Merge "Implement the new v4 signing scheme in adb" into rvc-dev am: 742ef23e

    return result;

}

static inline int32_t read_be_int32(borrowed_fd fd) {

    return int32_t(be32toh(read_int32(fd)));

}

static inline void append_int(borrowed_fd fd, std::vector<char>* bytes) {

    int32_t be_val = read_int32(fd);

    int32_t le_val = read_int32(fd);

    auto old_size = bytes->size();

    bytes->resize(old_size + sizeof(be_val));

    memcpy(bytes->data() + old_size, &be_val, sizeof(be_val));

    bytes->resize(old_size + sizeof(le_val));

    memcpy(bytes->data() + old_size, &le_val, sizeof(le_val));

}

static inline void append_bytes_with_size(borrowed_fd fd, std::vector<char>* bytes) {

    int32_t be_size = read_int32(fd);

    int32_t size = int32_t(be32toh(be_size));

    int32_t le_size = read_int32(fd);

    int32_t size = int32_t(le32toh(le_size));

    auto old_size = bytes->size();

    bytes->resize(old_size + sizeof(be_size) + size);

    memcpy(bytes->data() + old_size, &be_size, sizeof(be_size));

    ReadFully(fd, bytes->data() + old_size + sizeof(be_size), size);

    bytes->resize(old_size + sizeof(le_size) + size);

    memcpy(bytes->data() + old_size, &le_size, sizeof(le_size));

    ReadFully(fd, bytes->data() + old_size + sizeof(le_size), size);

}

static inline std::pair<std::vector<char>, int32_t> read_id_sig_headers(borrowed_fd fd) {

    std::vector<char> result;

    append_int(fd, &result);              // version

    append_bytes_with_size(fd, &result);  // verityRootHash

    append_bytes_with_size(fd, &result);  // v3Digest

    append_bytes_with_size(fd, &result);  // pkcs7SignatureBlock

    auto tree_size = read_be_int32(fd);   // size of the verity tree

    append_bytes_with_size(fd, &result);  // hashingInfo

    append_bytes_with_size(fd, &result);  // signingInfo

    auto le_tree_size = read_int32(fd);

    auto tree_size = int32_t(le32toh(le_tree_size));  // size of the verity tree

    return {std::move(result), tree_size};

}