xref: /developtools/hapsigner/hapsigntool_cpp/codesigning/fsverity/src/fs_verity_digest.cpp

/*
 * Copyright (c) 2024-2024 Huawei Device Co., Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
#include "securec.h"
#include "fs_verity_digest.h"
#include "signature_tools_log.h"

namespace OHOS {
namespace SignatureTools {
const std::string FsVerityDigest::FSVERITY_DIGEST_MAGIC = "FSVerity";
const int FsVerityDigest::DIGEST_HEADER_SIZE = 12;

void FsVerityDigest::GetFsVerityDigest(int8_t algoID, std::vector<int8_t>& digest,
                                       std::vector<int8_t> &ret)
{
    const int size = DIGEST_HEADER_SIZE + digest.size();
    if (size <= 0) {
        ret = std::vector<int8_t>();
        return;
    }
    std::unique_ptr<ByteBuffer> buffer = std::make_unique<ByteBuffer>(ByteBuffer(size));
    buffer->PutData(FSVERITY_DIGEST_MAGIC.c_str(), (int32_t)FSVERITY_DIGEST_MAGIC.length());
    buffer->PutInt16(algoID);
    buffer->PutInt16((int16_t)digest.size());
    buffer->PutData(digest.data(), digest.size());
    buffer->Flip();
    char dataArr[size];
    if (memset_s(dataArr, sizeof(dataArr), 0, sizeof(dataArr)) != RET_OK) {
        SIGNATURE_TOOLS_LOGE("memcpy_s failed");
        ret = std::vector<int8_t>();
        return;
    }
    buffer->GetData(dataArr, size);
    ret = std::vector<int8_t>(dataArr, dataArr + size);
    return;
}
} // namespace SignatureTools
} // namespace OHOS