">Search</string>
+    <string name="btn_export_to_server">Export To Server</string>
 
     <!-- menu_lowerCase: capitalized words, no punctuation -->
     <string name="menu_about">About</string>
@@ -92,6 +96,10 @@
     <string name="menu_help">Help</string>
     <string name="menu_keyServer">Key Server</string>
     <string name="menu_updateKey">Update</string>
+    <string name="menu_exportKeyToServer">Export To Server</string>
+    <string name="menu_share">Share</string>
+    <string name="menu_scanQRCode">Scan QR Code</string>
+    <string name="menu_signKey">Sign Key</string>
 
     <!-- label_lowerCase: capitalized words, no punctuation -->
     <string name="label_sign">Sign</string>
@@ -124,6 +132,7 @@
     <string name="label_name">Name</string>
     <string name="label_comment">Comment</string>
     <string name="label_email">Email</string>
+    <string name="label_sendKey">Send Key to Server?</string>
 
     <string name="noKeysSelected">Select</string>
     <string name="oneKeySelected">1 Selected</string>
@@ -217,6 +226,9 @@
     <string name="keyEditingIsBeta">Key editing is still kind of beta.</string>
     <string name="badKeysEncountered">%s bad secret key(s) ignored. Perhaps you exported with the option\n --export-secret-subkeys\nMake sure you export with\n --export-secret-keys\ninstead.</string>
     <string name="lookupUnknownKey">Unknown key %s, do you want to try finding it on a keyserver?</string>
+    <string name="keySendSuccess">Successfully sent key to server</string>
+    <string name="keySignSuccess">Successfully signed key</string>
+    <string name="qrScanImportSuccess">Successfully validated and imported key</string>
 
     <!-- error_lowerCase: phrases, no punctuation, all lowercase,
          they will be put after "errorMessage", e.g. "Error: file not found" -->

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

@@ -61,6 +61,7 @@ import org.spongycastle.openpgp.PGPEncryptedDataGenerator;
 import org.spongycastle.openpgp.PGPEncryptedDataList;
 import org.spongycastle.openpgp.PGPException;
 import org.spongycastle.openpgp.PGPKeyPair;
+import org.spongycastle.openpgp.PGPKeyRing;
 import org.spongycastle.openpgp.PGPKeyRingGenerator;
 import org.spongycastle.openpgp.PGPLiteralData;
 import org.spongycastle.openpgp.PGPLiteralDataGenerator;
@@ -81,6 +82,7 @@ import org.spongycastle.openpgp.PGPSignatureSubpacketGenerator;
 import org.spongycastle.openpgp.PGPSignatureSubpacketVector;
 import org.spongycastle.openpgp.PGPUtil;
 import org.spongycastle.openpgp.PGPV3SignatureGenerator;
+import org.thialfihar.android.apg.KeyServer.AddKeyException;
 import org.thialfihar.android.apg.provider.DataProvider;
 import org.thialfihar.android.apg.provider.Database;
 import org.thialfihar.android.apg.provider.KeyRings;
@@ -119,6 +121,8 @@ public class Apg {
         public static final String LOOK_UP_KEY_ID = "org.thialfihar.android.apg.intent.LOOK_UP_KEY_ID";
         public static final String LOOK_UP_KEY_ID_AND_RETURN = "org.thialfihar.android.apg.intent.LOOK_UP_KEY_ID_AND_RETURN";
         public static final String GENERATE_SIGNATURE = "org.thialfihar.android.apg.intent.GENERATE_SIGNATURE";
+        public static final String EXPORT_KEY_TO_SERVER = "org.thialfihar.android.apg.intent.EXPORT_KEY_TO_SERVER";
+        public static final String IMPORT_FROM_QR_CODE = "org.thialfihar.android.apg.intent.IMPORT_FROM_QR_CODE";
     }
 
     public static final String EXTRA_TEXT = "text";
@@ -147,6 +151,7 @@ public class Apg {
     public static final String EXTRA_ASCII_ARMOUR = "asciiArmour";
     public static final String EXTRA_BINARY = "binary";
     public static final String EXTRA_KEY_SERVERS = "keyServers";
+    public static final String EXTRA_EXPECTED_FINGERPRINT = "org.thialfihar.android.apg.EXPECTED_FINGERPRINT";
 
     public static final String AUTHORITY = DataProvider.AUTHORITY;
 
@@ -591,6 +596,75 @@ public class Apg {
         progress.setProgress(R.string.progress_done, 100, 100);
     }
     
+    public static PGPKeyRing decodeKeyRing(InputStream is) throws IOException {
+        InputStream in = PGPUtil.getDecoderStream(is);
+        PGPObjectFactory objectFactory = new PGPObjectFactory(in);
+        Object obj = objectFactory.nextObject();
+        
+        if (obj instanceof PGPKeyRing) {
+            return (PGPKeyRing) obj;
+        }
+        
+        return null;
+    }
+    
+    public static int storeKeyRingInCache(PGPKeyRing keyring) {
+        int status = Integer.MIN_VALUE; // out of bounds value (Id.retrun_value.*)
+        try {
+            if (keyring instanceof PGPSecretKeyRing) {
+                PGPSecretKeyRing secretKeyRing = (PGPSecretKeyRing) keyring;
+                boolean save = true;
+                try {
+                    PGPPrivateKey testKey = secretKeyRing.getSecretKey().extractPrivateKey(new char[] {}, new BouncyCastleProvider());
+                    if (testKey == null) {
+                        // this is bad, something is very wrong... likely a --export-secret-subkeys export
+                        save = false;
+                        status = Id.return_value.bad;
+                    }
+                } catch (PGPException e) {
+                    // all good if this fails, we likely didn't use the right password
+                }
+                
+                if (save) {
+                    status = mDatabase.saveKeyRing(secretKeyRing);
+                }
+            } else if (keyring instanceof PGPPublicKeyRing) {
+                PGPPublicKeyRing publicKeyRing = (PGPPublicKeyRing) keyring;
+                status = mDatabase.saveKeyRing(publicKeyRing);
+            }
+        } catch (IOException e) {
+            status = Id.return_value.error;
+        } catch (Database.GeneralException e) {
+            status = Id.return_value.error;
+        }
+        
+        return status;
+    }
+    
+    public static boolean uploadKeyRingToServer(HkpKeyServer server, PGPPublicKeyRing keyring) {
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        ArmoredOutputStream aos = new ArmoredOutputStream(bos);
+        try {
+            aos.write(keyring.getEncoded());
+            aos.close();
+            
+            String armouredKey = bos.toString("UTF-8");
+            server.add(armouredKey);
+            
+            return true;
+        } catch (IOException e) {
+            return false;
+        } catch(AddKeyException e) {
+            // TODO: tell the user?
+            return false;
+        } finally {
+            try {
+                bos.close();
+            } catch (IOException e) {
+            }
+        }
+    }
+
     public static Bundle importKeyRings(Activity context, int type,
                                         InputData data,
                                         ProgressDialogUpdater progress)
@@ -616,64 +690,32 @@ public class Apg {
         int oldKeys = 0;
         int badKeys = 0;
         try {
-            while (true) {
+            PGPKeyRing keyring = decodeKeyRing(bufferedInput);
-                InputStream in = PGPUtil.getDecoderStream(bufferedInput);
+            while (keyring != null) {
-                PGPObjectFactory objectFactory = new PGPObjectFactory(in);
+                int status = Integer.MIN_VALUE; // out of bounds value
-                Object obj = objectFactory.nextObject();
-                // if the first is already a null object, then we can stop trying
-                if (obj == null) {
-                    break;
-                }
-                while (obj != null) {
-                    PGPPublicKeyRing publicKeyRing;
-                    PGPSecretKeyRing secretKeyRing;
-                    // a return value that doesn't match any Id.return_value.* values, in case
-                    // saveKeyRing is never called
-                    int retValue = 2107;
                 
-                    try {
+                // if this key is what we expect it to be, save it
-                        if (type == Id.type.secret_key && obj instanceof PGPSecretKeyRing) {
+                if ((type == Id.type.secret_key && keyring instanceof PGPSecretKeyRing) ||
-                            secretKeyRing = (PGPSecretKeyRing) obj;
+                        (type == Id.type.public_key && keyring instanceof PGPPublicKeyRing)) {
-                            boolean save = true;
+                    status = storeKeyRingInCache(keyring);
-                            try {
-                                PGPPrivateKey testKey = secretKeyRing.getSecretKey()
-                                        .extractPrivateKey(new char[] {}, new BouncyCastleProvider());
-                                if (testKey == null) {
-                                    // this is bad, something is very wrong... likely a
-                                    // --export-secret-subkeys export
-                                    retValue = Id.return_value.bad;
-                                    save = false;
-                                }
-                            } catch (PGPException e) {
-                                // all good if this fails, we likely didn't use the right password
-                            }
-                            if (save) {
-                                retValue = mDatabase.saveKeyRing(secretKeyRing);
-                            }
-                        } else if (type == Id.type.public_key && obj instanceof PGPPublicKeyRing) {
-                            publicKeyRing = (PGPPublicKeyRing) obj;
-                            retValue = mDatabase.saveKeyRing(publicKeyRing);
-                        }
-                    } catch (IOException e) {
-                        retValue = Id.return_value.error;
-                    } catch (Database.GeneralException e) {
-                        retValue = Id.return_value.error;
                 }
 
-                    if (retValue == Id.return_value.error) {
+                if (status == Id.return_value.error) {
                     throw new GeneralException(context.getString(R.string.error_savingKeys));
                 }
 
-                    if (retValue == Id.return_value.updated) {
+                // update the counts to display to the user at the end
+                if (status == Id.return_value.updated) {
                     ++oldKeys;
-                    } else if (retValue == Id.return_value.ok) {
+                } else if (status == Id.return_value.ok) {
                     ++newKeys;
-                    } else if (retValue == Id.return_value.bad) {
+                } else if (status == Id.return_value.bad) {
                     ++badKeys;
                 }
+                
                 progress.setProgress((int)(100 * progressIn.position() / data.getSize()), 100);
-                    obj = objectFactory.nextObject();
+                
-                }
+                keyring = decodeKeyRing(bufferedInput);
             }
         } catch (EOFException e) {
             // nothing to do, we are done
@@ -1038,18 +1080,8 @@ public class Apg {
         return algorithmStr + ", " + keySize + "bit";
     }
 
-    public static String getFingerPrint(long keyId) {
+    public static String convertToHex(byte[] fp) {
-        PGPPublicKey key = Apg.getPublicKey(keyId);
-        if (key == null) {
-            PGPSecretKey secretKey = Apg.getSecretKey(keyId);
-            if (secretKey == null) {
-                return "";
-            }
-            key = secretKey.getPublicKey();
-        }
-
         String fingerPrint = "";
-        byte fp[] = key.getFingerprint();
         for (int i = 0; i < fp.length; ++i) {
             if (i != 0 && i % 10 == 0) {
                 fingerPrint += "  ";
@@ -1064,6 +1096,20 @@ public class Apg {
         }
 
         return fingerPrint;
+        
+    }
+    
+    public static String getFingerPrint(long keyId) {
+        PGPPublicKey key = Apg.getPublicKey(keyId);
+        if (key == null) {
+            PGPSecretKey secretKey = Apg.getSecretKey(keyId);
+            if (secretKey == null) {
+                return "";
+            }
+            key = secretKey.getPublicKey();
+        }
+
+        return convertToHex(key.getFingerprint());
     }
 
     public static String getSmallFingerPrint(long keyId) {
@@ -1089,8 +1135,8 @@ public class Apg {
         mDatabase.deleteKeyRing(keyRingId);
     }
 
-    public static Object getKeyRing(int keyRingId) {
+    public static PGPKeyRing getKeyRing(int keyRingId) {
-        return mDatabase.getKeyRing(keyRingId);
+        return (PGPKeyRing) mDatabase.getKeyRing(keyRingId);
     }
 
     public static PGPSecretKeyRing getSecretKeyRing(long keyId) {

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

@@ -164,6 +164,13 @@ public class BaseActivity extends Activity
                 return mProgressDialog;
             }
             
+            case Id.dialog.signing: {
+                mProgressDialog.setMessage(this.getString(R.string.progress_signing));
+                mProgressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
+                mProgressDialog.setCancelable(false);
+                return mProgressDialog;
+            }
+
             default: {
                 break;
             }

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

@@ -10,12 +10,25 @@ import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLEncoder;
 import java.net.UnknownHostException;
+import java.util.ArrayList;
 import java.util.GregorianCalendar;
 import java.util.List;
 import java.util.Vector;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import org.apache.http.HttpEntity;
+import org.apache.http.HttpResponse;
+import org.apache.http.HttpStatus;
+import org.apache.http.NameValuePair;
+import org.apache.http.client.HttpClient;
+import org.apache.http.client.entity.UrlEncodedFormEntity;
+import org.apache.http.client.methods.HttpGet;
+import org.apache.http.client.methods.HttpPost;
+import org.apache.http.impl.client.DefaultHttpClient;
+import org.apache.http.message.BasicNameValuePair;
+import org.apache.http.util.EntityUtils;
+
 import android.text.Html;
 
 public class HkpKeyServer extends KeyServer {
@@ -38,16 +51,14 @@ public class HkpKeyServer extends KeyServer {
             return mData;
         }
     }
+
     private String mHost;
     private short mPort = 11371;
 
     // example:
     // pub  2048R/<a href="/pks/lookup?op=get&search=0x887DF4BE9F5C9090">9F5C9090</a> 2009-08-17 <a href="/pks/lookup?op=vindex&search=0x887DF4BE9F5C9090">Jörg Runge &lt;joerg@joergrunge.de&gt;</a>
-    public static Pattern PUB_KEY_LINE =
+    public static Pattern PUB_KEY_LINE = Pattern.compile("pub +([0-9]+)([a-z]+)/.*?0x([0-9a-z]+).*? +([0-9-]+) +(.+)[\n\r]+((?:    +.+[\n\r]+)*)", Pattern.CASE_INSENSITIVE);
-            Pattern.compile("pub +([0-9]+)([a-z]+)/.*?0x([0-9a-z]+).*? +([0-9-]+) +(.+)[\n\r]+((?:    +.+[\n\r]+)*)",
+    public static Pattern USER_ID_LINE = Pattern.compile("^   +(.+)$", Pattern.MULTILINE | Pattern.CASE_INSENSITIVE);
-                            Pattern.CASE_INSENSITIVE);
-    public static Pattern USER_ID_LINE =
-            Pattern.compile("^   +(.+)$", Pattern.MULTILINE | Pattern.CASE_INSENSITIVE);
 
     public HkpKeyServer(String host) {
         mHost = host;
@@ -58,8 +69,7 @@ public class HkpKeyServer extends KeyServer {
         mPort = port;
     }
 
-    static private String readAll(InputStream in, String encoding)
+    static private String readAll(InputStream in, String encoding) throws IOException {
-            throws IOException {
         ByteArrayOutputStream raw = new ByteArrayOutputStream();
 
         byte buffer[] = new byte[1 << 16];
@@ -74,8 +84,8 @@ public class HkpKeyServer extends KeyServer {
         return raw.toString(encoding);
     }
 
-    private String query(String request)
+    // TODO: replace this with httpclient
-            throws QueryException, HttpError {
+    private String query(String request) throws QueryException, HttpError {
         InetAddress ips[];
         try {
             ips = InetAddress.getAllByName(mHost);
@@ -93,8 +103,7 @@ public class HkpKeyServer extends KeyServer {
                 int response = conn.getResponseCode();
                 if (response >= 200 && response < 300) {
                     return readAll(conn.getInputStream(), conn.getContentEncoding());
-                }
+                } else {
-                else {
                     String data = readAll(conn.getErrorStream(), conn.getContentEncoding());
                     throw new HttpError(response, data);
                 }
@@ -108,9 +117,9 @@ public class HkpKeyServer extends KeyServer {
         throw new QueryException("querying server(s) for '" + mHost + "' failed");
     }
 
+    // TODO: replace this with httpclient
     @Override
-    List<KeyInfo> search(String query)
+    List<KeyInfo> search(String query) throws QueryException, TooManyResponses, InsufficientQuery {
-            throws QueryException, TooManyResponses, InsufficientQuery {
         Vector<KeyInfo> results = new Vector<KeyInfo>();
 
         if (query.length() < 3) {
@@ -151,9 +160,7 @@ public class HkpKeyServer extends KeyServer {
             info.keyId = Apg.keyFromHex(matcher.group(3));
             info.fingerPrint = Apg.getSmallFingerPrint(info.keyId);
             String chunks[] = matcher.group(4).split("-");
-            info.date = new GregorianCalendar(Integer.parseInt(chunks[0]),
+            info.date = new GregorianCalendar(Integer.parseInt(chunks[0]), Integer.parseInt(chunks[1]), Integer.parseInt(chunks[2])).getTime();
-                                              Integer.parseInt(chunks[1]),
-                                              Integer.parseInt(chunks[2])).getTime();
             info.userIds = new Vector<String>();
             if (matcher.group(5).startsWith("*** KEY")) {
                 info.revoked = matcher.group(5);
@@ -177,21 +184,50 @@ public class HkpKeyServer extends KeyServer {
     }
 
     @Override
-    String get(long keyId)
+    String get(long keyId) throws QueryException {
-            throws QueryException {
+        HttpClient client = new DefaultHttpClient();
-        String request = "/pks/lookup?op=get&search=0x" + Apg.keyToHex(keyId);
-
-        String data = null;
         try {
-            data = query(request);
+            HttpGet get = new HttpGet("http://" + mHost + ":" + mPort + "/pks/lookup?op=get&search=0x" + Apg.keyToHex(keyId));
-        } catch (HttpError e) {
+            
+            HttpResponse response = client.execute(get);
+            if (response.getStatusLine().getStatusCode() != HttpStatus.SC_OK) {
                 throw new QueryException("not found");
             }
+            
+            HttpEntity entity = response.getEntity();
+            InputStream is = entity.getContent();
+            String data = readAll(is, EntityUtils.getContentCharSet(entity));
             Matcher matcher = Apg.PGP_PUBLIC_KEY.matcher(data);
             if (matcher.find()) {
                 return matcher.group(1);
             }
+        } catch (IOException e) {
+            // nothing to do, better luck on the next keyserver
+        } finally {
+            client.getConnectionManager().shutdown();
+        }
         
         return null;
     }
+
+    @Override
+    void add(String armouredText) throws AddKeyException {
+        HttpClient client = new DefaultHttpClient();
+        try {
+            HttpPost post = new HttpPost("http://" + mHost + ":" + mPort + "/pks/add");
+            
+            List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
+            nameValuePairs.add(new BasicNameValuePair("keytext", armouredText));
+            post.setEntity(new UrlEncodedFormEntity(nameValuePairs));
+            
+            HttpResponse response = client.execute(post);
+            if (response.getStatusLine().getStatusCode() != HttpStatus.SC_OK) {
+                throw new AddKeyException();
+            }
+        } catch (IOException e) {
+            // nothing to do, better luck on the next keyserver
+        } finally {
+            client.getConnectionManager().shutdown();
+        }
+    }
 }

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

@@ -18,12 +18,16 @@ package org.thialfihar.android.apg;
 
 import org.spongycastle.bcpg.CompressionAlgorithmTags;
 
+
 public final class Id {
     public static final class menu {
         public static final int export = 0x21070001;
         public static final int delete = 0x21070002;
         public static final int edit = 0x21070003;
         public static final int update = 0x21070004;
+        public static final int exportToServer = 0x21070005;
+        public static final int share = 0x21070006;
+        public static final int signKey = 0x21070007;
 
         public static final class option {
             public static final int new_pass_phrase = 0x21070001;
@@ -37,6 +41,7 @@ public final class Id {
             public static final int search = 0x21070009;
             public static final int help = 0x21070010;
             public static final int key_server = 0x21070011;
+            public static final int scanQRCode = 0x21070012;
         }
     }
 
@@ -61,6 +66,9 @@ public final class Id {
         public static final int output_filename = 0x21070004;
         public static final int key_server_preference = 0x21070005;
         public static final int look_up_key_id = 0x21070006;
+        public static final int export_to_server = 0x21070007;
+        public static final int import_from_qr_code = 0x21070008;
+        public static final int sign_key = 0x21070009;
     }
 
     public static final class dialog {
@@ -86,6 +94,7 @@ public final class Id {
         public static final int help = 0x21070014;
         public static final int querying = 0x21070015;
         public static final int lookup_unknown_key = 0x21070016;
+        public static final int signing = 0x21070017;
     }
 
     public static final class task {
@@ -166,8 +175,9 @@ public final class Id {
         public static final int keys = 2;
     }
 
-    public static final class query {
+    public static final class keyserver {
         public static final int search = 0x21070001;
         public static final int get = 0x21070002;
+        public static final int add = 0x21070003;
     }
 }

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

@@ -0,0 +1,133 @@
+package org.thialfihar.android.apg;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+
+import org.spongycastle.openpgp.PGPKeyRing;
+import org.spongycastle.openpgp.PGPPublicKeyRing;
+import org.thialfihar.android.apg.KeyServer.QueryException;
+
+import android.content.Intent;
+import android.os.Bundle;
+import android.os.Message;
+import android.util.Log;
+import android.widget.Toast;
+
+import com.google.zxing.integration.android.IntentIntegrator;
+import com.google.zxing.integration.android.IntentResult;
+
+public class ImportFromQRCodeActivity extends BaseActivity {
+    private static final String TAG = "ImportFromQRCodeActivity";
+
+    private final Bundle status = new Bundle();
+    private final Message msg = new Message();
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        IntentIntegrator.initiateScan(this);
+    }
+
+    private void importAndSign(final long keyId, final String expectedFingerprint) {
+        if (expectedFingerprint != null && expectedFingerprint.length() > 0) {
+            
+            Thread t = new Thread() {
+                @Override
+                public void run() {
+                    try {
+                        // TODO: display some sort of spinner here while the user waits
+                        
+                        HkpKeyServer server = new HkpKeyServer(mPreferences.getKeyServers()[0]); // TODO: there should be only 1
+                        String encodedKey = server.get(keyId);
+
+                        PGPKeyRing keyring = Apg.decodeKeyRing(new ByteArrayInputStream(encodedKey.getBytes()));
+                        if (keyring != null && keyring instanceof PGPPublicKeyRing) {
+                            PGPPublicKeyRing publicKeyRing = (PGPPublicKeyRing) keyring;
+
+                            // make sure the fingerprints match before we cache this thing
+                            String actualFingerprint = Apg.convertToHex(publicKeyRing.getPublicKey().getFingerprint());
+                            if (expectedFingerprint.equals(actualFingerprint)) {
+                                // store the signed key in our local cache
+                                int retval = Apg.storeKeyRingInCache(publicKeyRing);
+                                if (retval != Id.return_value.ok && retval != Id.return_value.updated) {
+                                    status.putString(Apg.EXTRA_ERROR, "Failed to store signed key in local cache");
+                                } else {
+                                    Intent intent = new Intent(ImportFromQRCodeActivity.this, SignKeyActivity.class);
+                                    intent.putExtra(Apg.EXTRA_KEY_ID, keyId);
+                                    startActivityForResult(intent, Id.request.sign_key);
+                                }
+                            } else {
+                                status.putString(Apg.EXTRA_ERROR, "Scanned fingerprint does NOT match the fingerprint of the received key.  You shouldnt trust this key.");
+                            }
+                        }
+                    } catch (QueryException e) {
+                        Log.e(TAG, "Failed to query KeyServer", e);
+                        status.putString(Apg.EXTRA_ERROR, "Failed to query KeyServer");
+                        status.putInt(Constants.extras.status, Id.message.done);
+                    } catch (IOException e) {
+                        Log.e(TAG, "Failed to query KeyServer", e);
+                        status.putString(Apg.EXTRA_ERROR, "Failed to query KeyServer");
+                        status.putInt(Constants.extras.status, Id.message.done);
+                    }
+                }
+            };
+
+            t.setName("KeyExchange Download Thread");
+            t.setDaemon(true);
+            t.start();
+        }
+    }
+
+    @Override
+    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
+        switch (requestCode) {
+            case IntentIntegrator.REQUEST_CODE: {
+                boolean debug = true; // TODO: remove this!!!
+                IntentResult scanResult = IntentIntegrator.parseActivityResult(requestCode, resultCode, data);
+                if (debug || (scanResult != null && scanResult.getFormatName() != null)) {
+                    String[] bits = debug ? new String[] { "5993515643896327656", "0816 F68A 6816 68FB 01BF  2CA5 532D 3EB9 1E2F EDE8" } : scanResult.getContents().split(",");
+                    if (bits.length != 2) {
+                        return; // dont know how to handle this.  Not a valid code
+                    }
+
+                    long keyId = Long.parseLong(bits[0]);
+                    String expectedFingerprint = bits[1];
+                    
+                    importAndSign(keyId, expectedFingerprint);
+                    
+                    break;
+                }
+            }
+            
+            case Id.request.sign_key: {
+                // signals the end of processing.  Signature was either applied, or it wasnt
+                status.putInt(Constants.extras.status, Id.message.done);
+                
+                msg.setData(status);
+                sendMessage(msg);
+                
+                break;
+            }
+
+            default: {
+                super.onActivityResult(requestCode, resultCode, data);
+            }
+        }
+    }
+    
+    @Override
+    public void doneCallback(Message msg) {
+        super.doneCallback(msg);
+        
+        Bundle data = msg.getData();
+        String error = data.getString(Apg.EXTRA_ERROR);
+        if (error != null) {
+            Toast.makeText(this, getString(R.string.errorMessage, error), Toast.LENGTH_SHORT).show();
+            return;
+        }
+
+        Toast.makeText(this, R.string.keySignSuccess, Toast.LENGTH_SHORT).show(); // TODO
+        finish();
+    }
+}

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

@@ -33,6 +33,9 @@ import org.thialfihar.android.apg.provider.KeyRings;
 import org.thialfihar.android.apg.provider.Keys;
 import org.thialfihar.android.apg.provider.UserIds;
 
+import com.google.zxing.integration.android.IntentIntegrator;
+import com.google.zxing.integration.android.IntentResult;
+
 import android.app.AlertDialog;
 import android.app.Dialog;
 import android.app.SearchManager;

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

@@ -12,12 +12,19 @@ public abstract class KeyServer {
             super(message);
         }
     }
+    
     static public class TooManyResponses extends Exception {
         private static final long serialVersionUID = 2703768928624654513L;
     }
+    
     static public class InsufficientQuery extends Exception {
         private static final long serialVersionUID = 2703768928624654514L;
     }
+    
+    static public class AddKeyException extends Exception {
+        private static final long serialVersionUID = -507574859137295530L;
+    }
+    
     static public class KeyInfo implements Serializable {
         private static final long serialVersionUID = -7797972113284992662L;
         Vector<String> userIds;
@@ -28,6 +35,8 @@ public abstract class KeyServer {
         int size;
         String algorithm;
     }
+    
     abstract List<KeyInfo> search(String query) throws QueryException, TooManyResponses, InsufficientQuery;
     abstract String get(long keyId) throws QueryException;
+    abstract void add(String armouredText) throws AddKeyException;
 }

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

@@ -99,7 +99,7 @@ public class KeyServerQueryActivity extends BaseActivity {
 
     private void search(String query) {
         showDialog(Id.dialog.querying);
-        mQueryType = Id.query.search;
+        mQueryType = Id.keyserver.search;
         mQueryString = query;
         mAdapter.setKeys(new Vector<KeyInfo>());
         startThread();
@@ -107,7 +107,7 @@ public class KeyServerQueryActivity extends BaseActivity {
 
     private void get(long keyId) {
         showDialog(Id.dialog.querying);
-        mQueryType = Id.query.get;
+        mQueryType = Id.keyserver.get;
         mQueryId = keyId;
         startThread();
     }
@@ -127,9 +127,9 @@ public class KeyServerQueryActivity extends BaseActivity {
 
         try {
             HkpKeyServer server = new HkpKeyServer((String)mKeyServer.getSelectedItem());
-            if (mQueryType == Id.query.search) {
+            if (mQueryType == Id.keyserver.search) {
                 mSearchResult = server.search(mQueryString);
-            } else if (mQueryType == Id.query.get) {
+            } else if (mQueryType == Id.keyserver.get) {
                 mKeyData = server.get(mQueryId);
             }
         } catch (QueryException e) {
@@ -163,12 +163,12 @@ public class KeyServerQueryActivity extends BaseActivity {
             return;
         }
 
-        if (mQueryType == Id.query.search) {
+        if (mQueryType == Id.keyserver.search) {
             if (mSearchResult != null) {
                 Toast.makeText(this, getString(R.string.keysFound, mSearchResult.size()), Toast.LENGTH_SHORT).show();
                 mAdapter.setKeys(mSearchResult);
             }
-        } else if (mQueryType == Id.query.get) {
+        } else if (mQueryType == Id.keyserver.get) {
             Intent orgIntent = getIntent();
             if (Apg.Intent.LOOK_UP_KEY_ID_AND_RETURN.equals(orgIntent.getAction())) {
                 if (mKeyData != null) {

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

@@ -16,9 +16,11 @@
 
 package org.thialfihar.android.apg;
 
+import java.security.Security;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
+import org.spongycastle.jce.provider.BouncyCastleProvider;
 import org.thialfihar.android.apg.provider.Accounts;
 
 import android.app.AlertDialog;
@@ -51,6 +53,10 @@ import android.widget.TextView;
 import android.widget.Toast;
 
 public class MainActivity extends BaseActivity {
+    static {
+        Security.addProvider(new BouncyCastleProvider());
+    }
+    
     private ListView mAccounts = null;
     private AccountListAdapter mListAdapter = null;
     private Cursor mAccountCursor;

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

@@ -18,6 +18,9 @@ package org.thialfihar.android.apg;
 
 import org.spongycastle.openpgp.PGPPublicKeyRing;
 
+import com.google.zxing.integration.android.IntentIntegrator;
+import com.google.zxing.integration.android.IntentResult;
+
 import android.content.Intent;
 import android.os.Bundle;
 import android.view.ContextMenu;
@@ -48,6 +51,8 @@ public class PublicKeyListActivity extends KeyListActivity {
                 .setIcon(android.R.drawable.ic_menu_preferences);
         menu.add(1, Id.menu.option.about, 4, R.string.menu_about)
                 .setIcon(android.R.drawable.ic_menu_info_details);
+        menu.add(1, Id.menu.option.scanQRCode, 5, R.string.menu_scanQRCode)
+                .setIcon(android.R.drawable.ic_menu_add);
         return true;
     }
 
@@ -63,6 +68,8 @@ public class PublicKeyListActivity extends KeyListActivity {
             menu.add(0, Id.menu.export, 0, R.string.menu_exportKey);
             menu.add(0, Id.menu.delete, 1, R.string.menu_deleteKey);
             menu.add(0, Id.menu.update, 1, R.string.menu_updateKey);
+            menu.add(0, Id.menu.exportToServer, 1, R.string.menu_exportKeyToServer);
+            menu.add(0, Id.menu.signKey, 1, R.string.menu_signKey);
         }
     }
 
@@ -94,6 +101,40 @@ public class PublicKeyListActivity extends KeyListActivity {
                 intent.setAction(Apg.Intent.LOOK_UP_KEY_ID_AND_RETURN);
                 intent.putExtra(Apg.EXTRA_KEY_ID, keyId);
                 startActivityForResult(intent, Id.request.look_up_key_id);
+                
+                return true;
+            }
+
+            case Id.menu.exportToServer: {
+                mSelectedItem = groupPosition;
+                final int keyRingId = mListAdapter.getKeyRingId(groupPosition);
+                
+                Intent intent = new Intent(this, SendKeyActivity.class);
+                intent.setAction(Apg.Intent.EXPORT_KEY_TO_SERVER);
+                intent.putExtra(Apg.EXTRA_KEY_ID, keyRingId);
+                startActivityForResult(intent, Id.request.export_to_server);
+                
+                return true;
+            }
+            
+            case Id.menu.signKey: {
+                mSelectedItem = groupPosition;
+                final int keyRingId = mListAdapter.getKeyRingId(groupPosition);
+                long keyId = 0;
+                Object keyRing = Apg.getKeyRing(keyRingId);
+                if (keyRing != null && keyRing instanceof PGPPublicKeyRing) {
+                    keyId = Apg.getMasterKey((PGPPublicKeyRing) keyRing).getKeyID();
+                }
+                
+                if (keyId == 0) {
+                    // this shouldn't happen
+                    return true;
+                }
+                
+                Intent intent = new Intent(this, SignKeyActivity.class);
+                intent.putExtra(Apg.EXTRA_KEY_ID, keyId);
+                startActivity(intent);
+                
                 return true;
             }
             
@@ -103,6 +144,23 @@ public class PublicKeyListActivity extends KeyListActivity {
         }
     }
     
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        switch (item.getItemId()) {
+            case Id.menu.option.scanQRCode: {
+                Intent intent = new Intent(this, ImportFromQRCodeActivity.class);
+                intent.setAction(Apg.Intent.IMPORT_FROM_QR_CODE);
+                startActivityForResult(intent, Id.request.import_from_qr_code);
+
+                return true;
+            }
+
+            default: {
+                return super.onOptionsItemSelected(item);
+            }
+        }
+    }
+
     @Override
     protected void onActivityResult(int requestCode, int resultCode, Intent data) {
         switch (requestCode) {

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

@@ -28,6 +28,8 @@ import android.widget.ExpandableListView;
 import android.widget.ExpandableListView.ExpandableListContextMenuInfo;
 import android.widget.ExpandableListView.OnChildClickListener;
 
+import com.google.zxing.integration.android.IntentIntegrator;
+
 public class SecretKeyListActivity extends KeyListActivity implements OnChildClickListener {
     @Override
     public void onCreate(Bundle savedInstanceState) {
@@ -80,6 +82,7 @@ public class SecretKeyListActivity extends KeyListActivity implements OnChildCli
             menu.add(0, Id.menu.edit, 0, R.string.menu_editKey);
             menu.add(0, Id.menu.export, 1, R.string.menu_exportKey);
             menu.add(0, Id.menu.delete, 2, R.string.menu_deleteKey);
+            menu.add(0, Id.menu.share, 2, R.string.menu_share);
         }
     }
 
@@ -100,6 +103,14 @@ public class SecretKeyListActivity extends KeyListActivity implements OnChildCli
                 return true;
             }
 
+            case Id.menu.share: {
+                mSelectedItem = groupPosition;
+                
+                long keyId = ((KeyListAdapter) mList.getExpandableListAdapter()).getGroupId(mSelectedItem);
+                String msg = keyId + "," + Apg.getFingerPrint(keyId);;
+                IntentIntegrator.shareText(this, msg);
+            }
+
             default: {
                 return super.onContextItemSelected(menuItem);
             }

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

@@ -0,0 +1,93 @@
+package org.thialfihar.android.apg;
+
+import org.spongycastle.openpgp.PGPKeyRing;
+import org.spongycastle.openpgp.PGPPublicKeyRing;
+
+import android.os.Bundle;
+import android.os.Message;
+import android.view.View;
+import android.view.View.OnClickListener;
+import android.widget.ArrayAdapter;
+import android.widget.Button;
+import android.widget.Spinner;
+import android.widget.Toast;
+
+/**
+ * gpg --send-key activity
+ * 
+ * Sends the selected public key to a key server
+ */
+public class SendKeyActivity extends BaseActivity {
+
+    private Button export;
+    private Spinner keyServer;
+
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        setContentView(R.layout.key_server_export_layout);
+
+        export = (Button) findViewById(R.id.btn_export_to_server);
+        keyServer = (Spinner) findViewById(R.id.keyServer);
+
+        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, mPreferences.getKeyServers());
+        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
+        keyServer.setAdapter(adapter);
+        if (adapter.getCount() > 0) {
+            keyServer.setSelection(0);
+        } else {
+            export.setEnabled(false);
+        }
+
+        export.setOnClickListener(new OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                startThread();
+            }
+        });
+    }
+
+    @Override
+    public void run() {
+        String error = null;
+        Bundle data = new Bundle();
+        Message msg = new Message();
+
+        HkpKeyServer server = new HkpKeyServer((String) keyServer.getSelectedItem());
+
+        int keyRingId = getIntent().getIntExtra(Apg.EXTRA_KEY_ID, -1);
+
+        PGPKeyRing keyring = Apg.getKeyRing(keyRingId);
+        if (keyring != null && keyring instanceof PGPPublicKeyRing) {
+            boolean uploaded = Apg.uploadKeyRingToServer(server, (PGPPublicKeyRing) keyring);
+            if (!uploaded) {
+                error = "Unable to export key to selected server";
+            }
+        }
+
+        data.putInt(Constants.extras.status, Id.message.export_done);
+
+        if (error != null) {
+            data.putString(Apg.EXTRA_ERROR, error);
+        }
+
+        msg.setData(data);
+        sendMessage(msg);
+    }
+
+    @Override
+    public void doneCallback(Message msg) {
+        super.doneCallback(msg);
+
+        Bundle data = msg.getData();
+        String error = data.getString(Apg.EXTRA_ERROR);
+        if (error != null) {
+            Toast.makeText(this, getString(R.string.errorMessage, error), Toast.LENGTH_SHORT).show();
+            return;
+        }
+
+        Toast.makeText(this, R.string.keySendSuccess, Toast.LENGTH_SHORT).show();
+        finish();
+    }
+}

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

@@ -0,0 +1,284 @@
+package org.thialfihar.android.apg;
+
+import java.security.NoSuchAlgorithmException;
+import java.security.NoSuchProviderException;
+import java.security.SignatureException;
+import java.util.Iterator;
+
+import org.spongycastle.jce.provider.BouncyCastleProvider;
+import org.spongycastle.openpgp.PGPException;
+import org.spongycastle.openpgp.PGPPrivateKey;
+import org.spongycastle.openpgp.PGPPublicKey;
+import org.spongycastle.openpgp.PGPPublicKeyRing;
+import org.spongycastle.openpgp.PGPSecretKey;
+import org.spongycastle.openpgp.PGPSignature;
+import org.spongycastle.openpgp.PGPSignatureGenerator;
+import org.spongycastle.openpgp.PGPSignatureSubpacketGenerator;
+import org.spongycastle.openpgp.PGPSignatureSubpacketVector;
+import org.spongycastle.openpgp.PGPUtil;
+
+import android.content.Intent;
+import android.os.Bundle;
+import android.os.Message;
+import android.util.Log;
+import android.view.View;
+import android.view.View.OnClickListener;
+import android.widget.ArrayAdapter;
+import android.widget.Button;
+import android.widget.CheckBox;
+import android.widget.CompoundButton;
+import android.widget.CompoundButton.OnCheckedChangeListener;
+import android.widget.Spinner;
+import android.widget.Toast;
+
+/**
+ * gpg --sign-key
+ * 
+ * signs the specified public key with the specified secret master key
+ */
+public class SignKeyActivity extends BaseActivity {
+    private static final String TAG = "SignKeyActivity";
+
+    private long pubKeyId = 0;
+    private long masterKeyId = 0;
+    
+    @Override
+    protected void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+
+        // check we havent already signed it
+        setContentView(R.layout.sign_key_layout);
+
+        final Spinner keyServer = (Spinner) findViewById(R.id.keyServer);
+        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, mPreferences.getKeyServers());
+        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
+        keyServer.setAdapter(adapter);
+
+        final CheckBox sendKey = (CheckBox) findViewById(R.id.sendKey);
+        if (!sendKey.isChecked()) {
+            keyServer.setEnabled(false);
+        } else {
+            keyServer.setEnabled(true);
+        }
+
+        sendKey.setOnCheckedChangeListener(new OnCheckedChangeListener() {
+
+            @Override
+            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
+                if (!isChecked) {
+                    keyServer.setEnabled(false);
+                } else {
+                    keyServer.setEnabled(true);
+                }
+            }
+        });
+
+        Button sign = (Button) findViewById(R.id.sign);
+        sign.setEnabled(false); // disabled until the user selects a key to sign with
+        sign.setOnClickListener(new OnClickListener() {
+
+            @Override
+            public void onClick(View v) {
+                if (pubKeyId != 0) {
+                    initiateSigning();
+                }
+            }
+        });
+        
+        pubKeyId = getIntent().getLongExtra(Apg.EXTRA_KEY_ID, 0);
+        if (pubKeyId == 0) {
+            finish(); // nothing to do if we dont know what key to sign
+        } else {
+            // kick off the SecretKey selection activity so the user chooses which key to sign with first
+            Intent intent = new Intent(this, SelectSecretKeyListActivity.class);
+            startActivityForResult(intent, Id.request.secret_keys);
+        }
+    }
+
+    /**
+     * handles the UI bits of the signing process on the UI thread
+     */
+    private void initiateSigning() {
+        PGPPublicKeyRing pubring = Apg.getPublicKeyRing(pubKeyId);
+        if (pubring != null) {
+            // if we have already signed this key, dont bother doing it again
+            boolean alreadySigned = false;
+    
+            @SuppressWarnings("unchecked")
+            Iterator<PGPSignature> itr = pubring.getPublicKey(pubKeyId).getSignatures();
+            while (itr.hasNext()) {
+                PGPSignature sig = itr.next();
+                if (sig.getKeyID() == masterKeyId) {
+                    alreadySigned = true;
+                    break;
+                }
+            }
+    
+            if (!alreadySigned) {
+                /*
+                 * get the user's passphrase for this key (if required)
+                 */
+                String passphrase = Apg.getCachedPassPhrase(masterKeyId);
+                if (passphrase == null) {
+                    showDialog(Id.dialog.pass_phrase);
+                    return; // bail out; need to wait until the user has entered the passphrase before trying again
+                } else {
+                    startSigning();
+                }
+            } else {
+                final Bundle status = new Bundle();
+                Message msg = new Message();
+
+                status.putString(Apg.EXTRA_ERROR, "Key has already been signed");
+
+                status.putInt(Constants.extras.status, Id.message.done);
+                
+                msg.setData(status);
+                sendMessage(msg);
+                
+                setResult(Id.return_value.error);
+                finish();
+            }
+        }
+    }
+    
+    @Override
+    public long getSecretKeyId() {
+        return masterKeyId;
+    }
+    
+    @Override
+    public void passPhraseCallback(long keyId, String passPhrase) {
+        super.passPhraseCallback(keyId, passPhrase);
+        startSigning();
+    }
+    
+    /**
+     * kicks off the actual signing process on a background thread
+     */
+    private void startSigning() {
+        showDialog(Id.dialog.signing);
+        startThread();
+    }
+    
+    @Override
+    public void run() {
+        final Bundle status = new Bundle();
+        Message msg = new Message();
+
+        try {
+            String passphrase = Apg.getCachedPassPhrase(masterKeyId);
+            if (passphrase == null || passphrase.length() <= 0) {
+                status.putString(Apg.EXTRA_ERROR, "Unable to obtain passphrase");
+            } else {
+                PGPPublicKeyRing pubring = Apg.getPublicKeyRing(pubKeyId);
+                
+                /*
+                 * sign the incoming key
+                 */
+                PGPSecretKey secretKey = Apg.getSecretKey(masterKeyId);
+                PGPPrivateKey signingKey = secretKey.extractPrivateKey(passphrase.toCharArray(), BouncyCastleProvider.PROVIDER_NAME);
+                PGPSignatureGenerator sGen = new PGPSignatureGenerator(secretKey.getPublicKey().getAlgorithm(), PGPUtil.SHA256, BouncyCastleProvider.PROVIDER_NAME);
+                sGen.initSign(PGPSignature.DIRECT_KEY, signingKey);
+    
+                PGPSignatureSubpacketGenerator spGen = new PGPSignatureSubpacketGenerator();
+    
+                PGPSignatureSubpacketVector packetVector = spGen.generate();
+                sGen.setHashedSubpackets(packetVector);
+    
+                PGPPublicKey signedKey = PGPPublicKey.addCertification(pubring.getPublicKey(pubKeyId), sGen.generate());
+                pubring = PGPPublicKeyRing.insertPublicKey(pubring, signedKey);
+    
+                // check if we need to send the key to the server or not
+                CheckBox sendKey = (CheckBox) findViewById(R.id.sendKey);
+                if (sendKey.isChecked()) {
+                    Spinner keyServer = (Spinner) findViewById(R.id.keyServer);
+                    HkpKeyServer server = new HkpKeyServer((String) keyServer.getSelectedItem());
+    
+                    /*
+                     * upload the newly signed key to the key server
+                     */
+    
+                    Apg.uploadKeyRingToServer(server, pubring);
+                }
+    
+                // store the signed key in our local cache
+                int retval = Apg.storeKeyRingInCache(pubring);
+                if (retval != Id.return_value.ok && retval != Id.return_value.updated) {
+                    status.putString(Apg.EXTRA_ERROR, "Failed to store signed key in local cache");
+                }
+            }
+        } catch (PGPException e) {
+            Log.e(TAG, "Failed to sign key", e);
+            status.putString(Apg.EXTRA_ERROR, "Failed to sign key");
+            status.putInt(Constants.extras.status, Id.message.done);
+            return;
+        } catch (NoSuchAlgorithmException e) {
+            Log.e(TAG, "Failed to sign key", e);
+            status.putString(Apg.EXTRA_ERROR, "Failed to sign key");
+            status.putInt(Constants.extras.status, Id.message.done);
+            return;
+        } catch (NoSuchProviderException e) {
+            Log.e(TAG, "Failed to sign key", e);
+            status.putString(Apg.EXTRA_ERROR, "Failed to sign key");
+            status.putInt(Constants.extras.status, Id.message.done);
+            return;
+        } catch (SignatureException e) {
+            Log.e(TAG, "Failed to sign key", e);
+            status.putString(Apg.EXTRA_ERROR, "Failed to sign key");
+            status.putInt(Constants.extras.status, Id.message.done);
+            return;
+        }
+        
+        status.putInt(Constants.extras.status, Id.message.done);
+        
+        msg.setData(status);
+        sendMessage(msg);
+        
+        if (status.containsKey(Apg.EXTRA_ERROR)) {
+            setResult(Id.return_value.error);
+        } else {
+            setResult(Id.return_value.ok);
+        }
+        
+        finish();
+    }
+    
+    @Override
+    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
+        switch (requestCode) {
+            case Id.request.secret_keys: {
+                if (resultCode == RESULT_OK) {
+                    masterKeyId = data.getLongExtra(Apg.EXTRA_KEY_ID, 0);
+                    
+                    // re-enable the sign button so the user can initiate the sign process
+                    Button sign = (Button) findViewById(R.id.sign);
+                    sign.setEnabled(true);
+                }
+                
+                break;
+            }
+            
+            default: {
+                super.onActivityResult(requestCode, resultCode, data);
+            }
+        }
+    }
+    
+    @Override
+    public void doneCallback(Message msg) {
+        super.doneCallback(msg);
+        
+        removeDialog(Id.dialog.signing);
+
+        Bundle data = msg.getData();
+        String error = data.getString(Apg.EXTRA_ERROR);
+        if (error != null) {
+            Toast.makeText(this, getString(R.string.errorMessage, error), Toast.LENGTH_SHORT).show();
+            return;
+        }
+
+        Toast.makeText(this, R.string.keySignSuccess, Toast.LENGTH_SHORT).show();
+        finish();
+    }
+}