Merge "fs-verity: replace ioctl(FS_IOC_MEASURE_VERITY) with statx()" into... (f7fcd218) · Commits · e / os / android_frameworks_base

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

+6 −10

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

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

	private static native int enableFsverityNative(@NonNull String filePath,		private static native int enableFsverityNative(@NonNull String filePath,
	@NonNull byte[] pkcs7Signature);		@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.		* 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	Original line	Diff line number	Diff line
	@@ -25,17 +25,14 @@
	#include <errno.h>		#include <errno.h>
	#include <fcntl.h>		#include <fcntl.h>
	#include <linux/fsverity.h>		#include <linux/fsverity.h>
			#include <linux/stat.h>
	#include <string.h>		#include <string.h>
	#include <sys/ioctl.h>		#include <sys/ioctl.h>
	#include <sys/stat.h>		#include <sys/stat.h>
	#include <sys/types.h>		#include <sys/types.h>

	#include <type_traits>

	#include <android-base/unique_fd.h>		#include <android-base/unique_fd.h>

	const int kSha256Bytes = 32;

	namespace android {		namespace android {

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

	int measureFsverity(JNIEnv* env, jobject /* clazz */, jstring filePath) {		// Returns whether the file has fs-verity enabled.
	using Storage = std::aligned_storage_t<sizeof(fsverity_digest) + kSha256Bytes>;		// 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) {
	Storage bytes;
	fsverity_digest data = reinterpret_cast<fsverity_digest >(&bytes);
	data->digest_size = kSha256Bytes; // the only input/output parameter

	ScopedUtfChars path(env, filePath);		ScopedUtfChars path(env, filePath);
	if (path.c_str() == nullptr) {
	return EINVAL;		struct statx out = {};
	}		if (statx(AT_FDCWD, path.c_str(), 0 /* flags */, STATX_ALL, &out) != 0) {
	::android::base::unique_fd rfd(open(path.c_str(), O_RDONLY \| O_CLOEXEC));		return -errno;
	if (rfd.get() < 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[] = {		const JNINativeMethod sMethods[] = {
	{"enableFsverityNative", "(Ljava/lang/String;[B)I", (void *)enableFsverity},		{"enableFsverityNative", "(Ljava/lang/String;[B)I", (void *)enableFsverity},
	{ "measureFsverityNative", "(Ljava/lang/String;)I", (void *)measureFsverity },		{"statxForFsverityNative", "(Ljava/lang/String;)I", (void *)statxForFsverity},
	};		};

	} // namespace		} // namespace