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bitcoin/src/script/descriptor.cpp

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// Copyright (c) 2018-present The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
#include <script/descriptor.h>
#include <hash.h>
#include <key_io.h>
#include <pubkey.h>
#include <script/miniscript.h>
#include <script/parsing.h>
#include <script/script.h>
#include <script/signingprovider.h>
#include <script/solver.h>
#include <uint256.h>
#include <common/args.h>
#include <span.h>
#include <util/bip32.h>
#include <util/check.h>
#include <util/strencodings.h>
#include <util/vector.h>
#include <algorithm>
#include <memory>
#include <numeric>
#include <optional>
#include <string>
#include <vector>
using util::Split;
namespace {
////////////////////////////////////////////////////////////////////////////
// Checksum //
////////////////////////////////////////////////////////////////////////////
// This section implements a checksum algorithm for descriptors with the
// following properties:
// * Mistakes in a descriptor string are measured in "symbol errors". The higher
// the number of symbol errors, the harder it is to detect:
// * An error substituting a character from 0123456789()[],'/*abcdefgh@:$%{} for
// another in that set always counts as 1 symbol error.
// * Note that hex encoded keys are covered by these characters. Xprvs and
// xpubs use other characters too, but already have their own checksum
// mechanism.
// * Function names like "multi()" use other characters, but mistakes in
// these would generally result in an unparsable descriptor.
// * A case error always counts as 1 symbol error.
// * Any other 1 character substitution error counts as 1 or 2 symbol errors.
// * Any 1 symbol error is always detected.
// * Any 2 or 3 symbol error in a descriptor of up to 49154 characters is always detected.
// * Any 4 symbol error in a descriptor of up to 507 characters is always detected.
// * Any 5 symbol error in a descriptor of up to 77 characters is always detected.
// * Is optimized to minimize the chance a 5 symbol error in a descriptor up to 387 characters is undetected
// * Random errors have a chance of 1 in 2**40 of being undetected.
//
// These properties are achieved by expanding every group of 3 (non checksum) characters into
// 4 GF(32) symbols, over which a cyclic code is defined.
/*
* Interprets c as 8 groups of 5 bits which are the coefficients of a degree 8 polynomial over GF(32),
* multiplies that polynomial by x, computes its remainder modulo a generator, and adds the constant term val.
*
* This generator is G(x) = x^8 + {30}x^7 + {23}x^6 + {15}x^5 + {14}x^4 + {10}x^3 + {6}x^2 + {12}x + {9}.
* It is chosen to define an cyclic error detecting code which is selected by:
* - Starting from all BCH codes over GF(32) of degree 8 and below, which by construction guarantee detecting
* 3 errors in windows up to 19000 symbols.
* - Taking all those generators, and for degree 7 ones, extend them to degree 8 by adding all degree-1 factors.
* - Selecting just the set of generators that guarantee detecting 4 errors in a window of length 512.
* - Selecting one of those with best worst-case behavior for 5 errors in windows of length up to 512.
*
* The generator and the constants to implement it can be verified using this Sage code:
* B = GF(2) # Binary field
* BP.<b> = B[] # Polynomials over the binary field
* F_mod = b**5 + b**3 + 1
* F.<f> = GF(32, modulus=F_mod, repr='int') # GF(32) definition
* FP.<x> = F[] # Polynomials over GF(32)
* E_mod = x**3 + x + F.fetch_int(8)
* E.<e> = F.extension(E_mod) # Extension field definition
* alpha = e**2743 # Choice of an element in extension field
* for p in divisors(E.order() - 1): # Verify alpha has order 32767.
* assert((alpha**p == 1) == (p % 32767 == 0))
* G = lcm([(alpha**i).minpoly() for i in [1056,1057,1058]] + [x + 1])
* print(G) # Print out the generator
* for i in [1,2,4,8,16]: # Print out {1,2,4,8,16}*(G mod x^8), packed in hex integers.
* v = 0
* for coef in reversed((F.fetch_int(i)*(G % x**8)).coefficients(sparse=True)):
* v = v*32 + coef.integer_representation()
* print("0x%x" % v)
*/
uint64_t PolyMod(uint64_t c, int val)
{
uint8_t c0 = c >> 35;
c = ((c & 0x7ffffffff) << 5) ^ val;
if (c0 & 1) c ^= 0xf5dee51989;
if (c0 & 2) c ^= 0xa9fdca3312;
if (c0 & 4) c ^= 0x1bab10e32d;
if (c0 & 8) c ^= 0x3706b1677a;
if (c0 & 16) c ^= 0x644d626ffd;
return c;
}
std::string DescriptorChecksum(const std::span<const char>& span)
{
/** A character set designed such that:
* - The most common 'unprotected' descriptor characters (hex, keypaths) are in the first group of 32.
* - Case errors cause an offset that's a multiple of 32.
* - As many alphabetic characters are in the same group (while following the above restrictions).
*
* If p(x) gives the position of a character c in this character set, every group of 3 characters
* (a,b,c) is encoded as the 4 symbols (p(a) & 31, p(b) & 31, p(c) & 31, (p(a) / 32) + 3 * (p(b) / 32) + 9 * (p(c) / 32).
* This means that changes that only affect the lower 5 bits of the position, or only the higher 2 bits, will just
* affect a single symbol.
*
* As a result, within-group-of-32 errors count as 1 symbol, as do cross-group errors that don't affect
* the position within the groups.
*/
static const std::string INPUT_CHARSET =
"0123456789()[],'/*abcdefgh@:$%{}"
"IJKLMNOPQRSTUVWXYZ&+-.;<=>?!^_|~"
"ijklmnopqrstuvwxyzABCDEFGH`#\"\\ ";
/** The character set for the checksum itself (same as bech32). */
static const std::string CHECKSUM_CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l";
uint64_t c = 1;
int cls = 0;
int clscount = 0;
for (auto ch : span) {
auto pos = INPUT_CHARSET.find(ch);
if (pos == std::string::npos) return "";
c = PolyMod(c, pos & 31); // Emit a symbol for the position inside the group, for every character.
cls = cls * 3 + (pos >> 5); // Accumulate the group numbers
if (++clscount == 3) {
// Emit an extra symbol representing the group numbers, for every 3 characters.
c = PolyMod(c, cls);
cls = 0;
clscount = 0;
}
}
if (clscount > 0) c = PolyMod(c, cls);
for (int j = 0; j < 8; ++j) c = PolyMod(c, 0); // Shift further to determine the checksum.
c ^= 1; // Prevent appending zeroes from not affecting the checksum.
std::string ret(8, ' ');
for (int j = 0; j < 8; ++j) ret[j] = CHECKSUM_CHARSET[(c >> (5 * (7 - j))) & 31];
return ret;
}
std::string AddChecksum(const std::string& str) { return str + "#" + DescriptorChecksum(str); }
////////////////////////////////////////////////////////////////////////////
// Internal representation //
////////////////////////////////////////////////////////////////////////////
typedef std::vector<uint32_t> KeyPath;
/** Interface for public key objects in descriptors. */
struct PubkeyProvider
{
protected:
//! Index of this key expression in the descriptor
//! E.g. If this PubkeyProvider is key1 in multi(2, key1, key2, key3), then m_expr_index = 0
uint32_t m_expr_index;
public:
explicit PubkeyProvider(uint32_t exp_index) : m_expr_index(exp_index) {}
virtual ~PubkeyProvider() = default;
/** Compare two public keys represented by this provider.
* Used by the Miniscript descriptors to check for duplicate keys in the script.
*/
bool operator<(PubkeyProvider& other) const {
FlatSigningProvider dummy;
std::optional<CPubKey> a = GetPubKey(0, dummy, dummy);
std::optional<CPubKey> b = other.GetPubKey(0, dummy, dummy);
return a < b;
}
/** Derive a public key and put it into out.
* read_cache is the cache to read keys from (if not nullptr)
* write_cache is the cache to write keys to (if not nullptr)
* Caches are not exclusive but this is not tested. Currently we use them exclusively
*/
virtual std::optional<CPubKey> GetPubKey(int pos, const SigningProvider& arg, FlatSigningProvider& out, const DescriptorCache* read_cache = nullptr, DescriptorCache* write_cache = nullptr) const = 0;
/** Whether this represent multiple public keys at different positions. */
virtual bool IsRange() const = 0;
/** Get the size of the generated public key(s) in bytes (33 or 65). */
virtual size_t GetSize() const = 0;
enum class StringType {
PUBLIC,
COMPAT // string calculation that mustn't change over time to stay compatible with previous software versions
};
/** Get the descriptor string form. */
virtual std::string ToString(StringType type=StringType::PUBLIC) const = 0;
/** Get the descriptor string form including private data (if available in arg). */
virtual bool ToPrivateString(const SigningProvider& arg, std::string& out) const = 0;
/** Get the descriptor string form with the xpub at the last hardened derivation,
* and always use h for hardened derivation.
*/
virtual bool ToNormalizedString(const SigningProvider& arg, std::string& out, const DescriptorCache* cache = nullptr) const = 0;
/** Derive a private key, if private data is available in arg and put it into out. */
virtual void GetPrivKey(int pos, const SigningProvider& arg, FlatSigningProvider& out) const = 0;
/** Return the non-extended public key for this PubkeyProvider, if it has one. */
virtual std::optional<CPubKey> GetRootPubKey() const = 0;
/** Return the extended public key for this PubkeyProvider, if it has one. */
virtual std::optional<CExtPubKey> GetRootExtPubKey() const = 0;
/** Make a deep copy of this PubkeyProvider */
virtual std::unique_ptr<PubkeyProvider> Clone() const = 0;
};
class OriginPubkeyProvider final : public PubkeyProvider
{
KeyOriginInfo m_origin;
std::unique_ptr<PubkeyProvider> m_provider;
bool m_apostrophe;
std::string OriginString(StringType type, bool normalized=false) const
{
// If StringType==COMPAT, always use the apostrophe to stay compatible with previous versions
bool use_apostrophe = (!normalized && m_apostrophe) || type == StringType::COMPAT;
return HexStr(m_origin.fingerprint) + FormatHDKeypath(m_origin.path, use_apostrophe);
}
public:
OriginPubkeyProvider(uint32_t exp_index, KeyOriginInfo info, std::unique_ptr<PubkeyProvider> provider, bool apostrophe) : PubkeyProvider(exp_index), m_origin(std::move(info)), m_provider(std::move(provider)), m_apostrophe(apostrophe) {}
std::optional<CPubKey> GetPubKey(int pos, const SigningProvider& arg, FlatSigningProvider& out, const DescriptorCache* read_cache = nullptr, DescriptorCache* write_cache = nullptr) const override
{
std::optional<CPubKey> pub = m_provider->GetPubKey(pos, arg, out, read_cache, write_cache);
if (!pub) return std::nullopt;
Assert(out.pubkeys.contains(pub->GetID()));
auto& [pubkey, suborigin] = out.origins[pub->GetID()];
Assert(pubkey == *pub); // m_provider must have a valid origin by this point.
std::copy(std::begin(m_origin.fingerprint), std::end(m_origin.fingerprint), suborigin.fingerprint);
suborigin.path.insert(suborigin.path.begin(), m_origin.path.begin(), m_origin.path.end());
return pub;
}
bool IsRange() const override { return m_provider->IsRange(); }
size_t GetSize() const override { return m_provider->GetSize(); }
std::string ToString(StringType type) const override { return "[" + OriginString(type) + "]" + m_provider->ToString(type); }
bool ToPrivateString(const SigningProvider& arg, std::string& ret) const override
{
std::string sub;
if (!m_provider->ToPrivateString(arg, sub)) return false;
ret = "[" + OriginString(StringType::PUBLIC) + "]" + std::move(sub);
return true;
}
bool ToNormalizedString(const SigningProvider& arg, std::string& ret, const DescriptorCache* cache) const override
{
std::string sub;
if (!m_provider->ToNormalizedString(arg, sub, cache)) return false;
// If m_provider is a BIP32PubkeyProvider, we may get a string formatted like a OriginPubkeyProvider
// In that case, we need to strip out the leading square bracket and fingerprint from the substring,
// and append that to our own origin string.
if (sub[0] == '[') {
sub = sub.substr(9);
ret = "[" + OriginString(StringType::PUBLIC, /*normalized=*/true) + std::move(sub);
} else {
ret = "[" + OriginString(StringType::PUBLIC, /*normalized=*/true) + "]" + std::move(sub);
}
return true;
}
void GetPrivKey(int pos, const SigningProvider& arg, FlatSigningProvider& out) const override
{
m_provider->GetPrivKey(pos, arg, out);
}
std::optional<CPubKey> GetRootPubKey() const override
{
return m_provider->GetRootPubKey();
}
std::optional<CExtPubKey> GetRootExtPubKey() const override
{
return m_provider->GetRootExtPubKey();
}
std::unique_ptr<PubkeyProvider> Clone() const override
{
return std::make_unique<OriginPubkeyProvider>(m_expr_index, m_origin, m_provider->Clone(), m_apostrophe);
}
};
/** An object representing a parsed constant public key in a descriptor. */
class ConstPubkeyProvider final : public PubkeyProvider
{
CPubKey m_pubkey;
bool m_xonly;
std::optional<CKey> GetPrivKey(const SigningProvider& arg) const
{
CKey key;
if (!(m_xonly ? arg.GetKeyByXOnly(XOnlyPubKey(m_pubkey), key) :
arg.GetKey(m_pubkey.GetID(), key))) return std::nullopt;
return key;
}
public:
ConstPubkeyProvider(uint32_t exp_index, const CPubKey& pubkey, bool xonly) : PubkeyProvider(exp_index), m_pubkey(pubkey), m_xonly(xonly) {}
std::optional<CPubKey> GetPubKey(int pos, const SigningProvider&, FlatSigningProvider& out, const DescriptorCache* read_cache = nullptr, DescriptorCache* write_cache = nullptr) const override
{
KeyOriginInfo info;
CKeyID keyid = m_pubkey.GetID();
std::copy(keyid.begin(), keyid.begin() + sizeof(info.fingerprint), info.fingerprint);
out.origins.emplace(keyid, std::make_pair(m_pubkey, info));
out.pubkeys.emplace(keyid, m_pubkey);
return m_pubkey;
}
bool IsRange() const override { return false; }
size_t GetSize() const override { return m_pubkey.size(); }
std::string ToString(StringType type) const override { return m_xonly ? HexStr(m_pubkey).substr(2) : HexStr(m_pubkey); }
bool ToPrivateString(const SigningProvider& arg, std::string& ret) const override
{
std::optional<CKey> key = GetPrivKey(arg);
if (!key) return false;
ret = EncodeSecret(*key);
return true;
}
bool ToNormalizedString(const SigningProvider& arg, std::string& ret, const DescriptorCache* cache) const override
{
ret = ToString(StringType::PUBLIC);
return true;
}
void GetPrivKey(int pos, const SigningProvider& arg, FlatSigningProvider& out) const override
{
std::optional<CKey> key = GetPrivKey(arg);
if (!key) return;
out.keys.emplace(key->GetPubKey().GetID(), *key);
}
std::optional<CPubKey> GetRootPubKey() const override
{
return m_pubkey;
}
std::optional<CExtPubKey> GetRootExtPubKey() const override
{
return std::nullopt;
}
std::unique_ptr<PubkeyProvider> Clone() const override
{
return std::make_unique<ConstPubkeyProvider>(m_expr_index, m_pubkey, m_xonly);
}
};
enum class DeriveType {
NO,
UNHARDENED,
HARDENED,
};
/** An object representing a parsed extended public key in a descriptor. */
class BIP32PubkeyProvider final : public PubkeyProvider
{
// Root xpub, path, and final derivation step type being used, if any
CExtPubKey m_root_extkey;
KeyPath m_path;
DeriveType m_derive;
// Whether ' or h is used in harded derivation
bool m_apostrophe;
bool GetExtKey(const SigningProvider& arg, CExtKey& ret) const
{
CKey key;
if (!arg.GetKey(m_root_extkey.pubkey.GetID(), key)) return false;
ret.nDepth = m_root_extkey.nDepth;
std::copy(m_root_extkey.vchFingerprint, m_root_extkey.vchFingerprint + sizeof(ret.vchFingerprint), ret.vchFingerprint);
ret.nChild = m_root_extkey.nChild;
ret.chaincode = m_root_extkey.chaincode;
ret.key = key;
return true;
}
// Derives the last xprv
bool GetDerivedExtKey(const SigningProvider& arg, CExtKey& xprv, CExtKey& last_hardened) const
{
if (!GetExtKey(arg, xprv)) return false;
for (auto entry : m_path) {
if (!xprv.Derive(xprv, entry)) return false;
if (entry >> 31) {
last_hardened = xprv;
}
}
return true;
}
bool IsHardened() const
{
if (m_derive == DeriveType::HARDENED) return true;
for (auto entry : m_path) {
if (entry >> 31) return true;
}
return false;
}
public:
BIP32PubkeyProvider(uint32_t exp_index, const CExtPubKey& extkey, KeyPath path, DeriveType derive, bool apostrophe) : PubkeyProvider(exp_index), m_root_extkey(extkey), m_path(std::move(path)), m_derive(derive), m_apostrophe(apostrophe) {}
bool IsRange() const override { return m_derive != DeriveType::NO; }
size_t GetSize() const override { return 33; }
std::optional<CPubKey> GetPubKey(int pos, const SigningProvider& arg, FlatSigningProvider& out, const DescriptorCache* read_cache = nullptr, DescriptorCache* write_cache = nullptr) const override
{
KeyOriginInfo info;
CKeyID keyid = m_root_extkey.pubkey.GetID();
std::copy(keyid.begin(), keyid.begin() + sizeof(info.fingerprint), info.fingerprint);
info.path = m_path;
if (m_derive == DeriveType::UNHARDENED) info.path.push_back((uint32_t)pos);
if (m_derive == DeriveType::HARDENED) info.path.push_back(((uint32_t)pos) | 0x80000000L);
// Derive keys or fetch them from cache
CExtPubKey final_extkey = m_root_extkey;
CExtPubKey parent_extkey = m_root_extkey;
CExtPubKey last_hardened_extkey;
bool der = true;
if (read_cache) {
if (!read_cache->GetCachedDerivedExtPubKey(m_expr_index, pos, final_extkey)) {
if (m_derive == DeriveType::HARDENED) return std::nullopt;
// Try to get the derivation parent
if (!read_cache->GetCachedParentExtPubKey(m_expr_index, parent_extkey)) return std::nullopt;
final_extkey = parent_extkey;
if (m_derive == DeriveType::UNHARDENED) der = parent_extkey.Derive(final_extkey, pos);
}
} else if (IsHardened()) {
CExtKey xprv;
CExtKey lh_xprv;
if (!GetDerivedExtKey(arg, xprv, lh_xprv)) return std::nullopt;
parent_extkey = xprv.Neuter();
if (m_derive == DeriveType::UNHARDENED) der = xprv.Derive(xprv, pos);
if (m_derive == DeriveType::HARDENED) der = xprv.Derive(xprv, pos | 0x80000000UL);
final_extkey = xprv.Neuter();
if (lh_xprv.key.IsValid()) {
last_hardened_extkey = lh_xprv.Neuter();
}
} else {
for (auto entry : m_path) {
if (!parent_extkey.Derive(parent_extkey, entry)) return std::nullopt;
}
final_extkey = parent_extkey;
if (m_derive == DeriveType::UNHARDENED) der = parent_extkey.Derive(final_extkey, pos);
assert(m_derive != DeriveType::HARDENED);
}
if (!der) return std::nullopt;
out.origins.emplace(final_extkey.pubkey.GetID(), std::make_pair(final_extkey.pubkey, info));
out.pubkeys.emplace(final_extkey.pubkey.GetID(), final_extkey.pubkey);
if (write_cache) {
// Only cache parent if there is any unhardened derivation
if (m_derive != DeriveType::HARDENED) {
write_cache->CacheParentExtPubKey(m_expr_index, parent_extkey);
// Cache last hardened xpub if we have it
if (last_hardened_extkey.pubkey.IsValid()) {
write_cache->CacheLastHardenedExtPubKey(m_expr_index, last_hardened_extkey);
}
} else if (info.path.size() > 0) {
write_cache->CacheDerivedExtPubKey(m_expr_index, pos, final_extkey);
}
}
return final_extkey.pubkey;
}
std::string ToString(StringType type, bool normalized) const
{
// If StringType==COMPAT, always use the apostrophe to stay compatible with previous versions
const bool use_apostrophe = (!normalized && m_apostrophe) || type == StringType::COMPAT;
std::string ret = EncodeExtPubKey(m_root_extkey) + FormatHDKeypath(m_path, /*apostrophe=*/use_apostrophe);
if (IsRange()) {
ret += "/*";
if (m_derive == DeriveType::HARDENED) ret += use_apostrophe ? '\'' : 'h';
}
return ret;
}
std::string ToString(StringType type=StringType::PUBLIC) const override
{
return ToString(type, /*normalized=*/false);
}
bool ToPrivateString(const SigningProvider& arg, std::string& out) const override
{
CExtKey key;
if (!GetExtKey(arg, key)) return false;
out = EncodeExtKey(key) + FormatHDKeypath(m_path, /*apostrophe=*/m_apostrophe);
if (IsRange()) {
out += "/*";
if (m_derive == DeriveType::HARDENED) out += m_apostrophe ? '\'' : 'h';
}
return true;
}
bool ToNormalizedString(const SigningProvider& arg, std::string& out, const DescriptorCache* cache) const override
{
if (m_derive == DeriveType::HARDENED) {
out = ToString(StringType::PUBLIC, /*normalized=*/true);
return true;
}
// Step backwards to find the last hardened step in the path
int i = (int)m_path.size() - 1;
for (; i >= 0; --i) {
if (m_path.at(i) >> 31) {
break;
}
}
// Either no derivation or all unhardened derivation
if (i == -1) {
out = ToString();
return true;
}
// Get the path to the last hardened stup
KeyOriginInfo origin;
int k = 0;
for (; k <= i; ++k) {
// Add to the path
origin.path.push_back(m_path.at(k));
}
// Build the remaining path
KeyPath end_path;
for (; k < (int)m_path.size(); ++k) {
end_path.push_back(m_path.at(k));
}
// Get the fingerprint
CKeyID id = m_root_extkey.pubkey.GetID();
std::copy(id.begin(), id.begin() + 4, origin.fingerprint);
CExtPubKey xpub;
CExtKey lh_xprv;
// If we have the cache, just get the parent xpub
if (cache != nullptr) {
cache->GetCachedLastHardenedExtPubKey(m_expr_index, xpub);
}
if (!xpub.pubkey.IsValid()) {
// Cache miss, or nor cache, or need privkey
CExtKey xprv;
if (!GetDerivedExtKey(arg, xprv, lh_xprv)) return false;
xpub = lh_xprv.Neuter();
}
assert(xpub.pubkey.IsValid());
// Build the string
std::string origin_str = HexStr(origin.fingerprint) + FormatHDKeypath(origin.path);
out = "[" + origin_str + "]" + EncodeExtPubKey(xpub) + FormatHDKeypath(end_path);
if (IsRange()) {
out += "/*";
assert(m_derive == DeriveType::UNHARDENED);
}
return true;
}
void GetPrivKey(int pos, const SigningProvider& arg, FlatSigningProvider& out) const override
{
CExtKey extkey;
CExtKey dummy;
if (!GetDerivedExtKey(arg, extkey, dummy)) return;
if (m_derive == DeriveType::UNHARDENED && !extkey.Derive(extkey, pos)) return;
if (m_derive == DeriveType::HARDENED && !extkey.Derive(extkey, pos | 0x80000000UL)) return;
out.keys.emplace(extkey.key.GetPubKey().GetID(), extkey.key);
}
std::optional<CPubKey> GetRootPubKey() const override
{
return std::nullopt;
}
std::optional<CExtPubKey> GetRootExtPubKey() const override
{
return m_root_extkey;
}
std::unique_ptr<PubkeyProvider> Clone() const override
{
return std::make_unique<BIP32PubkeyProvider>(m_expr_index, m_root_extkey, m_path, m_derive, m_apostrophe);
}
};
/** Base class for all Descriptor implementations. */
class DescriptorImpl : public Descriptor
{
protected:
//! Public key arguments for this descriptor (size 1 for PK, PKH, WPKH; any size for WSH and Multisig).
const std::vector<std::unique_ptr<PubkeyProvider>> m_pubkey_args;
//! The string name of the descriptor function.
const std::string m_name;
//! The sub-descriptor arguments (empty for everything but SH and WSH).
//! In doc/descriptors.m this is referred to as SCRIPT expressions sh(SCRIPT)
//! and wsh(SCRIPT), and distinct from KEY expressions and ADDR expressions.
//! Subdescriptors can only ever generate a single script.
const std::vector<std::unique_ptr<DescriptorImpl>> m_subdescriptor_args;
//! Return a serialization of anything except pubkey and script arguments, to be prepended to those.
virtual std::string ToStringExtra() const { return ""; }
/** A helper function to construct the scripts for this descriptor.
*
* This function is invoked once by ExpandHelper.
*
* @param pubkeys The evaluations of the m_pubkey_args field.
* @param scripts The evaluations of m_subdescriptor_args (one for each m_subdescriptor_args element).
* @param out A FlatSigningProvider to put scripts or public keys in that are necessary to the solver.
* The origin info of the provided pubkeys is automatically added.
* @return A vector with scriptPubKeys for this descriptor.
*/
virtual std::vector<CScript> MakeScripts(const std::vector<CPubKey>& pubkeys, std::span<const CScript> scripts, FlatSigningProvider& out) const = 0;
public:
DescriptorImpl(std::vector<std::unique_ptr<PubkeyProvider>> pubkeys, const std::string& name) : m_pubkey_args(std::move(pubkeys)), m_name(name), m_subdescriptor_args() {}
DescriptorImpl(std::vector<std::unique_ptr<PubkeyProvider>> pubkeys, std::unique_ptr<DescriptorImpl> script, const std::string& name) : m_pubkey_args(std::move(pubkeys)), m_name(name), m_subdescriptor_args(Vector(std::move(script))) {}
DescriptorImpl(std::vector<std::unique_ptr<PubkeyProvider>> pubkeys, std::vector<std::unique_ptr<DescriptorImpl>> scripts, const std::string& name) : m_pubkey_args(std::move(pubkeys)), m_name(name), m_subdescriptor_args(std::move(scripts)) {}
enum class StringType
{
PUBLIC,
PRIVATE,
NORMALIZED,
COMPAT, // string calculation that mustn't change over time to stay compatible with previous software versions
};
// NOLINTNEXTLINE(misc-no-recursion)
bool IsSolvable() const override
{
for (const auto& arg : m_subdescriptor_args) {
if (!arg->IsSolvable()) return false;
}
return true;
}
// NOLINTNEXTLINE(misc-no-recursion)
bool IsRange() const final
{
for (const auto& pubkey : m_pubkey_args) {
if (pubkey->IsRange()) return true;
}
for (const auto& arg : m_subdescriptor_args) {
if (arg->IsRange()) return true;
}
return false;
}
// NOLINTNEXTLINE(misc-no-recursion)
virtual bool ToStringSubScriptHelper(const SigningProvider* arg, std::string& ret, const StringType type, const DescriptorCache* cache = nullptr) const
{
size_t pos = 0;
for (const auto& scriptarg : m_subdescriptor_args) {
if (pos++) ret += ",";
std::string tmp;
if (!scriptarg->ToStringHelper(arg, tmp, type, cache)) return false;
ret += tmp;
}
return true;
}
// NOLINTNEXTLINE(misc-no-recursion)
virtual bool ToStringHelper(const SigningProvider* arg, std::string& out, const StringType type, const DescriptorCache* cache = nullptr) const
{
std::string extra = ToStringExtra();
size_t pos = extra.size() > 0 ? 1 : 0;
std::string ret = m_name + "(" + extra;
for (const auto& pubkey : m_pubkey_args) {
if (pos++) ret += ",";
std::string tmp;
switch (type) {
case StringType::NORMALIZED:
if (!pubkey->ToNormalizedString(*arg, tmp, cache)) return false;
break;
case StringType::PRIVATE:
if (!pubkey->ToPrivateString(*arg, tmp)) return false;
break;
case StringType::PUBLIC:
tmp = pubkey->ToString();
break;
case StringType::COMPAT:
tmp = pubkey->ToString(PubkeyProvider::StringType::COMPAT);
break;
}
ret += tmp;
}
std::string subscript;
if (!ToStringSubScriptHelper(arg, subscript, type, cache)) return false;
if (pos && subscript.size()) ret += ',';
out = std::move(ret) + std::move(subscript) + ")";
return true;
}
std::string ToString(bool compat_format) const final
{
std::string ret;
ToStringHelper(nullptr, ret, compat_format ? StringType::COMPAT : StringType::PUBLIC);
return AddChecksum(ret);
}
bool ToPrivateString(const SigningProvider& arg, std::string& out) const override
{
bool ret = ToStringHelper(&arg, out, StringType::PRIVATE);
out = AddChecksum(out);
return ret;
}
bool ToNormalizedString(const SigningProvider& arg, std::string& out, const DescriptorCache* cache) const override final
{
bool ret = ToStringHelper(&arg, out, StringType::NORMALIZED, cache);
out = AddChecksum(out);
return ret;
}
// NOLINTNEXTLINE(misc-no-recursion)
bool ExpandHelper(int pos, const SigningProvider& arg, const DescriptorCache* read_cache, std::vector<CScript>& output_scripts, FlatSigningProvider& out, DescriptorCache* write_cache) const
{
FlatSigningProvider subprovider;
std::vector<CPubKey> pubkeys;
pubkeys.reserve(m_pubkey_args.size());
// Construct temporary data in `pubkeys`, `subscripts`, and `subprovider` to avoid producing output in case of failure.
for (const auto& p : m_pubkey_args) {
std::optional<CPubKey> pubkey = p->GetPubKey(pos, arg, subprovider, read_cache, write_cache);
if (!pubkey) return false;
pubkeys.push_back(pubkey.value());
}
std::vector<CScript> subscripts;
for (const auto& subarg : m_subdescriptor_args) {
std::vector<CScript> outscripts;
if (!subarg->ExpandHelper(pos, arg, read_cache, outscripts, subprovider, write_cache)) return false;
assert(outscripts.size() == 1);
subscripts.emplace_back(std::move(outscripts[0]));
}
out.Merge(std::move(subprovider));
output_scripts = MakeScripts(pubkeys, std::span{subscripts}, out);
return true;
}
bool Expand(int pos, const SigningProvider& provider, std::vector<CScript>& output_scripts, FlatSigningProvider& out, DescriptorCache* write_cache = nullptr) const final
{
return ExpandHelper(pos, provider, nullptr, output_scripts, out, write_cache);
}
bool ExpandFromCache(int pos, const DescriptorCache& read_cache, std::vector<CScript>& output_scripts, FlatSigningProvider& out) const final
{
return ExpandHelper(pos, DUMMY_SIGNING_PROVIDER, &read_cache, output_scripts, out, nullptr);
}
// NOLINTNEXTLINE(misc-no-recursion)
void ExpandPrivate(int pos, const SigningProvider& provider, FlatSigningProvider& out) const final
{
for (const auto& p : m_pubkey_args) {
p->GetPrivKey(pos, provider, out);
}
for (const auto& arg : m_subdescriptor_args) {
arg->ExpandPrivate(pos, provider, out);
}
}
std::optional<OutputType> GetOutputType() const override { return std::nullopt; }
std::optional<int64_t> ScriptSize() const override { return {}; }
/** A helper for MaxSatisfactionWeight.
*
* @param use_max_sig Whether to assume ECDSA signatures will have a high-r.
* @return The maximum size of the satisfaction in raw bytes (with no witness meaning).
*/
virtual std::optional<int64_t> MaxSatSize(bool use_max_sig) const { return {}; }
std::optional<int64_t> MaxSatisfactionWeight(bool) const override { return {}; }
std::optional<int64_t> MaxSatisfactionElems() const override { return {}; }
// NOLINTNEXTLINE(misc-no-recursion)
void GetPubKeys(std::set<CPubKey>& pubkeys, std::set<CExtPubKey>& ext_pubs) const override
{
for (const auto& p : m_pubkey_args) {
std::optional<CPubKey> pub = p->GetRootPubKey();
if (pub) pubkeys.insert(*pub);
std::optional<CExtPubKey> ext_pub = p->GetRootExtPubKey();
if (ext_pub) ext_pubs.insert(*ext_pub);
}
for (const auto& arg : m_subdescriptor_args) {
arg->GetPubKeys(pubkeys, ext_pubs);
}
}
virtual std::unique_ptr<DescriptorImpl> Clone() const = 0;
};
/** A parsed addr(A) descriptor. */
class AddressDescriptor final : public DescriptorImpl
{
const CTxDestination m_destination;
protected:
std::string ToStringExtra() const override { return EncodeDestination(m_destination); }
std::vector<CScript> MakeScripts(const std::vector<CPubKey>&, std::span<const CScript>, FlatSigningProvider&) const override { return Vector(GetScriptForDestination(m_destination)); }
public:
AddressDescriptor(CTxDestination destination) : DescriptorImpl({}, "addr"), m_destination(std::move(destination)) {}
bool IsSolvable() const final { return false; }
std::optional<OutputType> GetOutputType() const override
{
return OutputTypeFromDestination(m_destination);
}
bool IsSingleType() const final { return true; }
bool IsSingleKey() const final { return false; }
bool ToPrivateString(const SigningProvider& arg, std::string& out) const final { return false; }
std::optional<int64_t> ScriptSize() const override { return GetScriptForDestination(m_destination).size(); }
std::unique_ptr<DescriptorImpl> Clone() const override
{
return std::make_unique<AddressDescriptor>(m_destination);
}
};
/** A parsed raw(H) descriptor. */
class RawDescriptor final : public DescriptorImpl
{
const CScript m_script;
protected:
std::string ToStringExtra() const override { return HexStr(m_script); }
std::vector<CScript> MakeScripts(const std::vector<CPubKey>&, std::span<const CScript>, FlatSigningProvider&) const override { return Vector(m_script); }
public:
RawDescriptor(CScript script) : DescriptorImpl({}, "raw"), m_script(std::move(script)) {}
bool IsSolvable() const final { return false; }
std::optional<OutputType> GetOutputType() const override
{
CTxDestination dest;
ExtractDestination(m_script, dest);
return OutputTypeFromDestination(dest);
}
bool IsSingleType() const final { return true; }
bool IsSingleKey() const final { return false; }
bool ToPrivateString(const SigningProvider& arg, std::string& out) const final { return false; }
std::optional<int64_t> ScriptSize() const override { return m_script.size(); }
std::unique_ptr<DescriptorImpl> Clone() const override
{
return std::make_unique<RawDescriptor>(m_script);
}
};
/** A parsed pk(P) descriptor. */
class PKDescriptor final : public DescriptorImpl
{
private:
const bool m_xonly;
protected:
std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, std::span<const CScript>, FlatSigningProvider&) const override
{
if (m_xonly) {
CScript script = CScript() << ToByteVector(XOnlyPubKey(keys[0])) << OP_CHECKSIG;
return Vector(std::move(script));
} else {
return Vector(GetScriptForRawPubKey(keys[0]));
}
}
public:
PKDescriptor(std::unique_ptr<PubkeyProvider> prov, bool xonly = false) : DescriptorImpl(Vector(std::move(prov)), "pk"), m_xonly(xonly) {}
bool IsSingleType() const final { return true; }
bool IsSingleKey() const final { return true; }
std::optional<int64_t> ScriptSize() const override {
return 1 + (m_xonly ? 32 : m_pubkey_args[0]->GetSize()) + 1;
}
std::optional<int64_t> MaxSatSize(bool use_max_sig) const override {
const auto ecdsa_sig_size = use_max_sig ? 72 : 71;
return 1 + (m_xonly ? 65 : ecdsa_sig_size);
}
std::optional<int64_t> MaxSatisfactionWeight(bool use_max_sig) const override {
return *MaxSatSize(use_max_sig) * WITNESS_SCALE_FACTOR;
}
std::optional<int64_t> MaxSatisfactionElems() const override { return 1; }
std::unique_ptr<DescriptorImpl> Clone() const override
{
return std::make_unique<PKDescriptor>(m_pubkey_args.at(0)->Clone(), m_xonly);
}
};
/** A parsed pkh(P) descriptor. */
class PKHDescriptor final : public DescriptorImpl
{
protected:
std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, std::span<const CScript>, FlatSigningProvider&) const override
{
CKeyID id = keys[0].GetID();
return Vector(GetScriptForDestination(PKHash(id)));
}
public:
PKHDescriptor(std::unique_ptr<PubkeyProvider> prov) : DescriptorImpl(Vector(std::move(prov)), "pkh") {}
std::optional<OutputType> GetOutputType() const override { return OutputType::LEGACY; }
bool IsSingleType() const final { return true; }
bool IsSingleKey() const final { return true; }
std::optional<int64_t> ScriptSize() const override { return 1 + 1 + 1 + 20 + 1 + 1; }
std::optional<int64_t> MaxSatSize(bool use_max_sig) const override {
const auto sig_size = use_max_sig ? 72 : 71;
return 1 + sig_size + 1 + m_pubkey_args[0]->GetSize();
}
std::optional<int64_t> MaxSatisfactionWeight(bool use_max_sig) const override {
return *MaxSatSize(use_max_sig) * WITNESS_SCALE_FACTOR;
}
std::optional<int64_t> MaxSatisfactionElems() const override { return 2; }
std::unique_ptr<DescriptorImpl> Clone() const override
{
return std::make_unique<PKHDescriptor>(m_pubkey_args.at(0)->Clone());
}
};
/** A parsed wpkh(P) descriptor. */
class WPKHDescriptor final : public DescriptorImpl
{
protected:
std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, std::span<const CScript>, FlatSigningProvider&) const override
{
CKeyID id = keys[0].GetID();
return Vector(GetScriptForDestination(WitnessV0KeyHash(id)));
}
public:
WPKHDescriptor(std::unique_ptr<PubkeyProvider> prov) : DescriptorImpl(Vector(std::move(prov)), "wpkh") {}
std::optional<OutputType> GetOutputType() const override { return OutputType::BECH32; }
bool IsSingleType() const final { return true; }
bool IsSingleKey() const final { return true; }
std::optional<int64_t> ScriptSize() const override { return 1 + 1 + 20; }
std::optional<int64_t> MaxSatSize(bool use_max_sig) const override {
const auto sig_size = use_max_sig ? 72 : 71;
return (1 + sig_size + 1 + 33);
}
std::optional<int64_t> MaxSatisfactionWeight(bool use_max_sig) const override {
return MaxSatSize(use_max_sig);
}
std::optional<int64_t> MaxSatisfactionElems() const override { return 2; }
std::unique_ptr<DescriptorImpl> Clone() const override
{
return std::make_unique<WPKHDescriptor>(m_pubkey_args.at(0)->Clone());
}
};
/** A parsed combo(P) descriptor. */
class ComboDescriptor final : public DescriptorImpl
{
protected:
std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, std::span<const CScript>, FlatSigningProvider& out) const override
{
std::vector<CScript> ret;
CKeyID id = keys[0].GetID();
ret.emplace_back(GetScriptForRawPubKey(keys[0])); // P2PK
ret.emplace_back(GetScriptForDestination(PKHash(id))); // P2PKH
if (keys[0].IsCompressed()) {
CScript p2wpkh = GetScriptForDestination(WitnessV0KeyHash(id));
out.scripts.emplace(CScriptID(p2wpkh), p2wpkh);
ret.emplace_back(p2wpkh);
ret.emplace_back(GetScriptForDestination(ScriptHash(p2wpkh))); // P2SH-P2WPKH
}
return ret;
}
public:
ComboDescriptor(std::unique_ptr<PubkeyProvider> prov) : DescriptorImpl(Vector(std::move(prov)), "combo") {}
bool IsSingleType() const final { return false; }
bool IsSingleKey() const final { return true; }
std::unique_ptr<DescriptorImpl> Clone() const override
{
return std::make_unique<ComboDescriptor>(m_pubkey_args.at(0)->Clone());
}
};
/** A parsed multi(...) or sortedmulti(...) descriptor */
class MultisigDescriptor final : public DescriptorImpl
{
const int m_threshold;
const bool m_sorted;
protected:
std::string ToStringExtra() const override { return strprintf("%i", m_threshold); }
std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, std::span<const CScript>, FlatSigningProvider&) const override {
if (m_sorted) {
std::vector<CPubKey> sorted_keys(keys);
std::sort(sorted_keys.begin(), sorted_keys.end());
return Vector(GetScriptForMultisig(m_threshold, sorted_keys));
}
return Vector(GetScriptForMultisig(m_threshold, keys));
}
public:
MultisigDescriptor(int threshold, std::vector<std::unique_ptr<PubkeyProvider>> providers, bool sorted = false) : DescriptorImpl(std::move(providers), sorted ? "sortedmulti" : "multi"), m_threshold(threshold), m_sorted(sorted) {}
bool IsSingleType() const final { return true; }
bool IsSingleKey() const final { return false; }
std::optional<int64_t> ScriptSize() const override {
const auto n_keys = m_pubkey_args.size();
auto op = [](int64_t acc, const std::unique_ptr<PubkeyProvider>& pk) { return acc + 1 + pk->GetSize();};
const auto pubkeys_size{std::accumulate(m_pubkey_args.begin(), m_pubkey_args.end(), int64_t{0}, op)};
return 1 + BuildScript(n_keys).size() + BuildScript(m_threshold).size() + pubkeys_size;
}
std::optional<int64_t> MaxSatSize(bool use_max_sig) const override {
const auto sig_size = use_max_sig ? 72 : 71;
return (1 + (1 + sig_size) * m_threshold);
}
std::optional<int64_t> MaxSatisfactionWeight(bool use_max_sig) const override {
return *MaxSatSize(use_max_sig) * WITNESS_SCALE_FACTOR;
}
std::optional<int64_t> MaxSatisfactionElems() const override { return 1 + m_threshold; }
std::unique_ptr<DescriptorImpl> Clone() const override
{
std::vector<std::unique_ptr<PubkeyProvider>> providers;
providers.reserve(m_pubkey_args.size());
std::transform(m_pubkey_args.begin(), m_pubkey_args.end(), providers.begin(), [](const std::unique_ptr<PubkeyProvider>& p) { return p->Clone(); });
return std::make_unique<MultisigDescriptor>(m_threshold, std::move(providers), m_sorted);
}
};
/** A parsed (sorted)multi_a(...) descriptor. Always uses x-only pubkeys. */
class MultiADescriptor final : public DescriptorImpl
{
const int m_threshold;
const bool m_sorted;
protected:
std::string ToStringExtra() const override { return strprintf("%i", m_threshold); }
std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, std::span<const CScript>, FlatSigningProvider&) const override {
CScript ret;
std::vector<XOnlyPubKey> xkeys;
xkeys.reserve(keys.size());
for (const auto& key : keys) xkeys.emplace_back(key);
if (m_sorted) std::sort(xkeys.begin(), xkeys.end());
ret << ToByteVector(xkeys[0]) << OP_CHECKSIG;
for (size_t i = 1; i < keys.size(); ++i) {
ret << ToByteVector(xkeys[i]) << OP_CHECKSIGADD;
}
ret << m_threshold << OP_NUMEQUAL;
return Vector(std::move(ret));
}
public:
MultiADescriptor(int threshold, std::vector<std::unique_ptr<PubkeyProvider>> providers, bool sorted = false) : DescriptorImpl(std::move(providers), sorted ? "sortedmulti_a" : "multi_a"), m_threshold(threshold), m_sorted(sorted) {}
bool IsSingleType() const final { return true; }
bool IsSingleKey() const final { return false; }
std::optional<int64_t> ScriptSize() const override {
const auto n_keys = m_pubkey_args.size();
return (1 + 32 + 1) * n_keys + BuildScript(m_threshold).size() + 1;
}
std::optional<int64_t> MaxSatSize(bool use_max_sig) const override {
return (1 + 65) * m_threshold + (m_pubkey_args.size() - m_threshold);
}
std::optional<int64_t> MaxSatisfactionElems() const override { return m_pubkey_args.size(); }
std::unique_ptr<DescriptorImpl> Clone() const override
{
std::vector<std::unique_ptr<PubkeyProvider>> providers;
providers.reserve(m_pubkey_args.size());
for (const auto& arg : m_pubkey_args) {
providers.push_back(arg->Clone());
}
return std::make_unique<MultiADescriptor>(m_threshold, std::move(providers), m_sorted);
}
};
/** A parsed sh(...) descriptor. */
class SHDescriptor final : public DescriptorImpl
{
protected:
std::vector<CScript> MakeScripts(const std::vector<CPubKey>&, std::span<const CScript> scripts, FlatSigningProvider& out) const override
{
auto ret = Vector(GetScriptForDestination(ScriptHash(scripts[0])));
if (ret.size()) out.scripts.emplace(CScriptID(scripts[0]), scripts[0]);
return ret;
}
bool IsSegwit() const { return m_subdescriptor_args[0]->GetOutputType() == OutputType::BECH32; }
public:
SHDescriptor(std::unique_ptr<DescriptorImpl> desc) : DescriptorImpl({}, std::move(desc), "sh") {}
std::optional<OutputType> GetOutputType() const override
{
assert(m_subdescriptor_args.size() == 1);
if (IsSegwit()) return OutputType::P2SH_SEGWIT;
return OutputType::LEGACY;
}
bool IsSingleType() const final { return true; }
bool IsSingleKey() const final { return m_subdescriptor_args[0]->IsSingleKey(); }
std::optional<int64_t> ScriptSize() const override { return 1 + 1 + 20 + 1; }
std::optional<int64_t> MaxSatisfactionWeight(bool use_max_sig) const override {
if (const auto sat_size = m_subdescriptor_args[0]->MaxSatSize(use_max_sig)) {
if (const auto subscript_size = m_subdescriptor_args[0]->ScriptSize()) {
// The subscript is never witness data.
const auto subscript_weight = (1 + *subscript_size) * WITNESS_SCALE_FACTOR;
// The weight depends on whether the inner descriptor is satisfied using the witness stack.
if (IsSegwit()) return subscript_weight + *sat_size;
return subscript_weight + *sat_size * WITNESS_SCALE_FACTOR;
}
}
return {};
}
std::optional<int64_t> MaxSatisfactionElems() const override {
if (const auto sub_elems = m_subdescriptor_args[0]->MaxSatisfactionElems()) return 1 + *sub_elems;
return {};
}
std::unique_ptr<DescriptorImpl> Clone() const override
{
return std::make_unique<SHDescriptor>(m_subdescriptor_args.at(0)->Clone());
}
};
/** A parsed wsh(...) descriptor. */
class WSHDescriptor final : public DescriptorImpl
{
protected:
std::vector<CScript> MakeScripts(const std::vector<CPubKey>&, std::span<const CScript> scripts, FlatSigningProvider& out) const override
{
auto ret = Vector(GetScriptForDestination(WitnessV0ScriptHash(scripts[0])));
if (ret.size()) out.scripts.emplace(CScriptID(scripts[0]), scripts[0]);
return ret;
}
public:
WSHDescriptor(std::unique_ptr<DescriptorImpl> desc) : DescriptorImpl({}, std::move(desc), "wsh") {}
std::optional<OutputType> GetOutputType() const override { return OutputType::BECH32; }
bool IsSingleType() const final { return true; }
bool IsSingleKey() const final { return m_subdescriptor_args[0]->IsSingleKey(); }
std::optional<int64_t> ScriptSize() const override { return 1 + 1 + 32; }
std::optional<int64_t> MaxSatSize(bool use_max_sig) const override {
if (const auto sat_size = m_subdescriptor_args[0]->MaxSatSize(use_max_sig)) {
if (const auto subscript_size = m_subdescriptor_args[0]->ScriptSize()) {
return GetSizeOfCompactSize(*subscript_size) + *subscript_size + *sat_size;
}
}
return {};
}
std::optional<int64_t> MaxSatisfactionWeight(bool use_max_sig) const override {
return MaxSatSize(use_max_sig);
}
std::optional<int64_t> MaxSatisfactionElems() const override {
if (const auto sub_elems = m_subdescriptor_args[0]->MaxSatisfactionElems()) return 1 + *sub_elems;
return {};
}
std::unique_ptr<DescriptorImpl> Clone() const override
{
return std::make_unique<WSHDescriptor>(m_subdescriptor_args.at(0)->Clone());
}
};
/** A parsed tr(...) descriptor. */
class TRDescriptor final : public DescriptorImpl
{
std::vector<int> m_depths;
protected:
std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, std::span<const CScript> scripts, FlatSigningProvider& out) const override
{
TaprootBuilder builder;
assert(m_depths.size() == scripts.size());
for (size_t pos = 0; pos < m_depths.size(); ++pos) {
builder.Add(m_depths[pos], scripts[pos], TAPROOT_LEAF_TAPSCRIPT);
}
if (!builder.IsComplete()) return {};
assert(keys.size() == 1);
XOnlyPubKey xpk(keys[0]);
if (!xpk.IsFullyValid()) return {};
builder.Finalize(xpk);
WitnessV1Taproot output = builder.GetOutput();
out.tr_trees[output] = builder;
return Vector(GetScriptForDestination(output));
}
bool ToStringSubScriptHelper(const SigningProvider* arg, std::string& ret, const StringType type, const DescriptorCache* cache = nullptr) const override
{
if (m_depths.empty()) return true;
std::vector<bool> path;
for (size_t pos = 0; pos < m_depths.size(); ++pos) {
if (pos) ret += ',';
while ((int)path.size() <= m_depths[pos]) {
if (path.size()) ret += '{';
path.push_back(false);
}
std::string tmp;
if (!m_subdescriptor_args[pos]->ToStringHelper(arg, tmp, type, cache)) return false;
ret += tmp;
while (!path.empty() && path.back()) {
if (path.size() > 1) ret += '}';
path.pop_back();
}
if (!path.empty()) path.back() = true;
}
return true;
}
public:
TRDescriptor(std::unique_ptr<PubkeyProvider> internal_key, std::vector<std::unique_ptr<DescriptorImpl>> descs, std::vector<int> depths) :
DescriptorImpl(Vector(std::move(internal_key)), std::move(descs), "tr"), m_depths(std::move(depths))
{
assert(m_subdescriptor_args.size() == m_depths.size());
}
std::optional<OutputType> GetOutputType() const override { return OutputType::BECH32M; }
bool IsSingleType() const final { return true; }
bool IsSingleKey() const final { return false; }
std::optional<int64_t> ScriptSize() const override { return 1 + 1 + 32; }
std::optional<int64_t> MaxSatisfactionWeight(bool) const override {
// FIXME: We assume keypath spend, which can lead to very large underestimations.
return 1 + 65;
}
std::optional<int64_t> MaxSatisfactionElems() const override {
// FIXME: See above, we assume keypath spend.
return 1;
}
std::unique_ptr<DescriptorImpl> Clone() const override
{
std::vector<std::unique_ptr<DescriptorImpl>> subdescs;
subdescs.reserve(m_subdescriptor_args.size());
std::transform(m_subdescriptor_args.begin(), m_subdescriptor_args.end(), subdescs.begin(), [](const std::unique_ptr<DescriptorImpl>& d) { return d->Clone(); });
return std::make_unique<TRDescriptor>(m_pubkey_args.at(0)->Clone(), std::move(subdescs), m_depths);
}
};
/* We instantiate Miniscript here with a simple integer as key type.
* The value of these key integers are an index in the
* DescriptorImpl::m_pubkey_args vector.
*/
/**
* The context for converting a Miniscript descriptor into a Script.
*/
class ScriptMaker {
//! Keys contained in the Miniscript (the evaluation of DescriptorImpl::m_pubkey_args).
const std::vector<CPubKey>& m_keys;
//! The script context we're operating within (Tapscript or P2WSH).
const miniscript::MiniscriptContext m_script_ctx;
//! Get the ripemd160(sha256()) hash of this key.
//! Any key that is valid in a descriptor serializes as 32 bytes within a Tapscript context. So we
//! must not hash the sign-bit byte in this case.
uint160 GetHash160(uint32_t key) const {
if (miniscript::IsTapscript(m_script_ctx)) {
return Hash160(XOnlyPubKey{m_keys[key]});
}
return m_keys[key].GetID();
}
public:
ScriptMaker(const std::vector<CPubKey>& keys LIFETIMEBOUND, const miniscript::MiniscriptContext script_ctx) : m_keys(keys), m_script_ctx{script_ctx} {}
std::vector<unsigned char> ToPKBytes(uint32_t key) const {
// In Tapscript keys always serialize as x-only, whether an x-only key was used in the descriptor or not.
if (!miniscript::IsTapscript(m_script_ctx)) {
return {m_keys[key].begin(), m_keys[key].end()};
}
const XOnlyPubKey xonly_pubkey{m_keys[key]};
return {xonly_pubkey.begin(), xonly_pubkey.end()};
}
std::vector<unsigned char> ToPKHBytes(uint32_t key) const {
auto id = GetHash160(key);
return {id.begin(), id.end()};
}
};
/**
* The context for converting a Miniscript descriptor to its textual form.
*/
class StringMaker {
//! To convert private keys for private descriptors.
const SigningProvider* m_arg;
//! Keys contained in the Miniscript (a reference to DescriptorImpl::m_pubkey_args).
const std::vector<std::unique_ptr<PubkeyProvider>>& m_pubkeys;
//! Whether to serialize keys as private or public.
bool m_private;
public:
StringMaker(const SigningProvider* arg LIFETIMEBOUND, const std::vector<std::unique_ptr<PubkeyProvider>>& pubkeys LIFETIMEBOUND, bool priv)
: m_arg(arg), m_pubkeys(pubkeys), m_private(priv) {}
std::optional<std::string> ToString(uint32_t key) const
{
std::string ret;
if (m_private) {
if (!m_pubkeys[key]->ToPrivateString(*m_arg, ret)) return {};
} else {
ret = m_pubkeys[key]->ToString();
}
return ret;
}
};
class MiniscriptDescriptor final : public DescriptorImpl
{
private:
miniscript::NodeRef<uint32_t> m_node;
protected:
std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, std::span<const CScript> scripts,
FlatSigningProvider& provider) const override
{
const auto script_ctx{m_node->GetMsCtx()};
for (const auto& key : keys) {
if (miniscript::IsTapscript(script_ctx)) {
provider.pubkeys.emplace(Hash160(XOnlyPubKey{key}), key);
} else {
provider.pubkeys.emplace(key.GetID(), key);
}
}
return Vector(m_node->ToScript(ScriptMaker(keys, script_ctx)));
}
public:
MiniscriptDescriptor(std::vector<std::unique_ptr<PubkeyProvider>> providers, miniscript::NodeRef<uint32_t> node)
: DescriptorImpl(std::move(providers), "?"), m_node(std::move(node)) {}
bool ToStringHelper(const SigningProvider* arg, std::string& out, const StringType type,
const DescriptorCache* cache = nullptr) const override
{
if (const auto res = m_node->ToString(StringMaker(arg, m_pubkey_args, type == StringType::PRIVATE))) {
out = *res;
return true;
}
return false;
}
bool IsSolvable() const override { return true; }
bool IsSingleType() const final { return true; }
bool IsSingleKey() const final { return false; }
std::optional<int64_t> ScriptSize() const override { return m_node->ScriptSize(); }
std::optional<int64_t> MaxSatSize(bool) const override {
// For Miniscript we always assume high-R ECDSA signatures.
return m_node->GetWitnessSize();
}
std::optional<int64_t> MaxSatisfactionElems() const override {
return m_node->GetStackSize();
}
std::unique_ptr<DescriptorImpl> Clone() const override
{
std::vector<std::unique_ptr<PubkeyProvider>> providers;
providers.reserve(m_pubkey_args.size());
for (const auto& arg : m_pubkey_args) {
providers.push_back(arg->Clone());
}
return std::make_unique<MiniscriptDescriptor>(std::move(providers), m_node->Clone());
}
};
/** A parsed rawtr(...) descriptor. */
class RawTRDescriptor final : public DescriptorImpl
{
protected:
std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, std::span<const CScript> scripts, FlatSigningProvider& out) const override
{
assert(keys.size() == 1);
XOnlyPubKey xpk(keys[0]);
if (!xpk.IsFullyValid()) return {};
WitnessV1Taproot output{xpk};
return Vector(GetScriptForDestination(output));
}
public:
RawTRDescriptor(std::unique_ptr<PubkeyProvider> output_key) : DescriptorImpl(Vector(std::move(output_key)), "rawtr") {}
std::optional<OutputType> GetOutputType() const override { return OutputType::BECH32M; }
bool IsSingleType() const final { return true; }
bool IsSingleKey() const final { return false; }
std::optional<int64_t> ScriptSize() const override { return 1 + 1 + 32; }
std::optional<int64_t> MaxSatisfactionWeight(bool) const override {
// We can't know whether there is a script path, so assume key path spend.
return 1 + 65;
}
std::optional<int64_t> MaxSatisfactionElems() const override {
// See above, we assume keypath spend.
return 1;
}
std::unique_ptr<DescriptorImpl> Clone() const override
{
return std::make_unique<RawTRDescriptor>(m_pubkey_args.at(0)->Clone());
}
};
////////////////////////////////////////////////////////////////////////////
// Parser //
////////////////////////////////////////////////////////////////////////////
enum class ParseScriptContext {
TOP, //!< Top-level context (script goes directly in scriptPubKey)
P2SH, //!< Inside sh() (script becomes P2SH redeemScript)
P2WPKH, //!< Inside wpkh() (no script, pubkey only)
P2WSH, //!< Inside wsh() (script becomes v0 witness script)
P2TR, //!< Inside tr() (either internal key, or BIP342 script leaf)
};
std::optional<uint32_t> ParseKeyPathNum(std::span<const char> elem, bool& apostrophe, std::string& error)
{
bool hardened = false;
if (elem.size() > 0) {
const char last = elem[elem.size() - 1];
if (last == '\'' || last == 'h') {
elem = elem.first(elem.size() - 1);
hardened = true;
apostrophe = last == '\'';
}
}
const auto p{ToIntegral<uint32_t>(std::string_view{elem.begin(), elem.end()})};
if (!p) {
error = strprintf("Key path value '%s' is not a valid uint32", std::string_view{elem.begin(), elem.end()});
return std::nullopt;
} else if (*p > 0x7FFFFFFFUL) {
error = strprintf("Key path value %u is out of range", *p);
return std::nullopt;
}
return std::make_optional<uint32_t>(*p | (((uint32_t)hardened) << 31));
}
/**
* Parse a key path, being passed a split list of elements (the first element is ignored because it is always the key).
*
* @param[in] split BIP32 path string, using either ' or h for hardened derivation
* @param[out] out Vector of parsed key paths
* @param[out] apostrophe only updated if hardened derivation is found
* @param[out] error parsing error message
* @param[in] allow_multipath Allows the parsed path to use the multipath specifier
* @returns false if parsing failed
**/
[[nodiscard]] bool ParseKeyPath(const std::vector<std::span<const char>>& split, std::vector<KeyPath>& out, bool& apostrophe, std::string& error, bool allow_multipath)
{
KeyPath path;
struct MultipathSubstitutes {
size_t placeholder_index;
std::vector<uint32_t> values;
};
std::optional<MultipathSubstitutes> substitutes;
for (size_t i = 1; i < split.size(); ++i) {
const std::span<const char>& elem = split[i];
// Check if element contains multipath specifier
if (!elem.empty() && elem.front() == '<' && elem.back() == '>') {
if (!allow_multipath) {
error = strprintf("Key path value '%s' specifies multipath in a section where multipath is not allowed", std::string(elem.begin(), elem.end()));
return false;
}
if (substitutes) {
error = "Multiple multipath key path specifiers found";
return false;
}
// Parse each possible value
std::vector<std::span<const char>> nums = Split(std::span(elem.begin()+1, elem.end()-1), ";");
if (nums.size() < 2) {
error = "Multipath key path specifiers must have at least two items";
return false;
}
substitutes.emplace();
std::unordered_set<uint32_t> seen_substitutes;
for (const auto& num : nums) {
const auto& op_num = ParseKeyPathNum(num, apostrophe, error);
if (!op_num) return false;
auto [_, inserted] = seen_substitutes.insert(*op_num);
if (!inserted) {
error = strprintf("Duplicated key path value %u in multipath specifier", *op_num);
return false;
}
substitutes->values.emplace_back(*op_num);
}
path.emplace_back(); // Placeholder for multipath segment
substitutes->placeholder_index = path.size() - 1;
} else {
const auto& op_num = ParseKeyPathNum(elem, apostrophe, error);
if (!op_num) return false;
path.emplace_back(*op_num);
}
}
if (!substitutes) {
out.emplace_back(std::move(path));
} else {
// Replace the multipath placeholder with each value while generating paths
for (uint32_t substitute : substitutes->values) {
KeyPath branch_path = path;
branch_path[substitutes->placeholder_index] = substitute;
out.emplace_back(std::move(branch_path));
}
}
return true;
}
/** Parse a public key that excludes origin information. */
std::vector<std::unique_ptr<PubkeyProvider>> ParsePubkeyInner(uint32_t key_exp_index, const std::span<const char>& sp, ParseScriptContext ctx, FlatSigningProvider& out, bool& apostrophe, std::string& error)
{
std::vector<std::unique_ptr<PubkeyProvider>> ret;
bool permit_uncompressed = ctx == ParseScriptContext::TOP || ctx == ParseScriptContext::P2SH;
auto split = Split(sp, '/');
std::string str(split[0].begin(), split[0].end());
if (str.size() == 0) {
error = "No key provided";
return {};
}
if (IsSpace(str.front()) || IsSpace(str.back())) {
error = strprintf("Key '%s' is invalid due to whitespace", str);
return {};
}
if (split.size() == 1) {
if (IsHex(str)) {
std::vector<unsigned char> data = ParseHex(str);
CPubKey pubkey(data);
if (pubkey.IsValid() && !pubkey.IsValidNonHybrid()) {
error = "Hybrid public keys are not allowed";
return {};
}
if (pubkey.IsFullyValid()) {
if (permit_uncompressed || pubkey.IsCompressed()) {
ret.emplace_back(std::make_unique<ConstPubkeyProvider>(key_exp_index, pubkey, false));
return ret;
} else {
error = "Uncompressed keys are not allowed";
return {};
}
} else if (data.size() == 32 && ctx == ParseScriptContext::P2TR) {
unsigned char fullkey[33] = {0x02};
std::copy(data.begin(), data.end(), fullkey + 1);
pubkey.Set(std::begin(fullkey), std::end(fullkey));
if (pubkey.IsFullyValid()) {
ret.emplace_back(std::make_unique<ConstPubkeyProvider>(key_exp_index, pubkey, true));
return ret;
}
}
error = strprintf("Pubkey '%s' is invalid", str);
return {};
}
CKey key = DecodeSecret(str);
if (key.IsValid()) {
if (permit_uncompressed || key.IsCompressed()) {
CPubKey pubkey = key.GetPubKey();
out.keys.emplace(pubkey.GetID(), key);
ret.emplace_back(std::make_unique<ConstPubkeyProvider>(key_exp_index, pubkey, ctx == ParseScriptContext::P2TR));
return ret;
} else {
error = "Uncompressed keys are not allowed";
return {};
}
}
}
CExtKey extkey = DecodeExtKey(str);
CExtPubKey extpubkey = DecodeExtPubKey(str);
if (!extkey.key.IsValid() && !extpubkey.pubkey.IsValid()) {
error = strprintf("key '%s' is not valid", str);
return {};
}
std::vector<KeyPath> paths;
DeriveType type = DeriveType::NO;
if (std::ranges::equal(split.back(), std::span{"*"}.first(1))) {
split.pop_back();
type = DeriveType::UNHARDENED;
} else if (std::ranges::equal(split.back(), std::span{"*'"}.first(2)) || std::ranges::equal(split.back(), std::span{"*h"}.first(2))) {
apostrophe = std::ranges::equal(split.back(), std::span{"*'"}.first(2));
split.pop_back();
type = DeriveType::HARDENED;
}
if (!ParseKeyPath(split, paths, apostrophe, error, /*allow_multipath=*/true)) return {};
if (extkey.key.IsValid()) {
extpubkey = extkey.Neuter();
out.keys.emplace(extpubkey.pubkey.GetID(), extkey.key);
}
for (auto& path : paths) {
ret.emplace_back(std::make_unique<BIP32PubkeyProvider>(key_exp_index, extpubkey, std::move(path), type, apostrophe));
}
return ret;
}
/** Parse a public key including origin information (if enabled). */
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;
auto origin_split = Split(sp, ']');
if (origin_split.size() > 2) {
error = "Multiple ']' characters found for a single pubkey";
return {};
}
// This is set if either the origin or path suffix contains a hardened derivation.
bool apostrophe = false;
if (origin_split.size() == 1) {
return ParsePubkeyInner(key_exp_index, origin_split[0], ctx, out, apostrophe, error);
}
if (origin_split[0].empty() || origin_split[0][0] != '[') {
error = strprintf("Key origin start '[ character expected but not found, got '%c' instead",
origin_split[0].empty() ? /** empty, implies split char */ ']' : origin_split[0][0]);
return {};
}
auto slash_split = Split(origin_split[0].subspan(1), '/');
if (slash_split[0].size() != 8) {
error = strprintf("Fingerprint is not 4 bytes (%u characters instead of 8 characters)", slash_split[0].size());
return {};
}
std::string fpr_hex = std::string(slash_split[0].begin(), slash_split[0].end());
if (!IsHex(fpr_hex)) {
error = strprintf("Fingerprint '%s' is not hex", fpr_hex);
return {};
}
auto fpr_bytes = ParseHex(fpr_hex);
KeyOriginInfo info;
static_assert(sizeof(info.fingerprint) == 4, "Fingerprint must be 4 bytes");
assert(fpr_bytes.size() == 4);
std::copy(fpr_bytes.begin(), fpr_bytes.end(), info.fingerprint);
std::vector<KeyPath> path;
if (!ParseKeyPath(slash_split, path, apostrophe, error, /*allow_multipath=*/false)) return {};
info.path = path.at(0);
auto providers = ParsePubkeyInner(key_exp_index, origin_split[1], ctx, out, apostrophe, error);
if (providers.empty()) return {};
ret.reserve(providers.size());
for (auto& prov : providers) {
ret.emplace_back(std::make_unique<OriginPubkeyProvider>(key_exp_index, info, std::move(prov), apostrophe));
}
return ret;
}
std::unique_ptr<PubkeyProvider> InferPubkey(const CPubKey& pubkey, ParseScriptContext ctx, const SigningProvider& provider)
{
// Key cannot be hybrid
if (!pubkey.IsValidNonHybrid()) {
return nullptr;
}
// Uncompressed is only allowed in TOP and P2SH contexts
if (ctx != ParseScriptContext::TOP && ctx != ParseScriptContext::P2SH && !pubkey.IsCompressed()) {
return nullptr;
}
std::unique_ptr<PubkeyProvider> key_provider = std::make_unique<ConstPubkeyProvider>(0, pubkey, false);
KeyOriginInfo info;
if (provider.GetKeyOrigin(pubkey.GetID(), info)) {
return std::make_unique<OriginPubkeyProvider>(0, std::move(info), std::move(key_provider), /*apostrophe=*/false);
}
return key_provider;
}
std::unique_ptr<PubkeyProvider> InferXOnlyPubkey(const XOnlyPubKey& xkey, ParseScriptContext ctx, const SigningProvider& provider)
{
CPubKey pubkey{xkey.GetEvenCorrespondingCPubKey()};
std::unique_ptr<PubkeyProvider> key_provider = std::make_unique<ConstPubkeyProvider>(0, pubkey, true);
KeyOriginInfo info;
if (provider.GetKeyOriginByXOnly(xkey, info)) {
return std::make_unique<OriginPubkeyProvider>(0, std::move(info), std::move(key_provider), /*apostrophe=*/false);
}
return key_provider;
}
/**
* The context for parsing a Miniscript descriptor (either from Script or from its textual representation).
*/
struct KeyParser {
//! The Key type is an index in DescriptorImpl::m_pubkey_args
using Key = uint32_t;
//! Must not be nullptr if parsing from string.
FlatSigningProvider* m_out;
//! Must not be nullptr if parsing from Script.
const SigningProvider* m_in;
//! List of multipath expanded keys contained in the Miniscript.
mutable std::vector<std::vector<std::unique_ptr<PubkeyProvider>>> m_keys;
//! Used to detect key parsing errors within a Miniscript.
mutable std::string m_key_parsing_error;
//! The script context we're operating within (Tapscript or P2WSH).
const miniscript::MiniscriptContext m_script_ctx;
//! The number of keys that were parsed before starting to parse this Miniscript descriptor.
uint32_t m_offset;
KeyParser(FlatSigningProvider* out LIFETIMEBOUND, const SigningProvider* in LIFETIMEBOUND,
miniscript::MiniscriptContext ctx, uint32_t offset = 0)
: m_out(out), m_in(in), m_script_ctx(ctx), m_offset(offset) {}
bool KeyCompare(const Key& a, const Key& b) const {
return *m_keys.at(a).at(0) < *m_keys.at(b).at(0);
}
ParseScriptContext ParseContext() const {
switch (m_script_ctx) {
case miniscript::MiniscriptContext::P2WSH: return ParseScriptContext::P2WSH;
case miniscript::MiniscriptContext::TAPSCRIPT: return ParseScriptContext::P2TR;
}
assert(false);
}
template<typename I> std::optional<Key> FromString(I begin, I end) const
{
assert(m_out);
Key key = m_keys.size();
auto pk = ParsePubkey(m_offset + key, {&*begin, &*end}, ParseContext(), *m_out, m_key_parsing_error);
if (pk.empty()) return {};
m_keys.emplace_back(std::move(pk));
return key;
}
std::optional<std::string> ToString(const Key& key) const
{
return m_keys.at(key).at(0)->ToString();
}
template<typename I> std::optional<Key> FromPKBytes(I begin, I end) const
{
assert(m_in);
Key key = m_keys.size();
if (miniscript::IsTapscript(m_script_ctx) && end - begin == 32) {
XOnlyPubKey pubkey;
std::copy(begin, end, pubkey.begin());
if (auto pubkey_provider = InferXOnlyPubkey(pubkey, ParseContext(), *m_in)) {
m_keys.emplace_back();
m_keys.back().push_back(std::move(pubkey_provider));
return key;
}
} else if (!miniscript::IsTapscript(m_script_ctx)) {
CPubKey pubkey(begin, end);
if (auto pubkey_provider = InferPubkey(pubkey, ParseContext(), *m_in)) {
m_keys.emplace_back();
m_keys.back().push_back(std::move(pubkey_provider));
return key;
}
}
return {};
}
template<typename I> std::optional<Key> FromPKHBytes(I begin, I end) const
{
assert(end - begin == 20);
assert(m_in);
uint160 hash;
std::copy(begin, end, hash.begin());
CKeyID keyid(hash);
CPubKey pubkey;
if (m_in->GetPubKey(keyid, pubkey)) {
if (auto pubkey_provider = InferPubkey(pubkey, ParseContext(), *m_in)) {
Key key = m_keys.size();
m_keys.emplace_back();
m_keys.back().push_back(std::move(pubkey_provider));
return key;
}
}
return {};
}
miniscript::MiniscriptContext MsContext() const {
return m_script_ctx;
}
};
/** Parse a script in a particular context. */
// NOLINTNEXTLINE(misc-no-recursion)
std::vector<std::unique_ptr<DescriptorImpl>> ParseScript(uint32_t& key_exp_index, std::span<const char>& sp, ParseScriptContext ctx, FlatSigningProvider& out, std::string& error)
{
using namespace script;
Assume(ctx == ParseScriptContext::TOP || ctx == ParseScriptContext::P2SH || ctx == ParseScriptContext::P2WSH || ctx == ParseScriptContext::P2TR);
std::vector<std::unique_ptr<DescriptorImpl>> ret;
auto expr = Expr(sp);
if (Func("pk", expr)) {
auto pubkeys = ParsePubkey(key_exp_index, expr, ctx, out, error);
if (pubkeys.empty()) {
error = strprintf("pk(): %s", error);
return {};
}
++key_exp_index;
for (auto& pubkey : pubkeys) {
ret.emplace_back(std::make_unique<PKDescriptor>(std::move(pubkey), ctx == ParseScriptContext::P2TR));
}
return ret;
}
if ((ctx == ParseScriptContext::TOP || ctx == ParseScriptContext::P2SH || ctx == ParseScriptContext::P2WSH) && Func("pkh", expr)) {
auto pubkeys = ParsePubkey(key_exp_index, expr, ctx, out, error);
if (pubkeys.empty()) {
error = strprintf("pkh(): %s", error);
return {};
}
++key_exp_index;
for (auto& pubkey : pubkeys) {
ret.emplace_back(std::make_unique<PKHDescriptor>(std::move(pubkey)));
}
return ret;
}
if (ctx == ParseScriptContext::TOP && Func("combo", expr)) {
auto pubkeys = ParsePubkey(key_exp_index, expr, ctx, out, error);
if (pubkeys.empty()) {
error = strprintf("combo(): %s", error);
return {};
}
++key_exp_index;
for (auto& pubkey : pubkeys) {
ret.emplace_back(std::make_unique<ComboDescriptor>(std::move(pubkey)));
}
return ret;
} else if (Func("combo", expr)) {
error = "Can only have combo() at top level";
return {};
}
const bool multi = Func("multi", expr);
const bool sortedmulti = !multi && Func("sortedmulti", expr);
const bool multi_a = !(multi || sortedmulti) && Func("multi_a", expr);
const bool sortedmulti_a = !(multi || sortedmulti || multi_a) && Func("sortedmulti_a", expr);
if (((ctx == ParseScriptContext::TOP || ctx == ParseScriptContext::P2SH || ctx == ParseScriptContext::P2WSH) && (multi || sortedmulti)) ||
(ctx == ParseScriptContext::P2TR && (multi_a || sortedmulti_a))) {
auto threshold = Expr(expr);
uint32_t thres;
std::vector<std::vector<std::unique_ptr<PubkeyProvider>>> providers; // List of multipath expanded pubkeys
if (const auto maybe_thres{ToIntegral<uint32_t>(std::string_view{threshold.begin(), threshold.end()})}) {
thres = *maybe_thres;
} else {
error = strprintf("Multi threshold '%s' is not valid", std::string(threshold.begin(), threshold.end()));
return {};
}
size_t script_size = 0;
size_t max_providers_len = 0;
while (expr.size()) {
if (!Const(",", expr)) {
error = strprintf("Multi: expected ',', got '%c'", expr[0]);
return {};
}
auto arg = Expr(expr);
auto pks = ParsePubkey(key_exp_index, arg, ctx, out, error);
if (pks.empty()) {
error = strprintf("Multi: %s", error);
return {};
}
script_size += pks.at(0)->GetSize() + 1;
max_providers_len = std::max(max_providers_len, pks.size());
providers.emplace_back(std::move(pks));
key_exp_index++;
}
if ((multi || sortedmulti) && (providers.empty() || providers.size() > MAX_PUBKEYS_PER_MULTISIG)) {
error = strprintf("Cannot have %u keys in multisig; must have between 1 and %d keys, inclusive", providers.size(), MAX_PUBKEYS_PER_MULTISIG);
return {};
} else if ((multi_a || sortedmulti_a) && (providers.empty() || providers.size() > MAX_PUBKEYS_PER_MULTI_A)) {
error = strprintf("Cannot have %u keys in multi_a; must have between 1 and %d keys, inclusive", providers.size(), MAX_PUBKEYS_PER_MULTI_A);
return {};
} else if (thres < 1) {
error = strprintf("Multisig threshold cannot be %d, must be at least 1", thres);
return {};
} else if (thres > providers.size()) {
error = strprintf("Multisig threshold cannot be larger than the number of keys; threshold is %d but only %u keys specified", thres, providers.size());
return {};
}
if (ctx == ParseScriptContext::TOP) {
if (providers.size() > 3) {
error = strprintf("Cannot have %u pubkeys in bare multisig; only at most 3 pubkeys", providers.size());
return {};
}
}
if (ctx == ParseScriptContext::P2SH) {
// This limits the maximum number of compressed pubkeys to 15.
if (script_size + 3 > MAX_SCRIPT_ELEMENT_SIZE) {
error = strprintf("P2SH script is too large, %d bytes is larger than %d bytes", script_size + 3, MAX_SCRIPT_ELEMENT_SIZE);
return {};
}
}
// Make sure all vecs are of the same length, or exactly length 1
// For length 1 vectors, clone key providers until vector is the same length
for (auto& vec : providers) {
if (vec.size() == 1) {
for (size_t i = 1; i < max_providers_len; ++i) {
vec.emplace_back(vec.at(0)->Clone());
}
} else if (vec.size() != max_providers_len) {
error = strprintf("multi(): Multipath derivation paths have mismatched lengths");
return {};
}
}
// Build the final descriptors vector
for (size_t i = 0; i < max_providers_len; ++i) {
// Build final pubkeys vectors by retrieving the i'th subscript for each vector in subscripts
std::vector<std::unique_ptr<PubkeyProvider>> pubs;
pubs.reserve(providers.size());
for (auto& pub : providers) {
pubs.emplace_back(std::move(pub.at(i)));
}
if (multi || sortedmulti) {
ret.emplace_back(std::make_unique<MultisigDescriptor>(thres, std::move(pubs), sortedmulti));
} else {
ret.emplace_back(std::make_unique<MultiADescriptor>(thres, std::move(pubs), sortedmulti_a));
}
}
return ret;
} else if (multi || sortedmulti) {
error = "Can only have multi/sortedmulti at top level, in sh(), or in wsh()";
return {};
} else if (multi_a || sortedmulti_a) {
error = "Can only have multi_a/sortedmulti_a inside tr()";
return {};
}
if ((ctx == ParseScriptContext::TOP || ctx == ParseScriptContext::P2SH) && Func("wpkh", expr)) {
auto pubkeys = ParsePubkey(key_exp_index, expr, ParseScriptContext::P2WPKH, out, error);
if (pubkeys.empty()) {
error = strprintf("wpkh(): %s", error);
return {};
}
key_exp_index++;
for (auto& pubkey : pubkeys) {
ret.emplace_back(std::make_unique<WPKHDescriptor>(std::move(pubkey)));
}
return ret;
} else if (Func("wpkh", expr)) {
error = "Can only have wpkh() at top level or inside sh()";
return {};
}
if (ctx == ParseScriptContext::TOP && Func("sh", expr)) {
auto descs = ParseScript(key_exp_index, expr, ParseScriptContext::P2SH, out, error);
if (descs.empty() || expr.size()) return {};
std::vector<std::unique_ptr<DescriptorImpl>> ret;
ret.reserve(descs.size());
for (auto& desc : descs) {
ret.push_back(std::make_unique<SHDescriptor>(std::move(desc)));
}
return ret;
} else if (Func("sh", expr)) {
error = "Can only have sh() at top level";
return {};
}
if ((ctx == ParseScriptContext::TOP || ctx == ParseScriptContext::P2SH) && Func("wsh", expr)) {
auto descs = ParseScript(key_exp_index, expr, ParseScriptContext::P2WSH, out, error);
if (descs.empty() || expr.size()) return {};
for (auto& desc : descs) {
ret.emplace_back(std::make_unique<WSHDescriptor>(std::move(desc)));
}
return ret;
} else if (Func("wsh", expr)) {
error = "Can only have wsh() at top level or inside sh()";
return {};
}
if (ctx == ParseScriptContext::TOP && Func("addr", expr)) {
CTxDestination dest = DecodeDestination(std::string(expr.begin(), expr.end()));
if (!IsValidDestination(dest)) {
error = "Address is not valid";
return {};
}
ret.emplace_back(std::make_unique<AddressDescriptor>(std::move(dest)));
return ret;
} else if (Func("addr", expr)) {
error = "Can only have addr() at top level";
return {};
}
if (ctx == ParseScriptContext::TOP && Func("tr", expr)) {
auto arg = Expr(expr);
auto internal_keys = ParsePubkey(key_exp_index, arg, ParseScriptContext::P2TR, out, error);
if (internal_keys.empty()) {
error = strprintf("tr(): %s", error);
return {};
}
size_t max_providers_len = internal_keys.size();
++key_exp_index;
std::vector<std::vector<std::unique_ptr<DescriptorImpl>>> subscripts; //!< list of multipath expanded script subexpressions
std::vector<int> depths; //!< depth in the tree of each subexpression (same length subscripts)
if (expr.size()) {
if (!Const(",", expr)) {
error = strprintf("tr: expected ',', got '%c'", expr[0]);
return {};
}
/** The path from the top of the tree to what we're currently processing.
* branches[i] == false: left branch in the i'th step from the top; true: right branch.
*/
std::vector<bool> branches;
// Loop over all provided scripts. In every iteration exactly one script will be processed.
// Use a do-loop because inside this if-branch we expect at least one script.
do {
// First process all open braces.
while (Const("{", expr)) {
branches.push_back(false); // new left branch
if (branches.size() > TAPROOT_CONTROL_MAX_NODE_COUNT) {
error = strprintf("tr() supports at most %i nesting levels", TAPROOT_CONTROL_MAX_NODE_COUNT);
return {};
}
}
// Process the actual script expression.
auto sarg = Expr(expr);
subscripts.emplace_back(ParseScript(key_exp_index, sarg, ParseScriptContext::P2TR, out, error));
if (subscripts.back().empty()) return {};
max_providers_len = std::max(max_providers_len, subscripts.back().size());
depths.push_back(branches.size());
// Process closing braces; one is expected for every right branch we were in.
while (branches.size() && branches.back()) {
if (!Const("}", expr)) {
error = strprintf("tr(): expected '}' after script expression");
return {};
}
branches.pop_back(); // move up one level after encountering '}'
}
// If after that, we're at the end of a left branch, expect a comma.
if (branches.size() && !branches.back()) {
if (!Const(",", expr)) {
error = strprintf("tr(): expected ',' after script expression");
return {};
}
branches.back() = true; // And now we're in a right branch.
}
} while (branches.size());
// After we've explored a whole tree, we must be at the end of the expression.
if (expr.size()) {
error = strprintf("tr(): expected ')' after script expression");
return {};
}
}
assert(TaprootBuilder::ValidDepths(depths));
// Make sure all vecs are of the same length, or exactly length 1
// For length 1 vectors, clone subdescs until vector is the same length
for (auto& vec : subscripts) {
if (vec.size() == 1) {
for (size_t i = 1; i < max_providers_len; ++i) {
vec.emplace_back(vec.at(0)->Clone());
}
} else if (vec.size() != max_providers_len) {
error = strprintf("tr(): Multipath subscripts have mismatched lengths");
return {};
}
}
if (internal_keys.size() > 1 && internal_keys.size() != max_providers_len) {
error = strprintf("tr(): Multipath internal key mismatches multipath subscripts lengths");
return {};
}
while (internal_keys.size() < max_providers_len) {
internal_keys.emplace_back(internal_keys.at(0)->Clone());
}
// Build the final descriptors vector
for (size_t i = 0; i < max_providers_len; ++i) {
// Build final subscripts vectors by retrieving the i'th subscript for each vector in subscripts
std::vector<std::unique_ptr<DescriptorImpl>> this_subs;
this_subs.reserve(subscripts.size());
for (auto& subs : subscripts) {
this_subs.emplace_back(std::move(subs.at(i)));
}
ret.emplace_back(std::make_unique<TRDescriptor>(std::move(internal_keys.at(i)), std::move(this_subs), depths));
}
return ret;
} else if (Func("tr", expr)) {
error = "Can only have tr at top level";
return {};
}
if (ctx == ParseScriptContext::TOP && Func("rawtr", expr)) {
auto arg = Expr(expr);
if (expr.size()) {
error = strprintf("rawtr(): only one key expected.");
return {};
}
auto output_keys = ParsePubkey(key_exp_index, arg, ParseScriptContext::P2TR, out, error);
if (output_keys.empty()) {
error = strprintf("rawtr(): %s", error);
return {};
}
++key_exp_index;
for (auto& pubkey : output_keys) {
ret.emplace_back(std::make_unique<RawTRDescriptor>(std::move(pubkey)));
}
return ret;
} else if (Func("rawtr", expr)) {
error = "Can only have rawtr at top level";
return {};
}
if (ctx == ParseScriptContext::TOP && Func("raw", expr)) {
std::string str(expr.begin(), expr.end());
if (!IsHex(str)) {
error = "Raw script is not hex";
return {};
}
auto bytes = ParseHex(str);
ret.emplace_back(std::make_unique<RawDescriptor>(CScript(bytes.begin(), bytes.end())));
return ret;
} else if (Func("raw", expr)) {
error = "Can only have raw() at top level";
return {};
}
// Process miniscript expressions.
{
const auto script_ctx{ctx == ParseScriptContext::P2WSH ? miniscript::MiniscriptContext::P2WSH : miniscript::MiniscriptContext::TAPSCRIPT};
KeyParser parser(/*out = */&out, /* in = */nullptr, /* ctx = */script_ctx, key_exp_index);
auto node = miniscript::FromString(std::string(expr.begin(), expr.end()), parser);
if (parser.m_key_parsing_error != "") {
error = std::move(parser.m_key_parsing_error);
return {};
}
if (node) {
if (ctx != ParseScriptContext::P2WSH && ctx != ParseScriptContext::P2TR) {
error = "Miniscript expressions can only be used in wsh or tr.";
return {};
}
if (!node->IsSane() || node->IsNotSatisfiable()) {
// Try to find the first insane sub for better error reporting.
auto insane_node = node.get();
if (const auto sub = node->FindInsaneSub()) insane_node = sub;
if (const auto str = insane_node->ToString(parser)) error = *str;
if (!insane_node->IsValid()) {
error += " is invalid";
} else if (!node->IsSane()) {
error += " is not sane";
if (!insane_node->IsNonMalleable()) {
error += ": malleable witnesses exist";
} else if (insane_node == node.get() && !insane_node->NeedsSignature()) {
error += ": witnesses without signature exist";
} else if (!insane_node->CheckTimeLocksMix()) {
error += ": contains mixes of timelocks expressed in blocks and seconds";
} else if (!insane_node->CheckDuplicateKey()) {
error += ": contains duplicate public keys";
} else if (!insane_node->ValidSatisfactions()) {
error += ": needs witnesses that may exceed resource limits";
}
} else {
error += " is not satisfiable";
}
return {};
}
// A signature check is required for a miniscript to be sane. Therefore no sane miniscript
// may have an empty list of public keys.
CHECK_NONFATAL(!parser.m_keys.empty());
key_exp_index += parser.m_keys.size();
// Make sure all vecs are of the same length, or exactly length 1
// For length 1 vectors, clone subdescs until vector is the same length
size_t num_multipath = std::max_element(parser.m_keys.begin(), parser.m_keys.end(),
[](const std::vector<std::unique_ptr<PubkeyProvider>>& a, const std::vector<std::unique_ptr<PubkeyProvider>>& b) {
return a.size() < b.size();
})->size();
for (auto& vec : parser.m_keys) {
if (vec.size() == 1) {
for (size_t i = 1; i < num_multipath; ++i) {
vec.emplace_back(vec.at(0)->Clone());
}
} else if (vec.size() != num_multipath) {
error = strprintf("Miniscript: Multipath derivation paths have mismatched lengths");
return {};
}
}
// Build the final descriptors vector
for (size_t i = 0; i < num_multipath; ++i) {
// Build final pubkeys vectors by retrieving the i'th subscript for each vector in subscripts
std::vector<std::unique_ptr<PubkeyProvider>> pubs;
pubs.reserve(parser.m_keys.size());
for (auto& pub : parser.m_keys) {
pubs.emplace_back(std::move(pub.at(i)));
}
ret.emplace_back(std::make_unique<MiniscriptDescriptor>(std::move(pubs), node->Clone()));
}
return ret;
}
}
if (ctx == ParseScriptContext::P2SH) {
error = "A function is needed within P2SH";
return {};
} else if (ctx == ParseScriptContext::P2WSH) {
error = "A function is needed within P2WSH";
return {};
}
error = strprintf("'%s' is not a valid descriptor function", std::string(expr.begin(), expr.end()));
return {};
}
std::unique_ptr<DescriptorImpl> InferMultiA(const CScript& script, ParseScriptContext ctx, const SigningProvider& provider)
{
auto match = MatchMultiA(script);
if (!match) return {};
std::vector<std::unique_ptr<PubkeyProvider>> keys;
keys.reserve(match->second.size());
for (const auto keyspan : match->second) {
if (keyspan.size() != 32) return {};
auto key = InferXOnlyPubkey(XOnlyPubKey{keyspan}, ctx, provider);
if (!key) return {};
keys.push_back(std::move(key));
}
return std::make_unique<MultiADescriptor>(match->first, std::move(keys));
}
// NOLINTNEXTLINE(misc-no-recursion)
std::unique_ptr<DescriptorImpl> InferScript(const CScript& script, ParseScriptContext ctx, const SigningProvider& provider)
{
if (ctx == ParseScriptContext::P2TR && script.size() == 34 && script[0] == 32 && script[33] == OP_CHECKSIG) {
XOnlyPubKey key{std::span{script}.subspan(1, 32)};
return std::make_unique<PKDescriptor>(InferXOnlyPubkey(key, ctx, provider), true);
}
if (ctx == ParseScriptContext::P2TR) {
auto ret = InferMultiA(script, ctx, provider);
if (ret) return ret;
}
std::vector<std::vector<unsigned char>> data;
TxoutType txntype = Solver(script, data);
if (txntype == TxoutType::PUBKEY && (ctx == ParseScriptContext::TOP || ctx == ParseScriptContext::P2SH || ctx == ParseScriptContext::P2WSH)) {
CPubKey pubkey(data[0]);
if (auto pubkey_provider = InferPubkey(pubkey, ctx, provider)) {
return std::make_unique<PKDescriptor>(std::move(pubkey_provider));
}
}
if (txntype == TxoutType::PUBKEYHASH && (ctx == ParseScriptContext::TOP || ctx == ParseScriptContext::P2SH || ctx == ParseScriptContext::P2WSH)) {
uint160 hash(data[0]);
CKeyID keyid(hash);
CPubKey pubkey;
if (provider.GetPubKey(keyid, pubkey)) {
if (auto pubkey_provider = InferPubkey(pubkey, ctx, provider)) {
return std::make_unique<PKHDescriptor>(std::move(pubkey_provider));
}
}
}
if (txntype == TxoutType::WITNESS_V0_KEYHASH && (ctx == ParseScriptContext::TOP || ctx == ParseScriptContext::P2SH)) {
uint160 hash(data[0]);
CKeyID keyid(hash);
CPubKey pubkey;
if (provider.GetPubKey(keyid, pubkey)) {
if (auto pubkey_provider = InferPubkey(pubkey, ParseScriptContext::P2WPKH, provider)) {
return std::make_unique<WPKHDescriptor>(std::move(pubkey_provider));
}
}
}
if (txntype == TxoutType::MULTISIG && (ctx == ParseScriptContext::TOP || ctx == ParseScriptContext::P2SH || ctx == ParseScriptContext::P2WSH)) {
bool ok = true;
std::vector<std::unique_ptr<PubkeyProvider>> providers;
for (size_t i = 1; i + 1 < data.size(); ++i) {
CPubKey pubkey(data[i]);
if (auto pubkey_provider = InferPubkey(pubkey, ctx, provider)) {
providers.push_back(std::move(pubkey_provider));
} else {
ok = false;
break;
}
}
if (ok) return std::make_unique<MultisigDescriptor>((int)data[0][0], std::move(providers));
}
if (txntype == TxoutType::SCRIPTHASH && ctx == ParseScriptContext::TOP) {
uint160 hash(data[0]);
CScriptID scriptid(hash);
CScript subscript;
if (provider.GetCScript(scriptid, subscript)) {
auto sub = InferScript(subscript, ParseScriptContext::P2SH, provider);
if (sub) return std::make_unique<SHDescriptor>(std::move(sub));
}
}
if (txntype == TxoutType::WITNESS_V0_SCRIPTHASH && (ctx == ParseScriptContext::TOP || ctx == ParseScriptContext::P2SH)) {
CScriptID scriptid{RIPEMD160(data[0])};
CScript subscript;
if (provider.GetCScript(scriptid, subscript)) {
auto sub = InferScript(subscript, ParseScriptContext::P2WSH, provider);
if (sub) return std::make_unique<WSHDescriptor>(std::move(sub));
}
}
if (txntype == TxoutType::WITNESS_V1_TAPROOT && ctx == ParseScriptContext::TOP) {
// Extract x-only pubkey from output.
XOnlyPubKey pubkey;
std::copy(data[0].begin(), data[0].end(), pubkey.begin());
// Request spending data.
TaprootSpendData tap;
if (provider.GetTaprootSpendData(pubkey, tap)) {
// If found, convert it back to tree form.
auto tree = InferTaprootTree(tap, pubkey);
if (tree) {
// If that works, try to infer subdescriptors for all leaves.
bool ok = true;
std::vector<std::unique_ptr<DescriptorImpl>> subscripts; //!< list of script subexpressions
std::vector<int> depths; //!< depth in the tree of each subexpression (same length subscripts)
for (const auto& [depth, script, leaf_ver] : *tree) {
std::unique_ptr<DescriptorImpl> subdesc;
if (leaf_ver == TAPROOT_LEAF_TAPSCRIPT) {
subdesc = InferScript(CScript(script.begin(), script.end()), ParseScriptContext::P2TR, provider);
}
if (!subdesc) {
ok = false;
break;
} else {
subscripts.push_back(std::move(subdesc));
depths.push_back(depth);
}
}
if (ok) {
auto key = InferXOnlyPubkey(tap.internal_key, ParseScriptContext::P2TR, provider);
return std::make_unique<TRDescriptor>(std::move(key), std::move(subscripts), std::move(depths));
}
}
}
// If the above doesn't work, construct a rawtr() descriptor with just the encoded x-only pubkey.
if (pubkey.IsFullyValid()) {
auto key = InferXOnlyPubkey(pubkey, ParseScriptContext::P2TR, provider);
if (key) {
return std::make_unique<RawTRDescriptor>(std::move(key));
}
}
}
if (ctx == ParseScriptContext::P2WSH || ctx == ParseScriptContext::P2TR) {
const auto script_ctx{ctx == ParseScriptContext::P2WSH ? miniscript::MiniscriptContext::P2WSH : miniscript::MiniscriptContext::TAPSCRIPT};
KeyParser parser(/* out = */nullptr, /* in = */&provider, /* ctx = */script_ctx);
auto node = miniscript::FromScript(script, parser);
if (node && node->IsSane()) {
std::vector<std::unique_ptr<PubkeyProvider>> keys;
keys.reserve(parser.m_keys.size());
for (auto& key : parser.m_keys) {
keys.emplace_back(std::move(key.at(0)));
}
return std::make_unique<MiniscriptDescriptor>(std::move(keys), std::move(node));
}
}
// The following descriptors are all top-level only descriptors.
// So if we are not at the top level, return early.
if (ctx != ParseScriptContext::TOP) return nullptr;
CTxDestination dest;
if (ExtractDestination(script, dest)) {
if (GetScriptForDestination(dest) == script) {
return std::make_unique<AddressDescriptor>(std::move(dest));
}
}
return std::make_unique<RawDescriptor>(script);
}
} // namespace
/** Check a descriptor checksum, and update desc to be the checksum-less part. */
bool CheckChecksum(std::span<const char>& sp, bool require_checksum, std::string& error, std::string* out_checksum = nullptr)
{
auto check_split = Split(sp, '#');
if (check_split.size() > 2) {
error = "Multiple '#' symbols";
return false;
}
if (check_split.size() == 1 && require_checksum){
error = "Missing checksum";
return false;
}
if (check_split.size() == 2) {
if (check_split[1].size() != 8) {
error = strprintf("Expected 8 character checksum, not %u characters", check_split[1].size());
return false;
}
}
auto checksum = DescriptorChecksum(check_split[0]);
if (checksum.empty()) {
error = "Invalid characters in payload";
return false;
}
if (check_split.size() == 2) {
if (!std::equal(checksum.begin(), checksum.end(), check_split[1].begin())) {
error = strprintf("Provided checksum '%s' does not match computed checksum '%s'", std::string(check_split[1].begin(), check_split[1].end()), checksum);
return false;
}
}
if (out_checksum) *out_checksum = std::move(checksum);
sp = check_split[0];
return true;
}
std::vector<std::unique_ptr<Descriptor>> Parse(const std::string& descriptor, FlatSigningProvider& out, std::string& error, bool require_checksum)
{
std::span<const char> sp{descriptor};
if (!CheckChecksum(sp, require_checksum, error)) return {};
uint32_t key_exp_index = 0;
auto ret = ParseScript(key_exp_index, sp, ParseScriptContext::TOP, out, error);
if (sp.size() == 0 && !ret.empty()) {
std::vector<std::unique_ptr<Descriptor>> descs;
descs.reserve(ret.size());
for (auto& r : ret) {
descs.emplace_back(std::unique_ptr<Descriptor>(std::move(r)));
}
return descs;
}
return {};
}
std::string GetDescriptorChecksum(const std::string& descriptor)
{
std::string ret;
std::string error;
std::span<const char> sp{descriptor};
if (!CheckChecksum(sp, false, error, &ret)) return "";
return ret;
}
std::unique_ptr<Descriptor> InferDescriptor(const CScript& script, const SigningProvider& provider)
{
return InferScript(script, ParseScriptContext::TOP, provider);
}
uint256 DescriptorID(const Descriptor& desc)
{
std::string desc_str = desc.ToString(/*compat_format=*/true);
uint256 id;
CSHA256().Write((unsigned char*)desc_str.data(), desc_str.size()).Finalize(id.begin());
return id;
}
void DescriptorCache::CacheParentExtPubKey(uint32_t key_exp_pos, const CExtPubKey& xpub)
{
m_parent_xpubs[key_exp_pos] = xpub;
}
void DescriptorCache::CacheDerivedExtPubKey(uint32_t key_exp_pos, uint32_t der_index, const CExtPubKey& xpub)
{
auto& xpubs = m_derived_xpubs[key_exp_pos];
xpubs[der_index] = xpub;
}
void DescriptorCache::CacheLastHardenedExtPubKey(uint32_t key_exp_pos, const CExtPubKey& xpub)
{
m_last_hardened_xpubs[key_exp_pos] = xpub;
}
bool DescriptorCache::GetCachedParentExtPubKey(uint32_t key_exp_pos, CExtPubKey& xpub) const
{
const auto& it = m_parent_xpubs.find(key_exp_pos);
if (it == m_parent_xpubs.end()) return false;
xpub = it->second;
return true;
}
bool DescriptorCache::GetCachedDerivedExtPubKey(uint32_t key_exp_pos, uint32_t der_index, CExtPubKey& xpub) const
{
const auto& key_exp_it = m_derived_xpubs.find(key_exp_pos);
if (key_exp_it == m_derived_xpubs.end()) return false;
const auto& der_it = key_exp_it->second.find(der_index);
if (der_it == key_exp_it->second.end()) return false;
xpub = der_it->second;
return true;
}
bool DescriptorCache::GetCachedLastHardenedExtPubKey(uint32_t key_exp_pos, CExtPubKey& xpub) const
{
const auto& it = m_last_hardened_xpubs.find(key_exp_pos);
if (it == m_last_hardened_xpubs.end()) return false;
xpub = it->second;
return true;
}
DescriptorCache DescriptorCache::MergeAndDiff(const DescriptorCache& other)
{
DescriptorCache diff;
for (const auto& parent_xpub_pair : other.GetCachedParentExtPubKeys()) {
CExtPubKey xpub;
if (GetCachedParentExtPubKey(parent_xpub_pair.first, xpub)) {
if (xpub != parent_xpub_pair.second) {
throw std::runtime_error(std::string(__func__) + ": New cached parent xpub does not match already cached parent xpub");
}
continue;
}
CacheParentExtPubKey(parent_xpub_pair.first, parent_xpub_pair.second);
diff.CacheParentExtPubKey(parent_xpub_pair.first, parent_xpub_pair.second);
}
for (const auto& derived_xpub_map_pair : other.GetCachedDerivedExtPubKeys()) {
for (const auto& derived_xpub_pair : derived_xpub_map_pair.second) {
CExtPubKey xpub;
if (GetCachedDerivedExtPubKey(derived_xpub_map_pair.first, derived_xpub_pair.first, xpub)) {
if (xpub != derived_xpub_pair.second) {
throw std::runtime_error(std::string(__func__) + ": New cached derived xpub does not match already cached derived xpub");
}
continue;
}
CacheDerivedExtPubKey(derived_xpub_map_pair.first, derived_xpub_pair.first, derived_xpub_pair.second);
diff.CacheDerivedExtPubKey(derived_xpub_map_pair.first, derived_xpub_pair.first, derived_xpub_pair.second);
}
}
for (const auto& lh_xpub_pair : other.GetCachedLastHardenedExtPubKeys()) {
CExtPubKey xpub;
if (GetCachedLastHardenedExtPubKey(lh_xpub_pair.first, xpub)) {
if (xpub != lh_xpub_pair.second) {
throw std::runtime_error(std::string(__func__) + ": New cached last hardened xpub does not match already cached last hardened xpub");
}
continue;
}
CacheLastHardenedExtPubKey(lh_xpub_pair.first, lh_xpub_pair.second);
diff.CacheLastHardenedExtPubKey(lh_xpub_pair.first, lh_xpub_pair.second);
}
return diff;
}
ExtPubKeyMap DescriptorCache::GetCachedParentExtPubKeys() const
{
return m_parent_xpubs;
}
std::unordered_map<uint32_t, ExtPubKeyMap> DescriptorCache::GetCachedDerivedExtPubKeys() const
{
return m_derived_xpubs;
}
ExtPubKeyMap DescriptorCache::GetCachedLastHardenedExtPubKeys() const
{
return m_last_hardened_xpubs;
}
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