diff options
Diffstat (limited to 'src/script/descriptor.cpp')
| -rw-r--r-- | src/script/descriptor.cpp | 729 |
1 files changed, 534 insertions, 195 deletions
diff --git a/src/script/descriptor.cpp b/src/script/descriptor.cpp index 45b097dde6..a333d4d4ac 100644 --- a/src/script/descriptor.cpp +++ b/src/script/descriptor.cpp @@ -10,8 +10,9 @@ #include <script/standard.h> #include <span.h> -#include <util.h> -#include <utilstrencodings.h> +#include <util/bip32.h> +#include <util/system.h> +#include <util/strencodings.h> #include <memory> #include <string> @@ -20,28 +21,137 @@ namespace { //////////////////////////////////////////////////////////////////////////// -// Internal representation // +// Checksum // //////////////////////////////////////////////////////////////////////////// -typedef std::vector<uint32_t> KeyPath; +// 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 unparseable 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 FormatKeyPath(const KeyPath& path) +std::string DescriptorChecksum(const Span<const char>& span) { - std::string ret; - for (auto i : path) { - ret += strprintf("/%i", (i << 1) >> 1); - if (i >> 31) ret += '\''; + /** 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 std::string INPUT_CHARSET = + "0123456789()[],'/*abcdefgh@:$%{}" + "IJKLMNOPQRSTUVWXYZ&+-.;<=>?!^_|~" + "ijklmnopqrstuvwxyzABCDEFGH`#\"\\ "; + + /** The character set for the checksum itself (same as bech32). */ + static 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(MakeSpan(str)); } + +//////////////////////////////////////////////////////////////////////////// +// Internal representation // +//////////////////////////////////////////////////////////////////////////// + +typedef std::vector<uint32_t> KeyPath; + /** Interface for public key objects in descriptors. */ struct PubkeyProvider { virtual ~PubkeyProvider() = default; - /** Derive a public key. */ - virtual bool GetPubKey(int pos, const SigningProvider& arg, CPubKey& out) const = 0; + /** Derive a public key. If key==nullptr, only info is desired. */ + virtual bool GetPubKey(int pos, const SigningProvider& arg, CPubKey* key, KeyOriginInfo& info) const = 0; /** Whether this represent multiple public keys at different positions. */ virtual bool IsRange() const = 0; @@ -56,6 +166,37 @@ struct PubkeyProvider virtual bool ToPrivateString(const SigningProvider& arg, std::string& out) const = 0; }; +class OriginPubkeyProvider final : public PubkeyProvider +{ + KeyOriginInfo m_origin; + std::unique_ptr<PubkeyProvider> m_provider; + + std::string OriginString() const + { + return HexStr(std::begin(m_origin.fingerprint), std::end(m_origin.fingerprint)) + FormatHDKeypath(m_origin.path); + } + +public: + OriginPubkeyProvider(KeyOriginInfo info, std::unique_ptr<PubkeyProvider> provider) : m_origin(std::move(info)), m_provider(std::move(provider)) {} + bool GetPubKey(int pos, const SigningProvider& arg, CPubKey* key, KeyOriginInfo& info) const override + { + if (!m_provider->GetPubKey(pos, arg, key, info)) return false; + std::copy(std::begin(m_origin.fingerprint), std::end(m_origin.fingerprint), info.fingerprint); + info.path.insert(info.path.begin(), m_origin.path.begin(), m_origin.path.end()); + return true; + } + bool IsRange() const override { return m_provider->IsRange(); } + size_t GetSize() const override { return m_provider->GetSize(); } + std::string ToString() const override { return "[" + OriginString() + "]" + m_provider->ToString(); } + bool ToPrivateString(const SigningProvider& arg, std::string& ret) const override + { + std::string sub; + if (!m_provider->ToPrivateString(arg, sub)) return false; + ret = "[" + OriginString() + "]" + std::move(sub); + return true; + } +}; + /** An object representing a parsed constant public key in a descriptor. */ class ConstPubkeyProvider final : public PubkeyProvider { @@ -63,9 +204,12 @@ class ConstPubkeyProvider final : public PubkeyProvider public: ConstPubkeyProvider(const CPubKey& pubkey) : m_pubkey(pubkey) {} - bool GetPubKey(int pos, const SigningProvider& arg, CPubKey& out) const override + bool GetPubKey(int pos, const SigningProvider& arg, CPubKey* key, KeyOriginInfo& info) const override { - out = m_pubkey; + if (key) *key = m_pubkey; + info.path.clear(); + CKeyID keyid = m_pubkey.GetID(); + std::copy(keyid.begin(), keyid.begin() + sizeof(info.fingerprint), info.fingerprint); return true; } bool IsRange() const override { return false; } @@ -98,7 +242,7 @@ class BIP32PubkeyProvider final : public PubkeyProvider CKey key; if (!arg.GetKey(m_extkey.pubkey.GetID(), key)) return false; ret.nDepth = m_extkey.nDepth; - std::copy(m_extkey.vchFingerprint, m_extkey.vchFingerprint + 4, ret.vchFingerprint); + std::copy(m_extkey.vchFingerprint, m_extkey.vchFingerprint + sizeof(ret.vchFingerprint), ret.vchFingerprint); ret.nChild = m_extkey.nChild; ret.chaincode = m_extkey.chaincode; ret.key = key; @@ -118,32 +262,39 @@ public: BIP32PubkeyProvider(const CExtPubKey& extkey, KeyPath path, DeriveType derive) : m_extkey(extkey), m_path(std::move(path)), m_derive(derive) {} bool IsRange() const override { return m_derive != DeriveType::NO; } size_t GetSize() const override { return 33; } - bool GetPubKey(int pos, const SigningProvider& arg, CPubKey& out) const override + bool GetPubKey(int pos, const SigningProvider& arg, CPubKey* key, KeyOriginInfo& info) const override { - if (IsHardened()) { - CExtKey key; - if (!GetExtKey(arg, key)) return false; - for (auto entry : m_path) { - key.Derive(key, entry); - } - if (m_derive == DeriveType::UNHARDENED) key.Derive(key, pos); - if (m_derive == DeriveType::HARDENED) key.Derive(key, pos | 0x80000000UL); - out = key.Neuter().pubkey; - } else { - // TODO: optimize by caching - CExtPubKey key = m_extkey; - for (auto entry : m_path) { - key.Derive(key, entry); + if (key) { + if (IsHardened()) { + CExtKey extkey; + if (!GetExtKey(arg, extkey)) return false; + for (auto entry : m_path) { + extkey.Derive(extkey, entry); + } + if (m_derive == DeriveType::UNHARDENED) extkey.Derive(extkey, pos); + if (m_derive == DeriveType::HARDENED) extkey.Derive(extkey, pos | 0x80000000UL); + *key = extkey.Neuter().pubkey; + } else { + // TODO: optimize by caching + CExtPubKey extkey = m_extkey; + for (auto entry : m_path) { + extkey.Derive(extkey, entry); + } + if (m_derive == DeriveType::UNHARDENED) extkey.Derive(extkey, pos); + assert(m_derive != DeriveType::HARDENED); + *key = extkey.pubkey; } - if (m_derive == DeriveType::UNHARDENED) key.Derive(key, pos); - assert(m_derive != DeriveType::HARDENED); - out = key.pubkey; } + CKeyID keyid = m_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); return true; } std::string ToString() const override { - std::string ret = EncodeExtPubKey(m_extkey) + FormatKeyPath(m_path); + std::string ret = EncodeExtPubKey(m_extkey) + FormatHDKeypath(m_path); if (IsRange()) { ret += "/*"; if (m_derive == DeriveType::HARDENED) ret += '\''; @@ -154,7 +305,7 @@ public: { CExtKey key; if (!GetExtKey(arg, key)) return false; - out = EncodeExtKey(key) + FormatKeyPath(m_path); + out = EncodeExtKey(key) + FormatHDKeypath(m_path); if (IsRange()) { out += "/*"; if (m_derive == DeriveType::HARDENED) out += '\''; @@ -163,204 +314,276 @@ public: } }; -/** A parsed addr(A) descriptor. */ -class AddressDescriptor final : public Descriptor +/** Base class for all Descriptor implementations. */ +class DescriptorImpl : public Descriptor { - CTxDestination m_destination; + //! Public key arguments for this descriptor (size 1 for PK, PKH, WPKH; any size of Multisig). + const std::vector<std::unique_ptr<PubkeyProvider>> m_pubkey_args; + //! The sub-descriptor argument (nullptr for everything but SH and WSH). + const std::unique_ptr<DescriptorImpl> m_script_arg; + //! The string name of the descriptor function. + const std::string m_name; + +protected: + //! 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 for every CScript produced by evaluating + * m_script_arg, or just once in case m_script_arg is nullptr. + + * @param pubkeys The evaluations of the m_pubkey_args field. + * @param script The evaluation of m_script_arg (or nullptr when m_script_arg is nullptr). + * @param out A FlatSigningProvider to put scripts or public keys in that are necessary to the solver. + * The script arguments to this function are automatically added, as is the origin info of the provided pubkeys. + * @return A vector with scriptPubKeys for this descriptor. + */ + virtual std::vector<CScript> MakeScripts(const std::vector<CPubKey>& pubkeys, const CScript* script, FlatSigningProvider& out) const = 0; public: - AddressDescriptor(CTxDestination destination) : m_destination(std::move(destination)) {} + DescriptorImpl(std::vector<std::unique_ptr<PubkeyProvider>> pubkeys, std::unique_ptr<DescriptorImpl> script, const std::string& name) : m_pubkey_args(std::move(pubkeys)), m_script_arg(std::move(script)), m_name(name) {} - bool IsRange() const override { return false; } - std::string ToString() const override { return "addr(" + EncodeDestination(m_destination) + ")"; } - bool ToPrivateString(const SigningProvider& arg, std::string& out) const override { out = ToString(); return true; } - bool Expand(int pos, const SigningProvider& arg, std::vector<CScript>& output_scripts, FlatSigningProvider& out) const override + bool IsSolvable() const override { - output_scripts = std::vector<CScript>{GetScriptForDestination(m_destination)}; + if (m_script_arg) { + if (!m_script_arg->IsSolvable()) return false; + } return true; } -}; - -/** A parsed raw(H) descriptor. */ -class RawDescriptor final : public Descriptor -{ - CScript m_script; -public: - RawDescriptor(CScript script) : m_script(std::move(script)) {} + bool IsRange() const final + { + for (const auto& pubkey : m_pubkey_args) { + if (pubkey->IsRange()) return true; + } + if (m_script_arg) { + if (m_script_arg->IsRange()) return true; + } + return false; + } - bool IsRange() const override { return false; } - std::string ToString() const override { return "raw(" + HexStr(m_script.begin(), m_script.end()) + ")"; } - bool ToPrivateString(const SigningProvider& arg, std::string& out) const override { out = ToString(); return true; } - bool Expand(int pos, const SigningProvider& arg, std::vector<CScript>& output_scripts, FlatSigningProvider& out) const override + bool ToStringHelper(const SigningProvider* arg, std::string& out, bool priv) const { - output_scripts = std::vector<CScript>{m_script}; + 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; + if (priv) { + if (!pubkey->ToPrivateString(*arg, tmp)) return false; + } else { + tmp = pubkey->ToString(); + } + ret += std::move(tmp); + } + if (m_script_arg) { + if (pos++) ret += ","; + std::string tmp; + if (!m_script_arg->ToStringHelper(arg, tmp, priv)) return false; + ret += std::move(tmp); + } + out = std::move(ret) + ")"; return true; } -}; - -/** A parsed pk(P), pkh(P), or wpkh(P) descriptor. */ -class SingleKeyDescriptor final : public Descriptor -{ - const std::function<CScript(const CPubKey&)> m_script_fn; - const std::string m_fn_name; - std::unique_ptr<PubkeyProvider> m_provider; - -public: - SingleKeyDescriptor(std::unique_ptr<PubkeyProvider> prov, const std::function<CScript(const CPubKey&)>& fn, const std::string& name) : m_script_fn(fn), m_fn_name(name), m_provider(std::move(prov)) {} - bool IsRange() const override { return m_provider->IsRange(); } - std::string ToString() const override { return m_fn_name + "(" + m_provider->ToString() + ")"; } - bool ToPrivateString(const SigningProvider& arg, std::string& out) const override + std::string ToString() const final { std::string ret; - if (!m_provider->ToPrivateString(arg, ret)) return false; - out = m_fn_name + "(" + std::move(ret) + ")"; - return true; + ToStringHelper(nullptr, ret, false); + return AddChecksum(ret); } - bool Expand(int pos, const SigningProvider& arg, std::vector<CScript>& output_scripts, FlatSigningProvider& out) const override + + bool ToPrivateString(const SigningProvider& arg, std::string& out) const override final { - CPubKey key; - if (!m_provider->GetPubKey(pos, arg, key)) return false; - output_scripts = std::vector<CScript>{m_script_fn(key)}; - out.pubkeys.emplace(key.GetID(), std::move(key)); - return true; + bool ret = ToStringHelper(&arg, out, true); + out = AddChecksum(out); + return ret; } -}; - -CScript P2PKHGetScript(const CPubKey& pubkey) { return GetScriptForDestination(pubkey.GetID()); } -CScript P2PKGetScript(const CPubKey& pubkey) { return GetScriptForRawPubKey(pubkey); } -CScript P2WPKHGetScript(const CPubKey& pubkey) { return GetScriptForDestination(WitnessV0KeyHash(pubkey.GetID())); } - -/** A parsed multi(...) descriptor. */ -class MultisigDescriptor : public Descriptor -{ - int m_threshold; - std::vector<std::unique_ptr<PubkeyProvider>> m_providers; -public: - MultisigDescriptor(int threshold, std::vector<std::unique_ptr<PubkeyProvider>> providers) : m_threshold(threshold), m_providers(std::move(providers)) {} - - bool IsRange() const override + bool ExpandHelper(int pos, const SigningProvider& arg, Span<const unsigned char>* cache_read, std::vector<CScript>& output_scripts, FlatSigningProvider& out, std::vector<unsigned char>* cache_write) const { - for (const auto& p : m_providers) { - if (p->IsRange()) return true; + std::vector<std::pair<CPubKey, KeyOriginInfo>> entries; + entries.reserve(m_pubkey_args.size()); + + // Construct temporary data in `entries` and `subscripts`, to avoid producing output in case of failure. + for (const auto& p : m_pubkey_args) { + entries.emplace_back(); + if (!p->GetPubKey(pos, arg, cache_read ? nullptr : &entries.back().first, entries.back().second)) return false; + if (cache_read) { + // Cached expanded public key exists, use it. + if (cache_read->size() == 0) return false; + bool compressed = ((*cache_read)[0] == 0x02 || (*cache_read)[0] == 0x03) && cache_read->size() >= 33; + bool uncompressed = ((*cache_read)[0] == 0x04) && cache_read->size() >= 65; + if (!(compressed || uncompressed)) return false; + CPubKey pubkey(cache_read->begin(), cache_read->begin() + (compressed ? 33 : 65)); + entries.back().first = pubkey; + *cache_read = cache_read->subspan(compressed ? 33 : 65); + } + if (cache_write) { + cache_write->insert(cache_write->end(), entries.back().first.begin(), entries.back().first.end()); + } + } + std::vector<CScript> subscripts; + if (m_script_arg) { + FlatSigningProvider subprovider; + if (!m_script_arg->ExpandHelper(pos, arg, cache_read, subscripts, subprovider, cache_write)) return false; + out = Merge(out, subprovider); } - return false; - } - std::string ToString() const override - { - std::string ret = strprintf("multi(%i", m_threshold); - for (const auto& p : m_providers) { - ret += "," + p->ToString(); + std::vector<CPubKey> pubkeys; + pubkeys.reserve(entries.size()); + for (auto& entry : entries) { + pubkeys.push_back(entry.first); + out.origins.emplace(entry.first.GetID(), std::make_pair<CPubKey, KeyOriginInfo>(CPubKey(entry.first), std::move(entry.second))); + } + if (m_script_arg) { + for (const auto& subscript : subscripts) { + out.scripts.emplace(CScriptID(subscript), subscript); + std::vector<CScript> addscripts = MakeScripts(pubkeys, &subscript, out); + for (auto& addscript : addscripts) { + output_scripts.push_back(std::move(addscript)); + } + } + } else { + output_scripts = MakeScripts(pubkeys, nullptr, out); } - return std::move(ret) + ")"; + return true; } - bool ToPrivateString(const SigningProvider& arg, std::string& out) const override + bool Expand(int pos, const SigningProvider& provider, std::vector<CScript>& output_scripts, FlatSigningProvider& out, std::vector<unsigned char>* cache = nullptr) const final { - std::string ret = strprintf("multi(%i", m_threshold); - for (const auto& p : m_providers) { - std::string sub; - if (!p->ToPrivateString(arg, sub)) return false; - ret += "," + std::move(sub); - } - out = std::move(ret) + ")"; - return true; + return ExpandHelper(pos, provider, nullptr, output_scripts, out, cache); } - bool Expand(int pos, const SigningProvider& arg, std::vector<CScript>& output_scripts, FlatSigningProvider& out) const override + bool ExpandFromCache(int pos, const std::vector<unsigned char>& cache, std::vector<CScript>& output_scripts, FlatSigningProvider& out) const final { - std::vector<CPubKey> pubkeys; - pubkeys.reserve(m_providers.size()); - for (const auto& p : m_providers) { - CPubKey key; - if (!p->GetPubKey(pos, arg, key)) return false; - pubkeys.push_back(key); - } - for (const CPubKey& key : pubkeys) { - out.pubkeys.emplace(key.GetID(), std::move(key)); - } - output_scripts = std::vector<CScript>{GetScriptForMultisig(m_threshold, pubkeys)}; - return true; + Span<const unsigned char> span = MakeSpan(cache); + return ExpandHelper(pos, DUMMY_SIGNING_PROVIDER, &span, output_scripts, out, nullptr) && span.size() == 0; } }; -/** A parsed sh(S) or wsh(S) descriptor. */ -class ConvertorDescriptor : public Descriptor +/** Construct a vector with one element, which is moved into it. */ +template<typename T> +std::vector<T> Singleton(T elem) { - const std::function<CScript(const CScript&)> m_convert_fn; - const std::string m_fn_name; - std::unique_ptr<Descriptor> m_descriptor; + std::vector<T> ret; + ret.emplace_back(std::move(elem)); + return ret; +} +/** 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>&, const CScript*, FlatSigningProvider&) const override { return Singleton(GetScriptForDestination(m_destination)); } public: - ConvertorDescriptor(std::unique_ptr<Descriptor> descriptor, const std::function<CScript(const CScript&)>& fn, const std::string& name) : m_convert_fn(fn), m_fn_name(name), m_descriptor(std::move(descriptor)) {} - - bool IsRange() const override { return m_descriptor->IsRange(); } - std::string ToString() const override { return m_fn_name + "(" + m_descriptor->ToString() + ")"; } - bool ToPrivateString(const SigningProvider& arg, std::string& out) const override - { - std::string ret; - if (!m_descriptor->ToPrivateString(arg, ret)) return false; - out = m_fn_name + "(" + std::move(ret) + ")"; - return true; - } - bool Expand(int pos, const SigningProvider& arg, std::vector<CScript>& output_scripts, FlatSigningProvider& out) const override - { - std::vector<CScript> sub; - if (!m_descriptor->Expand(pos, arg, sub, out)) return false; - output_scripts.clear(); - for (const auto& script : sub) { - CScriptID id(script); - out.scripts.emplace(CScriptID(script), script); - output_scripts.push_back(m_convert_fn(script)); - } - return true; - } + AddressDescriptor(CTxDestination destination) : DescriptorImpl({}, {}, "addr"), m_destination(std::move(destination)) {} + bool IsSolvable() const final { return false; } }; -CScript ConvertP2SH(const CScript& script) { return GetScriptForDestination(CScriptID(script)); } -CScript ConvertP2WSH(const CScript& script) { return GetScriptForDestination(WitnessV0ScriptHash(script)); } +/** A parsed raw(H) descriptor. */ +class RawDescriptor final : public DescriptorImpl +{ + const CScript m_script; +protected: + std::string ToStringExtra() const override { return HexStr(m_script.begin(), m_script.end()); } + std::vector<CScript> MakeScripts(const std::vector<CPubKey>&, const CScript*, FlatSigningProvider&) const override { return Singleton(m_script); } +public: + RawDescriptor(CScript script) : DescriptorImpl({}, {}, "raw"), m_script(std::move(script)) {} + bool IsSolvable() const final { return false; } +}; -/** A parsed combo(P) descriptor. */ -class ComboDescriptor final : public Descriptor +/** A parsed pk(P) descriptor. */ +class PKDescriptor final : public DescriptorImpl { - std::unique_ptr<PubkeyProvider> m_provider; +protected: + std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, const CScript*, FlatSigningProvider&) const override { return Singleton(GetScriptForRawPubKey(keys[0])); } +public: + PKDescriptor(std::unique_ptr<PubkeyProvider> prov) : DescriptorImpl(Singleton(std::move(prov)), {}, "pk") {} +}; +/** A parsed pkh(P) descriptor. */ +class PKHDescriptor final : public DescriptorImpl +{ +protected: + std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, const CScript*, FlatSigningProvider& out) const override + { + CKeyID id = keys[0].GetID(); + out.pubkeys.emplace(id, keys[0]); + return Singleton(GetScriptForDestination(id)); + } public: - ComboDescriptor(std::unique_ptr<PubkeyProvider> provider) : m_provider(std::move(provider)) {} + PKHDescriptor(std::unique_ptr<PubkeyProvider> prov) : DescriptorImpl(Singleton(std::move(prov)), {}, "pkh") {} +}; - bool IsRange() const override { return m_provider->IsRange(); } - std::string ToString() const override { return "combo(" + m_provider->ToString() + ")"; } - bool ToPrivateString(const SigningProvider& arg, std::string& out) const override +/** A parsed wpkh(P) descriptor. */ +class WPKHDescriptor final : public DescriptorImpl +{ +protected: + std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, const CScript*, FlatSigningProvider& out) const override { - std::string ret; - if (!m_provider->ToPrivateString(arg, ret)) return false; - out = "combo(" + std::move(ret) + ")"; - return true; + CKeyID id = keys[0].GetID(); + out.pubkeys.emplace(id, keys[0]); + return Singleton(GetScriptForDestination(WitnessV0KeyHash(id))); } - bool Expand(int pos, const SigningProvider& arg, std::vector<CScript>& output_scripts, FlatSigningProvider& out) const override +public: + WPKHDescriptor(std::unique_ptr<PubkeyProvider> prov) : DescriptorImpl(Singleton(std::move(prov)), {}, "wpkh") {} +}; + +/** A parsed combo(P) descriptor. */ +class ComboDescriptor final : public DescriptorImpl +{ +protected: + std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, const CScript*, FlatSigningProvider& out) const override { - CPubKey key; - if (!m_provider->GetPubKey(pos, arg, key)) return false; - CKeyID keyid = key.GetID(); - { - CScript p2pk = GetScriptForRawPubKey(key); - CScript p2pkh = GetScriptForDestination(keyid); - output_scripts = std::vector<CScript>{std::move(p2pk), std::move(p2pkh)}; - out.pubkeys.emplace(keyid, key); - } - if (key.IsCompressed()) { - CScript p2wpkh = GetScriptForDestination(WitnessV0KeyHash(keyid)); - CScriptID p2wpkh_id(p2wpkh); - CScript p2sh_p2wpkh = GetScriptForDestination(p2wpkh_id); - out.scripts.emplace(p2wpkh_id, p2wpkh); - output_scripts.push_back(std::move(p2wpkh)); - output_scripts.push_back(std::move(p2sh_p2wpkh)); + std::vector<CScript> ret; + CKeyID id = keys[0].GetID(); + out.pubkeys.emplace(id, keys[0]); + ret.emplace_back(GetScriptForRawPubKey(keys[0])); // P2PK + ret.emplace_back(GetScriptForDestination(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(CScriptID(p2wpkh))); // P2SH-P2WPKH } - return true; + return ret; } +public: + ComboDescriptor(std::unique_ptr<PubkeyProvider> prov) : DescriptorImpl(Singleton(std::move(prov)), {}, "combo") {} +}; + +/** A parsed multi(...) descriptor. */ +class MultisigDescriptor final : public DescriptorImpl +{ + const int m_threshold; +protected: + std::string ToStringExtra() const override { return strprintf("%i", m_threshold); } + std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, const CScript*, FlatSigningProvider&) const override { return Singleton(GetScriptForMultisig(m_threshold, keys)); } +public: + MultisigDescriptor(int threshold, std::vector<std::unique_ptr<PubkeyProvider>> providers) : DescriptorImpl(std::move(providers), {}, "multi"), m_threshold(threshold) {} +}; + +/** A parsed sh(...) descriptor. */ +class SHDescriptor final : public DescriptorImpl +{ +protected: + std::vector<CScript> MakeScripts(const std::vector<CPubKey>&, const CScript* script, FlatSigningProvider&) const override { return Singleton(GetScriptForDestination(CScriptID(*script))); } +public: + SHDescriptor(std::unique_ptr<DescriptorImpl> desc) : DescriptorImpl({}, std::move(desc), "sh") {} +}; + +/** A parsed wsh(...) descriptor. */ +class WSHDescriptor final : public DescriptorImpl +{ +protected: + std::vector<CScript> MakeScripts(const std::vector<CPubKey>&, const CScript* script, FlatSigningProvider&) const override { return Singleton(GetScriptForDestination(WitnessV0ScriptHash(*script))); } +public: + WSHDescriptor(std::unique_ptr<DescriptorImpl> desc) : DescriptorImpl({}, std::move(desc), "wsh") {} }; //////////////////////////////////////////////////////////////////////////// @@ -431,7 +654,7 @@ std::vector<Span<const char>> Split(const Span<const char>& sp, char sep) } /** Parse a key path, being passed a split list of elements (the first element is ignored). */ -bool ParseKeyPath(const std::vector<Span<const char>>& split, KeyPath& out) +NODISCARD bool ParseKeyPath(const std::vector<Span<const char>>& split, KeyPath& out) { for (size_t i = 1; i < split.size(); ++i) { Span<const char> elem = split[i]; @@ -447,7 +670,8 @@ bool ParseKeyPath(const std::vector<Span<const char>>& split, KeyPath& out) return true; } -std::unique_ptr<PubkeyProvider> ParsePubkey(const Span<const char>& sp, bool permit_uncompressed, FlatSigningProvider& out) +/** Parse a public key that excludes origin information. */ +std::unique_ptr<PubkeyProvider> ParsePubkeyInner(const Span<const char>& sp, bool permit_uncompressed, FlatSigningProvider& out) { auto split = Split(sp, '/'); std::string str(split[0].begin(), split[0].end()); @@ -484,19 +708,41 @@ std::unique_ptr<PubkeyProvider> ParsePubkey(const Span<const char>& sp, bool per return MakeUnique<BIP32PubkeyProvider>(extpubkey, std::move(path), type); } +/** Parse a public key including origin information (if enabled). */ +std::unique_ptr<PubkeyProvider> ParsePubkey(const Span<const char>& sp, bool permit_uncompressed, FlatSigningProvider& out) +{ + auto origin_split = Split(sp, ']'); + if (origin_split.size() > 2) return nullptr; + if (origin_split.size() == 1) return ParsePubkeyInner(origin_split[0], permit_uncompressed, out); + if (origin_split[0].size() < 1 || origin_split[0][0] != '[') return nullptr; + auto slash_split = Split(origin_split[0].subspan(1), '/'); + if (slash_split[0].size() != 8) return nullptr; + std::string fpr_hex = std::string(slash_split[0].begin(), slash_split[0].end()); + if (!IsHex(fpr_hex)) return nullptr; + 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); + if (!ParseKeyPath(slash_split, info.path)) return nullptr; + auto provider = ParsePubkeyInner(origin_split[1], permit_uncompressed, out); + if (!provider) return nullptr; + return MakeUnique<OriginPubkeyProvider>(std::move(info), std::move(provider)); +} + /** Parse a script in a particular context. */ -std::unique_ptr<Descriptor> ParseScript(Span<const char>& sp, ParseScriptContext ctx, FlatSigningProvider& out) +std::unique_ptr<DescriptorImpl> ParseScript(Span<const char>& sp, ParseScriptContext ctx, FlatSigningProvider& out) { auto expr = Expr(sp); if (Func("pk", expr)) { auto pubkey = ParsePubkey(expr, ctx != ParseScriptContext::P2WSH, out); if (!pubkey) return nullptr; - return MakeUnique<SingleKeyDescriptor>(std::move(pubkey), P2PKGetScript, "pk"); + return MakeUnique<PKDescriptor>(std::move(pubkey)); } if (Func("pkh", expr)) { auto pubkey = ParsePubkey(expr, ctx != ParseScriptContext::P2WSH, out); if (!pubkey) return nullptr; - return MakeUnique<SingleKeyDescriptor>(std::move(pubkey), P2PKHGetScript, "pkh"); + return MakeUnique<PKHDescriptor>(std::move(pubkey)); } if (ctx == ParseScriptContext::TOP && Func("combo", expr)) { auto pubkey = ParsePubkey(expr, true, out); @@ -529,17 +775,17 @@ std::unique_ptr<Descriptor> ParseScript(Span<const char>& sp, ParseScriptContext if (ctx != ParseScriptContext::P2WSH && Func("wpkh", expr)) { auto pubkey = ParsePubkey(expr, false, out); if (!pubkey) return nullptr; - return MakeUnique<SingleKeyDescriptor>(std::move(pubkey), P2WPKHGetScript, "wpkh"); + return MakeUnique<WPKHDescriptor>(std::move(pubkey)); } if (ctx == ParseScriptContext::TOP && Func("sh", expr)) { auto desc = ParseScript(expr, ParseScriptContext::P2SH, out); if (!desc || expr.size()) return nullptr; - return MakeUnique<ConvertorDescriptor>(std::move(desc), ConvertP2SH, "sh"); + return MakeUnique<SHDescriptor>(std::move(desc)); } if (ctx != ParseScriptContext::P2WSH && Func("wsh", expr)) { auto desc = ParseScript(expr, ParseScriptContext::P2WSH, out); if (!desc || expr.size()) return nullptr; - return MakeUnique<ConvertorDescriptor>(std::move(desc), ConvertP2WSH, "wsh"); + return MakeUnique<WSHDescriptor>(std::move(desc)); } if (ctx == ParseScriptContext::TOP && Func("addr", expr)) { CTxDestination dest = DecodeDestination(std::string(expr.begin(), expr.end())); @@ -555,12 +801,105 @@ std::unique_ptr<Descriptor> ParseScript(Span<const char>& sp, ParseScriptContext return nullptr; } +std::unique_ptr<PubkeyProvider> InferPubkey(const CPubKey& pubkey, ParseScriptContext, const SigningProvider& provider) +{ + std::unique_ptr<PubkeyProvider> key_provider = MakeUnique<ConstPubkeyProvider>(pubkey); + KeyOriginInfo info; + if (provider.GetKeyOrigin(pubkey.GetID(), info)) { + return MakeUnique<OriginPubkeyProvider>(std::move(info), std::move(key_provider)); + } + return key_provider; +} + +std::unique_ptr<DescriptorImpl> InferScript(const CScript& script, ParseScriptContext ctx, const SigningProvider& provider) +{ + std::vector<std::vector<unsigned char>> data; + txnouttype txntype = Solver(script, data); + + if (txntype == TX_PUBKEY) { + CPubKey pubkey(data[0].begin(), data[0].end()); + if (pubkey.IsValid()) { + return MakeUnique<PKDescriptor>(InferPubkey(pubkey, ctx, provider)); + } + } + if (txntype == TX_PUBKEYHASH) { + uint160 hash(data[0]); + CKeyID keyid(hash); + CPubKey pubkey; + if (provider.GetPubKey(keyid, pubkey)) { + return MakeUnique<PKHDescriptor>(InferPubkey(pubkey, ctx, provider)); + } + } + if (txntype == TX_WITNESS_V0_KEYHASH && ctx != ParseScriptContext::P2WSH) { + uint160 hash(data[0]); + CKeyID keyid(hash); + CPubKey pubkey; + if (provider.GetPubKey(keyid, pubkey)) { + return MakeUnique<WPKHDescriptor>(InferPubkey(pubkey, ctx, provider)); + } + } + if (txntype == TX_MULTISIG) { + std::vector<std::unique_ptr<PubkeyProvider>> providers; + for (size_t i = 1; i + 1 < data.size(); ++i) { + CPubKey pubkey(data[i].begin(), data[i].end()); + providers.push_back(InferPubkey(pubkey, ctx, provider)); + } + return MakeUnique<MultisigDescriptor>((int)data[0][0], std::move(providers)); + } + if (txntype == TX_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 MakeUnique<SHDescriptor>(std::move(sub)); + } + } + if (txntype == TX_WITNESS_V0_SCRIPTHASH && ctx != ParseScriptContext::P2WSH) { + CScriptID scriptid; + CRIPEMD160().Write(data[0].data(), data[0].size()).Finalize(scriptid.begin()); + CScript subscript; + if (provider.GetCScript(scriptid, subscript)) { + auto sub = InferScript(subscript, ParseScriptContext::P2WSH, provider); + if (sub) return MakeUnique<WSHDescriptor>(std::move(sub)); + } + } + + CTxDestination dest; + if (ExtractDestination(script, dest)) { + if (GetScriptForDestination(dest) == script) { + return MakeUnique<AddressDescriptor>(std::move(dest)); + } + } + + return MakeUnique<RawDescriptor>(script); +} + + } // namespace -std::unique_ptr<Descriptor> Parse(const std::string& descriptor, FlatSigningProvider& out) +std::unique_ptr<Descriptor> Parse(const std::string& descriptor, FlatSigningProvider& out, bool require_checksum) { Span<const char> sp(descriptor.data(), descriptor.size()); + + // Checksum checks + auto check_split = Split(sp, '#'); + if (check_split.size() > 2) return nullptr; // Multiple '#' symbols + if (check_split.size() == 1 && require_checksum) return nullptr; // Missing checksum + if (check_split.size() == 2) { + if (check_split[1].size() != 8) return nullptr; // Unexpected length for checksum + auto checksum = DescriptorChecksum(check_split[0]); + if (checksum.empty()) return nullptr; // Invalid characters in payload + if (!std::equal(checksum.begin(), checksum.end(), check_split[1].begin())) return nullptr; // Checksum mismatch + } + sp = check_split[0]; + auto ret = ParseScript(sp, ParseScriptContext::TOP, out); - if (sp.size() == 0 && ret) return ret; + if (sp.size() == 0 && ret) return std::unique_ptr<Descriptor>(std::move(ret)); return nullptr; } + +std::unique_ptr<Descriptor> InferDescriptor(const CScript& script, const SigningProvider& provider) +{ + return InferScript(script, ParseScriptContext::TOP, provider); +} |