diff options
Diffstat (limited to 'src/script/descriptor.cpp')
| -rw-r--r-- | src/script/descriptor.cpp | 310 |
1 files changed, 277 insertions, 33 deletions
diff --git a/src/script/descriptor.cpp b/src/script/descriptor.cpp index cece0b60ce..9bcbe1ceef 100644 --- a/src/script/descriptor.cpp +++ b/src/script/descriptor.cpp @@ -6,6 +6,7 @@ #include <key_io.h> #include <pubkey.h> +#include <script/miniscript.h> #include <script/script.h> #include <script/standard.h> @@ -161,6 +162,20 @@ public: 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 { + CPubKey a, b; + SigningProvider dummy; + KeyOriginInfo dummy_info; + + GetPubKey(0, dummy, a, dummy_info); + other.GetPubKey(0, dummy, b, dummy_info); + + return a < b; + } + /** Derive a public key. * read_cache is the cache to read keys from (if not nullptr) * write_cache is the cache to write keys to (if not nullptr) @@ -313,7 +328,7 @@ class BIP32PubkeyProvider final : public PubkeyProvider { if (!GetExtKey(arg, xprv)) return false; for (auto entry : m_path) { - xprv.Derive(xprv, entry); + if (!xprv.Derive(xprv, entry)) return false; if (entry >> 31) { last_hardened = xprv; } @@ -373,14 +388,13 @@ public: } } else { for (auto entry : m_path) { - der = parent_extkey.Derive(parent_extkey, entry); - assert(der); + if (!parent_extkey.Derive(parent_extkey, entry)) return false; } final_extkey = parent_extkey; if (m_derive == DeriveType::UNHARDENED) der = parent_extkey.Derive(final_extkey, pos); assert(m_derive != DeriveType::HARDENED); } - assert(der); + if (!der) return false; final_info_out = final_info_out_tmp; key_out = final_extkey.pubkey; @@ -483,8 +497,8 @@ public: CExtKey extkey; CExtKey dummy; if (!GetDerivedExtKey(arg, extkey, dummy)) return false; - if (m_derive == DeriveType::UNHARDENED) extkey.Derive(extkey, pos); - if (m_derive == DeriveType::HARDENED) extkey.Derive(extkey, pos | 0x80000000UL); + if (m_derive == DeriveType::UNHARDENED && !extkey.Derive(extkey, pos)) return false; + if (m_derive == DeriveType::HARDENED && !extkey.Derive(extkey, pos | 0x80000000UL)) return false; key = extkey.key; return true; } @@ -493,12 +507,12 @@ public: /** Base class for all Descriptor implementations. */ class DescriptorImpl : public Descriptor { - //! Public key arguments for this descriptor (size 1 for PK, PKH, WPKH; any size for Multisig). +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; -protected: //! 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. @@ -563,7 +577,7 @@ public: return true; } - bool ToStringHelper(const SigningProvider* arg, std::string& out, const StringType type, const DescriptorCache* cache = nullptr) const + 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; @@ -882,7 +896,7 @@ protected: if (!xpk.IsFullyValid()) return {}; builder.Finalize(xpk); WitnessV1Taproot output = builder.GetOutput(); - out.tr_spenddata[output].Merge(builder.GetSpendData()); + out.tr_trees[output] = builder; out.pubkeys.emplace(keys[0].GetID(), keys[0]); return Vector(GetScriptForDestination(output)); } @@ -917,6 +931,107 @@ public: bool IsSingleType() const final { return true; } }; +/* 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; + +public: + ScriptMaker(const std::vector<CPubKey>& keys LIFETIMEBOUND) : m_keys(keys) {} + + std::vector<unsigned char> ToPKBytes(uint32_t key) const { + return {m_keys[key].begin(), m_keys[key].end()}; + } + + std::vector<unsigned char> ToPKHBytes(uint32_t key) const { + auto id = m_keys[key].GetID(); + 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, Span<const CScript> scripts, + FlatSigningProvider& provider) const override + { + for (const auto& key : keys) provider.pubkeys.emplace(key.GetID(), key); + return Vector(m_node->ToScript(ScriptMaker(keys))); + } + +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 false; } // For now, mark these descriptors as non-solvable (as we don't have signing logic for them). + bool IsSingleType() const final { return true; } +}; + +/** A parsed rawtr(...) descriptor. */ +class RawTRDescriptor final : public DescriptorImpl +{ +protected: + std::vector<CScript> MakeScripts(const std::vector<CPubKey>& keys, 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; } +}; + //////////////////////////////////////////////////////////////////////////// // Parser // //////////////////////////////////////////////////////////////////////////// @@ -1058,6 +1173,94 @@ std::unique_ptr<PubkeyProvider> ParsePubkey(uint32_t key_exp_index, const Span<c return std::make_unique<OriginPubkeyProvider>(key_exp_index, std::move(info), std::move(provider)); } +std::unique_ptr<PubkeyProvider> InferPubkey(const CPubKey& pubkey, ParseScriptContext, const SigningProvider& provider) +{ + 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)); + } + return key_provider; +} + +std::unique_ptr<PubkeyProvider> InferXOnlyPubkey(const XOnlyPubKey& xkey, ParseScriptContext ctx, const SigningProvider& provider) +{ + unsigned char full_key[CPubKey::COMPRESSED_SIZE] = {0x02}; + std::copy(xkey.begin(), xkey.end(), full_key + 1); + CPubKey pubkey(full_key); + 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)); + } + 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 keys contained in the Miniscript. + mutable std::vector<std::unique_ptr<PubkeyProvider>> m_keys; + //! Used to detect key parsing errors within a Miniscript. + mutable std::string m_key_parsing_error; + + KeyParser(FlatSigningProvider* out LIFETIMEBOUND, const SigningProvider* in LIFETIMEBOUND) : m_out(out), m_in(in) {} + + bool KeyCompare(const Key& a, const Key& b) const { + return *m_keys.at(a) < *m_keys.at(b); + } + + template<typename I> std::optional<Key> FromString(I begin, I end) const + { + assert(m_out); + Key key = m_keys.size(); + auto pk = ParsePubkey(key, {&*begin, &*end}, ParseScriptContext::P2WSH, *m_out, m_key_parsing_error); + if (!pk) return {}; + m_keys.push_back(std::move(pk)); + return key; + } + + std::optional<std::string> ToString(const Key& key) const + { + return m_keys.at(key)->ToString(); + } + + template<typename I> std::optional<Key> FromPKBytes(I begin, I end) const + { + assert(m_in); + CPubKey pubkey(begin, end); + if (pubkey.IsValid()) { + Key key = m_keys.size(); + m_keys.push_back(InferPubkey(pubkey, ParseScriptContext::P2WSH, *m_in)); + 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)) { + Key key = m_keys.size(); + m_keys.push_back(InferPubkey(pubkey, ParseScriptContext::P2WSH, *m_in)); + return key; + } + return {}; + } +}; + /** Parse a script in a particular context. */ std::unique_ptr<DescriptorImpl> ParseScript(uint32_t& key_exp_index, Span<const char>& sp, ParseScriptContext ctx, FlatSigningProvider& out, std::string& error) { @@ -1267,6 +1470,16 @@ std::unique_ptr<DescriptorImpl> ParseScript(uint32_t& key_exp_index, Span<const error = "Can only have tr at top level"; return nullptr; } + if (ctx == ParseScriptContext::TOP && Func("rawtr", expr)) { + auto arg = Expr(expr); + auto output_key = ParsePubkey(key_exp_index, arg, ParseScriptContext::P2TR, out, error); + if (!output_key) return nullptr; + ++key_exp_index; + return std::make_unique<RawTRDescriptor>(std::move(output_key)); + } else if (Func("rawtr", expr)) { + error = "Can only have rawtr at top level"; + return nullptr; + } if (ctx == ParseScriptContext::TOP && Func("raw", expr)) { std::string str(expr.begin(), expr.end()); if (!IsHex(str)) { @@ -1279,6 +1492,45 @@ std::unique_ptr<DescriptorImpl> ParseScript(uint32_t& key_exp_index, Span<const error = "Can only have raw() at top level"; return nullptr; } + // Process miniscript expressions. + { + KeyParser parser(&out, nullptr); + auto node = miniscript::FromString(std::string(expr.begin(), expr.end()), parser); + if (node) { + if (ctx != ParseScriptContext::P2WSH) { + error = "Miniscript expressions can only be used in wsh"; + return nullptr; + } + if (parser.m_key_parsing_error != "") { + error = std::move(parser.m_key_parsing_error); + return nullptr; + } + if (!node->IsSane()) { + // 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 { + 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"; + } + } + return nullptr; + } + return std::make_unique<MiniscriptDescriptor>(std::move(parser.m_keys), std::move(node)); + } + } if (ctx == ParseScriptContext::P2SH) { error = "A function is needed within P2SH"; return nullptr; @@ -1290,29 +1542,6 @@ std::unique_ptr<DescriptorImpl> ParseScript(uint32_t& key_exp_index, Span<const return nullptr; } -std::unique_ptr<PubkeyProvider> InferPubkey(const CPubKey& pubkey, ParseScriptContext, const SigningProvider& provider) -{ - 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)); - } - return key_provider; -} - -std::unique_ptr<PubkeyProvider> InferXOnlyPubkey(const XOnlyPubKey& xkey, ParseScriptContext ctx, const SigningProvider& provider) -{ - unsigned char full_key[CPubKey::COMPRESSED_SIZE] = {0x02}; - std::copy(xkey.begin(), xkey.end(), full_key + 1); - CPubKey pubkey(full_key); - 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)); - } - return key_provider; -} - std::unique_ptr<DescriptorImpl> InferMultiA(const CScript& script, ParseScriptContext ctx, const SigningProvider& provider) { auto match = MatchMultiA(script); @@ -1424,6 +1653,21 @@ std::unique_ptr<DescriptorImpl> InferScript(const CScript& script, ParseScriptCo } } } + // 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) { + KeyParser parser(nullptr, &provider); + auto node = miniscript::FromScript(script, parser); + if (node && node->IsSane()) { + return std::make_unique<MiniscriptDescriptor>(std::move(parser.m_keys), std::move(node)); + } } CTxDestination dest; |