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-rw-r--r--src/script/descriptor.cpp241
1 files changed, 181 insertions, 60 deletions
diff --git a/src/script/descriptor.cpp b/src/script/descriptor.cpp
index 50119ba184..b782ebbd1f 100644
--- a/src/script/descriptor.cpp
+++ b/src/script/descriptor.cpp
@@ -335,10 +335,12 @@ 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 of Multisig).
+ //! Public key arguments for this descriptor (size 1 for PK, PKH, WPKH; any size for 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;
+ //! In doc/descriptors.m this is referred to as SCRIPT expressions sh(SCRIPT)
+ //! and wsh(SCRIPT), and distinct from KEY expressions and ADDR expressions.
+ const std::unique_ptr<DescriptorImpl> m_subdescriptor_arg;
//! The string name of the descriptor function.
const std::string m_name;
@@ -349,10 +351,10 @@ protected:
/** 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.
+ * m_subdescriptor_arg, or just once in case m_subdescriptor_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 script The evaluation of m_subdescriptor_arg (or nullptr when m_subdescriptor_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.
@@ -360,12 +362,12 @@ protected:
virtual std::vector<CScript> MakeScripts(const std::vector<CPubKey>& pubkeys, const CScript* script, FlatSigningProvider& out) const = 0;
public:
- 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) {}
+ DescriptorImpl(std::vector<std::unique_ptr<PubkeyProvider>> pubkeys, std::unique_ptr<DescriptorImpl> script, const std::string& name) : m_pubkey_args(std::move(pubkeys)), m_subdescriptor_arg(std::move(script)), m_name(name) {}
bool IsSolvable() const override
{
- if (m_script_arg) {
- if (!m_script_arg->IsSolvable()) return false;
+ if (m_subdescriptor_arg) {
+ if (!m_subdescriptor_arg->IsSolvable()) return false;
}
return true;
}
@@ -375,8 +377,8 @@ public:
for (const auto& pubkey : m_pubkey_args) {
if (pubkey->IsRange()) return true;
}
- if (m_script_arg) {
- if (m_script_arg->IsRange()) return true;
+ if (m_subdescriptor_arg) {
+ if (m_subdescriptor_arg->IsRange()) return true;
}
return false;
}
@@ -396,10 +398,10 @@ public:
}
ret += std::move(tmp);
}
- if (m_script_arg) {
+ if (m_subdescriptor_arg) {
if (pos++) ret += ",";
std::string tmp;
- if (!m_script_arg->ToStringHelper(arg, tmp, priv)) return false;
+ if (!m_subdescriptor_arg->ToStringHelper(arg, tmp, priv)) return false;
ret += std::move(tmp);
}
out = std::move(ret) + ")";
@@ -428,6 +430,8 @@ public:
// 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 we have a cache, we don't need GetPubKey to compute the public key.
+ // Pass in nullptr to signify only origin info is desired.
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.
@@ -444,9 +448,9 @@ public:
}
}
std::vector<CScript> subscripts;
- if (m_script_arg) {
+ if (m_subdescriptor_arg) {
FlatSigningProvider subprovider;
- if (!m_script_arg->ExpandHelper(pos, arg, cache_read, subscripts, subprovider, cache_write)) return false;
+ if (!m_subdescriptor_arg->ExpandHelper(pos, arg, cache_read, subscripts, subprovider, cache_write)) return false;
out = Merge(out, subprovider);
}
@@ -456,7 +460,7 @@ public:
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) {
+ if (m_subdescriptor_arg) {
for (const auto& subscript : subscripts) {
out.scripts.emplace(CScriptID(subscript), subscript);
std::vector<CScript> addscripts = MakeScripts(pubkeys, &subscript, out);
@@ -488,9 +492,9 @@ public:
if (!p->GetPrivKey(pos, provider, key)) continue;
out.keys.emplace(key.GetPubKey().GetID(), key);
}
- if (m_script_arg) {
+ if (m_subdescriptor_arg) {
FlatSigningProvider subprovider;
- m_script_arg->ExpandPrivate(pos, provider, subprovider);
+ m_subdescriptor_arg->ExpandPrivate(pos, provider, subprovider);
out = Merge(out, subprovider);
}
}
@@ -686,7 +690,7 @@ 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). */
-NODISCARD bool ParseKeyPath(const std::vector<Span<const char>>& split, KeyPath& out)
+NODISCARD bool ParseKeyPath(const std::vector<Span<const char>>& split, KeyPath& out, std::string& error)
{
for (size_t i = 1; i < split.size(); ++i) {
Span<const char> elem = split[i];
@@ -696,33 +700,60 @@ NODISCARD bool ParseKeyPath(const std::vector<Span<const char>>& split, KeyPath&
hardened = true;
}
uint32_t p;
- if (!ParseUInt32(std::string(elem.begin(), elem.end()), &p) || p > 0x7FFFFFFFUL) return false;
+ if (!ParseUInt32(std::string(elem.begin(), elem.end()), &p)) {
+ error = strprintf("Key path value '%s' is not a valid uint32", std::string(elem.begin(), elem.end()).c_str());
+ return false;
+ } else if (p > 0x7FFFFFFFUL) {
+ error = strprintf("Key path value %u is out of range", p);
+ return false;
+ }
out.push_back(p | (((uint32_t)hardened) << 31));
}
return true;
}
/** Parse a public key that excludes origin information. */
-std::unique_ptr<PubkeyProvider> ParsePubkeyInner(const Span<const char>& sp, bool permit_uncompressed, FlatSigningProvider& out)
+std::unique_ptr<PubkeyProvider> ParsePubkeyInner(const Span<const char>& sp, bool permit_uncompressed, FlatSigningProvider& out, std::string& error)
{
auto split = Split(sp, '/');
std::string str(split[0].begin(), split[0].end());
+ if (str.size() == 0) {
+ error = "No key provided";
+ return nullptr;
+ }
if (split.size() == 1) {
if (IsHex(str)) {
std::vector<unsigned char> data = ParseHex(str);
CPubKey pubkey(data);
- if (pubkey.IsFullyValid() && (permit_uncompressed || pubkey.IsCompressed())) return MakeUnique<ConstPubkeyProvider>(pubkey);
+ if (pubkey.IsFullyValid()) {
+ if (permit_uncompressed || pubkey.IsCompressed()) {
+ return MakeUnique<ConstPubkeyProvider>(pubkey);
+ } else {
+ error = "Uncompressed keys are not allowed";
+ return nullptr;
+ }
+ }
+ error = strprintf("Pubkey '%s' is invalid", str);
+ return nullptr;
}
CKey key = DecodeSecret(str);
- if (key.IsValid() && (permit_uncompressed || key.IsCompressed())) {
- CPubKey pubkey = key.GetPubKey();
- out.keys.emplace(pubkey.GetID(), key);
- return MakeUnique<ConstPubkeyProvider>(pubkey);
+ if (key.IsValid()) {
+ if (permit_uncompressed || key.IsCompressed()) {
+ CPubKey pubkey = key.GetPubKey();
+ out.keys.emplace(pubkey.GetID(), key);
+ return MakeUnique<ConstPubkeyProvider>(pubkey);
+ } else {
+ error = "Uncompressed keys are not allowed";
+ return nullptr;
+ }
}
}
CExtKey extkey = DecodeExtKey(str);
CExtPubKey extpubkey = DecodeExtPubKey(str);
- if (!extkey.key.IsValid() && !extpubkey.pubkey.IsValid()) return nullptr;
+ if (!extkey.key.IsValid() && !extpubkey.pubkey.IsValid()) {
+ error = strprintf("key '%s' is not valid", str);
+ return nullptr;
+ }
KeyPath path;
DeriveType type = DeriveType::NO;
if (split.back() == MakeSpan("*").first(1)) {
@@ -732,7 +763,7 @@ std::unique_ptr<PubkeyProvider> ParsePubkeyInner(const Span<const char>& sp, boo
split.pop_back();
type = DeriveType::HARDENED;
}
- if (!ParseKeyPath(split, path)) return nullptr;
+ if (!ParseKeyPath(split, path, error)) return nullptr;
if (extkey.key.IsValid()) {
extpubkey = extkey.Neuter();
out.keys.emplace(extpubkey.pubkey.GetID(), extkey.key);
@@ -741,95 +772,154 @@ std::unique_ptr<PubkeyProvider> ParsePubkeyInner(const Span<const char>& sp, boo
}
/** Parse a public key including origin information (if enabled). */
-std::unique_ptr<PubkeyProvider> ParsePubkey(const Span<const char>& sp, bool permit_uncompressed, FlatSigningProvider& out)
+std::unique_ptr<PubkeyProvider> ParsePubkey(const Span<const char>& sp, bool permit_uncompressed, FlatSigningProvider& out, std::string& error)
{
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;
+ if (origin_split.size() > 2) {
+ error = "Multiple ']' characters found for a single pubkey";
+ return nullptr;
+ }
+ if (origin_split.size() == 1) return ParsePubkeyInner(origin_split[0], permit_uncompressed, out, error);
+ if (origin_split[0].size() < 1 || origin_split[0][0] != '[') {
+ error = strprintf("Key origin start '[ character expected but not found, got '%c' instead", origin_split[0][0]);
+ return nullptr;
+ }
auto slash_split = Split(origin_split[0].subspan(1), '/');
- if (slash_split[0].size() != 8) return nullptr;
+ if (slash_split[0].size() != 8) {
+ error = strprintf("Fingerprint is not 4 bytes (%u characters instead of 8 characters)", slash_split[0].size());
+ return nullptr;
+ }
std::string fpr_hex = std::string(slash_split[0].begin(), slash_split[0].end());
- if (!IsHex(fpr_hex)) return nullptr;
+ if (!IsHex(fpr_hex)) {
+ error = strprintf("Fingerprint '%s' is not hex", 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 (!ParseKeyPath(slash_split, info.path, error)) return nullptr;
+ auto provider = ParsePubkeyInner(origin_split[1], permit_uncompressed, out, error);
if (!provider) return nullptr;
return MakeUnique<OriginPubkeyProvider>(std::move(info), std::move(provider));
}
/** Parse a script in a particular context. */
-std::unique_ptr<DescriptorImpl> ParseScript(Span<const char>& sp, ParseScriptContext ctx, FlatSigningProvider& out)
+std::unique_ptr<DescriptorImpl> ParseScript(Span<const char>& sp, ParseScriptContext ctx, FlatSigningProvider& out, std::string& error)
{
auto expr = Expr(sp);
if (Func("pk", expr)) {
- auto pubkey = ParsePubkey(expr, ctx != ParseScriptContext::P2WSH, out);
+ auto pubkey = ParsePubkey(expr, ctx != ParseScriptContext::P2WSH, out, error);
if (!pubkey) return nullptr;
return MakeUnique<PKDescriptor>(std::move(pubkey));
}
if (Func("pkh", expr)) {
- auto pubkey = ParsePubkey(expr, ctx != ParseScriptContext::P2WSH, out);
+ auto pubkey = ParsePubkey(expr, ctx != ParseScriptContext::P2WSH, out, error);
if (!pubkey) return nullptr;
return MakeUnique<PKHDescriptor>(std::move(pubkey));
}
if (ctx == ParseScriptContext::TOP && Func("combo", expr)) {
- auto pubkey = ParsePubkey(expr, true, out);
+ auto pubkey = ParsePubkey(expr, true, out, error);
if (!pubkey) return nullptr;
return MakeUnique<ComboDescriptor>(std::move(pubkey));
+ } else if (ctx != ParseScriptContext::TOP && Func("combo", expr)) {
+ error = "Cannot have combo in non-top level";
+ return nullptr;
}
if (Func("multi", expr)) {
auto threshold = Expr(expr);
uint32_t thres;
std::vector<std::unique_ptr<PubkeyProvider>> providers;
- if (!ParseUInt32(std::string(threshold.begin(), threshold.end()), &thres)) return nullptr;
+ if (!ParseUInt32(std::string(threshold.begin(), threshold.end()), &thres)) {
+ error = strprintf("Multi threshold '%s' is not valid", std::string(threshold.begin(), threshold.end()).c_str());
+ return nullptr;
+ }
size_t script_size = 0;
while (expr.size()) {
- if (!Const(",", expr)) return nullptr;
+ if (!Const(",", expr)) {
+ error = strprintf("Multi: expected ',', got '%c'", expr[0]);
+ return nullptr;
+ }
auto arg = Expr(expr);
- auto pk = ParsePubkey(arg, ctx != ParseScriptContext::P2WSH, out);
+ auto pk = ParsePubkey(arg, ctx != ParseScriptContext::P2WSH, out, error);
if (!pk) return nullptr;
script_size += pk->GetSize() + 1;
providers.emplace_back(std::move(pk));
}
- if (providers.size() < 1 || providers.size() > 16 || thres < 1 || thres > providers.size()) return nullptr;
+ if (providers.size() < 1 || providers.size() > 16) {
+ error = strprintf("Cannot have %u keys in multisig; must have between 1 and 16 keys, inclusive", providers.size());
+ return nullptr;
+ } else if (thres < 1) {
+ error = strprintf("Multisig threshold cannot be %d, must be at least 1", thres);
+ return nullptr;
+ } 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 nullptr;
+ }
if (ctx == ParseScriptContext::TOP) {
- if (providers.size() > 3) return nullptr; // Not more than 3 pubkeys for raw multisig
+ if (providers.size() > 3) {
+ error = strprintf("Cannot have %u pubkeys in bare multisig; only at most 3 pubkeys", providers.size());
+ return nullptr;
+ }
}
if (ctx == ParseScriptContext::P2SH) {
- if (script_size + 3 > 520) return nullptr; // Enforce P2SH script size limit
+ if (script_size + 3 > 520) {
+ error = strprintf("P2SH script is too large, %d bytes is larger than 520 bytes", script_size + 3);
+ return nullptr;
+ }
}
return MakeUnique<MultisigDescriptor>(thres, std::move(providers));
}
if (ctx != ParseScriptContext::P2WSH && Func("wpkh", expr)) {
- auto pubkey = ParsePubkey(expr, false, out);
+ auto pubkey = ParsePubkey(expr, false, out, error);
if (!pubkey) return nullptr;
return MakeUnique<WPKHDescriptor>(std::move(pubkey));
+ } else if (ctx == ParseScriptContext::P2WSH && Func("wpkh", expr)) {
+ error = "Cannot have wpkh within wsh";
+ return nullptr;
}
if (ctx == ParseScriptContext::TOP && Func("sh", expr)) {
- auto desc = ParseScript(expr, ParseScriptContext::P2SH, out);
+ auto desc = ParseScript(expr, ParseScriptContext::P2SH, out, error);
if (!desc || expr.size()) return nullptr;
return MakeUnique<SHDescriptor>(std::move(desc));
+ } else if (ctx != ParseScriptContext::TOP && Func("sh", expr)) {
+ error = "Cannot have sh in non-top level";
+ return nullptr;
}
if (ctx != ParseScriptContext::P2WSH && Func("wsh", expr)) {
- auto desc = ParseScript(expr, ParseScriptContext::P2WSH, out);
+ auto desc = ParseScript(expr, ParseScriptContext::P2WSH, out, error);
if (!desc || expr.size()) return nullptr;
return MakeUnique<WSHDescriptor>(std::move(desc));
+ } else if (ctx == ParseScriptContext::P2WSH && Func("wsh", expr)) {
+ error = "Cannot have wsh within wsh";
+ return nullptr;
}
if (ctx == ParseScriptContext::TOP && Func("addr", expr)) {
CTxDestination dest = DecodeDestination(std::string(expr.begin(), expr.end()));
- if (!IsValidDestination(dest)) return nullptr;
+ if (!IsValidDestination(dest)) {
+ error = "Address is not valid";
+ return nullptr;
+ }
return MakeUnique<AddressDescriptor>(std::move(dest));
}
if (ctx == ParseScriptContext::TOP && Func("raw", expr)) {
std::string str(expr.begin(), expr.end());
- if (!IsHex(str)) return nullptr;
+ if (!IsHex(str)) {
+ error = "Raw script is not hex";
+ return nullptr;
+ }
auto bytes = ParseHex(str);
return MakeUnique<RawDescriptor>(CScript(bytes.begin(), bytes.end()));
}
+ if (ctx == ParseScriptContext::P2SH) {
+ error = "A function is needed within P2SH";
+ return nullptr;
+ } else if (ctx == ParseScriptContext::P2WSH) {
+ error = "A function is needed within P2WSH";
+ return nullptr;
+ }
+ error = strprintf("%s is not a valid descriptor function", std::string(expr.begin(), expr.end()));
return nullptr;
}
@@ -910,27 +1000,58 @@ std::unique_ptr<DescriptorImpl> InferScript(const CScript& script, ParseScriptCo
} // namespace
-std::unique_ptr<Descriptor> Parse(const std::string& descriptor, FlatSigningProvider& out, bool require_checksum)
+/** Check a descriptor checksum, and update desc to be the checksum-less part. */
+bool CheckChecksum(Span<const char>& sp, bool require_checksum, std::string& error, std::string* out_checksum = nullptr)
{
- 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) {
+ 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 (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
+ 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;
+}
- auto ret = ParseScript(sp, ParseScriptContext::TOP, out);
+std::unique_ptr<Descriptor> Parse(const std::string& descriptor, FlatSigningProvider& out, std::string& error, bool require_checksum)
+{
+ Span<const char> sp(descriptor.data(), descriptor.size());
+ if (!CheckChecksum(sp, require_checksum, error)) return nullptr;
+ auto ret = ParseScript(sp, ParseScriptContext::TOP, out, error);
if (sp.size() == 0 && ret) return std::unique_ptr<Descriptor>(std::move(ret));
return nullptr;
}
+std::string GetDescriptorChecksum(const std::string& descriptor)
+{
+ std::string ret;
+ std::string error;
+ Span<const char> sp(descriptor.data(), descriptor.size());
+ 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);
generated by cgit v1.2.3 (git 2.26.2) at 2024-07-25 06:24:25 +0000