Victor Hsieh | 38c5503 | 2018-09-26 12:44:53 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (C) 2018 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | #define LOG_TAG "VerityUtils" |
| 18 | |
| 19 | #include <nativehelper/JNIHelp.h> |
| 20 | #include "jni.h" |
| 21 | #include <utils/Log.h> |
| 22 | |
| 23 | #include <string.h> |
| 24 | |
| 25 | // TODO(112037636): Always include once fsverity.h is upstreamed and backported. |
| 26 | #define HAS_FSVERITY 0 |
| 27 | |
| 28 | #if HAS_FSVERITY |
| 29 | #include <linux/fsverity.h> |
| 30 | #endif |
| 31 | |
| 32 | namespace android { |
| 33 | |
| 34 | namespace { |
| 35 | |
| 36 | class JavaByteArrayHolder { |
| 37 | public: |
| 38 | static JavaByteArrayHolder* newArray(JNIEnv* env, jsize size) { |
| 39 | return new JavaByteArrayHolder(env, size); |
| 40 | } |
| 41 | |
| 42 | jbyte* getRaw() { |
| 43 | return mElements; |
| 44 | } |
| 45 | |
| 46 | jbyteArray release() { |
| 47 | mEnv->ReleaseByteArrayElements(mBytes, mElements, 0); |
| 48 | mElements = nullptr; |
| 49 | return mBytes; |
| 50 | } |
| 51 | |
| 52 | private: |
| 53 | JavaByteArrayHolder(JNIEnv* env, jsize size) { |
| 54 | mEnv = env; |
| 55 | mBytes = mEnv->NewByteArray(size); |
| 56 | mElements = mEnv->GetByteArrayElements(mBytes, nullptr); |
| 57 | memset(mElements, 0, size); |
| 58 | } |
| 59 | |
| 60 | virtual ~JavaByteArrayHolder() { |
| 61 | LOG_ALWAYS_FATAL_IF(mElements == nullptr, "Elements are not released"); |
| 62 | } |
| 63 | |
| 64 | JNIEnv* mEnv; |
| 65 | jbyteArray mBytes; |
| 66 | jbyte* mElements; |
| 67 | }; |
| 68 | |
| 69 | jbyteArray constructFsverityDescriptor(JNIEnv* env, jobject /* clazz */, jlong fileSize) { |
| 70 | #if HAS_FSVERITY |
| 71 | auto raii = JavaByteArrayHolder::newArray(env, sizeof(fsverity_descriptor)); |
| 72 | fsverity_descriptor* desc = reinterpret_cast<fsverity_descriptor*>(raii->getRaw()); |
| 73 | |
| 74 | memcpy(desc->magic, FS_VERITY_MAGIC, sizeof(desc->magic)); |
| 75 | desc->major_version = 1; |
| 76 | desc->minor_version = 0; |
| 77 | desc->log_data_blocksize = 12; |
| 78 | desc->log_tree_blocksize = 12; |
| 79 | desc->data_algorithm = FS_VERITY_ALG_SHA256; |
| 80 | desc->tree_algorithm = FS_VERITY_ALG_SHA256; |
| 81 | desc->flags = 0; |
| 82 | desc->orig_file_size = fileSize; |
| 83 | desc->auth_ext_count = 1; |
| 84 | |
| 85 | return raii->release(); |
| 86 | #else |
| 87 | LOG_ALWAYS_FATAL("fs-verity is used while not enabled"); |
| 88 | return 0; |
| 89 | #endif // HAS_FSVERITY |
| 90 | } |
| 91 | |
| 92 | jbyteArray constructFsverityExtension(JNIEnv* env, jobject /* clazz */, jshort extensionId, |
| 93 | jint extensionDataSize) { |
| 94 | #if HAS_FSVERITY |
| 95 | auto raii = JavaByteArrayHolder::newArray(env, sizeof(fsverity_extension)); |
| 96 | fsverity_extension* ext = reinterpret_cast<fsverity_extension*>(raii->getRaw()); |
| 97 | |
| 98 | ext->length = sizeof(fsverity_extension) + extensionDataSize; |
| 99 | ext->type = extensionId; |
| 100 | |
| 101 | return raii->release(); |
| 102 | #else |
| 103 | LOG_ALWAYS_FATAL("fs-verity is used while not enabled"); |
| 104 | return 0; |
| 105 | #endif // HAS_FSVERITY |
| 106 | } |
| 107 | |
| 108 | jbyteArray constructFsverityFooter(JNIEnv* env, jobject /* clazz */, |
| 109 | jint offsetToDescriptorHead) { |
| 110 | #if HAS_FSVERITY |
| 111 | auto raii = JavaByteArrayHolder::newArray(env, sizeof(fsverity_footer)); |
| 112 | fsverity_footer* footer = reinterpret_cast<fsverity_footer*>(raii->getRaw()); |
| 113 | |
| 114 | footer->desc_reverse_offset = offsetToDescriptorHead + sizeof(fsverity_footer); |
| 115 | memcpy(footer->magic, FS_VERITY_MAGIC, sizeof(footer->magic)); |
| 116 | |
| 117 | return raii->release(); |
| 118 | #else |
| 119 | LOG_ALWAYS_FATAL("fs-verity is used while not enabled"); |
| 120 | return 0; |
| 121 | #endif // HAS_FSVERITY |
| 122 | } |
| 123 | |
| 124 | const JNINativeMethod sMethods[] = { |
| 125 | { "constructFsverityDescriptorNative", "(J)[B", (void *)constructFsverityDescriptor }, |
| 126 | { "constructFsverityExtensionNative", "(SI)[B", (void *)constructFsverityExtension }, |
| 127 | { "constructFsverityFooterNative", "(I)[B", (void *)constructFsverityFooter }, |
| 128 | }; |
| 129 | |
| 130 | } // namespace |
| 131 | |
| 132 | int register_android_server_security_VerityUtils(JNIEnv* env) { |
| 133 | return jniRegisterNativeMethods(env, |
| 134 | "com/android/server/security/VerityUtils", sMethods, NELEM(sMethods)); |
| 135 | } |
| 136 | |
| 137 | } // namespace android |