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Commit d163351b authored by Victor Hsieh's avatar Victor Hsieh
Browse files

Support fs-verity setup with null/no signature 

This is a partial cherry-pick from ag/20131484 (Enable fs-verity to all
APKs on install), where the change to InstallPackageHelper.java is
excluded to avoid the complexity of diverged code base in package
manager.

This is safe because:
1. The function signature does not change.
2. The caller isn't giving it a null signature in AOSP yet, so it won't
   break existing package manager use case.

This partial cherry-pick is desired in order to unblock some work across
internal and AOSP branches.

Bug: 258538225
Test: atest CtsAppSecurityHostTestCases:android.appsecurity.cts.ApkVerityInstallTest
Merged-In: I119e5189603af888dfa1ece2bee9e7635120854b
Change-Id: Ie0001bb74a0b7dffd9f6a3d2a23f5c66f381bea7
parent 1ea23229

core/java/com/android/internal/security/VerityUtils.java

+16 −8
Original line number Diff line number Diff line
@@ -17,6 +17,7 @@ 
package com.android.internal.security;



import android.annotation.NonNull;

import android.annotation.Nullable;

import android.os.Build;

import android.os.SystemProperties;

import android.system.Os;
@@ -41,6 +42,7 @@ import java.nio.ByteBuffer; 
import java.nio.ByteOrder;

import java.nio.charset.StandardCharsets;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.security.cert.CertificateException;

import java.security.cert.CertificateFactory;
@@ -77,17 +79,23 @@ public abstract class VerityUtils { 
        return filePath + FSVERITY_SIGNATURE_FILE_EXTENSION;

    }



    /** Enables fs-verity for the file with a PKCS#7 detached signature file. */

    public static void setUpFsverity(@NonNull String filePath, @NonNull String signaturePath)

    /** Enables fs-verity for the file with an optional PKCS#7 detached signature file. */

    public static void setUpFsverity(@NonNull String filePath, @Nullable String signaturePath)

            throws IOException {

        if (Files.size(Paths.get(signaturePath)) > MAX_SIGNATURE_FILE_SIZE_BYTES) {

            throw new SecurityException("Signature file is unexpectedly large: " + signaturePath);

        byte[] rawSignature = null;

        if (signaturePath != null) {

            Path path = Paths.get(signaturePath);

            if (Files.size(path) > MAX_SIGNATURE_FILE_SIZE_BYTES) {

                throw new SecurityException("Signature file is unexpectedly large: "

                        + signaturePath);

            }

        setUpFsverity(filePath, Files.readAllBytes(Paths.get(signaturePath)));

            rawSignature = Files.readAllBytes(path);

        }

        setUpFsverity(filePath, rawSignature);

    }



    /** Enables fs-verity for the file with a PKCS#7 detached signature bytes. */

    public static void setUpFsverity(@NonNull String filePath, @NonNull byte[] pkcs7Signature)

    /** Enables fs-verity for the file with an optional PKCS#7 detached signature bytes. */

    public static void setUpFsverity(@NonNull String filePath, @Nullable byte[] pkcs7Signature)

            throws IOException {

        // This will fail if the public key is not already in .fs-verity kernel keyring.

        int errno = enableFsverityNative(filePath, pkcs7Signature);
@@ -227,7 +235,7 @@ public abstract class VerityUtils { 
    }



    private static native int enableFsverityNative(@NonNull String filePath,

            @NonNull byte[] pkcs7Signature);

            @Nullable byte[] pkcs7Signature);

    private static native int measureFsverityNative(@NonNull String filePath,

            @NonNull byte[] digest);

    private static native int statxForFsverityNative(@NonNull String filePath);

core/jni/com_android_internal_security_VerityUtils.cpp

+12 −6
Original line number Diff line number Diff line
@@ -48,10 +48,6 @@ int enableFsverity(JNIEnv *env, jobject /* clazz */, jstring filePath, jbyteArra 
    if (rfd.get() < 0) {

        return errno;

    }

    ScopedByteArrayRO signature_bytes(env, signature);

    if (signature_bytes.get() == nullptr) {

        return EINVAL;

    }



    fsverity_enable_arg arg = {};

    arg.version = 1;
@@ -59,8 +55,18 @@ int enableFsverity(JNIEnv *env, jobject /* clazz */, jstring filePath, jbyteArra 
    arg.block_size = 4096;

    arg.salt_size = 0;

    arg.salt_ptr = reinterpret_cast<uintptr_t>(nullptr);



    if (signature != nullptr) {

        ScopedByteArrayRO signature_bytes(env, signature);

        if (signature_bytes.get() == nullptr) {

            return EINVAL;

        }

        arg.sig_size = signature_bytes.size();

        arg.sig_ptr = reinterpret_cast<uintptr_t>(signature_bytes.get());

    } else {

        arg.sig_size = 0;

        arg.sig_ptr = reinterpret_cast<uintptr_t>(nullptr);

    }



    if (ioctl(rfd.get(), FS_IOC_ENABLE_VERITY, &arg) < 0) {

        return errno;