re-merge libkeychain

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/analytics/AnalyticsConsentRequester.java

@@ -13,7 +13,6 @@ import android.text.method.LinkMovementMethod;
 import android.widget.TextView;
 
 import org.sufficientlysecure.keychain.BuildConfig;
-import org.sufficientlysecure.keychain.Constants;
 import org.sufficientlysecure.keychain.KeychainApplication;
 import org.sufficientlysecure.keychain.R;
 import org.sufficientlysecure.keychain.ui.SettingsActivity;

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/remote/ui/RequestKeyPermissionActivity.java

@@ -36,9 +36,7 @@ import android.widget.Button;
 import android.widget.ImageView;
 import android.widget.TextView;
 
-import org.openintents.openpgp.util.OpenPgpUtils.UserId;
 import org.sufficientlysecure.keychain.R;
-import org.sufficientlysecure.keychain.model.SubKey.UnifiedKeyInfo;
 import org.sufficientlysecure.keychain.remote.ui.RequestKeyPermissionPresenter.RequestKeyPermissionMvpView;
 import org.sufficientlysecure.keychain.ui.dialog.CustomAlertDialogBuilder;
 import org.sufficientlysecure.keychain.ui.util.KeyInfoFormatter;

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/securitytoken/NfcTransport.java

@@ -19,13 +19,10 @@ package org.sufficientlysecure.keychain.securitytoken;
 
 import android.nfc.Tag;
 import android.support.annotation.Nullable;
-import android.util.Log;
 
-import org.bouncycastle.util.encoders.Hex;
 import org.sufficientlysecure.keychain.Constants;
 import org.sufficientlysecure.keychain.securitytoken.SecurityTokenInfo.TokenType;
 import org.sufficientlysecure.keychain.securitytoken.SecurityTokenInfo.TransportType;
-import org.sufficientlysecure.keychain.ui.base.BaseSecurityTokenActivity;
 
 import java.io.IOException;
 

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/service/ContactSyncAdapterService.java

@@ -18,7 +18,6 @@
 package org.sufficientlysecure.keychain.service;
 
 
-import android.Manifest;
 import android.accounts.Account;
 import android.app.PendingIntent;
 import android.app.Service;

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/BackupCodeFragment.java

@@ -35,8 +35,6 @@ import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.CheckBox;
-import android.widget.CompoundButton;
-import android.widget.CompoundButton.OnCheckedChangeListener;
 import android.widget.TextView;
 
 import org.sufficientlysecure.keychain.Constants;

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/CertifyFingerprintActivity.java

@@ -18,10 +18,7 @@
 package org.sufficientlysecure.keychain.ui;
 
 import android.arch.lifecycle.ViewModelProviders;
-import android.content.Intent;
-import android.net.Uri;
 import android.os.Bundle;
-import android.view.View;
 
 import org.sufficientlysecure.keychain.R;
 import org.sufficientlysecure.keychain.ui.base.BaseActivity;

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/CreateSecurityTokenAlgorithmFragment.java

@@ -32,7 +32,6 @@ import android.widget.TextView;
 
 import org.sufficientlysecure.keychain.R;
 import org.sufficientlysecure.keychain.securitytoken.KeyFormat;
-import org.sufficientlysecure.keychain.securitytoken.SecurityTokenConnection;
 import org.sufficientlysecure.keychain.ui.CreateKeyActivity.FragAction;
 import org.sufficientlysecure.keychain.util.Choice;
 

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/CreateSecurityTokenPinFragment.java

@@ -30,7 +30,6 @@ import android.widget.TextView;
 
 import org.sufficientlysecure.keychain.Constants;
 import org.sufficientlysecure.keychain.R;
-import org.sufficientlysecure.keychain.securitytoken.SecurityTokenConnection;
 import org.sufficientlysecure.keychain.ui.CreateKeyActivity.FragAction;
 import org.sufficientlysecure.keychain.util.Passphrase;
 

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/EncryptModeAsymmetricFragment.java

@@ -42,12 +42,8 @@ import org.sufficientlysecure.keychain.livedata.GenericLiveData;
 import org.sufficientlysecure.keychain.model.SubKey.UnifiedKeyInfo;
 import org.sufficientlysecure.keychain.ui.chips.EncryptRecipientChipsInput;
 import org.sufficientlysecure.keychain.ui.chips.EncryptRecipientChipsInput.EncryptRecipientChip;
-import org.sufficientlysecure.keychain.ui.util.KeyFormattingUtils;
-import org.sufficientlysecure.keychain.ui.util.Notify;
-import org.sufficientlysecure.keychain.ui.util.Notify.Style;
 import org.sufficientlysecure.keychain.ui.widget.KeySpinner;
 import org.sufficientlysecure.keychain.util.Passphrase;
-import timber.log.Timber;
 
 
 public class EncryptModeAsymmetricFragment extends EncryptModeFragment {

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/EncryptTextActivity.java

@@ -22,10 +22,8 @@ import java.io.IOException;
 
 import android.app.Activity;
 import android.content.Intent;
-import android.net.Uri;
 import android.os.Bundle;
 import android.support.v4.app.FragmentTransaction;
-import android.util.Log;
 import android.widget.Toast;
 
 import org.apache.james.mime4j.util.MimeUtil;
@@ -34,7 +32,6 @@ import org.sufficientlysecure.keychain.R;
 import org.sufficientlysecure.keychain.ui.util.Notify;
 import org.sufficientlysecure.keychain.ui.util.Notify.Style;
 import org.sufficientlysecure.keychain.util.FileHelper;
-import timber.log.Timber;
 
 
 public class EncryptTextActivity extends EncryptActivity {

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/SettingsSmartPGPAuthoritiesActivity.java

@@ -27,13 +27,9 @@ import org.sufficientlysecure.keychain.ui.base.BaseActivity;
 
 import java.io.File;
 import java.io.FileInputStream;
-import java.io.FileNotFoundException;
 import java.io.FileOutputStream;
-import java.io.IOException;
 import java.security.KeyStore;
-import java.security.KeyStoreException;
-import java.security.NoSuchAlgorithmException;
-import java.security.cert.CertificateException;
+
 
 public class SettingsSmartPGPAuthoritiesActivity extends BaseActivity {
 

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/adapter/FlexibleKeyHeader.java

@@ -7,7 +7,6 @@ import android.view.View;
 import android.widget.TextView;
 
 import eu.davidea.flexibleadapter.FlexibleAdapter;
-import eu.davidea.flexibleadapter.items.AbstractHeaderItem;
 import eu.davidea.flexibleadapter.items.IFlexible;
 import eu.davidea.flexibleadapter.items.IHeader;
 import eu.davidea.viewholders.FlexibleViewHolder;

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/adapter/SubkeyAddedItem.java

@@ -18,27 +18,20 @@
 package org.sufficientlysecure.keychain.ui.adapter;
 
 
-import java.util.Calendar;
 import java.util.Date;
 import java.util.List;
-import java.util.TimeZone;
 
-import android.content.Context;
-import android.graphics.Typeface;
-import android.text.format.DateFormat;
 import android.view.View;
 
 import eu.davidea.flexibleadapter.FlexibleAdapter;
 import eu.davidea.flexibleadapter.items.AbstractFlexibleItem;
 import eu.davidea.flexibleadapter.items.IFlexible;
-import org.bouncycastle.bcpg.sig.KeyFlags;
 import org.sufficientlysecure.keychain.R;
 import org.sufficientlysecure.keychain.pgp.CanonicalizedSecretKey.SecretKeyType;
 import org.sufficientlysecure.keychain.service.SaveKeyringParcel.SubkeyAdd;
 import org.sufficientlysecure.keychain.ui.SubKeyItem.SubkeyViewHolder;
 import org.sufficientlysecure.keychain.ui.ViewKeyAdvSubkeysFragment;
 import org.sufficientlysecure.keychain.ui.ViewKeyAdvSubkeysFragment.SubkeyEditViewModel;
-import org.sufficientlysecure.keychain.ui.util.KeyFormattingUtils;
 
 
 public class SubkeyAddedItem extends AbstractFlexibleItem<SubkeyViewHolder> {

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/keyview/view/IdentitiesCardView.java

@@ -26,7 +26,6 @@ import android.support.v7.widget.RecyclerView.AdapterDataObserver;
 import android.util.AttributeSet;
 import android.view.LayoutInflater;
 import android.view.View;
-import android.widget.Button;
 
 import org.sufficientlysecure.keychain.R;
 import org.sufficientlysecure.keychain.ui.adapter.IdentityAdapter;

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/transfer/view/TransferFragment.java

@@ -28,7 +28,6 @@ import android.content.Intent;
 import android.content.IntentFilter;
 import android.graphics.Bitmap;
 import android.net.NetworkInfo;
-import android.net.Uri;
 import android.net.wifi.WifiManager;
 import android.os.Build.VERSION_CODES;
 import android.os.Bundle;

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/ui/util/FormattingUtils.java

@@ -19,9 +19,6 @@ package org.sufficientlysecure.keychain.ui.util;
 
 import android.content.Context;
 import android.content.res.Resources.Theme;
-import android.text.SpannableStringBuilder;
-import android.text.Spanned;
-import android.text.style.StrikethroughSpan;
 import android.util.TypedValue;
 
 public class FormattingUtils {

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/CharsetVerifier.java

@@ -0,0 +1,171 @@
+/*
+ * Copyright (C) 2017 Dominik Schürmann <dominik@dominikschuermann.de>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.sufficientlysecure.keychain.util;
+
+
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.Charset;
+import java.nio.charset.CharsetDecoder;
+import java.nio.charset.CoderResult;
+import java.nio.charset.CodingErrorAction;
+
+import android.content.ClipDescription;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
+/** This class can be used to guess whether a stream of data is encoded in a given
+ * charset or not.
+ *
+ * An object of this class must be initialized with a byte[] buffer, which should
+ * be filled with data, then processed with {@link #readBytesFromBuffer}. This can
+ * be done any number of times. Once all data has been read, a final status can be
+ * read using the getter methods.
+ */
+public class CharsetVerifier {
+
+    private final ByteBuffer bufWrap;
+    private final CharBuffer dummyOutput;
+
+    private final CharsetDecoder charsetDecoder;
+
+    private boolean isFinished;
+    private boolean isFaulty;
+    private boolean isGuessed;
+    private boolean isPossibleTextMimeType;
+    private boolean isTextMimeType;
+    private String charset;
+    private String mimeType;
+
+    public CharsetVerifier(@NonNull  byte[] buf, @NonNull String mimeType, @Nullable String charset) {
+
+        this.mimeType = mimeType;
+        isTextMimeType = ClipDescription.compareMimeTypes(mimeType, "text/*");
+        isPossibleTextMimeType = isTextMimeType
+                || ClipDescription.compareMimeTypes(mimeType, "application/octet-stream")
+                || ClipDescription.compareMimeTypes(mimeType, "application/x-download");
+        if (!isPossibleTextMimeType) {
+            charsetDecoder = null;
+            bufWrap = null;
+            dummyOutput = null;
+            return;
+        }
+
+        bufWrap = ByteBuffer.wrap(buf);
+        dummyOutput = CharBuffer.allocate(buf.length);
+
+        // the charset defaults to us-ascii, but we want to default to utf-8
+        if (charset == null || "us-ascii".equals(charset)) {
+            charset = "utf-8";
+            isGuessed = true;
+        } else {
+            isGuessed = false;
+        }
+        this.charset = charset;
+
+        charsetDecoder = Charset.forName(charset).newDecoder();
+        charsetDecoder.onMalformedInput(CodingErrorAction.REPORT);
+        charsetDecoder.onUnmappableCharacter(CodingErrorAction.REPORT);
+        charsetDecoder.reset();
+    }
+
+    public void readBytesFromBuffer(int pos, int len) {
+        if (isFinished) {
+            throw new IllegalStateException("cannot write again after reading charset status!");
+        }
+        if (isFaulty || bufWrap == null) {
+            return;
+        }
+        bufWrap.rewind();
+        bufWrap.position(pos);
+        bufWrap.limit(len);
+        dummyOutput.rewind();
+        CoderResult result = charsetDecoder.decode(bufWrap, dummyOutput, false);
+        if (result.isError()) {
+            isFaulty = true;
+        }
+    }
+
+    private void finishIfNecessary() {
+        if (isFinished || isFaulty || bufWrap == null) {
+            return;
+        }
+        isFinished = true;
+        bufWrap.rewind();
+        bufWrap.limit(0);
+        dummyOutput.rewind();
+        CoderResult result = charsetDecoder.decode(bufWrap, dummyOutput, true);
+        if (result.isError()) {
+            isFaulty = true;
+        }
+    }
+
+    public String getGuessedMimeType() {
+        if (isTextMimeType) {
+            return mimeType;
+        }
+        if (isProbablyText()) {
+            return "text/plain";
+        }
+        return mimeType;
+    }
+
+    public boolean isCharsetFaulty() {
+        finishIfNecessary();
+        return isFaulty;
+    }
+
+    public boolean isCharsetGuessed() {
+        finishIfNecessary();
+        return isGuessed;
+    }
+
+    public String getCharset() {
+        finishIfNecessary();
+        if (!isPossibleTextMimeType || (isGuessed && isFaulty)) {
+            return null;
+        }
+        return charset;
+    }
+
+    public String getMaybeFaultyCharset() {
+        return charset;
+    }
+
+    /** Returns true if the data which was read is definitely binary.
+     *
+     * This can happen when either the supplied mimeType indicated a non-ambiguous
+     * binary data type, or if we guessed a charset but got errors while decoding.
+     */
+    public boolean isDefinitelyBinary() {
+        finishIfNecessary();
+        return !isTextMimeType && (!isPossibleTextMimeType || (isGuessed && isFaulty));
+    }
+
+    /** Returns true iff the data which was read is probably (or
+     * definitely) text.
+     *
+     * The corner case where isDefinitelyBinary returns false but isProbablyText
+     * returns true is where the charset was provided by the data (so is not
+     * guessed) but is still faulty.
+     */
+    public boolean isProbablyText() {
+        finishIfNecessary();
+        return isTextMimeType || isPossibleTextMimeType && (!isGuessed || !isFaulty);
+    }
+}

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/CountingOutputStream.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2007 The Guava Authors
+ *
+ * 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.sufficientlysecure.keychain.util;
+
+
+import java.io.FilterOutputStream;
+import java.io.IOException;
+import java.io.OutputStream;
+
+import android.support.annotation.NonNull;
+
+
+public final class CountingOutputStream extends FilterOutputStream {
+
+    private long count;
+
+    /**
+     * Wraps another output stream, counting the number of bytes written.
+     *
+     * @param out
+     *         the output stream to be wrapped
+     */
+    public CountingOutputStream(@NonNull OutputStream out) {
+        super(out);
+    }
+
+    /**
+     * Returns the number of bytes written.
+     */
+    public long getCount() {
+        return count;
+    }
+
+    @Override
+    public void write(@NonNull byte[] b, int off, int len) throws IOException {
+        out.write(b, off, len);
+        count += len;
+    }
+
+    @Override
+    public void write(int b) throws IOException {
+        out.write(b);
+        count++;
+    }
+
+    // Overriding close() because FilterOutputStream's close() method pre-JDK8 has bad behavior:
+    // it silently ignores any exception thrown by flush(). Instead, just close the delegate stream.
+    // It should flush itself if necessary.
+    @Override
+    public void close() throws IOException {
+        out.close();
+    }
+}

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/FileHelper.java

@@ -52,7 +52,6 @@ import android.provider.OpenableColumns;
 import android.support.v4.app.Fragment;
 import android.widget.Toast;
 
-import org.sufficientlysecure.keychain.Constants;
 import org.sufficientlysecure.keychain.R;
 import timber.log.Timber;
 

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/InputData.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2010-2014 Thialfihar <thi@thialfihar.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.sufficientlysecure.keychain.util;
+
+import java.io.InputStream;
+
+/**
+ * Wrapper to include size besides an InputStream
+ */
+public class InputData {
+    public static final int UNKNOWN_FILESIZE = -1;
+
+    private PositionAwareInputStream mInputStream;
+    private long mSize;
+    String mOriginalFilename;
+
+    public InputData(InputStream inputStream, long size, String originalFilename) {
+        mInputStream = new PositionAwareInputStream(inputStream);
+        mSize = size;
+        mOriginalFilename = originalFilename;
+    }
+
+    public InputData(InputStream inputStream, long size) {
+        mInputStream = new PositionAwareInputStream(inputStream);
+        mSize = size;
+        mOriginalFilename = "";
+    }
+
+    public InputStream getInputStream() {
+        return mInputStream;
+    }
+
+    public String getOriginalFilename () {
+        return mOriginalFilename;
+    }
+
+    public long getSize() {
+        return mSize;
+    }
+
+    public long getStreamPosition() {
+        return mInputStream.position();
+    }
+}

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/IterableIterator.java

@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2010-2014 Thialfihar <thi@thialfihar.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.sufficientlysecure.keychain.util;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+
+public class IterableIterator<T> implements Iterable<T> {
+    private Iterator<T> mIter;
+
+    public IterableIterator(Iterator<T> iter, boolean failsafe) {
+        mIter = iter;
+        if (failsafe && mIter == null) {
+            // is there a better way?
+            mIter = new ArrayList<T>().iterator();
+        }
+    }
+    public IterableIterator(Iterator<T> iter) {
+        this(iter, false);
+    }
+
+    public Iterator<T> iterator() {
+        return mIter;
+    }
+}

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/IteratorWithSize.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright (C) 2017 Dominik Schürmann <dominik@dominikschuermann.de>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.sufficientlysecure.keychain.util;
+
+import java.util.Iterator;
+
+/**
+ * An extended iterator interface, which knows the total number of its entries beforehand.
+ */
+public interface IteratorWithSize<E> extends Iterator<E> {
+
+    /**
+     * Returns the total number of entries in this iterator.
+     *
+     * @return the number of entries in this iterator.
+     */
+    int getSize();
+
+}

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/PRNGFixes.java

@@ -12,7 +12,6 @@ package org.sufficientlysecure.keychain.util;
 
 import android.os.Build;
 import android.os.Process;
-import android.util.Log;
 
 import java.io.ByteArrayOutputStream;
 import java.io.DataInputStream;

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/PositionAwareInputStream.java

@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2010-2014 Thialfihar <thi@thialfihar.org>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.sufficientlysecure.keychain.util;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+public class PositionAwareInputStream extends InputStream {
+    private InputStream mStream;
+    private long mPosition;
+
+    public PositionAwareInputStream(InputStream in) {
+        mStream = in;
+        mPosition = 0;
+    }
+
+    @Override
+    public int read() throws IOException {
+        int ch = mStream.read();
+        ++mPosition;
+        return ch;
+    }
+
+    @Override
+    public int available() throws IOException {
+        return mStream.available();
+    }
+
+    @Override
+    public void close() throws IOException {
+        mStream.close();
+    }
+
+    @Override
+    public boolean markSupported() {
+        return false;
+    }
+
+    @Override
+    public int read(byte[] b) throws IOException {
+        int result = mStream.read(b);
+        mPosition += result;
+        return result;
+    }
+
+    @Override
+    public int read(byte[] b, int offset, int length) throws IOException {
+        int result = mStream.read(b, offset, length);
+        mPosition += result;
+        return result;
+    }
+
+    @Override
+    public synchronized void reset() throws IOException {
+        mStream.reset();
+        mPosition = 0;
+    }
+
+    @Override
+    public long skip(long n) throws IOException {
+        long result = mStream.skip(n);
+        mPosition += result;
+        return result;
+    }
+
+    public long position() {
+        return mPosition;
+    }
+}

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/Utf8Util.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright (C) 2014 Dominik Schürmann <dominik@dominikschuermann.de>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.sufficientlysecure.keychain.util;
+
+import org.sufficientlysecure.keychain.Constants;
+
+import java.nio.ByteBuffer;
+import java.nio.charset.CharacterCodingException;
+import java.nio.charset.Charset;
+import java.nio.charset.CharsetDecoder;
+import java.nio.charset.CodingErrorAction;
+
+import android.util.Log;
+
+
+public class Utf8Util {
+
+    public static boolean isValidUTF8(byte[] input) {
+        CharsetDecoder cs = Charset.forName("UTF-8").newDecoder();
+
+        try {
+            cs.decode(ByteBuffer.wrap(input));
+            return true;
+        } catch (CharacterCodingException e) {
+            return false;
+        }
+    }
+
+    public static String fromUTF8ByteArrayReplaceBadEncoding(byte[] input) {
+        final CharsetDecoder charsetDecoder = Charset.forName("UTF-8").newDecoder();
+        charsetDecoder.onMalformedInput(CodingErrorAction.REPLACE);
+        charsetDecoder.onUnmappableCharacter(CodingErrorAction.REPLACE);
+
+        try {
+            return charsetDecoder.decode(ByteBuffer.wrap(input)).toString();
+        } catch (CharacterCodingException e) {
+            Log.e(Constants.TAG, "Decoding failed!", e);
+            return charsetDecoder.replacement();
+        }
+    }
+}