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Zero out trailing bytes in CryptoInfo.iv
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CryptoInfo.iv length is always 16. When the actual initialization vector
is shorter, zero out the trailing bytes.

Issue: #6982
PiperOrigin-RevId: 295575845
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@ojw28 @icbaker
ojw28 authored and icbaker committed Feb 17, 2020
1 parent 27bd129 commit d1e4a63
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Showing 5 changed files with 114 additions and 74 deletions.
6 changes: 6 additions & 0 deletions RELEASENOTES.md
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Expand Up @@ -71,6 +71,12 @@
show how to render video to a `GLSurfaceView` while applying a GL shader.
([#6920](https://github.com/google/ExoPlayer/issues/6920)).

### 2.11.3 (2020-02-19) ###

* DRM: Fix issue switching from protected content that uses a 16-byte
initialization vector to one that uses an 8-byte initialization vector
([#6982](https://github.com/google/ExoPlayer/issues/6982)).

### 2.11.2 (2020-02-13) ###

* Add Java FLAC extractor
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44 changes: 23 additions & 21 deletions library/common/src/main/java/com/google/android/exoplayer2/decoder/CryptoInfo.java
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Expand Up @@ -27,27 +27,41 @@
public final class CryptoInfo {

/**
* The 16 byte initialization vector. If the initialization vector of the content is shorter than
* 16 bytes, 0 byte padding is appended to extend the vector to the required 16 byte length.
*
* @see android.media.MediaCodec.CryptoInfo#iv
*/
public byte[] iv;
/**
* The 16 byte key id.
*
* @see android.media.MediaCodec.CryptoInfo#key
*/
public byte[] key;
/**
* The type of encryption that has been applied. Must be one of the {@link C.CryptoMode} values.
*
* @see android.media.MediaCodec.CryptoInfo#mode
*/
@C.CryptoMode
public int mode;
@C.CryptoMode public int mode;
/**
* The number of leading unencrypted bytes in each sub-sample. If null, all bytes are treated as
* encrypted and {@link #numBytesOfEncryptedData} must be specified.
*
* @see android.media.MediaCodec.CryptoInfo#numBytesOfClearData
*/
public int[] numBytesOfClearData;
/**
* The number of trailing encrypted bytes in each sub-sample. If null, all bytes are treated as
* clear and {@link #numBytesOfClearData} must be specified.
*
* @see android.media.MediaCodec.CryptoInfo#numBytesOfEncryptedData
*/
public int[] numBytesOfEncryptedData;
/**
* The number of subSamples that make up the buffer's contents.
*
* @see android.media.MediaCodec.CryptoInfo#numSubSamples
*/
public int numSubSamples;
Expand Down Expand Up @@ -112,10 +126,10 @@ public void copyTo(android.media.MediaCodec.CryptoInfo cryptoInfo) {
// Update cryptoInfo fields directly because CryptoInfo.set performs an unnecessary
// object allocation on Android N.
cryptoInfo.numSubSamples = numSubSamples;
cryptoInfo.numBytesOfClearData = copyOrNull(frameworkCryptoInfo.numBytesOfClearData);
cryptoInfo.numBytesOfEncryptedData = copyOrNull(frameworkCryptoInfo.numBytesOfEncryptedData);
cryptoInfo.key = copyOrNull(frameworkCryptoInfo.key);
cryptoInfo.iv = copyOrNull(frameworkCryptoInfo.iv);
cryptoInfo.numBytesOfClearData = copyOrNull(numBytesOfClearData);
cryptoInfo.numBytesOfEncryptedData = copyOrNull(numBytesOfEncryptedData);
cryptoInfo.key = copyOrNull(key);
cryptoInfo.iv = copyOrNull(iv);
cryptoInfo.mode = mode;
if (Util.SDK_INT >= 24) {
android.media.MediaCodec.CryptoInfo.Pattern pattern = patternHolder.pattern;
Expand Down Expand Up @@ -148,31 +162,19 @@ public void increaseClearDataFirstSubSampleBy(int count) {
if (count == 0) {
return;
}

if (numBytesOfClearData == null) {
numBytesOfClearData = new int[1];
}
numBytesOfClearData[0] += count;

// It is OK to have numBytesOfClearData and frameworkCryptoInfo.numBytesOfClearData point to
// the same array, see set().
if (frameworkCryptoInfo.numBytesOfClearData == null) {
frameworkCryptoInfo.numBytesOfClearData = numBytesOfClearData;
}

// Update frameworkCryptoInfo.numBytesOfClearData only if it points to a different array than
// numBytesOfClearData (all fields are public and non-final, therefore they can set be set
// directly without calling set()). Otherwise, the array has been updated already in the steps
// above.
if (frameworkCryptoInfo.numBytesOfClearData != numBytesOfClearData) {
frameworkCryptoInfo.numBytesOfClearData[0] += count;
}
numBytesOfClearData[0] += count;
}

@Nullable
private static int[] copyOrNull(@Nullable int[] array) {
return array != null ? Arrays.copyOf(array, array.length) : null;
}

@Nullable
private static byte[] copyOrNull(@Nullable byte[] array) {
return array != null ? Arrays.copyOf(array, array.length) : null;
}
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31 changes: 0 additions & 31 deletions library/common/src/test/java/com/google/android/exoplayer2/decoder/CryptoInfoTest.java
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Expand Up @@ -65,35 +65,4 @@ public void increaseClearDataFirstSubSampleBy_withSharedClearDataPointer_setsVal
assertThat(cryptoInfo.numBytesOfClearData[0]).isEqualTo(6);
assertThat(cryptoInfo.getFrameworkCryptoInfo().numBytesOfClearData[0]).isEqualTo(6);
}

@Test
public void increaseClearDataFirstSubSampleBy_withDifferentClearDataArrays_setsValue() {
cryptoInfo.numBytesOfClearData = new int[] {1, 1, 1, 1};
cryptoInfo.getFrameworkCryptoInfo().numBytesOfClearData = new int[] {5, 5, 5, 5};

cryptoInfo.increaseClearDataFirstSubSampleBy(5);

assertThat(cryptoInfo.numBytesOfClearData[0]).isEqualTo(6);
assertThat(cryptoInfo.getFrameworkCryptoInfo().numBytesOfClearData[0]).isEqualTo(10);
}

@Test
public void increaseClearDataFirstSubSampleBy_withInternalClearDataArraysNull_setsValue() {
cryptoInfo.numBytesOfClearData = new int[] {10, 10, 10, 10};

cryptoInfo.increaseClearDataFirstSubSampleBy(5);

assertThat(cryptoInfo.numBytesOfClearData[0]).isEqualTo(15);
assertThat(cryptoInfo.getFrameworkCryptoInfo().numBytesOfClearData[0]).isEqualTo(15);
}

@Test
public void increaseClearDataFirstSubSampleBy_internalClearDataIsNotNull_setsValue() {
cryptoInfo.getFrameworkCryptoInfo().numBytesOfClearData = new int[] {5, 5, 5, 5};

cryptoInfo.increaseClearDataFirstSubSampleBy(5);

assertThat(cryptoInfo.numBytesOfClearData[0]).isEqualTo(5);
assertThat(cryptoInfo.getFrameworkCryptoInfo().numBytesOfClearData[0]).isEqualTo(10);
}
}
20 changes: 13 additions & 7 deletions library/core/src/main/java/com/google/android/exoplayer2/source/SampleDataQueue.java
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Expand Up @@ -17,6 +17,7 @@

import androidx.annotation.Nullable;
import com.google.android.exoplayer2.C;
import com.google.android.exoplayer2.decoder.CryptoInfo;
import com.google.android.exoplayer2.decoder.DecoderInputBuffer;
import com.google.android.exoplayer2.extractor.SampleDataReader;
import com.google.android.exoplayer2.extractor.TrackOutput.CryptoData;
Expand All @@ -28,6 +29,7 @@
import java.io.EOFException;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.Arrays;

/** A queue of media sample data. */
/* package */ class SampleDataQueue {
Expand Down Expand Up @@ -229,10 +231,14 @@ private void readEncryptionData(DecoderInputBuffer buffer, SampleExtrasHolder ex
int ivSize = signalByte & 0x7F;

// Read the initialization vector.
if (buffer.cryptoInfo.iv == null) {
buffer.cryptoInfo.iv = new byte[16];
CryptoInfo cryptoInfo = buffer.cryptoInfo;
if (cryptoInfo.iv == null) {
cryptoInfo.iv = new byte[16];
} else {
// Zero out cryptoInfo.iv so that if ivSize < 16, the remaining bytes are correctly set to 0.
Arrays.fill(cryptoInfo.iv, (byte) 0);
}
readData(offset, buffer.cryptoInfo.iv, ivSize);
readData(offset, cryptoInfo.iv, ivSize);
offset += ivSize;

// Read the subsample count, if present.
Expand All @@ -247,11 +253,11 @@ private void readEncryptionData(DecoderInputBuffer buffer, SampleExtrasHolder ex
}

// Write the clear and encrypted subsample sizes.
@Nullable int[] clearDataSizes = buffer.cryptoInfo.numBytesOfClearData;
@Nullable int[] clearDataSizes = cryptoInfo.numBytesOfClearData;
if (clearDataSizes == null || clearDataSizes.length < subsampleCount) {
clearDataSizes = new int[subsampleCount];
}
@Nullable int[] encryptedDataSizes = buffer.cryptoInfo.numBytesOfEncryptedData;
@Nullable int[] encryptedDataSizes = cryptoInfo.numBytesOfEncryptedData;
if (encryptedDataSizes == null || encryptedDataSizes.length < subsampleCount) {
encryptedDataSizes = new int[subsampleCount];
}
Expand All @@ -272,12 +278,12 @@ private void readEncryptionData(DecoderInputBuffer buffer, SampleExtrasHolder ex

// Populate the cryptoInfo.
CryptoData cryptoData = Util.castNonNull(extrasHolder.cryptoData);
buffer.cryptoInfo.set(
cryptoInfo.set(
subsampleCount,
clearDataSizes,
encryptedDataSizes,
cryptoData.encryptionKey,
buffer.cryptoInfo.iv,
cryptoInfo.iv,
cryptoData.cryptoMode,
cryptoData.encryptedBlocks,
cryptoData.clearBlocks);
Expand Down
87 changes: 72 additions & 15 deletions library/core/src/test/java/com/google/android/exoplayer2/source/SampleQueueTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -15,13 +15,15 @@
*/
package com.google.android.exoplayer2.source;

import static com.google.android.exoplayer2.C.BUFFER_FLAG_ENCRYPTED;
import static com.google.android.exoplayer2.C.BUFFER_FLAG_KEY_FRAME;
import static com.google.android.exoplayer2.C.RESULT_BUFFER_READ;
import static com.google.android.exoplayer2.C.RESULT_FORMAT_READ;
import static com.google.android.exoplayer2.C.RESULT_NOTHING_READ;
import static com.google.common.truth.Truth.assertThat;
import static java.lang.Long.MIN_VALUE;
import static java.util.Arrays.copyOfRange;
import static org.junit.Assert.assertArrayEquals;
import static org.mockito.Mockito.when;

import androidx.annotation.Nullable;
Expand Down Expand Up @@ -114,17 +116,13 @@ public final class SampleQueueTest {
C.BUFFER_FLAG_KEY_FRAME, C.BUFFER_FLAG_ENCRYPTED, 0, C.BUFFER_FLAG_ENCRYPTED,
};
private static final long[] ENCRYPTED_SAMPLE_TIMESTAMPS = new long[] {0, 1000, 2000, 3000};
private static final Format[] ENCRYPTED_SAMPLES_FORMATS =
private static final Format[] ENCRYPTED_SAMPLE_FORMATS =
new Format[] {FORMAT_ENCRYPTED, FORMAT_ENCRYPTED, FORMAT_1, FORMAT_ENCRYPTED};
/** Encrypted samples require the encryption preamble. */
private static final int[] ENCRYPTED_SAMPLES_SIZES = new int[] {1, 3, 1, 3};
private static final int[] ENCRYPTED_SAMPLE_SIZES = new int[] {1, 3, 1, 3};

private static final int[] ENCRYPTED_SAMPLES_OFFSETS = new int[] {7, 4, 3, 0};
private static final byte[] ENCRYPTED_SAMPLES_DATA = new byte[8];

static {
Arrays.fill(ENCRYPTED_SAMPLES_DATA, (byte) 1);
}
private static final int[] ENCRYPTED_SAMPLE_OFFSETS = new int[] {7, 4, 3, 0};
private static final byte[] ENCRYPTED_SAMPLE_DATA = new byte[] {1, 1, 1, 1, 1, 1, 1, 1};

private static final TrackOutput.CryptoData DUMMY_CRYPTO_DATA =
new TrackOutput.CryptoData(C.CRYPTO_MODE_AES_CTR, new byte[16], 0, 0);
Expand Down Expand Up @@ -461,6 +459,60 @@ public void testAllowPlaceholderSessionPopulatesDrmSession() {
/* decodeOnlyUntilUs= */ 0);
assertThat(result).isEqualTo(RESULT_FORMAT_READ);
assertThat(formatHolder.drmSession).isSameInstanceAs(mockDrmSession);
assertReadEncryptedSample(/* sampleIndex= */ 3);
}

@Test
@SuppressWarnings("unchecked")
public void testTrailingCryptoInfoInitializationVectorBytesZeroed() {
when(mockDrmSession.getState()).thenReturn(DrmSession.STATE_OPENED_WITH_KEYS);
DrmSession<ExoMediaCrypto> mockPlaceholderDrmSession =
(DrmSession<ExoMediaCrypto>) Mockito.mock(DrmSession.class);
when(mockPlaceholderDrmSession.getState()).thenReturn(DrmSession.STATE_OPENED_WITH_KEYS);
when(mockDrmSessionManager.acquirePlaceholderSession(
ArgumentMatchers.any(), ArgumentMatchers.anyInt()))
.thenReturn(mockPlaceholderDrmSession);

writeFormat(ENCRYPTED_SAMPLE_FORMATS[0]);
byte[] sampleData = new byte[] {0, 1, 2};
byte[] initializationVector = new byte[] {7, 6, 5, 4, 3, 2, 1, 0};
byte[] encryptedSampleData =
TestUtil.joinByteArrays(
new byte[] {
0x08, // subsampleEncryption = false (1 bit), ivSize = 8 (7 bits).
},
initializationVector,
sampleData);
writeSample(
encryptedSampleData, /* timestampUs= */ 0, BUFFER_FLAG_KEY_FRAME | BUFFER_FLAG_ENCRYPTED);

int result =
sampleQueue.read(
formatHolder,
inputBuffer,
/* formatRequired= */ false,
/* loadingFinished= */ false,
/* decodeOnlyUntilUs= */ 0);
assertThat(result).isEqualTo(RESULT_FORMAT_READ);

// Fill cryptoInfo.iv with non-zero data. When the 8 byte initialization vector is written into
// it, we expect the trailing 8 bytes to be zeroed.
inputBuffer.cryptoInfo.iv = new byte[16];
Arrays.fill(inputBuffer.cryptoInfo.iv, (byte) 1);

result =
sampleQueue.read(
formatHolder,
inputBuffer,
/* formatRequired= */ false,
/* loadingFinished= */ false,
/* decodeOnlyUntilUs= */ 0);
assertThat(result).isEqualTo(RESULT_BUFFER_READ);

// Assert cryptoInfo.iv contains the 8-byte initialization vector and that the trailing 8 bytes
// have been zeroed.
byte[] expectedInitializationVector = Arrays.copyOf(initializationVector, 16);
assertArrayEquals(expectedInitializationVector, inputBuffer.cryptoInfo.iv);
}

@Test
Expand Down Expand Up @@ -995,11 +1047,11 @@ private void writeTestData() {

private void writeTestDataWithEncryptedSections() {
writeTestData(
ENCRYPTED_SAMPLES_DATA,
ENCRYPTED_SAMPLES_SIZES,
ENCRYPTED_SAMPLES_OFFSETS,
ENCRYPTED_SAMPLE_DATA,
ENCRYPTED_SAMPLE_SIZES,
ENCRYPTED_SAMPLE_OFFSETS,
ENCRYPTED_SAMPLE_TIMESTAMPS,
ENCRYPTED_SAMPLES_FORMATS,
ENCRYPTED_SAMPLE_FORMATS,
ENCRYPTED_SAMPLES_FLAGS);
}

Expand Down Expand Up @@ -1033,7 +1085,12 @@ private void writeFormat(Format format) {
/** Writes a single sample to {@code sampleQueue}. */
private void writeSample(byte[] data, long timestampUs, int sampleFlags) {
sampleQueue.sampleData(new ParsableByteArray(data), data.length);
sampleQueue.sampleMetadata(timestampUs, sampleFlags, data.length, 0, null);
sampleQueue.sampleMetadata(
timestampUs,
sampleFlags,
data.length,
/* offset= */ 0,
(sampleFlags & C.BUFFER_FLAG_ENCRYPTED) != 0 ? DUMMY_CRYPTO_DATA : null);
}

/**
Expand Down Expand Up @@ -1206,7 +1263,7 @@ private void assertReadFormat(boolean formatRequired, Format format) {
}

private void assertReadEncryptedSample(int sampleIndex) {
byte[] sampleData = new byte[ENCRYPTED_SAMPLES_SIZES[sampleIndex]];
byte[] sampleData = new byte[ENCRYPTED_SAMPLE_SIZES[sampleIndex]];
Arrays.fill(sampleData, (byte) 1);
boolean isKeyFrame = (ENCRYPTED_SAMPLES_FLAGS[sampleIndex] & C.BUFFER_FLAG_KEY_FRAME) != 0;
boolean isEncrypted = (ENCRYPTED_SAMPLES_FLAGS[sampleIndex] & C.BUFFER_FLAG_ENCRYPTED) != 0;
Expand All @@ -1216,7 +1273,7 @@ private void assertReadEncryptedSample(int sampleIndex) {
isEncrypted,
sampleData,
/* offset= */ 0,
ENCRYPTED_SAMPLES_SIZES[sampleIndex] - (isEncrypted ? 2 : 0));
ENCRYPTED_SAMPLE_SIZES[sampleIndex] - (isEncrypted ? 2 : 0));
}

/**
Expand Down

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