79 lines
2.5 KiB
Java
79 lines
2.5 KiB
Java
package org.thoughtcrime.securesms.video;
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import android.annotation.TargetApi;
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import android.media.MediaDataSource;
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import android.os.Build;
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import androidx.annotation.NonNull;
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import androidx.annotation.Nullable;
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import org.thoughtcrime.securesms.crypto.AttachmentSecret;
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import org.thoughtcrime.securesms.crypto.ClassicDecryptingPartInputStream;
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import org.thoughtcrime.securesms.crypto.ModernDecryptingPartInputStream;
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import org.session.libsession.utilities.Util;
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import java.io.File;
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import java.io.IOException;
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import java.io.InputStream;
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@TargetApi(Build.VERSION_CODES.M)
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public class EncryptedMediaDataSource extends MediaDataSource {
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private final AttachmentSecret attachmentSecret;
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private final File mediaFile;
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private final byte[] random;
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private final long length;
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public EncryptedMediaDataSource(@NonNull AttachmentSecret attachmentSecret, @NonNull File mediaFile, @Nullable byte[] random, long length) {
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this.attachmentSecret = attachmentSecret;
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this.mediaFile = mediaFile;
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this.random = random;
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this.length = length;
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}
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@Override
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public int readAt(long position, byte[] bytes, int offset, int length) throws IOException {
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if (random == null) return readAtClassic(position, bytes, offset, length);
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else return readAtModern(position, bytes, offset, length);
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}
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private int readAtClassic(long position, byte[] bytes, int offset, int length) throws IOException {
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InputStream inputStream = ClassicDecryptingPartInputStream.createFor(attachmentSecret, mediaFile);
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byte[] buffer = new byte[4096];
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long headerRemaining = position;
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while (headerRemaining > 0) {
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int read = inputStream.read(buffer, 0, Util.toIntExact(Math.min((long)buffer.length, headerRemaining)));
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if (read == -1) return -1;
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headerRemaining -= read;
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}
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int returnValue = inputStream.read(bytes, offset, length);
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inputStream.close();
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return returnValue;
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}
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private int readAtModern(long position, byte[] bytes, int offset, int length) throws IOException {
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assert(random != null);
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InputStream inputStream = ModernDecryptingPartInputStream.createFor(attachmentSecret, random, mediaFile, position);
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int returnValue = inputStream.read(bytes, offset, length);
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inputStream.close();
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return returnValue;
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}
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@Override
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public long getSize() throws IOException {
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return length;
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}
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@Override
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public void close() throws IOException {
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}
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}
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