1// Copyright (c) 2019-present The Bitcoin Core developers
2// Distributed under the MIT software license, see the accompanying
3// file COPYING or http://www.opensource.org/licenses/mit-license.php.
4
5#ifndef BITCOIN_UTIL_BIP32_H
6#define BITCOIN_UTIL_BIP32_H
7
8#include <cstdint>
9#include <span>
10#include <string>
11#include <util/expected.h>
12#include <vector>
13
14/** BIP32 unhardened derivation index (no high bit set) */
15static constexpr uint32_t BIP32_UNHARDENED_FLAG = 0x0;
16/** BIP32 hardened derivation flag (2^31) */
17static constexpr uint32_t BIP32_HARDENED_FLAG = 0x80000000;
18
19struct KeyPathElement {
20    /** Derivation index, without the hardened flag */
21    uint32_t index;
22    bool is_hardened;
23
24    /** Derivation index with the hardened flag applied */
25    uint32_t ChildNumber() const { return index | (is_hardened ? BIP32_HARDENED_FLAG : BIP32_UNHARDENED_FLAG); }
26};
27
28/** Parse a single key path element like "0", "0'", or "0h".
29 *  Returns the derivation index and hardened status, or an error message. */
30util::Expected<KeyPathElement, std::string> ParseKeyPathElement(std::span<const char> elem);
31
32/** Parse an HD keypaths like "m/7/0'/2000". */
33[[nodiscard]] bool ParseHDKeypath(const std::string& keypath_str, std::vector<uint32_t>& keypath);
34
35/** Write HD keypaths as strings */
36std::string WriteHDKeypath(const std::vector<uint32_t>& keypath, bool apostrophe = false);
37std::string FormatHDKeypath(const std::vector<uint32_t>& path, bool apostrophe = false);
38
39/** Whether a parsed HD keypath contains at least one hardened derivation step. */
40bool HasHardenedDerivation(std::span<const uint32_t> keypath);
41
42#endif // BITCOIN_UTIL_BIP32_H
43