Merge "Redact ISOBMFF boxes with 'free'" into qt-dev am: f68a201ebc (9d659aef) · Commits · e / os / android_frameworks_base

core/java/android/os/RedactingFileDescriptor.java

+21 −5

Original line number	Diff line number	Diff line
		@@ -35,7 +35,7 @@ import java.util.Arrays;

		/**
		* Variant of {@link FileDescriptor} that allows its creator to specify regions
		* that should be redacted (appearing as zeros to the reader).
		* that should be redacted.
		*
		* @hide
		*/
		@@ -44,13 +44,16 @@ public class RedactingFileDescriptor {
		private static final boolean DEBUG = true;

		private volatile long[] mRedactRanges;
		private volatile long[] mFreeOffsets;

		private FileDescriptor mInner = null;
		private ParcelFileDescriptor mOuter = null;

		private RedactingFileDescriptor(Context context, File file, int mode, long[] redactRanges)
		private RedactingFileDescriptor(
		Context context, File file, int mode, long[] redactRanges, long[] freeOffsets)
		throws IOException {
		mRedactRanges = checkRangesArgument(redactRanges);
		mFreeOffsets = freeOffsets;

		try {
		try {
		@@ -88,13 +91,17 @@ public class RedactingFileDescriptor {
		*
		* @param file The underlying file to open.
		* @param mode The {@link ParcelFileDescriptor} mode to open with.
		* @param redactRanges List of file offsets that should be redacted, stored
		* @param redactRanges List of file ranges that should be redacted, stored
		* as {@code [start1, end1, start2, end2, ...]}. Start values are
		* inclusive and end values are exclusive.
		* @param freePositions List of file offsets at which the four byte value 'free' should be
		* written instead of zeros within parts of the file covered by {@code redactRanges}.
		* Non-redacted bytes will not be modified even if covered by a 'free'. This is
		* useful for overwriting boxes in ISOBMFF files with padding data.
		*/
		public static ParcelFileDescriptor open(Context context, File file, int mode,
		long[] redactRanges) throws IOException {
		return new RedactingFileDescriptor(context, file, mode, redactRanges).mOuter;
		long[] redactRanges, long[] freePositions) throws IOException {
		return new RedactingFileDescriptor(context, file, mode, redactRanges, freePositions).mOuter;
		}

		/**
		@@ -169,6 +176,15 @@ public class RedactingFileDescriptor {
		for (long j = start; j < end; j++) {
		data[(int) (j - offset)] = 0;
		}
		// Overwrite data at 'free' offsets within the redaction ranges.
		for (long freeOffset : mFreeOffsets) {
		final long freeEnd = freeOffset + 4;
		final long redactFreeStart = Math.max(freeOffset, start);
		final long redactFreeEnd = Math.min(freeEnd, end);
		for (long j = redactFreeStart; j < redactFreeEnd; j++) {
		data[(int) (j - offset)] = (byte) "free".charAt((int) (j - freeOffset));
		}
		}
		}
		return n;
		}

core/tests/coretests/src/android/os/RedactingFileDescriptorTest.java

+76 −4

Original line number	Diff line number	Diff line
		@@ -64,7 +64,7 @@ public class RedactingFileDescriptorTest {
		@Test
		public void testSingleByte() throws Exception {
		final FileDescriptor fd = RedactingFileDescriptor.open(mContext, mFile, MODE_READ_ONLY,
		new long[] { 10, 11 }).getFileDescriptor();
		new long[] { 10, 11 }, new long[] {}).getFileDescriptor();

		final byte[] buf = new byte[1_000];
		assertEquals(buf.length, Os.read(fd, buf, 0, buf.length));
		@@ -80,7 +80,7 @@ public class RedactingFileDescriptorTest {
		@Test
		public void testRanges() throws Exception {
		final FileDescriptor fd = RedactingFileDescriptor.open(mContext, mFile, MODE_READ_ONLY,
		new long[] { 100, 200, 300, 400 }).getFileDescriptor();
		new long[] { 100, 200, 300, 400 }, new long[] {}).getFileDescriptor();

		final byte[] buf = new byte[10];
		assertEquals(buf.length, Os.pread(fd, buf, 0, 10, 90));
		@@ -102,7 +102,7 @@ public class RedactingFileDescriptorTest {
		@Test
		public void testEntireFile() throws Exception {
		final FileDescriptor fd = RedactingFileDescriptor.open(mContext, mFile, MODE_READ_ONLY,
		new long[] { 0, 5_000_000 }).getFileDescriptor();
		new long[] { 0, 5_000_000 }, new long[] {}).getFileDescriptor();

		try (FileInputStream in = new FileInputStream(fd)) {
		int val;
		@@ -115,7 +115,7 @@ public class RedactingFileDescriptorTest {
		@Test
		public void testReadWrite() throws Exception {
		final FileDescriptor fd = RedactingFileDescriptor.open(mContext, mFile, MODE_READ_WRITE,
		new long[] { 100, 200, 300, 400 }).getFileDescriptor();
		new long[] { 100, 200, 300, 400 }, new long[] {}).getFileDescriptor();

		// Redacted at first
		final byte[] buf = new byte[10];
		@@ -168,4 +168,76 @@ public class RedactingFileDescriptorTest {
		assertArrayEquals(new long[] { 100, 200 },
		removeRange(new long[] { 100, 200 }, 150, 150));
		}

		@Test
		public void testFreeAtStart() throws Exception {
		final FileDescriptor fd = RedactingFileDescriptor.open(mContext, mFile, MODE_READ_WRITE,
		new long[] { 1, 10 }, new long[] {1}).getFileDescriptor();

		final byte[] buf = new byte[10];
		assertEquals(buf.length, Os.pread(fd, buf, 0, 10, 0));
		assertArrayEquals(
		new byte[] { 64, (byte) 'f', (byte) 'r', (byte) 'e', (byte) 'e', 0, 0, 0, 0, 0 },
		buf);
		}

		@Test
		public void testFreeAtOffset() throws Exception {
		final FileDescriptor fd = RedactingFileDescriptor.open(mContext, mFile, MODE_READ_WRITE,
		new long[] { 1, 10 }, new long[] {3}).getFileDescriptor();

		final byte[] buf = new byte[10];
		assertEquals(buf.length, Os.pread(fd, buf, 0, 10, 0));
		assertArrayEquals(
		new byte[] { 64, 0, 0, (byte) 'f', (byte) 'r', (byte) 'e', (byte) 'e', 0, 0, 0 },
		buf);
		}

		@Test
		public void testFreeAcrossRedactionStart() throws Exception {
		final FileDescriptor fd = RedactingFileDescriptor.open(mContext, mFile, MODE_READ_WRITE,
		new long[] { 1, 10 }, new long[] {0}).getFileDescriptor();

		final byte[] buf = new byte[10];
		assertEquals(buf.length, Os.pread(fd, buf, 0, 10, 0));
		assertArrayEquals(
		new byte[] { 64, (byte) 'r', (byte) 'e', (byte) 'e', 0, 0, 0, 0, 0, 0 },
		buf);
		}

		@Test
		public void testFreeAcrossRedactionEnd() throws Exception {
		final FileDescriptor fd = RedactingFileDescriptor.open(mContext, mFile, MODE_READ_WRITE,
		new long[] { 1, 3 }, new long[] {2}).getFileDescriptor();

		final byte[] buf = new byte[10];
		assertEquals(buf.length, Os.pread(fd, buf, 0, 10, 0));
		assertArrayEquals(
		new byte[] { 64, 0, (byte) 'f', 64, 64, 64, 64, 64, 64, 64 },
		buf);
		}

		@Test
		public void testFreeOutsideRedaction() throws Exception {
		final FileDescriptor fd = RedactingFileDescriptor.open(mContext, mFile, MODE_READ_WRITE,
		new long[] { 1, 8 }, new long[] { 8 }).getFileDescriptor();

		final byte[] buf = new byte[10];
		assertEquals(buf.length, Os.pread(fd, buf, 0, 10, 0));
		assertArrayEquals(
		new byte[] { 64, 0, 0, 0, 0, 0, 0, 0, 64, 64 },
		buf);
		}

		@Test
		public void testFreeMultipleRedactions() throws Exception {
		final FileDescriptor fd = RedactingFileDescriptor.open(mContext, mFile, MODE_READ_WRITE,
		new long[] { 1, 2, 3, 4 }, new long[] { 0 }).getFileDescriptor();

		final byte[] buf = new byte[10];
		assertEquals(buf.length, Os.pread(fd, buf, 0, 10, 0));
		assertArrayEquals(
		new byte[] { 64, (byte) 'r', 64, (byte) 'e', 64, 64, 64, 64, 64, 64 },
		buf);
		}
		}