Merge "Optimizations to reduce verity verification time" (e2adb2a6) · Commits · e / os / android_frameworks_base

core/java/android/util/apk/ApkVerityBuilder.java

+16 −13

Original line number	Diff line number	Diff line
		@@ -20,6 +20,7 @@ import java.io.IOException;
		import java.io.RandomAccessFile;
		import java.nio.ByteBuffer;
		import java.nio.ByteOrder;
		import java.security.DigestException;
		import java.security.MessageDigest;
		import java.security.NoSuchAlgorithmException;
		import java.util.ArrayList;
		@@ -66,7 +67,7 @@ abstract class ApkVerityBuilder {
		*/
		static ApkVerityResult generateApkVerity(RandomAccessFile apk,
		SignatureInfo signatureInfo, ByteBufferFactory bufferFactory)
		throws IOException, SecurityException, NoSuchAlgorithmException {
		throws IOException, SecurityException, NoSuchAlgorithmException, DigestException {
		assertSigningBlockAlignedAndHasFullPages(signatureInfo);

		long signingBlockSize =
		@@ -112,6 +113,7 @@ abstract class ApkVerityBuilder {
		private final ByteBuffer mOutput;

		private final MessageDigest mMd;
		private final byte[] mDigestBuffer = new byte[DIGEST_SIZE_BYTES];
		private final byte[] mSalt;

		private BufferedDigester(byte[] salt, ByteBuffer output) throws NoSuchAlgorithmException {
		@@ -129,21 +131,22 @@ abstract class ApkVerityBuilder {
		* consumption will continuous from there.
		*/
		@Override
		public void consume(ByteBuffer buffer) {
		public void consume(ByteBuffer buffer) throws DigestException {
		int offset = buffer.position();
		int remaining = buffer.remaining();
		while (remaining > 0) {
		int allowance = (int) Math.min(remaining, BUFFER_SIZE - mBytesDigestedSinceReset);
		mMd.update(slice(buffer, offset, offset + allowance));
		// Optimization: set the buffer limit to avoid allocating a new ByteBuffer object.
		buffer.limit(buffer.position() + allowance);
		mMd.update(buffer);
		offset += allowance;
		remaining -= allowance;
		mBytesDigestedSinceReset += allowance;

		if (mBytesDigestedSinceReset == BUFFER_SIZE) {
		byte[] digest = mMd.digest();
		mOutput.put(digest);

		mMd.reset();
		mMd.digest(mDigestBuffer, 0, mDigestBuffer.length);
		mOutput.put(mDigestBuffer);
		// After digest, MessageDigest resets automatically, so no need to reset again.
		mMd.update(mSalt);
		mBytesDigestedSinceReset = 0;
		}
		@@ -152,12 +155,12 @@ abstract class ApkVerityBuilder {

		/** Finish the current digestion if any. */
		@Override
		public void finish() {
		public void finish() throws DigestException {
		if (mBytesDigestedSinceReset == 0) {
		return;
		}
		byte[] digest = mMd.digest();
		mOutput.put(digest);
		mMd.digest(mDigestBuffer, 0, mDigestBuffer.length);
		mOutput.put(mDigestBuffer);
		}

		private void fillUpLastOutputChunk() {
		@@ -174,7 +177,7 @@ abstract class ApkVerityBuilder {
		* digest the remaining.
		*/
		private static void consumeByChunk(DataDigester digester, DataSource source, int chunkSize)
		throws IOException {
		throws IOException, DigestException {
		long inputRemaining = source.size();
		long inputOffset = 0;
		while (inputRemaining > 0) {
		@@ -191,7 +194,7 @@ abstract class ApkVerityBuilder {

		private static void generateApkVerityDigestAtLeafLevel(RandomAccessFile apk,
		SignatureInfo signatureInfo, byte[] salt, ByteBuffer output)
		throws IOException, NoSuchAlgorithmException {
		throws IOException, NoSuchAlgorithmException, DigestException {
		BufferedDigester digester = new BufferedDigester(salt, output);

		// 1. Digest from the beginning of the file, until APK Signing Block is reached.
		@@ -230,7 +233,7 @@ abstract class ApkVerityBuilder {

		private static byte[] generateApkVerityTree(RandomAccessFile apk, SignatureInfo signatureInfo,
		byte[] salt, int[] levelOffset, ByteBuffer output)
		throws IOException, NoSuchAlgorithmException {
		throws IOException, NoSuchAlgorithmException, DigestException {
		// 1. Digest the apk to generate the leaf level hashes.
		generateApkVerityDigestAtLeafLevel(apk, signatureInfo, salt, slice(output,
		levelOffset[levelOffset.length - 2], levelOffset[levelOffset.length - 1]));

core/java/android/util/apk/ByteBufferDataSource.java

+2 −1

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@ package android.util.apk;

		import java.io.IOException;
		import java.nio.ByteBuffer;
		import java.security.DigestException;

		/**
		* {@link DataSource} which provides data from a {@link ByteBuffer}.
		@@ -42,7 +43,7 @@ class ByteBufferDataSource implements DataSource {

		@Override
		public void feedIntoDataDigester(DataDigester md, long offset, int size)
		throws IOException {
		throws IOException, DigestException {
		// There's no way to tell MessageDigest to read data from ByteBuffer from a position
		// other than the buffer's current position. We thus need to change the buffer's
		// position to match the requested offset.

core/java/android/util/apk/DataDigester.java

+3 −2

Original line number	Diff line number	Diff line
		@@ -17,11 +17,12 @@
		package android.util.apk;

		import java.nio.ByteBuffer;
		import java.security.DigestException;

		interface DataDigester {
		/** Consumes the {@link ByteBuffer}. */
		void consume(ByteBuffer buffer);
		void consume(ByteBuffer buffer) throws DigestException;

		/** Finishes the digestion. Must be called after the last {@link #consume(ByteBuffer)}. */
		void finish();
		void finish() throws DigestException;
		}

core/java/android/util/apk/DataSource.java

+3 −1

Original line number	Diff line number	Diff line
		@@ -17,6 +17,7 @@
		package android.util.apk;

		import java.io.IOException;
		import java.security.DigestException;

		/** Source of data to be digested. */
		interface DataSource {
		@@ -32,5 +33,6 @@ interface DataSource {
		* @param offset offset of the region inside this data source.
		* @param size size (in bytes) of the region.
		*/
		void feedIntoDataDigester(DataDigester md, long offset, int size) throws IOException;
		void feedIntoDataDigester(DataDigester md, long offset, int size)
		throws IOException, DigestException;
		}

core/java/android/util/apk/MemoryMappedFileDataSource.java

+2 −1

Original line number	Diff line number	Diff line
		@@ -24,6 +24,7 @@ import java.io.FileDescriptor;
		import java.io.IOException;
		import java.nio.ByteBuffer;
		import java.nio.DirectByteBuffer;
		import java.security.DigestException;

		/**
		* {@link DataSource} which provides data from a file descriptor by memory-mapping the sections
		@@ -55,7 +56,7 @@ class MemoryMappedFileDataSource implements DataSource {

		@Override
		public void feedIntoDataDigester(DataDigester md, long offset, int size)
		throws IOException {
		throws IOException, DigestException {
		// IMPLEMENTATION NOTE: After a lot of experimentation, the implementation of this
		// method was settled on a straightforward mmap with prefaulting.
		//