Merge "Fix potential OOM issues when APEXs are too large." (55bfb23d) · Commits · e / os / android_frameworks_base

core/java/android/util/PackageUtils.java

+58 −0

Original line number	Diff line number	Diff line
		@@ -18,13 +18,17 @@ package android.util;

		import android.annotation.NonNull;
		import android.annotation.Nullable;
		import android.app.ActivityManager;
		import android.content.pm.Signature;
		import android.text.TextUtils;

		import libcore.util.HexEncoding;

		import java.io.ByteArrayOutputStream;
		import java.io.File;
		import java.io.FileInputStream;
		import java.io.IOException;
		import java.security.DigestInputStream;
		import java.security.MessageDigest;
		import java.security.NoSuchAlgorithmException;
		import java.util.Arrays;
		@@ -35,6 +39,9 @@ import java.util.Arrays;
		*/
		public final class PackageUtils {

		private static final int LOW_RAM_BUFFER_SIZE_BYTES = 1 * 1000; // 1 kB
		private static final int HIGH_RAM_BUFFER_SIZE_BYTES = 1 * 1000 * 1000; // 1 MB

		private PackageUtils() {
		/* hide constructor */
		}
		@@ -162,4 +169,55 @@ public final class PackageUtils {

		return TextUtils.join(separator, pieces);
		}

		/**
		* @see #computeSha256DigestForLargeFile(String, String)
		*/
		public static @Nullable String computeSha256DigestForLargeFile(@NonNull String filePath) {
		return computeSha256DigestForLargeFile(filePath, null);
		}

		/**
		* Computes the SHA256 digest of large files.
		* @param filePath The path to which the file's content is to be hashed.
		* @param separator Separator between each pair of characters, such as colon, or null to omit.
		* @return The digest or null if an error occurs.
		*/
		public static @Nullable String computeSha256DigestForLargeFile(@NonNull String filePath,
		@Nullable String separator) {
		MessageDigest messageDigest;
		try {
		messageDigest = MessageDigest.getInstance("SHA256");
		messageDigest.reset();
		} catch (NoSuchAlgorithmException e) {
		// this shouldn't happen!
		return null;
		}

		boolean isLowRamDevice = ActivityManager.isLowRamDeviceStatic();
		int bufferSize = isLowRamDevice ? LOW_RAM_BUFFER_SIZE_BYTES : HIGH_RAM_BUFFER_SIZE_BYTES;

		File f = new File(filePath);
		try {
		DigestInputStream digestStream = new DigestInputStream(new FileInputStream(f),
		messageDigest);
		byte[] buffer = new byte[bufferSize];
		while (digestStream.read(buffer) != -1);
		} catch (IOException e) {
		return null;
		}

		byte[] resultBytes = messageDigest.digest();

		if (separator == null) {
		return HexEncoding.encodeToString(resultBytes, true);
		}

		int length = resultBytes.length;
		String[] pieces = new String[length];
		for (int index = 0; index < length; index++) {
		pieces[index] = HexEncoding.encodeToString(resultBytes[index], true);
		}
		return TextUtils.join(separator, pieces);
		}
		}

services/core/java/com/android/server/BinaryTransparencyService.java

+4 −18

Original line number	Diff line number	Diff line
		@@ -36,11 +36,8 @@ import com.android.internal.annotations.VisibleForTesting;
		import com.android.internal.os.IBinaryTransparencyService;
		import com.android.internal.util.FrameworkStatsLog;

		import java.io.File;
		import java.io.FileDescriptor;
		import java.io.IOException;
		import java.io.PrintWriter;
		import java.nio.file.Files;
		import java.util.ArrayList;
		import java.util.HashMap;
		import java.util.List;
		@@ -434,7 +431,7 @@ public class BinaryTransparencyService extends SystemService {
		entry.setValue(packageInfo.lastUpdateTime);

		// compute the digest for the updated package
		String sha256digest = computeSha256DigestOfFile(
		String sha256digest = PackageUtils.computeSha256DigestForLargeFile(
		packageInfo.applicationInfo.sourceDir);
		if (sha256digest == null) {
		Slog.e(TAG, "Failed to compute SHA256sum for file at "
		@@ -471,7 +468,7 @@ public class BinaryTransparencyService extends SystemService {
		ApplicationInfo appInfo = packageInfo.applicationInfo;

		// compute SHA256 for these APEXs
		String sha256digest = computeSha256DigestOfFile(appInfo.sourceDir);
		String sha256digest = PackageUtils.computeSha256DigestForLargeFile(appInfo.sourceDir);
		if (sha256digest == null) {
		Slog.e(TAG, String.format("Failed to compute SHA256 digest for %s",
		packageInfo.packageName));
		@@ -506,7 +503,8 @@ public class BinaryTransparencyService extends SystemService {
		ApplicationInfo appInfo = packageInfo.applicationInfo;

		// compute SHA256 digest for these modules
		String sha256digest = computeSha256DigestOfFile(appInfo.sourceDir);
		String sha256digest = PackageUtils.computeSha256DigestForLargeFile(
		appInfo.sourceDir);
		if (sha256digest == null) {
		Slog.e(TAG, String.format("Failed to compute SHA256 digest for %s",
		packageName));
		@@ -525,16 +523,4 @@ public class BinaryTransparencyService extends SystemService {
		}
		}

		@Nullable
		private String computeSha256DigestOfFile(@NonNull String pathToFile) {
		File apexFile = new File(pathToFile);

		try {
		byte[] apexFileBytes = Files.readAllBytes(apexFile.toPath());
		return PackageUtils.computeSha256Digest(apexFileBytes);
		} catch (IOException e) {
		Slog.e(TAG, String.format("I/O error occurs when reading from %s", pathToFile));
		return null;
		}
		}
		}