Function ParsePubkey

src/script/descriptor.cpp:2018–2205

Parse a public key including origin information (if enabled). */ NOLINTNEXTLINE(misc-no-recursion)

/** Parse a public key including origin information (if enabled). */
// NOLINTNEXTLINE(misc-no-recursion)
std::vector<std::unique_ptr<PubkeyProvider>> ParsePubkey(uint32_t& key_exp_index, const std::span<const char>& sp, ParseScriptContext ctx, FlatSigningProvider& out, std::string& error)
{
    std::vector<std::unique_ptr<PubkeyProvider>> ret;

    using namespace script;

    // musig cannot be nested inside of an origin
    std::span<const char> span = sp;
    if (Const("musig(", span, /*skip=*/false)) {
        if (ctx != ParseScriptContext::P2TR) {
            error = "musig() is only allowed in tr() and rawtr()";
            return {};
        }

        // Split the span on the end parentheses. The end parentheses must
        // be included in the resulting span so that Expr is happy.
        auto split = Split(sp, ')', /*include_sep=*/true);
        if (split.size() > 2) {
            error = "Too many ')' in musig() expression";
            return {};
        }
        std::span<const char> expr(split.at(0).begin(), split.at(0).end());
        if (!Func("musig", expr)) {
            error = "Invalid musig() expression";
            return {};
        }

        // Parse the participant pubkeys
        bool any_ranged = false;
        bool all_bip32 = true;
        std::vector<std::vector<std::unique_ptr<PubkeyProvider>>> providers;
        bool any_key_parsed = false;
        size_t max_multipath_len = 0;
        while (expr.size()) {
            if (any_key_parsed && !Const(",", expr)) {
                error = strprintf("musig(): expected ',', got '%c'", expr[0]);
                return {};
            }
            auto arg = Expr(expr);
            auto pk = ParsePubkey(key_exp_index, arg, ParseScriptContext::MUSIG, out, error);
            if (pk.empty()) {
                error = strprintf("musig(): %s", error);
                return {};
            }
            any_key_parsed = true;

            any_ranged = any_ranged || pk.at(0)->IsRange();
            all_bip32 = all_bip32 &&  pk.at(0)->IsBIP32();

            max_multipath_len = std::max(max_multipath_len, pk.size());

            providers.emplace_back(std::move(pk));
        }
        if (!any_key_parsed) {
            error = "musig(): Must contain key expressions";
            return {};
        }