integration lib and demo

9 files changed, 792 insertions, 0 deletions

diff --git a/org_apg_integration_lib/.gitignore b/org_apg_integration_lib/.gitignore
new file mode 100644
index 000000000..2e423e1a3
--- /dev/null
+++ b/org_apg_integration_lib/.gitignore
@@ -0,0 +1,23 @@
+#Android generated
+bin
+gen
+obj
+libs/armeabi
+lint.xml
+local.properties
+
+#Eclipse
+.project
+.classpath
+.settings
+
+#IntelliJ IDEA
+.idea
+*.iml
+
+#Maven
+target
+release.properties
+
+#Mac
+.DS_Store
\ No newline at end of file
diff --git a/org_apg_integration_lib/AndroidManifest.xml b/org_apg_integration_lib/AndroidManifest.xml
new file mode 100644
index 000000000..646c383b7
--- /dev/null
+++ b/org_apg_integration_lib/AndroidManifest.xml
@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="org.apg.integration"
+    android:versionCode="1"
+    android:versionName="1.0" >
+
+    <uses-sdk
+        android:minSdkVersion="7"
+        android:targetSdkVersion="14" />
+
+</manifest>
\ No newline at end of file
diff --git a/org_apg_integration_lib/build.xml b/org_apg_integration_lib/build.xml
new file mode 100644
index 000000000..e6bcaf18d
--- /dev/null
+++ b/org_apg_integration_lib/build.xml
@@ -0,0 +1,83 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project name="org_apg_integration_lib" default="help">
+
+    <!-- The local.properties file is created and updated by the 'android' tool.
+         It contains the path to the SDK. It should *NOT* be checked into
+         Version Control Systems. -->
+    <property file="local.properties" />
+
+    <!-- The ant.properties file can be created by you. It is only edited by the
+         'android' tool to add properties to it.
+         This is the place to change some Ant specific build properties.
+         Here are some properties you may want to change/update:
+
+         source.dir
+             The name of the source directory. Default is 'src'.
+         out.dir
+             The name of the output directory. Default is 'bin'.
+
+         For other overridable properties, look at the beginning of the rules
+         files in the SDK, at tools/ant/build.xml
+
+         Properties related to the SDK location or the project target should
+         be updated using the 'android' tool with the 'update' action.
+
+         This file is an integral part of the build system for your
+         application and should be checked into Version Control Systems.
+
+         -->
+    <property file="ant.properties" />
+
+    <!-- The project.properties file is created and updated by the 'android'
+         tool, as well as ADT.
+
+         This contains project specific properties such as project target, and library
+         dependencies. Lower level build properties are stored in ant.properties
+         (or in .classpath for Eclipse projects).
+
+         This file is an integral part of the build system for your
+         application and should be checked into Version Control Systems. -->
+    <loadproperties srcFile="project.properties" />
+
+    <!-- quick check on sdk.dir -->
+    <fail
+            message="sdk.dir is missing. Make sure to generate local.properties using 'android update project' or to inject it through an env var"
+            unless="sdk.dir"
+    />
+
+    <!--
+        Import per project custom build rules if present at the root of the project.
+        This is the place to put custom intermediary targets such as:
+            -pre-build
+            -pre-compile
+            -post-compile (This is typically used for code obfuscation.
+                           Compiled code location: ${out.classes.absolute.dir}
+                           If this is not done in place, override ${out.dex.input.absolute.dir})
+            -post-package
+            -post-build
+            -pre-clean
+    -->
+    <import file="custom_rules.xml" optional="true" />
+
+    <!-- Import the actual build file.
+
+         To customize existing targets, there are two options:
+         - Customize only one target:
+             - copy/paste the target into this file, *before* the
+               <import> task.
+             - customize it to your needs.
+         - Customize the whole content of build.xml
+             - copy/paste the content of the rules files (minus the top node)
+               into this file, replacing the <import> task.
+             - customize to your needs.
+
+         ***********************
+         ****** IMPORTANT ******
+         ***********************
+         In all cases you must update the value of version-tag below to read 'custom' instead of an integer,
+         in order to avoid having your file be overridden by tools such as "android update project"
+    -->
+    <!-- version-tag: 1 -->
+    <import file="${sdk.dir}/tools/ant/build.xml" />
+
+</project>
diff --git a/org_apg_integration_lib/proguard-project.txt b/org_apg_integration_lib/proguard-project.txt
new file mode 100644
index 000000000..f2fe1559a
--- /dev/null
+++ b/org_apg_integration_lib/proguard-project.txt
@@ -0,0 +1,20 @@
+# To enable ProGuard in your project, edit project.properties
+# to define the proguard.config property as described in that file.
+#
+# Add project specific ProGuard rules here.
+# By default, the flags in this file are appended to flags specified
+# in ${sdk.dir}/tools/proguard/proguard-android.txt
+# You can edit the include path and order by changing the ProGuard
+# include property in project.properties.
+#
+# For more details, see
+#   http://developer.android.com/guide/developing/tools/proguard.html
+
+# Add any project specific keep options here:
+
+# If your project uses WebView with JS, uncomment the following
+# and specify the fully qualified class name to the JavaScript interface
+# class:
+#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
+#   public *;
+#}
diff --git a/org_apg_integration_lib/project.properties b/org_apg_integration_lib/project.properties
new file mode 100644
index 000000000..36f15941e
--- /dev/null
+++ b/org_apg_integration_lib/project.properties
@@ -0,0 +1,15 @@
+# This file is automatically generated by Android Tools.
+# Do not modify this file -- YOUR CHANGES WILL BE ERASED!
+#
+# This file must be checked in Version Control Systems.
+#
+# To customize properties used by the Ant build system edit
+# "ant.properties", and override values to adapt the script to your
+# project structure.
+#
+# To enable ProGuard to shrink and obfuscate your code, uncomment this (available properties: sdk.dir, user.home):
+#proguard.config=${sdk.dir}/tools/proguard/proguard-android.txt:proguard-project.txt
+
+# Project target.
+target=android-15
+android.library=true
diff --git a/org_apg_integration_lib/src/org/apg/integration/ApgData.java b/org_apg_integration_lib/src/org/apg/integration/ApgData.java
new file mode 100644
index 000000000..759e3ca12
--- /dev/null
+++ b/org_apg_integration_lib/src/org/apg/integration/ApgData.java
@@ -0,0 +1,107 @@
+/*
+ * Copyright (C) 2010-2011 K-9 Mail Contributors
+ * Copyright (C) 2012 Dominik Schürmann <dominik@dominikschuermann.de>
+ *
+ * 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.apg.integration;
+
+import java.io.Serializable;
+import java.util.Arrays;
+
+public class ApgData implements Serializable {
+    private static final long serialVersionUID = 6314045536270848410L;
+    protected long mEncryptionKeyIds[] = null;
+    protected long mSignatureKeyId = 0;
+    protected String mSignatureUserId = null;
+    protected boolean mSignatureSuccess = false;
+    protected boolean mSignatureUnknown = false;
+    protected String mDecryptedData = null;
+    protected String mEncryptedData = null;
+
+    public void setSignatureKeyId(long keyId) {
+        mSignatureKeyId = keyId;
+    }
+
+    public long getSignatureKeyId() {
+        return mSignatureKeyId;
+    }
+
+    public void setEncryptionKeys(long keyIds[]) {
+        mEncryptionKeyIds = keyIds;
+    }
+
+    public long[] getEncryptionKeys() {
+        return mEncryptionKeyIds;
+    }
+
+    public boolean hasSignatureKey() {
+        return mSignatureKeyId != 0;
+    }
+
+    public boolean hasEncryptionKeys() {
+        return (mEncryptionKeyIds != null) && (mEncryptionKeyIds.length > 0);
+    }
+
+    public String getEncryptedData() {
+        return mEncryptedData;
+    }
+
+    public void setEncryptedData(String data) {
+        mEncryptedData = data;
+    }
+
+    public String getDecryptedData() {
+        return mDecryptedData;
+    }
+
+    public void setDecryptedData(String data) {
+        mDecryptedData = data;
+    }
+
+    public void setSignatureUserId(String userId) {
+        mSignatureUserId = userId;
+    }
+
+    public String getSignatureUserId() {
+        return mSignatureUserId;
+    }
+
+    public boolean getSignatureSuccess() {
+        return mSignatureSuccess;
+    }
+
+    public void setSignatureSuccess(boolean success) {
+        mSignatureSuccess = success;
+    }
+
+    public boolean getSignatureUnknown() {
+        return mSignatureUnknown;
+    }
+
+    public void setSignatureUnknown(boolean unknown) {
+        mSignatureUnknown = unknown;
+    }
+
+    @Override
+    public String toString() {
+        String output = "mEncryptionKeyIds: " + Arrays.toString(mEncryptionKeyIds)
+                + "\nmSignatureKeyId: " + mSignatureKeyId + "\nmSignatureUserId: "
+                + mSignatureUserId + "\nmSignatureSuccess: " + mSignatureSuccess
+                + "\nmSignatureUnknown: " + mSignatureUnknown + "\nmDecryptedData: "
+                + mDecryptedData + "\nmEncryptedData: " + mEncryptedData;
+
+        return output;
+    }
+}
\ No newline at end of file
diff --git a/org_apg_integration_lib/src/org/apg/integration/ApgIntentHelper.java b/org_apg_integration_lib/src/org/apg/integration/ApgIntentHelper.java
new file mode 100644
index 000000000..506ec7a5c
--- /dev/null
+++ b/org_apg_integration_lib/src/org/apg/integration/ApgIntentHelper.java
@@ -0,0 +1,397 @@
+/*
+ * Copyright (C) 2010-2011 K-9 Mail Contributors
+ * Copyright (C) 2012 Dominik Schürmann <dominik@dominikschuermann.de>
+ *
+ * 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.apg.integration;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import android.app.Activity;
+import android.content.ActivityNotFoundException;
+import android.content.ContentUris;
+import android.content.Intent;
+import android.database.Cursor;
+import android.net.Uri;
+import android.widget.Toast;
+
+public class ApgIntentHelper {
+    private Activity activity;
+
+    public ApgIntentHelper(Activity activity) {
+        this.activity = activity;
+    }
+
+    /**
+     * Select the signature key.
+     * 
+     * @param activity
+     * @param pgpData
+     * @return success or failure
+     */
+    public boolean selectSecretKey() {
+        Intent intent = new Intent(Constants.Intent.SELECT_SECRET_KEY);
+        intent.putExtra(Constants.EXTRA_INTENT_VERSION, Constants.INTENT_VERSION);
+        try {
+            activity.startActivityForResult(intent, Constants.SELECT_SECRET_KEY);
+            return true;
+        } catch (ActivityNotFoundException e) {
+            activityNotFound();
+            return false;
+        }
+    }
+
+    /**
+     * Start the encrypt activity.
+     * 
+     * @param activity
+     * @param data
+     * @param pgpData
+     * @return success or failure
+     */
+    public boolean encrypt(String data, long[] encryptionKeyIds, long signatureKeyId) {
+        Intent intent = new Intent(Constants.Intent.ENCRYPT_AND_RETURN);
+        intent.putExtra(Constants.EXTRA_INTENT_VERSION, Constants.INTENT_VERSION);
+        intent.setType("text/plain");
+        intent.putExtra(Constants.EXTRA_TEXT, data);
+        intent.putExtra(Constants.EXTRA_ENCRYPTION_KEY_IDS, encryptionKeyIds);
+        intent.putExtra(Constants.EXTRA_SIGNATURE_KEY_ID, signatureKeyId);
+        try {
+            activity.startActivityForResult(intent, Constants.ENCRYPT_MESSAGE);
+            return true;
+        } catch (ActivityNotFoundException e) {
+            activityNotFound();
+            return false;
+        }
+    }
+
+    /**
+     * Start the decrypt activity.
+     * 
+     * @param activity
+     * @param data
+     * @param pgpData
+     * @return success or failure
+     */
+    public boolean decrypt(String data) {
+        Intent intent = new Intent(Constants.Intent.DECRYPT_AND_RETURN);
+        intent.putExtra(Constants.EXTRA_INTENT_VERSION, Constants.INTENT_VERSION);
+        intent.setType("text/plain");
+        if (data == null) {
+            return false;
+        }
+        try {
+            intent.putExtra(Constants.EXTRA_TEXT, data);
+            activity.startActivityForResult(intent, Constants.DECRYPT_MESSAGE);
+            return true;
+        } catch (ActivityNotFoundException e) {
+            activityNotFound();
+            return false;
+        }
+    }
+
+    /**
+     * Handle the activity results that concern us.
+     * 
+     * @param requestCode
+     * @param resultCode
+     * @param data
+     * @return handled or not
+     */
+    public boolean onActivityResult(int requestCode, int resultCode, Intent data, ApgData apgData) {
+
+        switch (requestCode) {
+        case Constants.SELECT_SECRET_KEY:
+            if (resultCode != Activity.RESULT_OK || data == null) {
+                break;
+            }
+            apgData.setSignatureKeyId(data.getLongExtra(Constants.EXTRA_KEY_ID, 0));
+            apgData.setSignatureUserId(data.getStringExtra(Constants.EXTRA_USER_ID));
+            break;
+
+        case Constants.SELECT_PUBLIC_KEYS:
+            if (resultCode != Activity.RESULT_OK || data == null) {
+                apgData.setEncryptionKeys(null);
+                break;
+            }
+            apgData.setEncryptionKeys(data.getLongArrayExtra(Constants.EXTRA_SELECTION));
+            break;
+
+        case Constants.ENCRYPT_MESSAGE:
+            if (resultCode != Activity.RESULT_OK || data == null) {
+                apgData.setEncryptionKeys(null);
+                break;
+            }
+            apgData.setEncryptedData(data.getStringExtra(Constants.EXTRA_ENCRYPTED_MESSAGE));
+            // this was a stupid bug in an earlier version, just gonna leave this in for an APG
+            // version or two
+            if (apgData.getEncryptedData() == null) {
+                apgData.setEncryptedData(data.getStringExtra(Constants.EXTRA_DECRYPTED_MESSAGE));
+            }
+            if (apgData.getEncryptedData() != null) {
+            }
+            break;
+
+        case Constants.DECRYPT_MESSAGE:
+            if (resultCode != Activity.RESULT_OK || data == null) {
+                break;
+            }
+
+            apgData.setSignatureUserId(data.getStringExtra(Constants.EXTRA_SIGNATURE_USER_ID));
+            apgData.setSignatureKeyId(data.getLongExtra(Constants.EXTRA_SIGNATURE_KEY_ID, 0));
+            apgData.setSignatureSuccess(data.getBooleanExtra(Constants.EXTRA_SIGNATURE_SUCCESS,
+                    false));
+            apgData.setSignatureUnknown(data.getBooleanExtra(Constants.EXTRA_SIGNATURE_UNKNOWN,
+                    false));
+
+            apgData.setDecryptedData(data.getStringExtra(Constants.EXTRA_DECRYPTED_MESSAGE));
+
+            break;
+
+        default:
+            return false;
+        }
+
+        return true;
+    }
+
+    /**
+     * Select encryption keys.
+     * 
+     * @param emails
+     *            The emails that should be used for preselection.
+     * @return false when activity could not be found!
+     */
+    public boolean selectEncryptionKeys(String emails) {
+        return selectEncryptionKeys(emails, null);
+    }
+
+    /**
+     * Select encryption keys.
+     * 
+     * @param emails
+     *            The emails that should be used for preselection.
+     * @param apgData
+     *            ApgData with encryption keys and signature keys preselected
+     * @return false when activity could not be found!
+     */
+    public boolean selectEncryptionKeys(String emails, ApgData apgData) {
+        Intent intent = new Intent(Constants.Intent.SELECT_PUBLIC_KEYS);
+        intent.putExtra(Constants.EXTRA_INTENT_VERSION, Constants.INTENT_VERSION);
+
+        long[] initialKeyIds = null;
+        if (apgData == null || !apgData.hasEncryptionKeys()) {
+            List<Long> keyIds = new ArrayList<Long>();
+            if (apgData != null && apgData.hasSignatureKey()) {
+                keyIds.add(apgData.getSignatureKeyId());
+            }
+
+            try {
+                Uri contentUri = Uri.withAppendedPath(
+                        Constants.CONTENT_URI_PUBLIC_KEY_RING_BY_EMAILS, emails);
+                Cursor c = activity.getContentResolver().query(contentUri,
+                        new String[] { "master_key_id" }, null, null, null);
+                if (c != null) {
+                    while (c.moveToNext()) {
+                        keyIds.add(c.getLong(0));
+                    }
+                }
+
+                if (c != null) {
+                    c.close();
+                }
+            } catch (SecurityException e) {
+                insufficientPermissions();
+            }
+            if (!keyIds.isEmpty()) {
+                initialKeyIds = new long[keyIds.size()];
+                for (int i = 0, size = keyIds.size(); i < size; ++i) {
+                    initialKeyIds[i] = keyIds.get(i);
+                }
+            }
+        } else {
+            initialKeyIds = apgData.getEncryptionKeys();
+        }
+        intent.putExtra(Constants.EXTRA_SELECTION, initialKeyIds);
+
+        try {
+            activity.startActivityForResult(intent, Constants.SELECT_PUBLIC_KEYS);
+            return true;
+        } catch (ActivityNotFoundException e) {
+            activityNotFound();
+            return false;
+        }
+    }
+
+    /**
+     * Get secret key ids based on a given email.
+     * 
+     * @param context
+     * @param email
+     *            The email in question.
+     * @return key ids
+     */
+    public long[] getSecretKeyIdsFromEmail(String email) {
+        long ids[] = null;
+        try {
+            Uri contentUri = Uri.withAppendedPath(Constants.CONTENT_URI_SECRET_KEY_RING_BY_EMAILS,
+                    email);
+            Cursor c = activity.getContentResolver().query(contentUri,
+                    new String[] { "master_key_id" }, null, null, null);
+            if (c != null && c.getCount() > 0) {
+                ids = new long[c.getCount()];
+                while (c.moveToNext()) {
+                    ids[c.getPosition()] = c.getLong(0);
+                }
+            }
+
+            if (c != null) {
+                c.close();
+            }
+        } catch (SecurityException e) {
+            insufficientPermissions();
+        }
+
+        return ids;
+    }
+
+    /**
+     * Get public key ids based on a given email.
+     * 
+     * @param context
+     * @param email
+     *            The email in question.
+     * @return key ids
+     */
+    public long[] getPublicKeyIdsFromEmail(String email) {
+        long ids[] = null;
+        try {
+            Uri contentUri = Uri.withAppendedPath(Constants.CONTENT_URI_PUBLIC_KEY_RING_BY_EMAILS,
+                    email);
+            Cursor c = activity.getContentResolver().query(contentUri,
+                    new String[] { "master_key_id" }, null, null, null);
+            if (c != null && c.getCount() > 0) {
+                ids = new long[c.getCount()];
+                while (c.moveToNext()) {
+                    ids[c.getPosition()] = c.getLong(0);
+                }
+            }
+
+            if (c != null) {
+                c.close();
+            }
+        } catch (SecurityException e) {
+            insufficientPermissions();
+        }
+
+        return ids;
+    }
+
+    /**
+     * Find out if a given email has a secret key.
+     * 
+     * @param context
+     * @param email
+     *            The email in question.
+     * @return true if there is a secret key for this email.
+     */
+    public boolean hasSecretKeyForEmail(String email) {
+        try {
+            Uri contentUri = Uri.withAppendedPath(Constants.CONTENT_URI_SECRET_KEY_RING_BY_EMAILS,
+                    email);
+            Cursor c = activity.getContentResolver().query(contentUri,
+                    new String[] { "master_key_id" }, null, null, null);
+            if (c != null && c.getCount() > 0) {
+                c.close();
+                return true;
+            }
+            if (c != null) {
+                c.close();
+            }
+        } catch (SecurityException e) {
+            insufficientPermissions();
+        }
+        return false;
+    }
+
+    /**
+     * Find out if a given email has a public key.
+     * 
+     * @param context
+     * @param email
+     *            The email in question.
+     * @return true if there is a public key for this email.
+     */
+    public boolean hasPublicKeyForEmail(String email) {
+        try {
+            Uri contentUri = Uri.withAppendedPath(Constants.CONTENT_URI_PUBLIC_KEY_RING_BY_EMAILS,
+                    email);
+            Cursor c = activity.getContentResolver().query(contentUri,
+                    new String[] { "master_key_id" }, null, null, null);
+            if (c != null && c.getCount() > 0) {
+                c.close();
+                return true;
+            }
+            if (c != null) {
+                c.close();
+            }
+        } catch (SecurityException e) {
+            insufficientPermissions();
+        }
+        return false;
+    }
+
+    /**
+     * Get the user id based on the key id.
+     * 
+     * @param context
+     * @param keyId
+     * @return user id
+     */
+    public String getUserId(long keyId) {
+        String userId = null;
+        try {
+            Uri contentUri = ContentUris.withAppendedId(
+                    Constants.CONTENT_URI_SECRET_KEY_RING_BY_KEY_ID, keyId);
+            Cursor c = activity.getContentResolver().query(contentUri, new String[] { "user_id" },
+                    null, null, null);
+            if (c != null && c.moveToFirst()) {
+                userId = c.getString(0);
+            }
+
+            if (c != null) {
+                c.close();
+            }
+        } catch (SecurityException e) {
+            insufficientPermissions();
+        }
+
+        if (userId == null) {
+            userId = "unknown";
+        }
+        return userId;
+    }
+
+    private void activityNotFound() {
+        Toast.makeText(activity, "APG Activity not found! Is APG installed correctly?",
+                Toast.LENGTH_LONG).show();
+    }
+
+    private void insufficientPermissions() {
+        Toast.makeText(activity, "Permission to access APG Provider is missing!", Toast.LENGTH_LONG)
+                .show();
+    }
+}
diff --git a/org_apg_integration_lib/src/org/apg/integration/Constants.java b/org_apg_integration_lib/src/org/apg/integration/Constants.java
new file mode 100644
index 000000000..017f88478
--- /dev/null
+++ b/org_apg_integration_lib/src/org/apg/integration/Constants.java
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2010-2011 K-9 Mail Contributors
+ * Copyright (C) 2012 Dominik Schürmann <dominik@dominikschuermann.de>
+ *
+ * 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.apg.integration;
+
+import android.net.Uri;
+
+public class Constants {
+    public static final String NAME = "apg";
+
+    public static final String APG_PACKAGE_NAME = "org.apg";
+    public static final int MIN_REQUIRED_VERSION = 50;
+
+    public static final String AUTHORITY = "org.apg.provider";
+    public static final Uri CONTENT_URI_SECRET_KEY_RING_BY_KEY_ID = Uri.parse("content://"
+            + AUTHORITY + "/key_rings/secret/key_id/");
+    public static final Uri CONTENT_URI_SECRET_KEY_RING_BY_EMAILS = Uri.parse("content://"
+            + AUTHORITY + "/key_rings/secret/emails/");
+
+    public static final Uri CONTENT_URI_PUBLIC_KEY_RING_BY_KEY_ID = Uri.parse("content://"
+            + AUTHORITY + "/key_rings/public/key_id/");
+    public static final Uri CONTENT_URI_PUBLIC_KEY_RING_BY_EMAILS = Uri.parse("content://"
+            + AUTHORITY + "/key_rings/public/emails/");
+
+    public static class Intent {
+        public static final String DECRYPT = APG_PACKAGE_NAME + ".intent.DECRYPT";
+        public static final String ENCRYPT = APG_PACKAGE_NAME + ".intent.ENCRYPT";
+        public static final String DECRYPT_FILE = APG_PACKAGE_NAME + ".intent.DECRYPT_FILE";
+        public static final String ENCRYPT_FILE = APG_PACKAGE_NAME + ".intent.ENCRYPT_FILE";
+        public static final String DECRYPT_AND_RETURN = APG_PACKAGE_NAME
+                + ".intent.DECRYPT_AND_RETURN";
+        public static final String ENCRYPT_AND_RETURN = APG_PACKAGE_NAME
+                + ".intent.ENCRYPT_AND_RETURN";
+        public static final String SELECT_PUBLIC_KEYS = APG_PACKAGE_NAME
+                + ".intent.SELECT_PUBLIC_KEYS";
+        public static final String SELECT_SECRET_KEY = APG_PACKAGE_NAME
+                + ".intent.SELECT_SECRET_KEY";
+    }
+
+    public static final String EXTRA_TEXT = "text";
+    public static final String EXTRA_DATA = "data";
+    public static final String EXTRA_ERROR = "error";
+    public static final String EXTRA_DECRYPTED_MESSAGE = "decryptedMessage";
+    public static final String EXTRA_ENCRYPTED_MESSAGE = "encryptedMessage";
+    public static final String EXTRA_SIGNATURE = "signature";
+    public static final String EXTRA_SIGNATURE_KEY_ID = "signatureKeyId";
+    public static final String EXTRA_SIGNATURE_USER_ID = "signatureUserId";
+    public static final String EXTRA_SIGNATURE_SUCCESS = "signatureSuccess";
+    public static final String EXTRA_SIGNATURE_UNKNOWN = "signatureUnknown";
+    public static final String EXTRA_USER_ID = "userId";
+    public static final String EXTRA_KEY_ID = "keyId";
+    public static final String EXTRA_ENCRYPTION_KEY_IDS = "encryptionKeyIds";
+    public static final String EXTRA_SELECTION = "selection";
+    public static final String EXTRA_MESSAGE = "message";
+    public static final String EXTRA_INTENT_VERSION = "intentVersion";
+
+    public static final String INTENT_VERSION = "1";
+
+    public static final int DECRYPT_MESSAGE = 0x21070001;
+    public static final int ENCRYPT_MESSAGE = 0x21070002;
+    public static final int SELECT_PUBLIC_KEYS = 0x21070003;
+    public static final int SELECT_SECRET_KEY = 0x21070004;
+
+    // public static Pattern PGP_MESSAGE = Pattern.compile(
+    // ".*?(-----BEGIN PGP MESSAGE-----.*?-----END PGP MESSAGE-----).*", Pattern.DOTALL);
+
+    // public static Pattern PGP_SIGNED_MESSAGE = Pattern
+    // .compile(
+    // ".*?(-----BEGIN PGP SIGNED MESSAGE-----.*?-----BEGIN PGP SIGNATURE-----.*?-----END PGP SIGNATURE-----).*",
+    // Pattern.DOTALL);
+}
diff --git a/org_apg_integration_lib/src/org/apg/integration/Util.java b/org_apg_integration_lib/src/org/apg/integration/Util.java
new file mode 100644
index 000000000..8991245f5
--- /dev/null
+++ b/org_apg_integration_lib/src/org/apg/integration/Util.java
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2010-2011 K-9 Mail Contributors
+ * Copyright (C) 2012 Dominik Schürmann <dominik@dominikschuermann.de>
+ *
+ * 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.apg.integration;
+
+import android.content.Context;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager.NameNotFoundException;
+
+import android.widget.Toast;
+
+public class Util {
+
+    /**
+     * Check whether APG is installed and at a high enough version.
+     * 
+     * @param context
+     * @return whether a suitable version of APG was found
+     */
+    public boolean isApgAvailable(Context context) {
+        try {
+            PackageInfo pi = context.getPackageManager().getPackageInfo(Constants.APG_PACKAGE_NAME,
+                    0);
+            if (pi.versionCode >= Constants.MIN_REQUIRED_VERSION) {
+                return true;
+            } else {
+                Toast.makeText(context,
+                        "This APG version is not supported! Please update to a newer one!",
+                        Toast.LENGTH_LONG).show();
+            }
+        } catch (NameNotFoundException e) {
+            // not found
+        }
+
+        return false;
+    }
+}