Merge "fs-verity: replace ioctl(FS_IOC_MEASURE_VERITY) with statx()" into... (62fc84bb) · Commits · e / os / android_frameworks_base

services/core/java/com/android/server/security/VerityUtils.java

+6 −10

Original line number	Diff line number	Diff line
		@@ -81,22 +81,18 @@ abstract public class VerityUtils {

		/** Returns whether the file has fs-verity enabled. */
		public static boolean hasFsverity(@NonNull String filePath) {
		// NB: only measure but not check the actual measurement here. As long as this succeeds,
		// the file is on readable if the measurement can be verified against a trusted key, and
		// this is good enough for installed apps.
		int errno = measureFsverityNative(filePath);
		if (errno != 0) {
		if (errno != OsConstants.ENODATA) {
		Slog.e(TAG, "Failed to measure fs-verity, errno " + errno + ": " + filePath);
		}
		int retval = statxForFsverityNative(filePath);
		if (retval < 0) {
		Slog.e(TAG, "Failed to check whether fs-verity is enabled, errno " + -retval + ": "
		+ filePath);
		return false;
		}
		return true;
		return (retval == 1);
		}

		private static native int enableFsverityNative(@NonNull String filePath,
		@NonNull byte[] pkcs7Signature);
		private static native int measureFsverityNative(@NonNull String filePath);
		private static native int statxForFsverityNative(@NonNull String filePath);

		/**
		* Generates legacy Merkle tree and fs-verity metadata with Signing Block skipped.

services/core/jni/com_android_server_security_VerityUtils.cpp

+17 −22

Original line number	Diff line number	Diff line
		@@ -25,17 +25,14 @@
		#include <errno.h>
		#include <fcntl.h>
		#include <linux/fsverity.h>
		#include <linux/stat.h>
		#include <string.h>
		#include <sys/ioctl.h>
		#include <sys/stat.h>
		#include <sys/types.h>

		#include <type_traits>

		#include <android-base/unique_fd.h>

		const int kSha256Bytes = 32;

		namespace android {

		namespace {
		@@ -69,30 +66,28 @@ int enableFsverity(JNIEnv* env, jobject /* clazz */, jstring filePath, jbyteArra
		return 0;
		}

		int measureFsverity(JNIEnv* env, jobject /* clazz */, jstring filePath) {
		using Storage = std::aligned_storage_t<sizeof(fsverity_digest) + kSha256Bytes>;

		Storage bytes;
		fsverity_digest data = reinterpret_cast<fsverity_digest >(&bytes);
		data->digest_size = kSha256Bytes; // the only input/output parameter

		// Returns whether the file has fs-verity enabled.
		// 0 if it is not present, 1 if is present, and -errno if there was an error.
		int statxForFsverity(JNIEnv env, jobject / clazz */, jstring filePath) {
		ScopedUtfChars path(env, filePath);
		if (path.c_str() == nullptr) {
		return EINVAL;
		}
		::android::base::unique_fd rfd(open(path.c_str(), O_RDONLY \| O_CLOEXEC));
		if (rfd.get() < 0) {
		return errno;

		struct statx out = {};
		if (statx(AT_FDCWD, path.c_str(), 0 /* flags */, STATX_ALL, &out) != 0) {
		return -errno;
		}
		if (ioctl(rfd.get(), FS_IOC_MEASURE_VERITY, data) < 0) {
		return errno;

		// Sanity check.
		if ((out.stx_attributes_mask & STATX_ATTR_VERITY) == 0) {
		ALOGE("Unexpected, STATX_ATTR_VERITY not supported by kernel");
		return -ENOSYS;
		}
		return 0;

		return (out.stx_attributes & STATX_ATTR_VERITY) != 0;
		}

		const JNINativeMethod sMethods[] = {
		{"enableFsverityNative", "(Ljava/lang/String;[B)I", (void *)enableFsverity},
		{ "measureFsverityNative", "(Ljava/lang/String;)I", (void *)measureFsverity },
		{"statxForFsverityNative", "(Ljava/lang/String;)I", (void *)statxForFsverity},
		};

		} // namespace