Build OpenKeychain API inline

app/build.gradle

@@ -299,7 +299,8 @@ dependencies {
 
     // https://github.com/open-keychain/openpgp-api
     // https://mvnrepository.com/artifact/org.sufficientlysecure/openpgp-api
-    implementation "org.sufficientlysecure:openpgp-api:$openpgp_version"
+    //implementation "org.sufficientlysecure:openpgp-api:$openpgp_version"
+    implementation project(':openpgp-api')
 
     // https://www.sqlite.org/changes.html
     // https://github.com/requery/sqlite-android/

openpgp-api/.gitignore

@@ -0,0 +1,33 @@
+#Android specific
+bin
+gen
+obj
+lint.xml
+local.properties
+release.properties
+ant.properties
+*.class
+*.apk
+
+#Gradle
+.gradle
+build
+gradle.properties
+
+#Maven
+target
+pom.xml.*
+
+#Eclipse
+.project
+.classpath
+.settings
+.metadata
+
+#IntelliJ IDEA
+.idea
+*.iml
+
+#Lint output
+lint-report.html
+lint-report_files/*

openpgp-api/build.gradle

@@ -0,0 +1,28 @@
+apply plugin: 'com.android.library'
+//apply plugin: 'bintray-release' // must be applied after your artifact generating plugin (eg. java / com.android.library)
+
+android {
+    compileSdkVersion 27
+    buildToolsVersion '27.0.3'
+
+    defaultConfig {
+        versionCode 9
+        versionName '12.0' // API-Version . minor
+        minSdkVersion 9
+        targetSdkVersion 25
+    }
+
+    // Do not abort build if lint finds errors
+    lintOptions {
+        abortOnError false
+    }
+}
+
+//publish {
+//    userOrg = 'sufficientlysecure'
+//    groupId = 'org.sufficientlysecure'
+//    artifactId = 'openpgp-api'
+//    version = '12.0'
+//    description = 'The OpenPGP API provides methods to execute OpenPGP operations, such as sign, encrypt, decrypt, verify, and more without user interaction from background threads.'
+//    website = 'https://github.com/open-keychain/openpgp-api'
+//}

openpgp-api/src/main/AndroidManifest.xml

@@ -0,0 +1,7 @@
+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+    package="org.openintents.openpgp">
+
+    <application/>
+
+</manifest>

openpgp-api/src/main/aidl/org/openintents/openpgp/IOpenPgpService.aidl

@@ -0,0 +1,27 @@
+/*
+ * Copyright (C) 2014-2015 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.openintents.openpgp;
+
+interface IOpenPgpService {
+
+    /**
+     * do NOT use this, data returned from the service through "output" may be truncated
+     * @deprecated
+     */
+    Intent execute(in Intent data, in ParcelFileDescriptor input, in ParcelFileDescriptor output);
+
+}

openpgp-api/src/main/aidl/org/openintents/openpgp/IOpenPgpService2.aidl

@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2015 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.openintents.openpgp;
+
+interface IOpenPgpService2 {
+
+    /**
+     * see org.openintents.openpgp.util.OpenPgpApi for documentation
+     */
+    ParcelFileDescriptor createOutputPipe(in int pipeId);
+
+    /**
+     * see org.openintents.openpgp.util.OpenPgpApi for documentation
+     */
+    Intent execute(in Intent data, in ParcelFileDescriptor input, int pipeId);
+}

openpgp-api/src/main/java/org/openintents/openpgp/AutocryptPeerUpdate.java

@@ -0,0 +1,131 @@
+/*
+ * Copyright (C) 2014-2015 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.openintents.openpgp;
+
+
+import java.util.Date;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+
+@SuppressWarnings("unused")
+public class AutocryptPeerUpdate implements Parcelable {
+    /**
+     * Since there might be a case where new versions of the client using the library getting
+     * old versions of the protocol (and thus old versions of this class), we need a versioning
+     * system for the parcels sent between the clients and the providers.
+     */
+    private static final int PARCELABLE_VERSION = 1;
+
+
+    private final byte[] keyData;
+    private final Date effectiveDate;
+    private final PreferEncrypt preferEncrypt;
+
+
+    private AutocryptPeerUpdate(byte[] keyData, Date effectiveDate, PreferEncrypt preferEncrypt) {
+        this.keyData = keyData;
+        this.effectiveDate = effectiveDate;
+        this.preferEncrypt = preferEncrypt;
+    }
+
+    private AutocryptPeerUpdate(Parcel source, int version) {
+        this.keyData = source.createByteArray();
+        this.effectiveDate = source.readInt() != 0 ? new Date(source.readLong()) : null;
+        this.preferEncrypt = PreferEncrypt.values()[source.readInt()];
+    }
+
+
+    public static AutocryptPeerUpdate create(byte[] keyData, Date timestamp, boolean isMutual) {
+        return new AutocryptPeerUpdate(keyData, timestamp, isMutual ? PreferEncrypt.MUTUAL : PreferEncrypt.NOPREFERENCE);
+    }
+
+    public byte[] getKeyData() {
+        return keyData;
+    }
+
+    public boolean hasKeyData() {
+        return keyData != null;
+    }
+
+    public Date getEffectiveDate() {
+        return effectiveDate;
+    }
+
+    public PreferEncrypt getPreferEncrypt() {
+        return preferEncrypt;
+    }
+
+
+    public int describeContents() {
+        return 0;
+    }
+
+    public void writeToParcel(Parcel dest, int flags) {
+        /**
+         * NOTE: When adding fields in the process of updating this API, make sure to bump
+         * {@link #PARCELABLE_VERSION}.
+         */
+        dest.writeInt(PARCELABLE_VERSION);
+        // Inject a placeholder that will store the parcel size from this point on
+        // (not including the size itself).
+        int sizePosition = dest.dataPosition();
+        dest.writeInt(0);
+        int startPosition = dest.dataPosition();
+
+        // version 1
+        dest.writeByteArray(keyData);
+        if (effectiveDate != null) {
+            dest.writeInt(1);
+            dest.writeLong(effectiveDate.getTime());
+        } else {
+            dest.writeInt(0);
+        }
+
+        dest.writeInt(preferEncrypt.ordinal());
+
+        // Go back and write the size
+        int parcelableSize = dest.dataPosition() - startPosition;
+        dest.setDataPosition(sizePosition);
+        dest.writeInt(parcelableSize);
+        dest.setDataPosition(startPosition + parcelableSize);
+    }
+
+    public static final Creator<AutocryptPeerUpdate> CREATOR = new Creator<AutocryptPeerUpdate>() {
+        public AutocryptPeerUpdate createFromParcel(final Parcel source) {
+            int version = source.readInt(); // parcelableVersion
+            int parcelableSize = source.readInt();
+            int startPosition = source.dataPosition();
+
+            AutocryptPeerUpdate vr = new AutocryptPeerUpdate(source, version);
+
+            // skip over all fields added in future versions of this parcel
+            source.setDataPosition(startPosition + parcelableSize);
+
+            return vr;
+        }
+
+        public AutocryptPeerUpdate[] newArray(final int size) {
+            return new AutocryptPeerUpdate[size];
+        }
+    };
+
+    public enum PreferEncrypt {
+        NOPREFERENCE, MUTUAL
+    }
+}

openpgp-api/src/main/java/org/openintents/openpgp/OpenPgpDecryptionResult.java

@@ -0,0 +1,121 @@
+/*
+ * Copyright (C) 2015 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.openintents.openpgp;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+public class OpenPgpDecryptionResult implements Parcelable {
+    /**
+     * Since there might be a case where new versions of the client using the library getting
+     * old versions of the protocol (and thus old versions of this class), we need a versioning
+     * system for the parcels sent between the clients and the providers.
+     */
+    public static final int PARCELABLE_VERSION = 2;
+
+    // content not encrypted
+    public static final int RESULT_NOT_ENCRYPTED = -1;
+    // insecure!
+    public static final int RESULT_INSECURE = 0;
+    // encrypted
+    public static final int RESULT_ENCRYPTED = 1;
+
+    public final int result;
+    public final byte[] sessionKey;
+    public final byte[] decryptedSessionKey;
+
+    public int getResult() {
+        return result;
+    }
+
+    public OpenPgpDecryptionResult(int result) {
+        this.result = result;
+        this.sessionKey = null;
+        this.decryptedSessionKey = null;
+    }
+
+    public OpenPgpDecryptionResult(int result, byte[] sessionKey, byte[] decryptedSessionKey) {
+        this.result = result;
+        if ((sessionKey == null) != (decryptedSessionKey == null)) {
+            throw new AssertionError("sessionkey must be null iff decryptedSessionKey is null");
+        }
+        this.sessionKey = sessionKey;
+        this.decryptedSessionKey = decryptedSessionKey;
+    }
+
+    public OpenPgpDecryptionResult(OpenPgpDecryptionResult b) {
+        this.result = b.result;
+        this.sessionKey = b.sessionKey;
+        this.decryptedSessionKey = b.decryptedSessionKey;
+    }
+
+    public int describeContents() {
+        return 0;
+    }
+
+    public void writeToParcel(Parcel dest, int flags) {
+        /**
+         * NOTE: When adding fields in the process of updating this API, make sure to bump
+         * {@link #PARCELABLE_VERSION}.
+         */
+        dest.writeInt(PARCELABLE_VERSION);
+        // Inject a placeholder that will store the parcel size from this point on
+        // (not including the size itself).
+        int sizePosition = dest.dataPosition();
+        dest.writeInt(0);
+        int startPosition = dest.dataPosition();
+        // version 1
+        dest.writeInt(result);
+        // version 2
+        dest.writeByteArray(sessionKey);
+        dest.writeByteArray(decryptedSessionKey);
+        // Go back and write the size
+        int parcelableSize = dest.dataPosition() - startPosition;
+        dest.setDataPosition(sizePosition);
+        dest.writeInt(parcelableSize);
+        dest.setDataPosition(startPosition + parcelableSize);
+    }
+
+    public static final Creator<OpenPgpDecryptionResult> CREATOR = new Creator<OpenPgpDecryptionResult>() {
+        public OpenPgpDecryptionResult createFromParcel(final Parcel source) {
+            int version = source.readInt(); // parcelableVersion
+            int parcelableSize = source.readInt();
+            int startPosition = source.dataPosition();
+
+            int result = source.readInt();
+            byte[] sessionKey = version > 1 ? source.createByteArray() : null;
+            byte[] decryptedSessionKey = version > 1 ? source.createByteArray() : null;
+
+            OpenPgpDecryptionResult vr = new OpenPgpDecryptionResult(result, sessionKey, decryptedSessionKey);
+
+            // skip over all fields added in future versions of this parcel
+            source.setDataPosition(startPosition + parcelableSize);
+
+            return vr;
+        }
+
+        public OpenPgpDecryptionResult[] newArray(final int size) {
+            return new OpenPgpDecryptionResult[size];
+        }
+    };
+
+    @Override
+    public String toString() {
+        return "\nresult: " + result;
+    }
+
+}

openpgp-api/src/main/java/org/openintents/openpgp/OpenPgpError.java

@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2014-2015 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.openintents.openpgp;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+public class OpenPgpError implements Parcelable {
+    /**
+     * Since there might be a case where new versions of the client using the library getting
+     * old versions of the protocol (and thus old versions of this class), we need a versioning
+     * system for the parcels sent between the clients and the providers.
+     */
+    public static final int PARCELABLE_VERSION = 1;
+
+    // possible values for errorId
+    public static final int CLIENT_SIDE_ERROR = -1;
+    public static final int GENERIC_ERROR = 0;
+    public static final int INCOMPATIBLE_API_VERSIONS = 1;
+    public static final int NO_OR_WRONG_PASSPHRASE = 2;
+    public static final int NO_USER_IDS = 3;
+    public static final int OPPORTUNISTIC_MISSING_KEYS = 4;
+
+    int errorId;
+    String message;
+
+    public OpenPgpError() {
+    }
+
+    public OpenPgpError(int errorId, String message) {
+        this.errorId = errorId;
+        this.message = message;
+    }
+
+    public OpenPgpError(OpenPgpError b) {
+        this.errorId = b.errorId;
+        this.message = b.message;
+    }
+
+    public int getErrorId() {
+        return errorId;
+    }
+
+    public void setErrorId(int errorId) {
+        this.errorId = errorId;
+    }
+
+    public String getMessage() {
+        return message;
+    }
+
+    public void setMessage(String message) {
+        this.message = message;
+    }
+
+    public int describeContents() {
+        return 0;
+    }
+
+    public String toString() {
+        return "OpenPGP-Api Error (" + errorId + "): " + message;
+    }
+
+    public void writeToParcel(Parcel dest, int flags) {
+        /**
+         * NOTE: When adding fields in the process of updating this API, make sure to bump
+         * {@link #PARCELABLE_VERSION}.
+         */
+        dest.writeInt(PARCELABLE_VERSION);
+        // Inject a placeholder that will store the parcel size from this point on
+        // (not including the size itself).
+        int sizePosition = dest.dataPosition();
+        dest.writeInt(0);
+        int startPosition = dest.dataPosition();
+        // version 1
+        dest.writeInt(errorId);
+        dest.writeString(message);
+        // Go back and write the size
+        int parcelableSize = dest.dataPosition() - startPosition;
+        dest.setDataPosition(sizePosition);
+        dest.writeInt(parcelableSize);
+        dest.setDataPosition(startPosition + parcelableSize);
+    }
+
+    public static final Creator<OpenPgpError> CREATOR = new Creator<OpenPgpError>() {
+        public OpenPgpError createFromParcel(final Parcel source) {
+            source.readInt(); // parcelableVersion
+            int parcelableSize = source.readInt();
+            int startPosition = source.dataPosition();
+
+            OpenPgpError error = new OpenPgpError();
+            error.errorId = source.readInt();
+            error.message = source.readString();
+
+            // skip over all fields added in future versions of this parcel
+            source.setDataPosition(startPosition + parcelableSize);
+
+            return error;
+        }
+
+        public OpenPgpError[] newArray(final int size) {
+            return new OpenPgpError[size];
+        }
+    };
+}

openpgp-api/src/main/java/org/openintents/openpgp/OpenPgpMetadata.java

@@ -0,0 +1,148 @@
+/*
+ * Copyright (C) 2014-2015 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.openintents.openpgp;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+public class OpenPgpMetadata implements Parcelable {
+    /**
+     * Since there might be a case where new versions of the client using the library getting
+     * old versions of the protocol (and thus old versions of this class), we need a versioning
+     * system for the parcels sent between the clients and the providers.
+     */
+    public static final int PARCELABLE_VERSION = 2;
+
+    String filename;
+    String mimeType;
+    String charset;
+    long modificationTime;
+    long originalSize;
+
+    public String getFilename() {
+        return filename;
+    }
+
+    public String getMimeType() {
+        return mimeType;
+    }
+
+    public long getModificationTime() {
+        return modificationTime;
+    }
+
+    public long getOriginalSize() {
+        return originalSize;
+    }
+
+    public String getCharset() {
+        return charset;
+    }
+
+    public OpenPgpMetadata() {
+    }
+
+    public OpenPgpMetadata(String filename, String mimeType, long modificationTime,
+            long originalSize, String charset) {
+        this.filename = filename;
+        this.mimeType = mimeType;
+        this.modificationTime = modificationTime;
+        this.originalSize = originalSize;
+        this.charset = charset;
+    }
+
+    public OpenPgpMetadata(String filename, String mimeType, long modificationTime,
+                           long originalSize) {
+        this.filename = filename;
+        this.mimeType = mimeType;
+        this.modificationTime = modificationTime;
+        this.originalSize = originalSize;
+    }
+
+    public OpenPgpMetadata(OpenPgpMetadata b) {
+        this.filename = b.filename;
+        this.mimeType = b.mimeType;
+        this.modificationTime = b.modificationTime;
+        this.originalSize = b.originalSize;
+    }
+
+    public int describeContents() {
+        return 0;
+    }
+
+    public void writeToParcel(Parcel dest, int flags) {
+        /**
+         * NOTE: When adding fields in the process of updating this API, make sure to bump
+         * {@link #PARCELABLE_VERSION}.
+         */
+        dest.writeInt(PARCELABLE_VERSION);
+        // Inject a placeholder that will store the parcel size from this point on
+        // (not including the size itself).
+        int sizePosition = dest.dataPosition();
+        dest.writeInt(0);
+        int startPosition = dest.dataPosition();
+        // version 1
+        dest.writeString(filename);
+        dest.writeString(mimeType);
+        dest.writeLong(modificationTime);
+        dest.writeLong(originalSize);
+        // version 2
+        dest.writeString(charset);
+        // Go back and write the size
+        int parcelableSize = dest.dataPosition() - startPosition;
+        dest.setDataPosition(sizePosition);
+        dest.writeInt(parcelableSize);
+        dest.setDataPosition(startPosition + parcelableSize);
+    }
+
+    public static final Creator<OpenPgpMetadata> CREATOR = new Creator<OpenPgpMetadata>() {
+        public OpenPgpMetadata createFromParcel(final Parcel source) {
+            int version = source.readInt(); // parcelableVersion
+            int parcelableSize = source.readInt();
+            int startPosition = source.dataPosition();
+
+            OpenPgpMetadata vr = new OpenPgpMetadata();
+            vr.filename = source.readString();
+            vr.mimeType = source.readString();
+            vr.modificationTime = source.readLong();
+            vr.originalSize = source.readLong();
+            if (version >= 2) {
+                vr.charset = source.readString();
+            }
+
+            // skip over all fields added in future versions of this parcel
+            source.setDataPosition(startPosition + parcelableSize);
+
+            return vr;
+        }
+
+        public OpenPgpMetadata[] newArray(final int size) {
+            return new OpenPgpMetadata[size];
+        }
+    };
+
+    @Override
+    public String toString() {
+        String out = "\nfilename: " + filename;
+        out += "\nmimeType: " + mimeType;
+        out += "\nmodificationTime: " + modificationTime;
+        out += "\noriginalSize: " + originalSize;
+        out += "\ncharset: " + charset;
+        return out;
+    }
+
+}

openpgp-api/src/main/java/org/openintents/openpgp/OpenPgpSignatureResult.java

@@ -0,0 +1,238 @@
+/*
+ * Copyright (C) 2014-2015 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.openintents.openpgp;
+
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+import org.openintents.openpgp.util.OpenPgpUtils;
+
+@SuppressWarnings("unused")
+public class OpenPgpSignatureResult implements Parcelable {
+    /**
+     * Since there might be a case where new versions of the client using the library getting
+     * old versions of the protocol (and thus old versions of this class), we need a versioning
+     * system for the parcels sent between the clients and the providers.
+     */
+    private static final int PARCELABLE_VERSION = 3;
+
+    // content not signed
+    public static final int RESULT_NO_SIGNATURE = -1;
+    // invalid signature!
+    public static final int RESULT_INVALID_SIGNATURE = 0;
+    // successfully verified signature, with confirmed key
+    @Deprecated
+    public static final int RESULT_VALID_CONFIRMED = 1;
+    public static final int RESULT_VALID_KEY_CONFIRMED = 1;
+    // no key was found for this signature verification
+    public static final int RESULT_KEY_MISSING = 2;
+    // successfully verified signature, but with unconfirmed key
+    @Deprecated
+    public static final int RESULT_VALID_UNCONFIRMED = 3;
+    public static final int RESULT_VALID_KEY_UNCONFIRMED = 3;
+    // key has been revoked -> invalid signature!
+    public static final int RESULT_INVALID_KEY_REVOKED = 4;
+    // key is expired -> invalid signature!
+    public static final int RESULT_INVALID_KEY_EXPIRED = 5;
+    // insecure cryptographic algorithms/protocol -> invalid signature!
+    @Deprecated
+    public static final int RESULT_INVALID_INSECURE = 6;
+    public static final int RESULT_INVALID_KEY_INSECURE = 6;
+
+    private final int result;
+    private final long keyId;
+    private final String primaryUserId;
+    private final ArrayList<String> userIds;
+    private final ArrayList<String> confirmedUserIds;
+    private final SenderStatusResult senderStatusResult;
+
+    private OpenPgpSignatureResult(int signatureStatus, String signatureUserId, long keyId,
+            ArrayList<String> userIds, ArrayList<String> confirmedUserIds, SenderStatusResult senderStatusResult,
+            Boolean signatureOnly) {
+        this.result = signatureStatus;
+        this.primaryUserId = signatureUserId;
+        this.keyId = keyId;
+        this.userIds = userIds;
+        this.confirmedUserIds = confirmedUserIds;
+        this.senderStatusResult = senderStatusResult;
+    }
+
+    private OpenPgpSignatureResult(Parcel source, int version) {
+        this.result = source.readInt();
+        // we dropped support for signatureOnly, but need to skip the value for compatibility
+        source.readByte();
+        this.primaryUserId = source.readString();
+        this.keyId = source.readLong();
+
+        if (version > 1) {
+            this.userIds = source.createStringArrayList();
+        } else {
+            this.userIds = null;
+        }
+        if (version > 2) {
+            this.senderStatusResult = readEnumWithNullAndFallback(
+                    source, SenderStatusResult.VALUES, SenderStatusResult.UNKNOWN);
+            this.confirmedUserIds = source.createStringArrayList();
+        } else {
+            this.senderStatusResult = SenderStatusResult.UNKNOWN;
+            this.confirmedUserIds = null;
+        }
+    }
+
+    public int getResult() {
+        return result;
+    }
+
+    public SenderStatusResult getSenderStatusResult() {
+        return senderStatusResult;
+    }
+
+    public String getPrimaryUserId() {
+        return primaryUserId;
+    }
+
+    public List<String> getUserIds() {
+        return Collections.unmodifiableList(userIds);
+    }
+
+    public List<String> getConfirmedUserIds() {
+        return Collections.unmodifiableList(confirmedUserIds);
+    }
+
+    public long getKeyId() {
+        return keyId;
+    }
+
+    public int describeContents() {
+        return 0;
+    }
+
+    public void writeToParcel(Parcel dest, int flags) {
+        /**
+         * NOTE: When adding fields in the process of updating this API, make sure to bump
+         * {@link #PARCELABLE_VERSION}.
+         */
+        dest.writeInt(PARCELABLE_VERSION);
+        // Inject a placeholder that will store the parcel size from this point on
+        // (not including the size itself).
+        int sizePosition = dest.dataPosition();
+        dest.writeInt(0);
+        int startPosition = dest.dataPosition();
+        // version 1
+        dest.writeInt(result);
+        // signatureOnly is deprecated since version 3. we pass a dummy value for compatibility
+        dest.writeByte((byte) 0);
+        dest.writeString(primaryUserId);
+        dest.writeLong(keyId);
+        // version 2
+        dest.writeStringList(userIds);
+        // version 3
+        writeEnumWithNull(dest, senderStatusResult);
+        dest.writeStringList(confirmedUserIds);
+        // Go back and write the size
+        int parcelableSize = dest.dataPosition() - startPosition;
+        dest.setDataPosition(sizePosition);
+        dest.writeInt(parcelableSize);
+        dest.setDataPosition(startPosition + parcelableSize);
+    }
+
+    public static final Creator<OpenPgpSignatureResult> CREATOR = new Creator<OpenPgpSignatureResult>() {
+        public OpenPgpSignatureResult createFromParcel(final Parcel source) {
+            int version = source.readInt(); // parcelableVersion
+            int parcelableSize = source.readInt();
+            int startPosition = source.dataPosition();
+
+            OpenPgpSignatureResult vr = new OpenPgpSignatureResult(source, version);
+
+            // skip over all fields added in future versions of this parcel
+            source.setDataPosition(startPosition + parcelableSize);
+
+            return vr;
+        }
+
+        public OpenPgpSignatureResult[] newArray(final int size) {
+            return new OpenPgpSignatureResult[size];
+        }
+    };
+
+    @Override
+    public String toString() {
+        String out = "\nresult: " + result;
+        out += "\nprimaryUserId: " + primaryUserId;
+        out += "\nuserIds: " + userIds;
+        out += "\nkeyId: " + OpenPgpUtils.convertKeyIdToHex(keyId);
+        return out;
+    }
+
+    public static OpenPgpSignatureResult createWithValidSignature(int signatureStatus, String primaryUserId,
+            long keyId, ArrayList<String> userIds, ArrayList<String> confirmedUserIds, SenderStatusResult senderStatusResult) {
+        if (signatureStatus == RESULT_NO_SIGNATURE || signatureStatus == RESULT_KEY_MISSING ||
+                signatureStatus == RESULT_INVALID_SIGNATURE) {
+            throw new IllegalArgumentException("can only use this method for valid types of signatures");
+        }
+        return new OpenPgpSignatureResult(
+                signatureStatus, primaryUserId, keyId, userIds, confirmedUserIds, senderStatusResult, null);
+    }
+
+    public static OpenPgpSignatureResult createWithNoSignature() {
+        return new OpenPgpSignatureResult(RESULT_NO_SIGNATURE, null, 0L, null, null, null, null);
+    }
+
+    public static OpenPgpSignatureResult createWithKeyMissing(long keyId) {
+        return new OpenPgpSignatureResult(RESULT_KEY_MISSING, null, keyId, null, null, null, null);
+    }
+
+    public static OpenPgpSignatureResult createWithInvalidSignature() {
+        return new OpenPgpSignatureResult(RESULT_INVALID_SIGNATURE, null, 0L, null, null, null, null);
+    }
+
+    @Deprecated
+    public OpenPgpSignatureResult withSignatureOnlyFlag(boolean signatureOnly) {
+        return new OpenPgpSignatureResult(
+                result, primaryUserId, keyId, userIds, confirmedUserIds, senderStatusResult, signatureOnly);
+    }
+
+    private static <T extends Enum<T>> T readEnumWithNullAndFallback(Parcel source, T[] enumValues, T fallback) {
+        int valueOrdinal = source.readInt();
+        if (valueOrdinal == -1) {
+            return null;
+        }
+        if (valueOrdinal >= enumValues.length) {
+            return fallback;
+        }
+        return enumValues[valueOrdinal];
+    }
+
+    private static void writeEnumWithNull(Parcel dest, Enum<?> enumValue) {
+        if (enumValue == null) {
+            dest.writeInt(-1);
+            return;
+        }
+        dest.writeInt(enumValue.ordinal());
+    }
+
+    public enum SenderStatusResult {
+        // Order is significant here - only add to the end for parcelable compatibility!
+        UNKNOWN, USER_ID_CONFIRMED, USER_ID_UNCONFIRMED, USER_ID_MISSING;
+        public static final SenderStatusResult[] VALUES = values();
+    }
+}

openpgp-api/src/main/java/org/openintents/openpgp/util/OpenPgpApi.java

@@ -0,0 +1,667 @@
+/*
+ * Copyright (C) 2014-2015 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.openintents.openpgp.util;
+
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import android.content.Context;
+import android.content.Intent;
+import android.os.AsyncTask;
+import android.os.Build;
+import android.os.Handler;
+import android.os.Message;
+import android.os.Messenger;
+import android.os.ParcelFileDescriptor;
+import android.util.Log;
+
+import org.openintents.openpgp.IOpenPgpService2;
+import org.openintents.openpgp.OpenPgpError;
+import org.openintents.openpgp.util.ParcelFileDescriptorUtil.DataSinkTransferThread;
+import org.openintents.openpgp.util.ParcelFileDescriptorUtil.DataSourceTransferThread;
+
+
+public class OpenPgpApi {
+
+    public static final String TAG = "OpenPgp API";
+
+    public static final String SERVICE_INTENT_2 = "org.openintents.openpgp.IOpenPgpService2";
+
+    /**
+     * see CHANGELOG.md
+     */
+    public static final int API_VERSION = 12;
+
+    /**
+     * General extras
+     * --------------
+     *
+     * required extras:
+     * int           EXTRA_API_VERSION           (always required)
+     *
+     * returned extras:
+     * int           RESULT_CODE                 (RESULT_CODE_ERROR, RESULT_CODE_SUCCESS or RESULT_CODE_USER_INTERACTION_REQUIRED)
+     * OpenPgpError  RESULT_ERROR                (if RESULT_CODE == RESULT_CODE_ERROR)
+     * PendingIntent RESULT_INTENT               (if RESULT_CODE == RESULT_CODE_USER_INTERACTION_REQUIRED)
+     */
+
+    /**
+     * This action performs no operation, but can be used to check if the App has permission
+     * to access the API in general, returning a user interaction PendingIntent otherwise.
+     * This can be used to trigger the permission dialog explicitly.
+     *
+     * This action uses no extras.
+     */
+    public static final String ACTION_CHECK_PERMISSION = "org.openintents.openpgp.action.CHECK_PERMISSION";
+
+    @Deprecated
+    public static final String ACTION_SIGN = "org.openintents.openpgp.action.SIGN";
+
+    /**
+     * Sign text resulting in a cleartext signature
+     * Some magic pre-processing of the text is done to convert it to a format usable for
+     * cleartext signatures per RFC 4880 before the text is actually signed:
+     * - end cleartext with newline
+     * - remove whitespaces on line endings
+     *
+     * required extras:
+     * long          EXTRA_SIGN_KEY_ID           (key id of signing key)
+     *
+     * optional extras:
+     * char[]        EXTRA_PASSPHRASE            (key passphrase)
+     */
+    public static final String ACTION_CLEARTEXT_SIGN = "org.openintents.openpgp.action.CLEARTEXT_SIGN";
+
+    /**
+     * Sign text or binary data resulting in a detached signature.
+     * No OutputStream necessary for ACTION_DETACHED_SIGN (No magic pre-processing like in ACTION_CLEARTEXT_SIGN)!
+     * The detached signature is returned separately in RESULT_DETACHED_SIGNATURE.
+     *
+     * required extras:
+     * long          EXTRA_SIGN_KEY_ID           (key id of signing key)
+     *
+     * optional extras:
+     * boolean       EXTRA_REQUEST_ASCII_ARMOR   (request ascii armor for detached signature)
+     * char[]        EXTRA_PASSPHRASE            (key passphrase)
+     *
+     * returned extras:
+     * byte[]        RESULT_DETACHED_SIGNATURE
+     * String        RESULT_SIGNATURE_MICALG     (contains the name of the used signature algorithm as a string)
+     */
+    public static final String ACTION_DETACHED_SIGN = "org.openintents.openpgp.action.DETACHED_SIGN";
+
+    /**
+     * Encrypt
+     *
+     * required extras:
+     * String[]      EXTRA_USER_IDS              (=emails of recipients, if more than one key has a user_id, a PendingIntent is returned via RESULT_INTENT)
+     * or
+     * long[]        EXTRA_KEY_IDS
+     *
+     * optional extras:
+     * boolean       EXTRA_REQUEST_ASCII_ARMOR   (request ascii armor for output)
+     * char[]        EXTRA_PASSPHRASE            (key passphrase)
+     * String        EXTRA_ORIGINAL_FILENAME     (original filename to be encrypted as metadata)
+     * boolean       EXTRA_ENABLE_COMPRESSION    (enable ZLIB compression, default ist true)
+     */
+    public static final String ACTION_ENCRYPT = "org.openintents.openpgp.action.ENCRYPT";
+
+    /**
+     * Sign and encrypt
+     *
+     * required extras:
+     * String[]      EXTRA_USER_IDS              (=emails of recipients, if more than one key has a user_id, a PendingIntent is returned via RESULT_INTENT)
+     * or
+     * long[]        EXTRA_KEY_IDS
+     *
+     * optional extras:
+     * long          EXTRA_SIGN_KEY_ID           (key id of signing key)
+     * boolean       EXTRA_REQUEST_ASCII_ARMOR   (request ascii armor for output)
+     * char[]        EXTRA_PASSPHRASE            (key passphrase)
+     * String        EXTRA_ORIGINAL_FILENAME     (original filename to be encrypted as metadata)
+     * boolean       EXTRA_ENABLE_COMPRESSION    (enable ZLIB compression, default ist true)
+     */
+    public static final String ACTION_SIGN_AND_ENCRYPT = "org.openintents.openpgp.action.SIGN_AND_ENCRYPT";
+
+    public static final String ACTION_QUERY_AUTOCRYPT_STATUS = "org.openintents.openpgp.action.QUERY_AUTOCRYPT_STATUS";
+
+    /**
+     * Decrypts and verifies given input stream. This methods handles encrypted-only, signed-and-encrypted,
+     * and also signed-only input.
+     * OutputStream is optional, e.g., for verifying detached signatures!
+     *
+     * If OpenPgpSignatureResult.getResult() == OpenPgpSignatureResult.RESULT_KEY_MISSING
+     * in addition a PendingIntent is returned via RESULT_INTENT to download missing keys.
+     * On all other status, in addition a PendingIntent is returned via RESULT_INTENT to open
+     * the key view in OpenKeychain.
+     *
+     * optional extras:
+     * byte[]        EXTRA_DETACHED_SIGNATURE    (detached signature)
+     *
+     * returned extras:
+     * OpenPgpSignatureResult   RESULT_SIGNATURE
+     * OpenPgpDecryptionResult  RESULT_DECRYPTION
+     * OpenPgpDecryptMetadata   RESULT_METADATA
+     * String                   RESULT_CHARSET   (charset which was specified in the headers of ascii armored input, if any)
+     */
+    public static final String ACTION_DECRYPT_VERIFY = "org.openintents.openpgp.action.DECRYPT_VERIFY";
+
+    /**
+     * Decrypts the header of an encrypted file to retrieve metadata such as original filename.
+     *
+     * This does not decrypt the actual content of the file.
+     *
+     * returned extras:
+     * OpenPgpDecryptMetadata   RESULT_METADATA
+     * String                   RESULT_CHARSET   (charset which was specified in the headers of ascii armored input, if any)
+     */
+    public static final String ACTION_DECRYPT_METADATA = "org.openintents.openpgp.action.DECRYPT_METADATA";
+
+    /**
+     * Select key id for signing
+     *
+     * optional extras:
+     * String      EXTRA_USER_ID
+     *
+     * returned extras:
+     * long        EXTRA_SIGN_KEY_ID
+     */
+    public static final String ACTION_GET_SIGN_KEY_ID = "org.openintents.openpgp.action.GET_SIGN_KEY_ID";
+
+    /**
+     * Get key ids based on given user ids (=emails)
+     *
+     * required extras:
+     * String[]      EXTRA_USER_IDS
+     *
+     * returned extras:
+     * long[]        RESULT_KEY_IDS
+     */
+    public static final String ACTION_GET_KEY_IDS = "org.openintents.openpgp.action.GET_KEY_IDS";
+
+    /**
+     * This action returns RESULT_CODE_SUCCESS if the OpenPGP Provider already has the key
+     * corresponding to the given key id in its database.
+     *
+     * It returns RESULT_CODE_USER_INTERACTION_REQUIRED if the Provider does not have the key.
+     * The PendingIntent from RESULT_INTENT can be used to retrieve those from a keyserver.
+     *
+     * If an Output stream has been defined the whole public key is returned.
+     * required extras:
+     * long        EXTRA_KEY_ID
+     *
+     * optional extras:
+     * String      EXTRA_REQUEST_ASCII_ARMOR (request that the returned key is encoded in ASCII Armor)
+     */
+    public static final String ACTION_GET_KEY = "org.openintents.openpgp.action.GET_KEY";
+
+    /**
+     * Backup all keys given by EXTRA_KEY_IDS and if requested their secret parts.
+     * The encrypted backup will be written to the OutputStream.
+     * The client app has no access to the backup code used to encrypt the backup!
+     * This operation always requires user interaction with RESULT_CODE_USER_INTERACTION_REQUIRED!
+     *
+     * required extras:
+     * long[]      EXTRA_KEY_IDS       (keys that should be included in the backup)
+     * boolean     EXTRA_BACKUP_SECRET (also backup secret keys)
+     */
+    public static final String ACTION_BACKUP = "org.openintents.openpgp.action.BACKUP";
+
+    /**
+     * Update the status of some Autocrypt peer, identified by their peer id.
+     *
+     * required extras:
+     * String                  EXTRA_AUTOCRYPT_PEER_ID       (autocrypt peer id to update)
+     * AutocryptPeerUpdate     EXTRA_AUTOCRYPT_PEER_UPDATE   (actual peer update)
+     */
+    public static final String ACTION_UPDATE_AUTOCRYPT_PEER = "org.openintents.openpgp.action.UPDATE_AUTOCRYPT_PEER";
+
+    /* Intent extras */
+    public static final String EXTRA_API_VERSION = "api_version";
+
+    // ACTION_DETACHED_SIGN, ENCRYPT, SIGN_AND_ENCRYPT, DECRYPT_VERIFY
+    // request ASCII Armor for output
+    // OpenPGP Radix-64, 33 percent overhead compared to binary, see http://tools.ietf.org/html/rfc4880#page-53)
+    public static final String EXTRA_REQUEST_ASCII_ARMOR = "ascii_armor";
+
+    // ACTION_DETACHED_SIGN
+    public static final String RESULT_DETACHED_SIGNATURE = "detached_signature";
+    public static final String RESULT_SIGNATURE_MICALG = "signature_micalg";
+
+    // ENCRYPT, SIGN_AND_ENCRYPT, QUERY_AUTOCRYPT_STATUS
+    public static final String EXTRA_USER_IDS = "user_ids";
+    public static final String EXTRA_KEY_IDS = "key_ids";
+    public static final String EXTRA_KEY_IDS_SELECTED = "key_ids_selected";
+    public static final String EXTRA_SIGN_KEY_ID = "sign_key_id";
+
+    public static final String RESULT_KEYS_CONFIRMED = "keys_confirmed";
+    public static final String RESULT_AUTOCRYPT_STATUS = "autocrypt_status";
+    public static final int AUTOCRYPT_STATUS_UNAVAILABLE = 0;
+    public static final int AUTOCRYPT_STATUS_DISCOURAGE = 1;
+    public static final int AUTOCRYPT_STATUS_AVAILABLE = 2;
+    public static final int AUTOCRYPT_STATUS_MUTUAL = 3;
+
+    // optional extras:
+    public static final String EXTRA_PASSPHRASE = "passphrase";
+    public static final String EXTRA_ORIGINAL_FILENAME = "original_filename";
+    public static final String EXTRA_ENABLE_COMPRESSION = "enable_compression";
+    public static final String EXTRA_OPPORTUNISTIC_ENCRYPTION = "opportunistic";
+
+    // GET_SIGN_KEY_ID
+    public static final String EXTRA_USER_ID = "user_id";
+    public static final String EXTRA_PRESELECT_KEY_ID = "preselect_key_id";
+    public static final String EXTRA_SHOW_AUTOCRYPT_HINT = "show_autocrypt_hint";
+
+    // GET_KEY
+    public static final String EXTRA_KEY_ID = "key_id";
+    public static final String EXTRA_MINIMIZE = "minimize";
+    public static final String EXTRA_MINIMIZE_USER_ID = "minimize_user_id";
+    public static final String RESULT_KEY_IDS = "key_ids";
+
+    // AUTOCRYPT_KEY_TRANSFER
+    public static final String ACTION_AUTOCRYPT_KEY_TRANSFER = "autocrypt_key_transfer";
+
+    // BACKUP
+    public static final String EXTRA_BACKUP_SECRET = "backup_secret";
+
+    /* Service Intent returns */
+    public static final String RESULT_CODE = "result_code";
+
+    // get actual error object from RESULT_ERROR
+    public static final int RESULT_CODE_ERROR = 0;
+    // success!
+    public static final int RESULT_CODE_SUCCESS = 1;
+    // get PendingIntent from RESULT_INTENT, start PendingIntent with startIntentSenderForResult,
+    // and execute service method again in onActivityResult
+    public static final int RESULT_CODE_USER_INTERACTION_REQUIRED = 2;
+
+    public static final String RESULT_ERROR = "error";
+    public static final String RESULT_INTENT = "intent";
+
+    // DECRYPT_VERIFY
+    public static final String EXTRA_DETACHED_SIGNATURE = "detached_signature";
+    public static final String EXTRA_PROGRESS_MESSENGER = "progress_messenger";
+    public static final String EXTRA_DATA_LENGTH = "data_length";
+    public static final String EXTRA_DECRYPTION_RESULT = "decryption_result";
+    public static final String EXTRA_SENDER_ADDRESS = "sender_address";
+    public static final String EXTRA_SUPPORT_OVERRIDE_CRYPTO_WARNING = "support_override_crpto_warning";
+    public static final String RESULT_SIGNATURE = "signature";
+    public static final String RESULT_DECRYPTION = "decryption";
+    public static final String RESULT_METADATA = "metadata";
+    public static final String RESULT_INSECURE_DETAIL_INTENT = "insecure_detail_intent";
+    public static final String RESULT_OVERRIDE_CRYPTO_WARNING = "override_crypto_warning";
+    // This will be the charset which was specified in the headers of ascii armored input, if any
+    public static final String RESULT_CHARSET = "charset";
+
+    // UPDATE_AUTOCRYPT_PEER
+    public static final String EXTRA_AUTOCRYPT_PEER_ID = "autocrypt_peer_id";
+    public static final String EXTRA_AUTOCRYPT_PEER_UPDATE = "autocrypt_peer_update";
+    public static final String EXTRA_AUTOCRYPT_PEER_GOSSIP_UPDATES = "autocrypt_peer_gossip_updates";
+
+    // INTERNAL, must not be used
+    public static final String EXTRA_CALL_UUID1 = "call_uuid1";
+    public static final String EXTRA_CALL_UUID2 = "call_uuid2";
+
+    IOpenPgpService2 mService;
+    Context mContext;
+    final AtomicInteger mPipeIdGen = new AtomicInteger();
+
+    public OpenPgpApi(Context context, IOpenPgpService2 service) {
+        this.mContext = context;
+        this.mService = service;
+    }
+
+    public interface IOpenPgpCallback {
+        void onReturn(final Intent result);
+    }
+
+    public interface IOpenPgpSinkResultCallback<T> {
+        void onProgress(int current, int max);
+        void onReturn(final Intent result, T sinkResult);
+    }
+
+    public interface CancelableBackgroundOperation {
+        void cancelOperation();
+    }
+
+    private class OpenPgpSourceSinkAsyncTask<T> extends AsyncTask<Void, Integer, OpenPgpDataResult<T>>
+            implements CancelableBackgroundOperation {
+        Intent data;
+        OpenPgpDataSource dataSource;
+        OpenPgpDataSink<T> dataSink;
+        IOpenPgpSinkResultCallback<T> callback;
+
+        private OpenPgpSourceSinkAsyncTask(Intent data, OpenPgpDataSource dataSource,
+                OpenPgpDataSink<T> dataSink, IOpenPgpSinkResultCallback<T> callback) {
+            this.data = data;
+            this.dataSource = dataSource;
+            this.dataSink = dataSink;
+            this.callback = callback;
+        }
+
+        @Override
+        protected OpenPgpDataResult<T> doInBackground(Void... unused) {
+            return executeApi(data, dataSource, dataSink);
+        }
+
+        protected void onPostExecute(OpenPgpDataResult<T> result) {
+            callback.onReturn(result.apiResult, result.sinkResult);
+        }
+
+        @Override
+        public void cancelOperation() {
+            cancel(true);
+            if (dataSource != null) {
+                dataSource.cancel();
+            }
+        }
+    }
+
+    class OpenPgpAsyncTask extends AsyncTask<Void, Integer, Intent> {
+        Intent data;
+        InputStream is;
+        OutputStream os;
+        IOpenPgpCallback callback;
+
+        private OpenPgpAsyncTask(Intent data, InputStream is, OutputStream os, IOpenPgpCallback callback) {
+            this.data = data;
+            this.is = is;
+            this.os = os;
+            this.callback = callback;
+        }
+
+        @Override
+        protected Intent doInBackground(Void... unused) {
+            return executeApi(data, is, os);
+        }
+
+        protected void onPostExecute(Intent result) {
+            callback.onReturn(result);
+        }
+    }
+
+    public <T> CancelableBackgroundOperation executeApiAsync(Intent data, OpenPgpDataSource dataSource,
+            OpenPgpDataSink<T> dataSink, final IOpenPgpSinkResultCallback<T> callback) {
+        Messenger messenger = new Messenger(new Handler(new Handler.Callback() {
+            @Override
+            public boolean handleMessage(Message message) {
+                callback.onProgress(message.arg1, message.arg2);
+                return true;
+            }
+        }));
+        data.putExtra(EXTRA_PROGRESS_MESSENGER, messenger);
+
+        OpenPgpSourceSinkAsyncTask<T> task = new OpenPgpSourceSinkAsyncTask<>(data, dataSource, dataSink, callback);
+
+        // don't serialize async tasks!
+        // http://commonsware.com/blog/2012/04/20/asynctask-threading-regression-confirmed.html
+        task.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, (Void[]) null);
+
+        return task;
+    }
+
+    public AsyncTask executeApiAsync(Intent data, OpenPgpDataSource dataSource, IOpenPgpSinkResultCallback<Void> callback) {
+        OpenPgpSourceSinkAsyncTask<Void> task = new OpenPgpSourceSinkAsyncTask<>(data, dataSource, null, callback);
+
+        // don't serialize async tasks!
+        // http://commonsware.com/blog/2012/04/20/asynctask-threading-regression-confirmed.html
+        task.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, (Void[]) null);
+
+        return task;
+    }
+
+    public void executeApiAsync(Intent data, InputStream is, OutputStream os, IOpenPgpCallback callback) {
+        OpenPgpAsyncTask task = new OpenPgpAsyncTask(data, is, os, callback);
+
+        // don't serialize async tasks!
+        // http://commonsware.com/blog/2012/04/20/asynctask-threading-regression-confirmed.html
+        task.executeOnExecutor(AsyncTask.THREAD_POOL_EXECUTOR, (Void[]) null);
+    }
+
+    public static class OpenPgpDataResult<T> {
+        Intent apiResult;
+        T sinkResult;
+
+        public OpenPgpDataResult(Intent apiResult, T sinkResult) {
+            this.apiResult = apiResult;
+            this.sinkResult = sinkResult;
+        }
+    }
+
+    public <T> OpenPgpDataResult<T> executeApi(Intent data, OpenPgpDataSource dataSource, OpenPgpDataSink<T> dataSink) {
+        ParcelFileDescriptor input = null;
+        ParcelFileDescriptor output = null;
+        try {
+            if (dataSource != null) {
+                Long expectedSize = dataSource.getSizeForProgress();
+                if (expectedSize != null) {
+                    data.putExtra(EXTRA_DATA_LENGTH, (long) expectedSize);
+                } else {
+                    data.removeExtra(EXTRA_PROGRESS_MESSENGER);
+                }
+                input = dataSource.startPumpThread();
+            }
+
+            DataSinkTransferThread<T> pumpThread = null;
+            int outputPipeId = 0;
+
+            if (dataSink != null) {
+                outputPipeId = mPipeIdGen.incrementAndGet();
+                output = mService.createOutputPipe(outputPipeId);
+                pumpThread = ParcelFileDescriptorUtil.asyncPipeToDataSink(dataSink, output);
+            }
+
+            Intent result = executeApi(data, input, outputPipeId);
+
+            if (pumpThread == null) {
+                return new OpenPgpDataResult<>(result, null);
+            }
+
+            // wait for ALL data being pumped from remote side
+            pumpThread.join();
+            return new OpenPgpDataResult<>(result, pumpThread.getResult());
+        } catch (Exception e) {
+            Log.e(OpenPgpApi.TAG, "Exception in executeApi call", e);
+            Intent result = new Intent();
+            result.putExtra(RESULT_CODE, RESULT_CODE_ERROR);
+            result.putExtra(RESULT_ERROR,
+                    new OpenPgpError(OpenPgpError.CLIENT_SIDE_ERROR, e.getMessage()));
+            return new OpenPgpDataResult<>(result, null);
+        } finally {
+            closeLoudly(output);
+        }
+    }
+
+    public Intent executeApi(Intent data, InputStream is, OutputStream os) {
+        ParcelFileDescriptor input = null;
+        ParcelFileDescriptor output = null;
+        try {
+            if (is != null) {
+                input = ParcelFileDescriptorUtil.pipeFrom(is);
+            }
+
+            Thread pumpThread = null;
+            int outputPipeId = 0;
+
+            if (os != null) {
+                outputPipeId = mPipeIdGen.incrementAndGet();
+                output = mService.createOutputPipe(outputPipeId);
+                pumpThread = ParcelFileDescriptorUtil.pipeTo(os, output);
+            }
+
+            Intent result = executeApi(data, input, outputPipeId);
+
+            // wait for ALL data being pumped from remote side
+            if (pumpThread != null) {
+                pumpThread.join();
+            }
+
+            return result;
+        } catch (Exception e) {
+            Log.e(OpenPgpApi.TAG, "Exception in executeApi call", e);
+            Intent result = new Intent();
+            result.putExtra(RESULT_CODE, RESULT_CODE_ERROR);
+            result.putExtra(RESULT_ERROR,
+                    new OpenPgpError(OpenPgpError.CLIENT_SIDE_ERROR, e.getMessage()));
+            return result;
+        } finally {
+            closeLoudly(output);
+        }
+    }
+
+    public static abstract class OpenPgpDataSource {
+        private boolean isCancelled;
+        private ParcelFileDescriptor writeSidePfd;
+
+
+        public abstract void writeTo(OutputStream os) throws IOException;
+
+        public Long getSizeForProgress() {
+            return null;
+        }
+
+        public boolean isCancelled() {
+            return isCancelled;
+        }
+
+        public ParcelFileDescriptor startPumpThread() throws IOException {
+            if (writeSidePfd != null) {
+                throw new IllegalStateException("startPumpThread() must only be called once!");
+            }
+            ParcelFileDescriptor[] pipe = ParcelFileDescriptor.createPipe();
+            ParcelFileDescriptor readSidePfd = pipe[0];
+            writeSidePfd = pipe[1];
+
+            new DataSourceTransferThread(this, new ParcelFileDescriptor.AutoCloseOutputStream(writeSidePfd)).start();
+
+            return readSidePfd;
+        }
+
+        private void cancel() {
+            isCancelled = true;
+            try {
+                writeSidePfd.close();
+            } catch (IOException e) {
+                // this is fine
+            }
+        }
+    }
+
+    public interface OpenPgpDataSink<T> {
+        T processData(InputStream is) throws IOException;
+    }
+
+    public Intent executeApi(Intent data, OpenPgpDataSource dataSource, OutputStream os) {
+        ParcelFileDescriptor input = null;
+        ParcelFileDescriptor output;
+        try {
+            if (dataSource != null) {
+                Long expectedSize = dataSource.getSizeForProgress();
+                if (expectedSize != null) {
+                    data.putExtra(EXTRA_DATA_LENGTH, (long) expectedSize);
+                } else {
+                    data.removeExtra(EXTRA_PROGRESS_MESSENGER);
+                }
+                input = dataSource.startPumpThread();
+            }
+
+            Thread pumpThread = null;
+            int outputPipeId = 0;
+
+            if (os != null) {
+                outputPipeId = mPipeIdGen.incrementAndGet();
+                output = mService.createOutputPipe(outputPipeId);
+                pumpThread = ParcelFileDescriptorUtil.pipeTo(os, output);
+            }
+
+            Intent result = executeApi(data, input, outputPipeId);
+
+            // wait for ALL data being pumped from remote side
+            if (pumpThread != null) {
+                pumpThread.join();
+            }
+
+            return result;
+        } catch (Exception e) {
+            Log.e(OpenPgpApi.TAG, "Exception in executeApi call", e);
+            Intent result = new Intent();
+            result.putExtra(RESULT_CODE, RESULT_CODE_ERROR);
+            result.putExtra(RESULT_ERROR,
+                    new OpenPgpError(OpenPgpError.CLIENT_SIDE_ERROR, e.getMessage()));
+            return result;
+        }
+    }
+
+    /**
+     * InputStream and OutputStreams are always closed after operating on them!
+     */
+    private Intent executeApi(Intent data, ParcelFileDescriptor input, int outputPipeId) {
+        try {
+            // always send version from client
+            data.putExtra(EXTRA_API_VERSION, OpenPgpApi.API_VERSION);
+
+            Intent result;
+
+            // blocks until result is ready
+            result = mService.execute(data, input, outputPipeId);
+
+            // set class loader to current context to allow unparcelling
+            // of OpenPgpError and OpenPgpSignatureResult
+            // http://stackoverflow.com/a/3806769
+            result.setExtrasClassLoader(mContext.getClassLoader());
+
+            return result;
+        } catch (Exception e) {
+            Log.e(OpenPgpApi.TAG, "Exception in executeApi call", e);
+            Intent result = new Intent();
+            result.putExtra(RESULT_CODE, RESULT_CODE_ERROR);
+            result.putExtra(RESULT_ERROR,
+                    new OpenPgpError(OpenPgpError.CLIENT_SIDE_ERROR, e.getMessage()));
+            return result;
+        } finally {
+            // close() is required to halt the TransferThread
+            closeLoudly(input);
+        }
+    }
+
+    private static void closeLoudly(ParcelFileDescriptor input) {
+        if (input != null) {
+            try {
+                input.close();
+            } catch (IOException e) {
+                Log.e(OpenPgpApi.TAG, "IOException when closing ParcelFileDescriptor!", e);
+            }
+        }
+    }
+
+    public interface PermissionPingCallback {
+        void onPgpPermissionCheckResult(Intent result);
+    }
+
+    public void checkPermissionPing(final PermissionPingCallback permissionPingCallback) {
+        Intent intent = new Intent(OpenPgpApi.ACTION_CHECK_PERMISSION);
+        executeApiAsync(intent, null, null, new IOpenPgpCallback() {
+            @Override
+            public void onReturn(Intent result) {
+                permissionPingCallback.onPgpPermissionCheckResult(result);
+            }
+        });
+    }
+}

openpgp-api/src/main/java/org/openintents/openpgp/util/OpenPgpProviderUtil.java

@@ -0,0 +1,62 @@
+package org.openintents.openpgp.util;
+
+
+import java.util.ArrayList;
+import java.util.List;
+
+import android.content.Context;
+import android.content.Intent;
+import android.content.pm.PackageManager;
+import android.content.pm.ResolveInfo;
+
+
+public class OpenPgpProviderUtil {
+    private static final String PACKAGE_NAME_APG = "org.thialfihar.android.apg";
+    private static final ArrayList<String> PROVIDER_BLACKLIST = new ArrayList<>();
+    static {
+        PROVIDER_BLACKLIST.add(PACKAGE_NAME_APG);
+    }
+
+    public static List<String> getOpenPgpProviderPackages(Context context) {
+        ArrayList<String> result = new ArrayList<>();
+
+        Intent intent = new Intent(OpenPgpApi.SERVICE_INTENT_2);
+        List<ResolveInfo> resInfo = context.getPackageManager().queryIntentServices(intent, 0);
+        if (resInfo == null) {
+            return result;
+        }
+
+        for (ResolveInfo resolveInfo : resInfo) {
+            if (resolveInfo.serviceInfo == null) {
+                continue;
+            }
+
+            result.add(resolveInfo.serviceInfo.packageName);
+        }
+
+        return result;
+    }
+
+    public static String getOpenPgpProviderName(PackageManager packageManager, String openPgpProvider) {
+        Intent intent = new Intent(OpenPgpApi.SERVICE_INTENT_2);
+        intent.setPackage(openPgpProvider);
+        List<ResolveInfo> resInfo = packageManager.queryIntentServices(intent, 0);
+        if (resInfo == null) {
+            return null;
+        }
+
+        for (ResolveInfo resolveInfo : resInfo) {
+            if (resolveInfo.serviceInfo == null) {
+                continue;
+            }
+
+            return String.valueOf(resolveInfo.serviceInfo.loadLabel(packageManager));
+        }
+
+        return null;
+    }
+
+    public static boolean isBlacklisted(String packageName) {
+        return PROVIDER_BLACKLIST.contains(packageName);
+    }
+}

openpgp-api/src/main/java/org/openintents/openpgp/util/OpenPgpServiceConnection.java

@@ -0,0 +1,124 @@
+/*
+ * Copyright (C) 2014-2015 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.openintents.openpgp.util;
+
+import android.content.ComponentName;
+import android.content.Context;
+import android.content.Intent;
+import android.content.ServiceConnection;
+import android.os.IBinder;
+
+import org.openintents.openpgp.IOpenPgpService2;
+
+public class OpenPgpServiceConnection {
+
+    // callback interface
+    public interface OnBound {
+        void onBound(IOpenPgpService2 service);
+
+        void onError(Exception e);
+    }
+
+    private Context mApplicationContext;
+
+    private IOpenPgpService2 mService;
+    private String mProviderPackageName;
+
+    private OnBound mOnBoundListener;
+
+    /**
+     * Create new connection
+     *
+     * @param context
+     * @param providerPackageName specify package name of OpenPGP provider,
+     *                            e.g., "org.sufficientlysecure.keychain"
+     */
+    public OpenPgpServiceConnection(Context context, String providerPackageName) {
+        this.mApplicationContext = context.getApplicationContext();
+        this.mProviderPackageName = providerPackageName;
+    }
+
+    /**
+     * Create new connection with callback
+     *
+     * @param context
+     * @param providerPackageName specify package name of OpenPGP provider,
+     *                            e.g., "org.sufficientlysecure.keychain"
+     * @param onBoundListener     callback, executed when connection to service has been established
+     */
+    public OpenPgpServiceConnection(Context context, String providerPackageName,
+                                    OnBound onBoundListener) {
+        this(context, providerPackageName);
+        this.mOnBoundListener = onBoundListener;
+    }
+
+    public IOpenPgpService2 getService() {
+        return mService;
+    }
+
+    public boolean isBound() {
+        return (mService != null);
+    }
+
+    private ServiceConnection mServiceConnection = new ServiceConnection() {
+        public void onServiceConnected(ComponentName name, IBinder service) {
+            mService = IOpenPgpService2.Stub.asInterface(service);
+            if (mOnBoundListener != null) {
+                mOnBoundListener.onBound(mService);
+            }
+        }
+
+        public void onServiceDisconnected(ComponentName name) {
+            mService = null;
+        }
+    };
+
+    /**
+     * If not already bound, bind to service!
+     *
+     * @return
+     */
+    public void bindToService() {
+        // if not already bound...
+        if (mService == null) {
+            try {
+                Intent serviceIntent = new Intent(OpenPgpApi.SERVICE_INTENT_2);
+                // NOTE: setPackage is very important to restrict the intent to this provider only!
+                serviceIntent.setPackage(mProviderPackageName);
+                boolean connect = mApplicationContext.bindService(serviceIntent, mServiceConnection,
+                        Context.BIND_AUTO_CREATE);
+                if (!connect) {
+                    throw new Exception("bindService() returned false!");
+                }
+            } catch (Exception e) {
+                if (mOnBoundListener != null) {
+                    mOnBoundListener.onError(e);
+                }
+            }
+        } else {
+            // already bound, but also inform client about it with callback
+            if (mOnBoundListener != null) {
+                mOnBoundListener.onBound(mService);
+            }
+        }
+    }
+
+    public void unbindFromService() {
+        mApplicationContext.unbindService(mServiceConnection);
+    }
+
+}

openpgp-api/src/main/java/org/openintents/openpgp/util/OpenPgpUtils.java

@@ -0,0 +1,145 @@
+/*
+ * Copyright (C) 2014-2015 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.openintents.openpgp.util;
+
+
+import java.util.List;
+import java.util.Locale;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+import android.content.Context;
+import android.content.Intent;
+import android.content.pm.ResolveInfo;
+import android.text.TextUtils;
+
+public class OpenPgpUtils {
+
+    public static final Pattern PGP_MESSAGE = Pattern.compile(
+            "(-----BEGIN PGP MESSAGE-----.*?-----END PGP MESSAGE-----).*",
+            Pattern.DOTALL);
+
+    public static final String PGP_MARKER_CLEARSIGN_BEGIN_MESSAGE = "-----BEGIN PGP SIGNED MESSAGE-----";
+    public static final String PGP_MARKER_CLEARSIGN_BEGIN_SIGNATURE = "-----BEGIN PGP SIGNATURE-----";
+
+    public static final Pattern PGP_SIGNED_MESSAGE = Pattern.compile(
+            "(-----BEGIN PGP SIGNED MESSAGE-----.*?-----BEGIN PGP SIGNATURE-----.*?-----END PGP SIGNATURE-----).*",
+            Pattern.DOTALL);
+
+    public static final int PARSE_RESULT_NO_PGP = -1;
+    public static final int PARSE_RESULT_MESSAGE = 0;
+    public static final int PARSE_RESULT_SIGNED_MESSAGE = 1;
+
+    public static int parseMessage(String message) {
+        return parseMessage(message, false);
+    }
+
+    public static int parseMessage(String message, boolean anchorToStart) {
+        Matcher matcherSigned = PGP_SIGNED_MESSAGE.matcher(message);
+        Matcher matcherMessage = PGP_MESSAGE.matcher(message);
+
+        if (anchorToStart ? matcherMessage.matches() : matcherMessage.find()) {
+            return PARSE_RESULT_MESSAGE;
+        } else if (anchorToStart ? matcherSigned.matches() : matcherSigned.find()) {
+            return PARSE_RESULT_SIGNED_MESSAGE;
+        } else {
+            return PARSE_RESULT_NO_PGP;
+        }
+    }
+
+    public static boolean isAvailable(Context context) {
+        Intent intent = new Intent(OpenPgpApi.SERVICE_INTENT_2);
+        List<ResolveInfo> resInfo = context.getPackageManager().queryIntentServices(intent, 0);
+        return !resInfo.isEmpty();
+    }
+
+    public static String convertKeyIdToHex(long keyId) {
+        return "0x" + convertKeyIdToHex32bit(keyId >> 32) + convertKeyIdToHex32bit(keyId);
+    }
+
+    private static String convertKeyIdToHex32bit(long keyId) {
+        String hexString = Long.toHexString(keyId & 0xffffffffL).toLowerCase(Locale.ENGLISH);
+        while (hexString.length() < 8) {
+            hexString = "0" + hexString;
+        }
+        return hexString;
+    }
+
+    public static String extractClearsignedMessage(String text) {
+        if (text == null || !text.startsWith(PGP_MARKER_CLEARSIGN_BEGIN_MESSAGE)) {
+            return null;
+        }
+        int endOfHeader = text.indexOf("\r\n\r\n") +4;
+        if (endOfHeader < 0) {
+            return null;
+        }
+        int endOfCleartext = text.indexOf(PGP_MARKER_CLEARSIGN_BEGIN_SIGNATURE);
+        if (endOfCleartext < 0) {
+            endOfCleartext = text.length();
+        }
+
+        return text.substring(endOfHeader, endOfCleartext);
+    }
+
+    private static final Pattern USER_ID_PATTERN = Pattern.compile("^(.*?)(?: \\((.*)\\))?(?: <(.*)>)?$");
+
+    /**
+     * Splits userId string into naming part, email part, and comment part
+     * <p/>
+     * User ID matching:
+     * http://fiddle.re/t4p6f
+     *
+     * @param userId
+     * @return theParsedUserInfo
+     */
+    public static UserId splitUserId(final String userId) {
+        if (!TextUtils.isEmpty(userId)) {
+            final Matcher matcher = USER_ID_PATTERN.matcher(userId);
+            if (matcher.matches()) {
+                return new UserId(matcher.group(1), matcher.group(3), matcher.group(2));
+            }
+        }
+        return new UserId(null, null, null);
+    }
+
+    /**
+     * Returns a composed user id. Returns null if name is null!
+     */
+    public static String createUserId(UserId userId) {
+        String userIdString = userId.name; // consider name a required value
+        if (userIdString != null && !TextUtils.isEmpty(userId.comment)) {
+            userIdString += " (" + userId.comment + ")";
+        }
+        if (userIdString != null && !TextUtils.isEmpty(userId.email)) {
+            userIdString += " <" + userId.email + ">";
+        }
+
+        return userIdString;
+    }
+
+    public static class UserId {
+        public final String name;
+        public final String email;
+        public final String comment;
+
+        public UserId(String name, String email, String comment) {
+            this.name = name;
+            this.email = email;
+            this.comment = comment;
+        }
+    }
+}

openpgp-api/src/main/java/org/openintents/openpgp/util/ParcelFileDescriptorUtil.java

@@ -0,0 +1,178 @@
+/*
+ * Copyright (C) 2014-2015 Dominik Schürmann <dominik@dominikschuermann.de>
+ *               2013 Florian Schmaus <flo@geekplace.eu>
+ *
+ * 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.openintents.openpgp.util;
+
+
+import java.io.BufferedInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+
+import android.os.ParcelFileDescriptor;
+import android.os.ParcelFileDescriptor.AutoCloseInputStream;
+import android.system.ErrnoException;
+import android.system.OsConstants;
+import android.util.Log;
+
+import org.openintents.openpgp.util.OpenPgpApi.OpenPgpDataSink;
+import org.openintents.openpgp.util.OpenPgpApi.OpenPgpDataSource;
+
+
+public class ParcelFileDescriptorUtil {
+
+    public static ParcelFileDescriptor pipeFrom(InputStream inputStream)
+            throws IOException {
+        ParcelFileDescriptor[] pipe = ParcelFileDescriptor.createPipe();
+        ParcelFileDescriptor readSide = pipe[0];
+        ParcelFileDescriptor writeSide = pipe[1];
+
+        new TransferThread(inputStream, new ParcelFileDescriptor.AutoCloseOutputStream(writeSide))
+                .start();
+
+        return readSide;
+    }
+
+    public static TransferThread pipeTo(OutputStream outputStream, ParcelFileDescriptor output) {
+
+        AutoCloseInputStream InputStream = new AutoCloseInputStream(output);
+        TransferThread t = new TransferThread(InputStream, outputStream);
+
+        t.start();
+        return t;
+    }
+
+    static class TransferThread extends Thread {
+        final InputStream mIn;
+        final OutputStream mOut;
+
+        TransferThread(InputStream in, OutputStream out) {
+            super("IPC Transfer Thread");
+            mIn = in;
+            mOut = out;
+            setDaemon(true);
+        }
+
+        @Override
+        public void run() {
+            byte[] buf = new byte[4096];
+            int len;
+
+            try {
+                while ((len = mIn.read(buf)) > 0) {
+                    mOut.write(buf, 0, len);
+                }
+            } catch (IOException e) {
+                Log.e(OpenPgpApi.TAG, "IOException when writing to out", e);
+            } finally {
+                try {
+                    mIn.close();
+                } catch (IOException ignored) {
+                }
+                try {
+                    mOut.close();
+                } catch (IOException ignored) {
+                }
+            }
+        }
+    }
+
+    public static <T> DataSinkTransferThread<T> asyncPipeToDataSink(
+            OpenPgpDataSink<T> dataSink, ParcelFileDescriptor output) {
+        InputStream inputStream = new BufferedInputStream(new AutoCloseInputStream(output));
+        DataSinkTransferThread<T> dataSinkTransferThread = new DataSinkTransferThread<>(dataSink, inputStream);
+        dataSinkTransferThread.start();
+        return dataSinkTransferThread;
+    }
+
+    static class DataSourceTransferThread extends Thread {
+        final OpenPgpDataSource dataSource;
+        final OutputStream outputStream;
+
+        DataSourceTransferThread(OpenPgpDataSource dataSource, OutputStream outputStream) {
+            super("IPC Transfer Thread (TO service)");
+            this.dataSource = dataSource;
+            this.outputStream = outputStream;
+            setDaemon(true);
+        }
+
+        @Override
+        public void run() {
+            try {
+                dataSource.writeTo(outputStream);
+            } catch (IOException e) {
+                if (dataSource.isCancelled()) {
+                    Log.d(OpenPgpApi.TAG, "Stopped writing because operation was cancelled.");
+                } else if (isIOExceptionCausedByEPIPE(e)) {
+                    Log.d(OpenPgpApi.TAG, "Stopped writing due to broken pipe (other end closed pipe?)");
+                } else {
+                    Log.e(OpenPgpApi.TAG, "IOException when writing to out", e);
+                }
+            } finally {
+                try {
+                    outputStream.close();
+                } catch (IOException ignored) {
+                }
+            }
+        }
+    }
+
+    private static boolean isIOExceptionCausedByEPIPE(IOException e) {
+        Throwable cause = e.getCause();
+        return cause instanceof ErrnoException && ((ErrnoException) cause).errno == OsConstants.EPIPE;
+    }
+
+    static class DataSinkTransferThread<T> extends Thread {
+        final OpenPgpDataSink<T> dataSink;
+        final InputStream inputStream;
+        T sinkResult;
+
+        DataSinkTransferThread(OpenPgpDataSink<T> dataSink, InputStream inputStream) {
+            super("IPC Transfer Thread (FROM service)");
+            this.dataSink = dataSink;
+            this.inputStream = inputStream;
+            setDaemon(true);
+        }
+
+        @Override
+        public void run() {
+            try {
+                sinkResult = dataSink.processData(inputStream);
+            } catch (IOException e) {
+                if (isIOExceptionCausedByEPIPE(e)) {
+                    Log.e(OpenPgpApi.TAG, "Stopped read due to broken pipe (other end closed pipe?)");
+                } else {
+                    Log.e(OpenPgpApi.TAG, "IOException while reading from in", e);
+                }
+                sinkResult = null;
+            } finally {
+                try {
+                    inputStream.close();
+                } catch (IOException ignored) {
+                }
+            }
+        }
+
+        T getResult() {
+            if (isAlive()) {
+                throw new IllegalStateException("result must be accessed only *after* the thread finished execution!");
+            }
+            return sinkResult;
+        }
+    }
+
+}

openpgp-api/src/main/res/values-ar/strings.xml

@@ -0,0 +1,2 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources/>

openpgp-api/src/main/res/values-bg/strings.xml

@@ -0,0 +1,2 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources/>

openpgp-api/src/main/res/values-cs/strings.xml

@@ -0,0 +1,5 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_list_preference_none">Žádný</string>
+  <string name="openpgp_install_openkeychain_via">Instalovat OpenKeychain pomocí %s</string>
+</resources>

openpgp-api/src/main/res/values-de/strings.xml

@@ -0,0 +1,7 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_list_preference_none">Keine Auswahl</string>
+  <string name="openpgp_install_openkeychain_via">Installiere OpenKeychain über %s</string>
+  <string name="openpgp_no_key_selected">Kein Schlüssel ausgewählt</string>
+  <string name="openpgp_key_selected">Schlüssel wurde ausgewählt</string>
+</resources>

openpgp-api/src/main/res/values-es/strings.xml

@@ -0,0 +1,7 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_list_preference_none">Ninguno</string>
+  <string name="openpgp_install_openkeychain_via">Instalar OpenKeychain mediante %s</string>
+  <string name="openpgp_no_key_selected">No se seleccionó clave</string>
+  <string name="openpgp_key_selected">Se ha seleccionado clave</string>
+</resources>

openpgp-api/src/main/res/values-et/strings.xml

@@ -0,0 +1,2 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources/>

openpgp-api/src/main/res/values-eu/strings.xml

@@ -0,0 +1,7 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_list_preference_none">Ezer ez</string>
+  <string name="openpgp_install_openkeychain_via">Ezarri OpenKeychain %s bidez</string>
+  <string name="openpgp_no_key_selected">Ez da giltzarik hautatu</string>
+  <string name="openpgp_key_selected">Giltza hautatu da</string>
+</resources>

openpgp-api/src/main/res/values-fi/strings.xml

@@ -0,0 +1,2 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources/>

openpgp-api/src/main/res/values-fr/strings.xml

@@ -0,0 +1,7 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_list_preference_none">Aucun</string>
+  <string name="openpgp_install_openkeychain_via">Installer OpenKeychain par %s</string>
+  <string name="openpgp_no_key_selected">Aucune clef sélectionnée</string>
+  <string name="openpgp_key_selected">La clef a été sélectionnée</string>
+</resources>

openpgp-api/src/main/res/values-is/strings.xml

@@ -0,0 +1,2 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources/>

openpgp-api/src/main/res/values-it/strings.xml

@@ -0,0 +1,5 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_list_preference_none">Nessuno</string>
+  <string name="openpgp_install_openkeychain_via">Installa OpenKeychain via %s</string>
+</resources>

openpgp-api/src/main/res/values-ja/strings.xml

@@ -0,0 +1,7 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_list_preference_none">無し</string>
+  <string name="openpgp_install_openkeychain_via">%s 経由でOpenKeychainをインストール</string>
+  <string name="openpgp_no_key_selected">鍵が選択されていません</string>
+  <string name="openpgp_key_selected">鍵は選択済みです</string>
+</resources>

openpgp-api/src/main/res/values-nl/strings.xml

@@ -0,0 +1,7 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_list_preference_none">Geen</string>
+  <string name="openpgp_install_openkeychain_via">Installeer OpenKeychain via %s</string>
+  <string name="openpgp_no_key_selected">Geen sleutel geselecteerd</string>
+  <string name="openpgp_key_selected">Sleutel is geselecteerd</string>
+</resources>

openpgp-api/src/main/res/values-pl/strings.xml

@@ -0,0 +1,5 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_list_preference_none">Brak</string>
+  <string name="openpgp_install_openkeychain_via">Instaluj OpenKeychain przez %s</string>
+</resources>

openpgp-api/src/main/res/values-pt/strings.xml

@@ -0,0 +1,2 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources/>

openpgp-api/src/main/res/values-ro/strings.xml

@@ -0,0 +1,2 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources/>

openpgp-api/src/main/res/values-ru/strings.xml

@@ -0,0 +1,7 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_list_preference_none">Нет</string>
+  <string name="openpgp_install_openkeychain_via">Установить OpenKeychain через %s</string>
+  <string name="openpgp_no_key_selected">Ключ не выбран</string>
+  <string name="openpgp_key_selected">Ключ был выбран</string>
+</resources>

openpgp-api/src/main/res/values-sl/strings.xml

@@ -0,0 +1,7 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_list_preference_none">Brez</string>
+  <string name="openpgp_install_openkeychain_via">Namesti OpenKeychain prek %s</string>
+  <string name="openpgp_no_key_selected">Izbran ni noben ključ</string>
+  <string name="openpgp_key_selected">Ključ je bil izbran</string>
+</resources>

openpgp-api/src/main/res/values-sr/strings.xml

@@ -0,0 +1,7 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_list_preference_none">Ништа</string>
+  <string name="openpgp_install_openkeychain_via">Инсталирај Отворени кључарник преко %s</string>
+  <string name="openpgp_no_key_selected">Није изабран кључ</string>
+  <string name="openpgp_key_selected">Кључ је изабран</string>
+</resources>

openpgp-api/src/main/res/values-sv/strings.xml

@@ -0,0 +1,5 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_list_preference_none">Ingen</string>
+  <string name="openpgp_install_openkeychain_via">Installera OpenKeychain via %s</string>
+</resources>

openpgp-api/src/main/res/values-tr/strings.xml

@@ -0,0 +1,5 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_list_preference_none">Hiç</string>
+  <string name="openpgp_install_openkeychain_via">%s aracılığıyla OpenKeychain\'i yükle</string>
+</resources>

openpgp-api/src/main/res/values-uk/strings.xml

@@ -0,0 +1,5 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_list_preference_none">Жоден</string>
+  <string name="openpgp_install_openkeychain_via">Встановити OpenKeychain через %s</string>
+</resources>

openpgp-api/src/main/res/values-zh-rTW/strings.xml

@@ -0,0 +1,4 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_list_preference_none">無</string>
+</resources>

openpgp-api/src/main/res/values-zh/strings.xml

@@ -0,0 +1,5 @@
+<?xml version='1.0' encoding='UTF-8'?>
+<resources>
+  <string name="openpgp_no_key_selected">尚未选择密钥</string>
+  <string name="openpgp_key_selected">已经选中密钥</string>
+</resources>

openpgp-api/src/main/res/values/strings.xml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+
+    <string name="openpgp_list_preference_none">None</string>
+    <string name="openpgp_install_openkeychain_via">Install OpenKeychain via %s</string>
+
+    <string name="openpgp_key_title">"Configure end-to-end key"</string>
+    <string name="openpgp_no_key_selected">No end-to-end key selected</string>
+    <string name="openpgp_key_selected">End-to-end key selected</string>
+    <string name="openpgp_key_using">"Using key: %s"</string>
+    <string name="openpgp_key_using_no_name">"Using key: <![CDATA[<no name>]]>"</string>
+    <string name="openpgp_key_created">"Created %s"</string>
+</resources>

settings.gradle

@@ -1 +1,2 @@
-include ':app'
+include ':app', ':openpgp-api'
+project(':openpgp-api').projectDir = new File('openpgp-api')