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1 : : // Copyright (c) 2019-2022 The Bitcoin Core developers
2 : : // Distributed under the MIT software license, see the accompanying
3 : : // file COPYING or http://www.opensource.org/licenses/mit-license.php.
4 : :
5 : : #ifndef BITCOIN_SCRIPT_MINISCRIPT_H
6 : : #define BITCOIN_SCRIPT_MINISCRIPT_H
7 : :
8 : : #include <algorithm>
9 : : #include <functional>
10 : : #include <numeric>
11 : : #include <memory>
12 : : #include <optional>
13 : : #include <string>
14 : : #include <vector>
15 : :
16 : : #include <assert.h>
17 : : #include <cstdlib>
18 : :
19 : : #include <policy/policy.h>
20 : : #include <primitives/transaction.h>
21 : : #include <script/script.h>
22 : : #include <span.h>
23 : : #include <util/check.h>
24 : : #include <util/spanparsing.h>
25 : : #include <util/strencodings.h>
26 : : #include <util/string.h>
27 : : #include <util/vector.h>
28 : :
29 : : namespace miniscript {
30 : :
31 : : /** This type encapsulates the miniscript type system properties.
32 : : *
33 : : * Every miniscript expression is one of 4 basic types, and additionally has
34 : : * a number of boolean type properties.
35 : : *
36 : : * The basic types are:
37 : : * - "B" Base:
38 : : * - Takes its inputs from the top of the stack.
39 : : * - When satisfied, pushes a nonzero value of up to 4 bytes onto the stack.
40 : : * - When dissatisfied, pushes a 0 onto the stack.
41 : : * - This is used for most expressions, and required for the top level one.
42 : : * - For example: older(n) = <n> OP_CHECKSEQUENCEVERIFY.
43 : : * - "V" Verify:
44 : : * - Takes its inputs from the top of the stack.
45 : : * - When satisfied, pushes nothing.
46 : : * - Cannot be dissatisfied.
47 : : * - This can be obtained by adding an OP_VERIFY to a B, modifying the last opcode
48 : : * of a B to its -VERIFY version (only for OP_CHECKSIG, OP_CHECKSIGVERIFY,
49 : : * OP_NUMEQUAL and OP_EQUAL), or by combining a V fragment under some conditions.
50 : : * - For example vc:pk_k(key) = <key> OP_CHECKSIGVERIFY
51 : : * - "K" Key:
52 : : * - Takes its inputs from the top of the stack.
53 : : * - Becomes a B when followed by OP_CHECKSIG.
54 : : * - Always pushes a public key onto the stack, for which a signature is to be
55 : : * provided to satisfy the expression.
56 : : * - For example pk_h(key) = OP_DUP OP_HASH160 <Hash160(key)> OP_EQUALVERIFY
57 : : * - "W" Wrapped:
58 : : * - Takes its input from one below the top of the stack.
59 : : * - When satisfied, pushes a nonzero value (like B) on top of the stack, or one below.
60 : : * - When dissatisfied, pushes 0 op top of the stack or one below.
61 : : * - Is always "OP_SWAP [B]" or "OP_TOALTSTACK [B] OP_FROMALTSTACK".
62 : : * - For example sc:pk_k(key) = OP_SWAP <key> OP_CHECKSIG
63 : : *
64 : : * There a type properties that help reasoning about correctness:
65 : : * - "z" Zero-arg:
66 : : * - Is known to always consume exactly 0 stack elements.
67 : : * - For example after(n) = <n> OP_CHECKLOCKTIMEVERIFY
68 : : * - "o" One-arg:
69 : : * - Is known to always consume exactly 1 stack element.
70 : : * - Conflicts with property 'z'
71 : : * - For example sha256(hash) = OP_SIZE 32 OP_EQUALVERIFY OP_SHA256 <hash> OP_EQUAL
72 : : * - "n" Nonzero:
73 : : * - For every way this expression can be satisfied, a satisfaction exists that never needs
74 : : * a zero top stack element.
75 : : * - Conflicts with property 'z' and with type 'W'.
76 : : * - "d" Dissatisfiable:
77 : : * - There is an easy way to construct a dissatisfaction for this expression.
78 : : * - Conflicts with type 'V'.
79 : : * - "u" Unit:
80 : : * - In case of satisfaction, an exact 1 is put on the stack (rather than just nonzero).
81 : : * - Conflicts with type 'V'.
82 : : *
83 : : * Additional type properties help reasoning about nonmalleability:
84 : : * - "e" Expression:
85 : : * - This implies property 'd', but the dissatisfaction is nonmalleable.
86 : : * - This generally requires 'e' for all subexpressions which are invoked for that
87 : : * dissatifsaction, and property 'f' for the unexecuted subexpressions in that case.
88 : : * - Conflicts with type 'V'.
89 : : * - "f" Forced:
90 : : * - Dissatisfactions (if any) for this expression always involve at least one signature.
91 : : * - Is always true for type 'V'.
92 : : * - "s" Safe:
93 : : * - Satisfactions for this expression always involve at least one signature.
94 : : * - "m" Nonmalleable:
95 : : * - For every way this expression can be satisfied (which may be none),
96 : : * a nonmalleable satisfaction exists.
97 : : * - This generally requires 'm' for all subexpressions, and 'e' for all subexpressions
98 : : * which are dissatisfied when satisfying the parent.
99 : : *
100 : : * One type property is an implementation detail:
101 : : * - "x" Expensive verify:
102 : : * - Expressions with this property have a script whose last opcode is not EQUAL, CHECKSIG, or CHECKMULTISIG.
103 : : * - Not having this property means that it can be converted to a V at no cost (by switching to the
104 : : * -VERIFY version of the last opcode).
105 : : *
106 : : * Five more type properties for representing timelock information. Spend paths
107 : : * in miniscripts containing conflicting timelocks and heightlocks cannot be spent together.
108 : : * This helps users detect if miniscript does not match the semantic behaviour the
109 : : * user expects.
110 : : * - "g" Whether the branch contains a relative time timelock
111 : : * - "h" Whether the branch contains a relative height timelock
112 : : * - "i" Whether the branch contains an absolute time timelock
113 : : * - "j" Whether the branch contains an absolute height timelock
114 : : * - "k"
115 : : * - Whether all satisfactions of this expression don't contain a mix of heightlock and timelock
116 : : * of the same type.
117 : : * - If the miniscript does not have the "k" property, the miniscript template will not match
118 : : * the user expectation of the corresponding spending policy.
119 : : * For each of these properties the subset rule holds: an expression with properties X, Y, and Z, is also
120 : : * valid in places where an X, a Y, a Z, an XY, ... is expected.
121 : : */
122 : : class Type {
123 : : //! Internal bitmap of properties (see ""_mst operator for details).
124 : : uint32_t m_flags;
125 : :
126 : : //! Internal constructor used by the ""_mst operator.
127 : 0 : explicit constexpr Type(uint32_t flags) : m_flags(flags) {}
128 : :
129 : : public:
130 : : //! The only way to publicly construct a Type is using this literal operator.
131 : : friend constexpr Type operator"" _mst(const char* c, size_t l);
132 : :
133 : : //! Compute the type with the union of properties.
134 : 0 : constexpr Type operator|(Type x) const { return Type(m_flags | x.m_flags); }
135 : :
136 : : //! Compute the type with the intersection of properties.
137 : 0 : constexpr Type operator&(Type x) const { return Type(m_flags & x.m_flags); }
138 : :
139 : : //! Check whether the left hand's properties are superset of the right's (= left is a subtype of right).
140 : 0 : constexpr bool operator<<(Type x) const { return (x.m_flags & ~m_flags) == 0; }
141 : :
142 : : //! Comparison operator to enable use in sets/maps (total ordering incompatible with <<).
143 : 0 : constexpr bool operator<(Type x) const { return m_flags < x.m_flags; }
144 : :
145 : : //! Equality operator.
146 : 0 : constexpr bool operator==(Type x) const { return m_flags == x.m_flags; }
147 : :
148 : : //! The empty type if x is false, itself otherwise.
149 [ # # ]: 0 : constexpr Type If(bool x) const { return Type(x ? m_flags : 0); }
150 : : };
151 : :
152 : : //! Literal operator to construct Type objects.
153 : 0 : inline constexpr Type operator"" _mst(const char* c, size_t l) {
154 : 0 : Type typ{0};
155 : :
156 [ # # ]: 0 : for (const char *p = c; p < c + l; p++) {
157 : 0 : typ = typ | Type(
158 [ # # ]: 0 : *p == 'B' ? 1 << 0 : // Base type
159 [ # # ]: 0 : *p == 'V' ? 1 << 1 : // Verify type
160 [ # # ]: 0 : *p == 'K' ? 1 << 2 : // Key type
161 [ # # ]: 0 : *p == 'W' ? 1 << 3 : // Wrapped type
162 [ # # ]: 0 : *p == 'z' ? 1 << 4 : // Zero-arg property
163 [ # # ]: 0 : *p == 'o' ? 1 << 5 : // One-arg property
164 [ # # ]: 0 : *p == 'n' ? 1 << 6 : // Nonzero arg property
165 [ # # ]: 0 : *p == 'd' ? 1 << 7 : // Dissatisfiable property
166 [ # # ]: 0 : *p == 'u' ? 1 << 8 : // Unit property
167 [ # # ]: 0 : *p == 'e' ? 1 << 9 : // Expression property
168 [ # # ]: 0 : *p == 'f' ? 1 << 10 : // Forced property
169 [ # # ]: 0 : *p == 's' ? 1 << 11 : // Safe property
170 [ # # ]: 0 : *p == 'm' ? 1 << 12 : // Nonmalleable property
171 [ # # ]: 0 : *p == 'x' ? 1 << 13 : // Expensive verify
172 [ # # ]: 0 : *p == 'g' ? 1 << 14 : // older: contains relative time timelock (csv_time)
173 [ # # ]: 0 : *p == 'h' ? 1 << 15 : // older: contains relative height timelock (csv_height)
174 [ # # ]: 0 : *p == 'i' ? 1 << 16 : // after: contains time timelock (cltv_time)
175 [ # # ]: 0 : *p == 'j' ? 1 << 17 : // after: contains height timelock (cltv_height)
176 [ # # ]: 0 : *p == 'k' ? 1 << 18 : // does not contain a combination of height and time locks
177 [ # # ][ # # ]: 0 : (throw std::logic_error("Unknown character in _mst literal"), 0)
178 : : );
179 : 0 : }
180 : :
181 : 0 : return typ;
182 : 0 : }
183 : :
184 : : using Opcode = std::pair<opcodetype, std::vector<unsigned char>>;
185 : :
186 : : template<typename Key> struct Node;
187 : : template<typename Key> using NodeRef = std::shared_ptr<const Node<Key>>;
188 : :
189 : : //! Construct a miniscript node as a shared_ptr.
190 : : template<typename Key, typename... Args>
191 : 0 : NodeRef<Key> MakeNodeRef(Args&&... args) { return std::make_shared<const Node<Key>>(std::forward<Args>(args)...); }
192 : :
193 : : //! The different node types in miniscript.
194 : : enum class Fragment {
195 : : JUST_0, //!< OP_0
196 : : JUST_1, //!< OP_1
197 : : PK_K, //!< [key]
198 : : PK_H, //!< OP_DUP OP_HASH160 [keyhash] OP_EQUALVERIFY
199 : : OLDER, //!< [n] OP_CHECKSEQUENCEVERIFY
200 : : AFTER, //!< [n] OP_CHECKLOCKTIMEVERIFY
201 : : SHA256, //!< OP_SIZE 32 OP_EQUALVERIFY OP_SHA256 [hash] OP_EQUAL
202 : : HASH256, //!< OP_SIZE 32 OP_EQUALVERIFY OP_HASH256 [hash] OP_EQUAL
203 : : RIPEMD160, //!< OP_SIZE 32 OP_EQUALVERIFY OP_RIPEMD160 [hash] OP_EQUAL
204 : : HASH160, //!< OP_SIZE 32 OP_EQUALVERIFY OP_HASH160 [hash] OP_EQUAL
205 : : WRAP_A, //!< OP_TOALTSTACK [X] OP_FROMALTSTACK
206 : : WRAP_S, //!< OP_SWAP [X]
207 : : WRAP_C, //!< [X] OP_CHECKSIG
208 : : WRAP_D, //!< OP_DUP OP_IF [X] OP_ENDIF
209 : : WRAP_V, //!< [X] OP_VERIFY (or -VERIFY version of last opcode in X)
210 : : WRAP_J, //!< OP_SIZE OP_0NOTEQUAL OP_IF [X] OP_ENDIF
211 : : WRAP_N, //!< [X] OP_0NOTEQUAL
212 : : AND_V, //!< [X] [Y]
213 : : AND_B, //!< [X] [Y] OP_BOOLAND
214 : : OR_B, //!< [X] [Y] OP_BOOLOR
215 : : OR_C, //!< [X] OP_NOTIF [Y] OP_ENDIF
216 : : OR_D, //!< [X] OP_IFDUP OP_NOTIF [Y] OP_ENDIF
217 : : OR_I, //!< OP_IF [X] OP_ELSE [Y] OP_ENDIF
218 : : ANDOR, //!< [X] OP_NOTIF [Z] OP_ELSE [Y] OP_ENDIF
219 : : THRESH, //!< [X1] ([Xn] OP_ADD)* [k] OP_EQUAL
220 : : MULTI, //!< [k] [key_n]* [n] OP_CHECKMULTISIG (only available within P2WSH context)
221 : : MULTI_A, //!< [key_0] OP_CHECKSIG ([key_n] OP_CHECKSIGADD)* [k] OP_NUMEQUAL (only within Tapscript ctx)
222 : : // AND_N(X,Y) is represented as ANDOR(X,Y,0)
223 : : // WRAP_T(X) is represented as AND_V(X,1)
224 : : // WRAP_L(X) is represented as OR_I(0,X)
225 : : // WRAP_U(X) is represented as OR_I(X,0)
226 : : };
227 : :
228 : : enum class Availability {
229 : : NO,
230 : : YES,
231 : : MAYBE,
232 : : };
233 : :
234 : : enum class MiniscriptContext {
235 : : P2WSH,
236 : : TAPSCRIPT,
237 : : };
238 : :
239 : : /** Whether the context Tapscript, ensuring the only other possibility is P2WSH. */
240 : 0 : constexpr bool IsTapscript(MiniscriptContext ms_ctx)
241 : : {
242 [ # # # ]: 0 : switch (ms_ctx) {
243 : 0 : case MiniscriptContext::P2WSH: return false;
244 : 0 : case MiniscriptContext::TAPSCRIPT: return true;
245 : : }
246 : 0 : assert(false);
247 : 0 : }
248 : :
249 : : namespace internal {
250 : :
251 : : //! The maximum size of a witness item for a Miniscript under Tapscript context. (A BIP340 signature with a sighash type byte.)
252 : : static constexpr uint32_t MAX_TAPMINISCRIPT_STACK_ELEM_SIZE{65};
253 : :
254 : : //! nVersion + nLockTime
255 : : constexpr uint32_t TX_OVERHEAD{4 + 4};
256 : : //! prevout + nSequence + scriptSig
257 : : constexpr uint32_t TXIN_BYTES_NO_WITNESS{36 + 4 + 1};
258 : : //! nValue + script len + OP_0 + pushdata 32.
259 : : constexpr uint32_t P2WSH_TXOUT_BYTES{8 + 1 + 1 + 33};
260 : : //! Data other than the witness in a transaction. Overhead + vin count + one vin + vout count + one vout + segwit marker
261 : : constexpr uint32_t TX_BODY_LEEWAY_WEIGHT{(TX_OVERHEAD + GetSizeOfCompactSize(1) + TXIN_BYTES_NO_WITNESS + GetSizeOfCompactSize(1) + P2WSH_TXOUT_BYTES) * WITNESS_SCALE_FACTOR + 2};
262 : : //! Maximum possible stack size to spend a Taproot output (excluding the script itself).
263 : : constexpr uint32_t MAX_TAPSCRIPT_SAT_SIZE{GetSizeOfCompactSize(MAX_STACK_SIZE) + (GetSizeOfCompactSize(MAX_TAPMINISCRIPT_STACK_ELEM_SIZE) + MAX_TAPMINISCRIPT_STACK_ELEM_SIZE) * MAX_STACK_SIZE + GetSizeOfCompactSize(TAPROOT_CONTROL_MAX_SIZE) + TAPROOT_CONTROL_MAX_SIZE};
264 : : /** The maximum size of a script depending on the context. */
265 : 0 : constexpr uint32_t MaxScriptSize(MiniscriptContext ms_ctx)
266 : : {
267 [ # # ]: 0 : if (IsTapscript(ms_ctx)) {
268 : : // Leaf scripts under Tapscript are not explicitly limited in size. They are only implicitly
269 : : // bounded by the maximum standard size of a spending transaction. Let the maximum script
270 : : // size conservatively be small enough such that even a maximum sized witness and a reasonably
271 : : // sized spending transaction can spend an output paying to this script without running into
272 : : // the maximum standard tx size limit.
273 : 0 : constexpr auto max_size{MAX_STANDARD_TX_WEIGHT - TX_BODY_LEEWAY_WEIGHT - MAX_TAPSCRIPT_SAT_SIZE};
274 : 0 : return max_size - GetSizeOfCompactSize(max_size);
275 : : }
276 : 0 : return MAX_STANDARD_P2WSH_SCRIPT_SIZE;
277 : 0 : }
278 : :
279 : : //! Helper function for Node::CalcType.
280 : : Type ComputeType(Fragment fragment, Type x, Type y, Type z, const std::vector<Type>& sub_types, uint32_t k, size_t data_size, size_t n_subs, size_t n_keys, MiniscriptContext ms_ctx);
281 : :
282 : : //! Helper function for Node::CalcScriptLen.
283 : : size_t ComputeScriptLen(Fragment fragment, Type sub0typ, size_t subsize, uint32_t k, size_t n_subs, size_t n_keys, MiniscriptContext ms_ctx);
284 : :
285 : : //! A helper sanitizer/checker for the output of CalcType.
286 : : Type SanitizeType(Type x);
287 : :
288 : : //! An object representing a sequence of witness stack elements.
289 : 0 : struct InputStack {
290 : : /** Whether this stack is valid for its intended purpose (satisfaction or dissatisfaction of a Node).
291 : : * The MAYBE value is used for size estimation, when keys/preimages may actually be unavailable,
292 : : * but may be available at signing time. This makes the InputStack structure and signing logic,
293 : : * filled with dummy signatures/preimages usable for witness size estimation.
294 : : */
295 : 40 : Availability available = Availability::YES;
296 : : //! Whether this stack contains a digital signature.
297 : 40 : bool has_sig = false;
298 : : //! Whether this stack is malleable (can be turned into an equally valid other stack by a third party).
299 : 40 : bool malleable = false;
300 : : //! Whether this stack is non-canonical (using a construction known to be unnecessary for satisfaction).
301 : : //! Note that this flag does not affect the satisfaction algorithm; it is only used for sanity checking.
302 : 40 : bool non_canon = false;
303 : : //! Serialized witness size.
304 : 16 : size_t size = 0;
305 : : //! Data elements.
306 : : std::vector<std::vector<unsigned char>> stack;
307 : : //! Construct an empty stack (valid).
308 : 32 : InputStack() {}
309 : : //! Construct a valid single-element stack (with an element up to 75 bytes).
310 : 48 : InputStack(std::vector<unsigned char> in) : size(in.size() + 1), stack(Vector(std::move(in))) {}
311 : : //! Change availability
312 : : InputStack& SetAvailable(Availability avail);
313 : : //! Mark this input stack as having a signature.
314 : : InputStack& SetWithSig();
315 : : //! Mark this input stack as non-canonical (known to not be necessary in non-malleable satisfactions).
316 : : InputStack& SetNonCanon();
317 : : //! Mark this input stack as malleable.
318 : : InputStack& SetMalleable(bool x = true);
319 : : //! Concatenate two input stacks.
320 : : friend InputStack operator+(InputStack a, InputStack b);
321 : : //! Choose between two potential input stacks.
322 : : friend InputStack operator|(InputStack a, InputStack b);
323 : : };
324 : :
325 : : /** A stack consisting of a single zero-length element (interpreted as 0 by the script interpreter in numeric context). */
326 : : static const auto ZERO = InputStack(std::vector<unsigned char>());
327 : : /** A stack consisting of a single malleable 32-byte 0x0000...0000 element (for dissatisfying hash challenges). */
328 : : static const auto ZERO32 = InputStack(std::vector<unsigned char>(32, 0)).SetMalleable();
329 : : /** A stack consisting of a single 0x01 element (interpreted as 1 by the script interpreted in numeric context). */
330 : : static const auto ONE = InputStack(Vector((unsigned char)1));
331 : : /** The empty stack. */
332 : : static const auto EMPTY = InputStack();
333 : : /** A stack representing the lack of any (dis)satisfactions. */
334 : : static const auto INVALID = InputStack().SetAvailable(Availability::NO);
335 : :
336 : : //! A pair of a satisfaction and a dissatisfaction InputStack.
337 : 0 : struct InputResult {
338 : : InputStack nsat, sat;
339 : :
340 : : template<typename A, typename B>
341 [ # # ][ # # ]: 0 : InputResult(A&& in_nsat, B&& in_sat) : nsat(std::forward<A>(in_nsat)), sat(std::forward<B>(in_sat)) {}
[ # # ]
342 : : };
343 : :
344 : : //! Class whose objects represent the maximum of a list of integers.
345 : : template<typename I>
346 : : struct MaxInt {
347 : : const bool valid;
348 : : const I value;
349 : :
350 : 0 : MaxInt() : valid(false), value(0) {}
351 : 0 : MaxInt(I val) : valid(true), value(val) {}
352 : :
353 : 0 : friend MaxInt<I> operator+(const MaxInt<I>& a, const MaxInt<I>& b) {
354 [ # # ][ # # ]: 0 : if (!a.valid || !b.valid) return {};
355 : 0 : return a.value + b.value;
356 : 0 : }
357 : :
358 : 0 : friend MaxInt<I> operator|(const MaxInt<I>& a, const MaxInt<I>& b) {
359 [ # # ]: 0 : if (!a.valid) return b;
360 [ # # ]: 0 : if (!b.valid) return a;
361 : 0 : return std::max(a.value, b.value);
362 : 0 : }
363 : : };
364 : :
365 : : struct Ops {
366 : : //! Non-push opcodes.
367 : : uint32_t count;
368 : : //! Number of keys in possibly executed OP_CHECKMULTISIG(VERIFY)s to satisfy.
369 : : MaxInt<uint32_t> sat;
370 : : //! Number of keys in possibly executed OP_CHECKMULTISIG(VERIFY)s to dissatisfy.
371 : : MaxInt<uint32_t> dsat;
372 : :
373 : 0 : Ops(uint32_t in_count, MaxInt<uint32_t> in_sat, MaxInt<uint32_t> in_dsat) : count(in_count), sat(in_sat), dsat(in_dsat) {};
374 : : };
375 : :
376 : : /** A data structure to help the calculation of stack size limits.
377 : : *
378 : : * Conceptually, every SatInfo object corresponds to a (possibly empty) set of script execution
379 : : * traces (sequences of opcodes).
380 : : * - SatInfo{} corresponds to the empty set.
381 : : * - SatInfo{n, e} corresponds to a single trace whose net effect is removing n elements from the
382 : : * stack (may be negative for a net increase), and reaches a maximum of e stack elements more
383 : : * than it ends with.
384 : : * - operator| is the union operation: (a | b) corresponds to the union of the traces in a and the
385 : : * traces in b.
386 : : * - operator+ is the concatenation operator: (a + b) corresponds to the set of traces formed by
387 : : * concatenating any trace in a with any trace in b.
388 : : *
389 : : * Its fields are:
390 : : * - valid is true if the set is non-empty.
391 : : * - netdiff (if valid) is the largest difference between stack size at the beginning and at the
392 : : * end of the script across all traces in the set.
393 : : * - exec (if valid) is the largest difference between stack size anywhere during execution and at
394 : : * the end of the script, across all traces in the set (note that this is not necessarily due
395 : : * to the same trace as the one that resulted in the value for netdiff).
396 : : *
397 : : * This allows us to build up stack size limits for any script efficiently, by starting from the
398 : : * individual opcodes miniscripts correspond to, using concatenation to construct scripts, and
399 : : * using the union operation to choose between execution branches. Since any top-level script
400 : : * satisfaction ends with a single stack element, we know that for a full script:
401 : : * - netdiff+1 is the maximal initial stack size (relevant for P2WSH stack limits).
402 : : * - exec+1 is the maximal stack size reached during execution (relevant for P2TR stack limits).
403 : : *
404 : : * Mathematically, SatInfo forms a semiring:
405 : : * - operator| is the semiring addition operator, with identity SatInfo{}, and which is commutative
406 : : * and associative.
407 : : * - operator+ is the semiring multiplication operator, with identity SatInfo{0}, and which is
408 : : * associative.
409 : : * - operator+ is distributive over operator|, so (a + (b | c)) = (a+b | a+c). This means we do not
410 : : * need to actually materialize all possible full execution traces over the whole script (which
411 : : * may be exponential in the length of the script); instead we can use the union operation at the
412 : : * individual subexpression level, and concatenate the result with subexpressions before and
413 : : * after it.
414 : : * - It is not a commutative semiring, because a+b can differ from b+a. For example, "OP_1 OP_DROP"
415 : : * has exec=1, while "OP_DROP OP_1" has exec=0.
416 : : */
417 : : struct SatInfo {
418 : : //! Whether a canonical satisfaction/dissatisfaction is possible at all.
419 : : const bool valid;
420 : : //! How much higher the stack size at start of execution can be compared to at the end.
421 : : const int32_t netdiff;
422 : : //! Mow much higher the stack size can be during execution compared to at the end.
423 : : const int32_t exec;
424 : :
425 : : /** Empty script set. */
426 : 0 : constexpr SatInfo() noexcept : valid(false), netdiff(0), exec(0) {}
427 : :
428 : : /** Script set with a single script in it, with specified netdiff and exec. */
429 : 0 : constexpr SatInfo(int32_t in_netdiff, int32_t in_exec) noexcept :
430 : 0 : valid{true}, netdiff{in_netdiff}, exec{in_exec} {}
431 : :
432 : : /** Script set union. */
433 : 0 : constexpr friend SatInfo operator|(const SatInfo& a, const SatInfo& b) noexcept
434 : : {
435 : : // Union with an empty set is itself.
436 [ # # ]: 0 : if (!a.valid) return b;
437 [ # # ]: 0 : if (!b.valid) return a;
438 : : // Otherwise the netdiff and exec of the union is the maximum of the individual values.
439 : 0 : return {std::max(a.netdiff, b.netdiff), std::max(a.exec, b.exec)};
440 : 0 : }
441 : :
442 : : /** Script set concatenation. */
443 : 0 : constexpr friend SatInfo operator+(const SatInfo& a, const SatInfo& b) noexcept
444 : : {
445 : : // Concatenation with an empty set yields an empty set.
446 [ # # ][ # # ]: 0 : if (!a.valid || !b.valid) return {};
447 : : // Otherwise, the maximum stack size difference for the combined scripts is the sum of the
448 : : // netdiffs, and the maximum stack size difference anywhere is either b.exec (if the
449 : : // maximum occurred in b) or b.netdiff+a.exec (if the maximum occurred in a).
450 [ # # ]: 0 : return {a.netdiff + b.netdiff, std::max(b.exec, b.netdiff + a.exec)};
451 : 0 : }
452 : :
453 : : /** The empty script. */
454 : 0 : static constexpr SatInfo Empty() noexcept { return {0, 0}; }
455 : : /** A script consisting of a single push opcode. */
456 : 0 : static constexpr SatInfo Push() noexcept { return {-1, 0}; }
457 : : /** A script consisting of a single hash opcode. */
458 : 0 : static constexpr SatInfo Hash() noexcept { return {0, 0}; }
459 : : /** A script consisting of just a repurposed nop (OP_CHECKLOCKTIMEVERIFY, OP_CHECKSEQUENCEVERIFY). */
460 : 0 : static constexpr SatInfo Nop() noexcept { return {0, 0}; }
461 : : /** A script consisting of just OP_IF or OP_NOTIF. Note that OP_ELSE and OP_ENDIF have no stack effect. */
462 : 0 : static constexpr SatInfo If() noexcept { return {1, 1}; }
463 : : /** A script consisting of just a binary operator (OP_BOOLAND, OP_BOOLOR, OP_ADD). */
464 : 0 : static constexpr SatInfo BinaryOp() noexcept { return {1, 1}; }
465 : :
466 : : // Scripts for specific individual opcodes.
467 : 0 : static constexpr SatInfo OP_DUP() noexcept { return {-1, 0}; }
468 : 0 : static constexpr SatInfo OP_IFDUP(bool nonzero) noexcept { return {nonzero ? -1 : 0, 0}; }
469 : 0 : static constexpr SatInfo OP_EQUALVERIFY() noexcept { return {2, 2}; }
470 : 0 : static constexpr SatInfo OP_EQUAL() noexcept { return {1, 1}; }
471 : 0 : static constexpr SatInfo OP_SIZE() noexcept { return {-1, 0}; }
472 : 0 : static constexpr SatInfo OP_CHECKSIG() noexcept { return {1, 1}; }
473 : 0 : static constexpr SatInfo OP_0NOTEQUAL() noexcept { return {0, 0}; }
474 : 0 : static constexpr SatInfo OP_VERIFY() noexcept { return {1, 1}; }
475 : : };
476 : :
477 : : struct StackSize {
478 : : const SatInfo sat, dsat;
479 : :
480 : 0 : constexpr StackSize(SatInfo in_sat, SatInfo in_dsat) noexcept : sat(in_sat), dsat(in_dsat) {};
481 : 0 : constexpr StackSize(SatInfo in_both) noexcept : sat(in_both), dsat(in_both) {};
482 : : };
483 : :
484 : : struct WitnessSize {
485 : : //! Maximum witness size to satisfy;
486 : : MaxInt<uint32_t> sat;
487 : : //! Maximum witness size to dissatisfy;
488 : : MaxInt<uint32_t> dsat;
489 : :
490 : 0 : WitnessSize(MaxInt<uint32_t> in_sat, MaxInt<uint32_t> in_dsat) : sat(in_sat), dsat(in_dsat) {};
491 : : };
492 : :
493 : : struct NoDupCheck {};
494 : :
495 : : } // namespace internal
496 : :
497 : : //! A node in a miniscript expression.
498 : : template<typename Key>
499 : : struct Node {
500 : : //! What node type this node is.
501 : : const Fragment fragment;
502 : : //! The k parameter (time for OLDER/AFTER, threshold for THRESH(_M))
503 : : const uint32_t k = 0;
504 : : //! The keys used by this expression (only for PK_K/PK_H/MULTI)
505 : : const std::vector<Key> keys;
506 : : //! The data bytes in this expression (only for HASH160/HASH256/SHA256/RIPEMD10).
507 : : const std::vector<unsigned char> data;
508 : : //! Subexpressions (for WRAP_*/AND_*/OR_*/ANDOR/THRESH)
509 : : mutable std::vector<NodeRef<Key>> subs;
510 : : //! The Script context for this node. Either P2WSH or Tapscript.
511 : : const MiniscriptContext m_script_ctx;
512 : :
513 : : /* Destroy the shared pointers iteratively to avoid a stack-overflow due to recursive calls
514 : : * to the subs' destructors. */
515 : 0 : ~Node() {
516 [ # # ][ # # ]: 0 : while (!subs.empty()) {
517 : 0 : auto node = std::move(subs.back());
518 : 0 : subs.pop_back();
519 [ # # ][ # # ]: 0 : while (!node->subs.empty()) {
520 [ # # ][ # # ]: 0 : subs.push_back(std::move(node->subs.back()));
521 : 0 : node->subs.pop_back();
522 : : }
523 : 0 : }
524 : 0 : }
525 : :
526 : : private:
527 : : //! Cached ops counts.
528 : : const internal::Ops ops;
529 : : //! Cached stack size bounds.
530 : : const internal::StackSize ss;
531 : : //! Cached witness size bounds.
532 : : const internal::WitnessSize ws;
533 : : //! Cached expression type (computed by CalcType and fed through SanitizeType).
534 : : const Type typ;
535 : : //! Cached script length (computed by CalcScriptLen).
536 : : const size_t scriptlen;
537 : : //! Whether a public key appears more than once in this node. This value is initialized
538 : : //! by all constructors except the NoDupCheck ones. The NoDupCheck ones skip the
539 : : //! computation, requiring it to be done manually by invoking DuplicateKeyCheck().
540 : : //! DuplicateKeyCheck(), or a non-NoDupCheck constructor, will compute has_duplicate_keys
541 : : //! for all subnodes as well.
542 : : mutable std::optional<bool> has_duplicate_keys;
543 : :
544 : :
545 : : //! Compute the length of the script for this miniscript (including children).
546 : 0 : size_t CalcScriptLen() const {
547 : 0 : size_t subsize = 0;
548 [ # # ][ # # ]: 0 : for (const auto& sub : subs) {
549 : 0 : subsize += sub->ScriptSize();
550 : : }
551 [ # # ][ # # ]: 0 : Type sub0type = subs.size() > 0 ? subs[0]->GetType() : ""_mst;
552 : 0 : return internal::ComputeScriptLen(fragment, sub0type, subsize, k, subs.size(), keys.size(), m_script_ctx);
553 : : }
554 : :
555 : : /* Apply a recursive algorithm to a Miniscript tree, without actual recursive calls.
556 : : *
557 : : * The algorithm is defined by two functions: downfn and upfn. Conceptually, the
558 : : * result can be thought of as first using downfn to compute a "state" for each node,
559 : : * from the root down to the leaves. Then upfn is used to compute a "result" for each
560 : : * node, from the leaves back up to the root, which is then returned. In the actual
561 : : * implementation, both functions are invoked in an interleaved fashion, performing a
562 : : * depth-first traversal of the tree.
563 : : *
564 : : * In more detail, it is invoked as node.TreeEvalMaybe<Result>(root, downfn, upfn):
565 : : * - root is the state of the root node, of type State.
566 : : * - downfn is a callable (State&, const Node&, size_t) -> State, which given a
567 : : * node, its state, and an index of one of its children, computes the state of that
568 : : * child. It can modify the state. Children of a given node will have downfn()
569 : : * called in order.
570 : : * - upfn is a callable (State&&, const Node&, Span<Result>) -> std::optional<Result>,
571 : : * which given a node, its state, and a Span of the results of its children,
572 : : * computes the result of the node. If std::nullopt is returned by upfn,
573 : : * TreeEvalMaybe() immediately returns std::nullopt.
574 : : * The return value of TreeEvalMaybe is the result of the root node.
575 : : *
576 : : * Result type cannot be bool due to the std::vector<bool> specialization.
577 : : */
578 : : template<typename Result, typename State, typename DownFn, typename UpFn>
579 : 0 : std::optional<Result> TreeEvalMaybe(State root_state, DownFn downfn, UpFn upfn) const
580 : : {
581 : : /** Entries of the explicit stack tracked in this algorithm. */
582 : : struct StackElem
583 : : {
584 : : const Node& node; //!< The node being evaluated.
585 : : size_t expanded; //!< How many children of this node have been expanded.
586 : : State state; //!< The state for that node.
587 : :
588 : 0 : StackElem(const Node& node_, size_t exp_, State&& state_) :
589 : 0 : node(node_), expanded(exp_), state(std::move(state_)) {}
590 : : };
591 : : /* Stack of tree nodes being explored. */
592 : 0 : std::vector<StackElem> stack;
593 : : /* Results of subtrees so far. Their order and mapping to tree nodes
594 : : * is implicitly defined by stack. */
595 : 0 : std::vector<Result> results;
596 [ # # ][ # # ]: 0 : stack.emplace_back(*this, 0, std::move(root_state));
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
597 : :
598 : : /* Here is a demonstration of the algorithm, for an example tree A(B,C(D,E),F).
599 : : * State variables are omitted for simplicity.
600 : : *
601 : : * First: stack=[(A,0)] results=[]
602 : : * stack=[(A,1),(B,0)] results=[]
603 : : * stack=[(A,1)] results=[B]
604 : : * stack=[(A,2),(C,0)] results=[B]
605 : : * stack=[(A,2),(C,1),(D,0)] results=[B]
606 : : * stack=[(A,2),(C,1)] results=[B,D]
607 : : * stack=[(A,2),(C,2),(E,0)] results=[B,D]
608 : : * stack=[(A,2),(C,2)] results=[B,D,E]
609 : : * stack=[(A,2)] results=[B,C]
610 : : * stack=[(A,3),(F,0)] results=[B,C]
611 : : * stack=[(A,3)] results=[B,C,F]
612 : : * Final: stack=[] results=[A]
613 : : */
614 [ # # ][ # # ]: 0 : while (stack.size()) {
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
615 : 0 : const Node& node = stack.back().node;
616 [ # # ][ # # ]: 0 : if (stack.back().expanded < node.subs.size()) {
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
617 : : /* We encounter a tree node with at least one unexpanded child.
618 : : * Expand it. By the time we hit this node again, the result of
619 : : * that child (and all earlier children) will be at the end of `results`. */
620 : 0 : size_t child_index = stack.back().expanded++;
621 [ # # ][ # # ]: 0 : State child_state = downfn(stack.back().state, node, child_index);
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
622 [ # # ][ # # ]: 0 : stack.emplace_back(*node.subs[child_index], 0, std::move(child_state));
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
623 : 0 : continue;
624 : : }
625 : : // Invoke upfn with the last node.subs.size() elements of results as input.
626 [ # # ][ # # ]: 0 : assert(results.size() >= node.subs.size());
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
627 [ # # ][ # # ]: 0 : std::optional<Result> result{upfn(std::move(stack.back().state), node,
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
628 [ # # ][ # # ]: 0 : Span<Result>{results}.last(node.subs.size()))};
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
629 : : // If evaluation returns std::nullopt, abort immediately.
630 [ # # ][ # # ]: 0 : if (!result) return {};
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
631 : : // Replace the last node.subs.size() elements of results with the new result.
632 [ # # ][ # # ]: 0 : results.erase(results.end() - node.subs.size(), results.end());
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
633 [ # # ][ # # ]: 0 : results.push_back(std::move(*result));
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
634 : 0 : stack.pop_back();
635 [ # # ][ # # ]: 0 : }
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ]
636 : : // The final remaining results element is the root result, return it.
637 [ # # ][ # # ]: 0 : assert(results.size() == 1);
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
638 : 0 : return std::move(results[0]);
639 : 0 : }
640 : :
641 : : /** Like TreeEvalMaybe, but without downfn or State type.
642 : : * upfn takes (const Node&, Span<Result>) and returns std::optional<Result>. */
643 : : template<typename Result, typename UpFn>
644 : : std::optional<Result> TreeEvalMaybe(UpFn upfn) const
645 : : {
646 : : struct DummyState {};
647 : : return TreeEvalMaybe<Result>(DummyState{},
648 : : [](DummyState, const Node&, size_t) { return DummyState{}; },
649 : : [&upfn](DummyState, const Node& node, Span<Result> subs) {
650 : : return upfn(node, subs);
651 : : }
652 : : );
653 : : }
654 : :
655 : : /** Like TreeEvalMaybe, but always produces a result. upfn must return Result. */
656 : : template<typename Result, typename State, typename DownFn, typename UpFn>
657 : 0 : Result TreeEval(State root_state, DownFn&& downfn, UpFn upfn) const
658 : : {
659 : : // Invoke TreeEvalMaybe with upfn wrapped to return std::optional<Result>, and then
660 : : // unconditionally dereference the result (it cannot be std::nullopt).
661 : 0 : return std::move(*TreeEvalMaybe<Result>(std::move(root_state),
662 : 0 : std::forward<DownFn>(downfn),
663 : 0 : [&upfn](State&& state, const Node& node, Span<Result> subs) {
664 : 0 : Result res{upfn(std::move(state), node, subs)};
665 : 0 : return std::optional<Result>(std::move(res));
666 : 0 : }
667 : : ));
668 : : }
669 : :
670 : : /** Like TreeEval, but without downfn or State type.
671 : : * upfn takes (const Node&, Span<Result>) and returns Result. */
672 : : template<typename Result, typename UpFn>
673 : 0 : Result TreeEval(UpFn upfn) const
674 : : {
675 : : struct DummyState {};
676 : 0 : return std::move(*TreeEvalMaybe<Result>(DummyState{},
677 : 0 : [](DummyState, const Node&, size_t) { return DummyState{}; },
678 : 0 : [&upfn](DummyState, const Node& node, Span<Result> subs) {
679 : 0 : Result res{upfn(node, subs)};
680 : 0 : return std::optional<Result>(std::move(res));
681 : 0 : }
682 : : ));
683 : : }
684 : :
685 : : /** Compare two miniscript subtrees, using a non-recursive algorithm. */
686 : 0 : friend int Compare(const Node<Key>& node1, const Node<Key>& node2)
687 : : {
688 : 0 : std::vector<std::pair<const Node<Key>&, const Node<Key>&>> queue;
689 [ # # ]: 0 : queue.emplace_back(node1, node2);
690 [ # # ]: 0 : while (!queue.empty()) {
691 : 0 : const auto& [a, b] = queue.back();
692 : 0 : queue.pop_back();
693 [ # # ][ # # ]: 0 : if (std::tie(a.fragment, a.k, a.keys, a.data) < std::tie(b.fragment, b.k, b.keys, b.data)) return -1;
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ]
694 [ # # ][ # # ]: 0 : if (std::tie(b.fragment, b.k, b.keys, b.data) < std::tie(a.fragment, a.k, a.keys, a.data)) return 1;
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ]
695 [ # # ][ # # ]: 0 : if (a.subs.size() < b.subs.size()) return -1;
696 [ # # ][ # # ]: 0 : if (b.subs.size() < a.subs.size()) return 1;
697 : 0 : size_t n = a.subs.size();
698 [ # # ]: 0 : for (size_t i = 0; i < n; ++i) {
699 [ # # ][ # # ]: 0 : queue.emplace_back(*a.subs[n - 1 - i], *b.subs[n - 1 - i]);
700 : 0 : }
701 : : }
702 : 0 : return 0;
703 : 0 : }
704 : :
705 : : //! Compute the type for this miniscript.
706 : 0 : Type CalcType() const {
707 : : using namespace internal;
708 : :
709 : : // THRESH has a variable number of subexpressions
710 : 0 : std::vector<Type> sub_types;
711 [ # # ][ # # ]: 0 : if (fragment == Fragment::THRESH) {
712 [ # # ][ # # ]: 0 : for (const auto& sub : subs) sub_types.push_back(sub->GetType());
[ # # ][ # # ]
[ # # ]
713 : 0 : }
714 : : // All other nodes than THRESH can be computed just from the types of the 0-3 subexpressions.
715 [ # # ][ # # ]: 0 : Type x = subs.size() > 0 ? subs[0]->GetType() : ""_mst;
[ # # ][ # # ]
[ # # ][ # # ]
716 [ # # ][ # # ]: 0 : Type y = subs.size() > 1 ? subs[1]->GetType() : ""_mst;
[ # # ][ # # ]
[ # # ][ # # ]
717 [ # # ][ # # ]: 0 : Type z = subs.size() > 2 ? subs[2]->GetType() : ""_mst;
[ # # ][ # # ]
[ # # ][ # # ]
718 : :
719 [ # # ][ # # ]: 0 : return SanitizeType(ComputeType(fragment, x, y, z, sub_types, k, data.size(), subs.size(), keys.size(), m_script_ctx));
[ # # ][ # # ]
720 : 0 : }
721 : :
722 : : public:
723 : : template<typename Ctx>
724 : 0 : CScript ToScript(const Ctx& ctx) const
725 : : {
726 : : // To construct the CScript for a Miniscript object, we use the TreeEval algorithm.
727 : : // The State is a boolean: whether or not the node's script expansion is followed
728 : : // by an OP_VERIFY (which may need to be combined with the last script opcode).
729 : 0 : auto downfn = [](bool verify, const Node& node, size_t index) {
730 : : // For WRAP_V, the subexpression is certainly followed by OP_VERIFY.
731 [ # # ][ # # ]: 0 : if (node.fragment == Fragment::WRAP_V) return true;
732 : : // The subexpression of WRAP_S, and the last subexpression of AND_V
733 : : // inherit the followed-by-OP_VERIFY property from the parent.
734 [ # # ][ # # ]: 0 : if (node.fragment == Fragment::WRAP_S ||
[ # # ][ # # ]
735 [ # # ][ # # ]: 0 : (node.fragment == Fragment::AND_V && index == 1)) return verify;
736 : 0 : return false;
737 : 0 : };
738 : : // The upward function computes for a node, given its followed-by-OP_VERIFY status
739 : : // and the CScripts of its child nodes, the CScript of the node.
740 : 0 : const bool is_tapscript{IsTapscript(m_script_ctx)};
741 : 0 : auto upfn = [&ctx, is_tapscript](bool verify, const Node& node, Span<CScript> subs) -> CScript {
742 [ # # # # : 0 : switch (node.fragment) {
# # # # #
# # # # #
# # # # #
# # # # #
# # # # ]
[ # # # #
# # # # #
# # # # #
# # # # #
# # # # #
# # # # ]
743 [ # # ]: 0 : case Fragment::PK_K: return BuildScript(ctx.ToPKBytes(node.keys[0]));
744 [ # # ][ # # ]: 0 : case Fragment::PK_H: return BuildScript(OP_DUP, OP_HASH160, ctx.ToPKHBytes(node.keys[0]), OP_EQUALVERIFY);
745 : 0 : case Fragment::OLDER: return BuildScript(node.k, OP_CHECKSEQUENCEVERIFY);
746 : 0 : case Fragment::AFTER: return BuildScript(node.k, OP_CHECKLOCKTIMEVERIFY);
747 : 0 : case Fragment::SHA256: return BuildScript(OP_SIZE, 32, OP_EQUALVERIFY, OP_SHA256, node.data, verify ? OP_EQUALVERIFY : OP_EQUAL);
748 : 0 : case Fragment::RIPEMD160: return BuildScript(OP_SIZE, 32, OP_EQUALVERIFY, OP_RIPEMD160, node.data, verify ? OP_EQUALVERIFY : OP_EQUAL);
749 : 0 : case Fragment::HASH256: return BuildScript(OP_SIZE, 32, OP_EQUALVERIFY, OP_HASH256, node.data, verify ? OP_EQUALVERIFY : OP_EQUAL);
750 : 0 : case Fragment::HASH160: return BuildScript(OP_SIZE, 32, OP_EQUALVERIFY, OP_HASH160, node.data, verify ? OP_EQUALVERIFY : OP_EQUAL);
751 : 0 : case Fragment::WRAP_A: return BuildScript(OP_TOALTSTACK, subs[0], OP_FROMALTSTACK);
752 : 0 : case Fragment::WRAP_S: return BuildScript(OP_SWAP, subs[0]);
753 : 0 : case Fragment::WRAP_C: return BuildScript(std::move(subs[0]), verify ? OP_CHECKSIGVERIFY : OP_CHECKSIG);
754 : 0 : case Fragment::WRAP_D: return BuildScript(OP_DUP, OP_IF, subs[0], OP_ENDIF);
755 : : case Fragment::WRAP_V: {
756 [ # # ][ # # ]: 0 : if (node.subs[0]->GetType() << "x"_mst) {
757 : 0 : return BuildScript(std::move(subs[0]), OP_VERIFY);
758 : : } else {
759 : 0 : return std::move(subs[0]);
760 : : }
761 : : }
762 : 0 : case Fragment::WRAP_J: return BuildScript(OP_SIZE, OP_0NOTEQUAL, OP_IF, subs[0], OP_ENDIF);
763 : 0 : case Fragment::WRAP_N: return BuildScript(std::move(subs[0]), OP_0NOTEQUAL);
764 : 0 : case Fragment::JUST_1: return BuildScript(OP_1);
765 : 0 : case Fragment::JUST_0: return BuildScript(OP_0);
766 : 0 : case Fragment::AND_V: return BuildScript(std::move(subs[0]), subs[1]);
767 : 0 : case Fragment::AND_B: return BuildScript(std::move(subs[0]), subs[1], OP_BOOLAND);
768 : 0 : case Fragment::OR_B: return BuildScript(std::move(subs[0]), subs[1], OP_BOOLOR);
769 : 0 : case Fragment::OR_D: return BuildScript(std::move(subs[0]), OP_IFDUP, OP_NOTIF, subs[1], OP_ENDIF);
770 : 0 : case Fragment::OR_C: return BuildScript(std::move(subs[0]), OP_NOTIF, subs[1], OP_ENDIF);
771 : 0 : case Fragment::OR_I: return BuildScript(OP_IF, subs[0], OP_ELSE, subs[1], OP_ENDIF);
772 : 0 : case Fragment::ANDOR: return BuildScript(std::move(subs[0]), OP_NOTIF, subs[2], OP_ELSE, subs[1], OP_ENDIF);
773 : : case Fragment::MULTI: {
774 : 0 : CHECK_NONFATAL(!is_tapscript);
775 : 0 : CScript script = BuildScript(node.k);
776 [ # # ][ # # ]: 0 : for (const auto& key : node.keys) {
777 [ # # ][ # # ]: 0 : script = BuildScript(std::move(script), ctx.ToPKBytes(key));
[ # # ][ # # ]
778 : : }
779 [ # # ][ # # ]: 0 : return BuildScript(std::move(script), node.keys.size(), verify ? OP_CHECKMULTISIGVERIFY : OP_CHECKMULTISIG);
780 : 0 : }
781 : : case Fragment::MULTI_A: {
782 : 0 : CHECK_NONFATAL(is_tapscript);
783 [ # # ]: 0 : CScript script = BuildScript(ctx.ToPKBytes(*node.keys.begin()), OP_CHECKSIG);
784 [ # # ][ # # ]: 0 : for (auto it = node.keys.begin() + 1; it != node.keys.end(); ++it) {
785 [ # # ][ # # ]: 0 : script = BuildScript(std::move(script), ctx.ToPKBytes(*it), OP_CHECKSIGADD);
[ # # ][ # # ]
786 : 0 : }
787 [ # # ][ # # ]: 0 : return BuildScript(std::move(script), node.k, verify ? OP_NUMEQUALVERIFY : OP_NUMEQUAL);
788 : 0 : }
789 : : case Fragment::THRESH: {
790 : 0 : CScript script = std::move(subs[0]);
791 [ # # ][ # # ]: 0 : for (size_t i = 1; i < subs.size(); ++i) {
792 [ # # ][ # # ]: 0 : script = BuildScript(std::move(script), subs[i], OP_ADD);
793 : 0 : }
794 [ # # ][ # # ]: 0 : return BuildScript(std::move(script), node.k, verify ? OP_EQUALVERIFY : OP_EQUAL);
795 : 0 : }
796 : : }
797 : 0 : assert(false);
798 : 0 : };
799 : 0 : return TreeEval<CScript>(false, downfn, upfn);
800 : : }
801 : :
802 : : template<typename CTx>
803 : 0 : std::optional<std::string> ToString(const CTx& ctx) const {
804 : : // To construct the std::string representation for a Miniscript object, we use
805 : : // the TreeEvalMaybe algorithm. The State is a boolean: whether the parent node is a
806 : : // wrapper. If so, non-wrapper expressions must be prefixed with a ":".
807 : 0 : auto downfn = [](bool, const Node& node, size_t) {
808 [ # # ][ # # ]: 0 : return (node.fragment == Fragment::WRAP_A || node.fragment == Fragment::WRAP_S ||
[ # # ][ # # ]
809 [ # # ][ # # ]: 0 : node.fragment == Fragment::WRAP_D || node.fragment == Fragment::WRAP_V ||
[ # # ][ # # ]
810 [ # # ][ # # ]: 0 : node.fragment == Fragment::WRAP_J || node.fragment == Fragment::WRAP_N ||
[ # # ][ # # ]
811 [ # # ][ # # ]: 0 : node.fragment == Fragment::WRAP_C ||
812 [ # # ][ # # ]: 0 : (node.fragment == Fragment::AND_V && node.subs[1]->fragment == Fragment::JUST_1) ||
[ # # ][ # # ]
813 [ # # ][ # # ]: 0 : (node.fragment == Fragment::OR_I && node.subs[0]->fragment == Fragment::JUST_0) ||
814 [ # # ][ # # ]: 0 : (node.fragment == Fragment::OR_I && node.subs[1]->fragment == Fragment::JUST_0));
815 : : };
816 : : // The upward function computes for a node, given whether its parent is a wrapper,
817 : : // and the string representations of its child nodes, the string representation of the node.
818 : 0 : const bool is_tapscript{IsTapscript(m_script_ctx)};
819 : 0 : auto upfn = [&ctx, is_tapscript](bool wrapped, const Node& node, Span<std::string> subs) -> std::optional<std::string> {
820 [ # # ][ # # ]: 0 : std::string ret = wrapped ? ":" : "";
821 : :
822 [ # # # # : 0 : switch (node.fragment) {
# # # # #
# ][ # # #
# # # # #
# # ]
823 [ # # ][ # # ]: 0 : case Fragment::WRAP_A: return "a" + std::move(subs[0]);
824 [ # # ][ # # ]: 0 : case Fragment::WRAP_S: return "s" + std::move(subs[0]);
825 : : case Fragment::WRAP_C:
826 [ # # ][ # # ]: 0 : if (node.subs[0]->fragment == Fragment::PK_K) {
827 : : // pk(K) is syntactic sugar for c:pk_k(K)
828 [ # # ][ # # ]: 0 : auto key_str = ctx.ToString(node.subs[0]->keys[0]);
829 [ # # ][ # # ]: 0 : if (!key_str) return {};
830 [ # # ][ # # ]: 0 : return std::move(ret) + "pk(" + std::move(*key_str) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
831 : 0 : }
832 [ # # ][ # # ]: 0 : if (node.subs[0]->fragment == Fragment::PK_H) {
833 : : // pkh(K) is syntactic sugar for c:pk_h(K)
834 [ # # ][ # # ]: 0 : auto key_str = ctx.ToString(node.subs[0]->keys[0]);
835 [ # # ][ # # ]: 0 : if (!key_str) return {};
836 [ # # ][ # # ]: 0 : return std::move(ret) + "pkh(" + std::move(*key_str) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
837 : 0 : }
838 [ # # ][ # # ]: 0 : return "c" + std::move(subs[0]);
839 [ # # ][ # # ]: 0 : case Fragment::WRAP_D: return "d" + std::move(subs[0]);
840 [ # # ][ # # ]: 0 : case Fragment::WRAP_V: return "v" + std::move(subs[0]);
841 [ # # ][ # # ]: 0 : case Fragment::WRAP_J: return "j" + std::move(subs[0]);
842 [ # # ][ # # ]: 0 : case Fragment::WRAP_N: return "n" + std::move(subs[0]);
843 : : case Fragment::AND_V:
844 : : // t:X is syntactic sugar for and_v(X,1).
845 [ # # ][ # # ]: 0 : if (node.subs[1]->fragment == Fragment::JUST_1) return "t" + std::move(subs[0]);
[ # # ][ # # ]
846 : 0 : break;
847 : : case Fragment::OR_I:
848 [ # # ][ # # ]: 0 : if (node.subs[0]->fragment == Fragment::JUST_0) return "l" + std::move(subs[1]);
[ # # ][ # # ]
849 [ # # ][ # # ]: 0 : if (node.subs[1]->fragment == Fragment::JUST_0) return "u" + std::move(subs[0]);
[ # # ][ # # ]
850 : 0 : break;
851 : 0 : default: break;
852 : : }
853 [ # # # # : 0 : switch (node.fragment) {
# # # # #
# # # # #
# # # # #
# # ][ # #
# # # # #
# # # # #
# # # # #
# # # # ]
854 : : case Fragment::PK_K: {
855 [ # # ][ # # ]: 0 : auto key_str = ctx.ToString(node.keys[0]);
856 [ # # ][ # # ]: 0 : if (!key_str) return {};
857 [ # # ][ # # ]: 0 : return std::move(ret) + "pk_k(" + std::move(*key_str) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
858 : 0 : }
859 : : case Fragment::PK_H: {
860 [ # # ][ # # ]: 0 : auto key_str = ctx.ToString(node.keys[0]);
861 [ # # ][ # # ]: 0 : if (!key_str) return {};
862 [ # # ][ # # ]: 0 : return std::move(ret) + "pk_h(" + std::move(*key_str) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
863 : 0 : }
864 [ # # ][ # # ]: 0 : case Fragment::AFTER: return std::move(ret) + "after(" + ::ToString(node.k) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
865 [ # # ][ # # ]: 0 : case Fragment::OLDER: return std::move(ret) + "older(" + ::ToString(node.k) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
866 [ # # ][ # # ]: 0 : case Fragment::HASH256: return std::move(ret) + "hash256(" + HexStr(node.data) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
867 [ # # ][ # # ]: 0 : case Fragment::HASH160: return std::move(ret) + "hash160(" + HexStr(node.data) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
868 [ # # ][ # # ]: 0 : case Fragment::SHA256: return std::move(ret) + "sha256(" + HexStr(node.data) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
869 [ # # ][ # # ]: 0 : case Fragment::RIPEMD160: return std::move(ret) + "ripemd160(" + HexStr(node.data) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
870 [ # # ][ # # ]: 0 : case Fragment::JUST_1: return std::move(ret) + "1";
871 [ # # ][ # # ]: 0 : case Fragment::JUST_0: return std::move(ret) + "0";
872 [ # # ][ # # ]: 0 : case Fragment::AND_V: return std::move(ret) + "and_v(" + std::move(subs[0]) + "," + std::move(subs[1]) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
873 [ # # ][ # # ]: 0 : case Fragment::AND_B: return std::move(ret) + "and_b(" + std::move(subs[0]) + "," + std::move(subs[1]) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
874 [ # # ][ # # ]: 0 : case Fragment::OR_B: return std::move(ret) + "or_b(" + std::move(subs[0]) + "," + std::move(subs[1]) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
875 [ # # ][ # # ]: 0 : case Fragment::OR_D: return std::move(ret) + "or_d(" + std::move(subs[0]) + "," + std::move(subs[1]) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
876 [ # # ][ # # ]: 0 : case Fragment::OR_C: return std::move(ret) + "or_c(" + std::move(subs[0]) + "," + std::move(subs[1]) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
877 [ # # ][ # # ]: 0 : case Fragment::OR_I: return std::move(ret) + "or_i(" + std::move(subs[0]) + "," + std::move(subs[1]) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
878 : : case Fragment::ANDOR:
879 : : // and_n(X,Y) is syntactic sugar for andor(X,Y,0).
880 [ # # ][ # # ]: 0 : if (node.subs[2]->fragment == Fragment::JUST_0) return std::move(ret) + "and_n(" + std::move(subs[0]) + "," + std::move(subs[1]) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
881 [ # # ][ # # ]: 0 : return std::move(ret) + "andor(" + std::move(subs[0]) + "," + std::move(subs[1]) + "," + std::move(subs[2]) + ")";
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
882 : : case Fragment::MULTI: {
883 [ # # ][ # # ]: 0 : CHECK_NONFATAL(!is_tapscript);
884 [ # # ][ # # ]: 0 : auto str = std::move(ret) + "multi(" + ::ToString(node.k);
[ # # ][ # # ]
[ # # ][ # # ]
885 [ # # ][ # # ]: 0 : for (const auto& key : node.keys) {
886 [ # # ][ # # ]: 0 : auto key_str = ctx.ToString(key);
887 [ # # ][ # # ]: 0 : if (!key_str) return {};
888 [ # # ][ # # ]: 0 : str += "," + std::move(*key_str);
[ # # ][ # # ]
889 [ # # ][ # # ]: 0 : }
890 [ # # ][ # # ]: 0 : return std::move(str) + ")";
891 : 0 : }
892 : : case Fragment::MULTI_A: {
893 [ # # ][ # # ]: 0 : CHECK_NONFATAL(is_tapscript);
894 [ # # ][ # # ]: 0 : auto str = std::move(ret) + "multi_a(" + ::ToString(node.k);
[ # # ][ # # ]
[ # # ][ # # ]
895 [ # # ][ # # ]: 0 : for (const auto& key : node.keys) {
896 [ # # ][ # # ]: 0 : auto key_str = ctx.ToString(key);
897 [ # # ][ # # ]: 0 : if (!key_str) return {};
898 [ # # ][ # # ]: 0 : str += "," + std::move(*key_str);
[ # # ][ # # ]
899 [ # # ][ # # ]: 0 : }
900 [ # # ][ # # ]: 0 : return std::move(str) + ")";
901 : 0 : }
902 : : case Fragment::THRESH: {
903 [ # # ][ # # ]: 0 : auto str = std::move(ret) + "thresh(" + ::ToString(node.k);
[ # # ][ # # ]
[ # # ][ # # ]
904 [ # # ][ # # ]: 0 : for (auto& sub : subs) {
905 [ # # ][ # # ]: 0 : str += "," + std::move(sub);
[ # # ][ # # ]
906 : : }
907 [ # # ][ # # ]: 0 : return std::move(str) + ")";
908 : 0 : }
909 : 0 : default: break;
910 : : }
911 : 0 : assert(false);
912 : 0 : };
913 : :
914 : 0 : return TreeEvalMaybe<std::string>(false, downfn, upfn);
915 : : }
916 : :
917 : : private:
918 : 0 : internal::Ops CalcOps() const {
919 [ # # # # : 0 : switch (fragment) {
# # # # #
# # # # #
# # # # #
# # # ][ #
# # # # #
# # # # #
# # # # #
# # # # #
# ]
920 : 0 : case Fragment::JUST_1: return {0, 0, {}};
921 : 0 : case Fragment::JUST_0: return {0, {}, 0};
922 : 0 : case Fragment::PK_K: return {0, 0, 0};
923 : 0 : case Fragment::PK_H: return {3, 0, 0};
924 : : case Fragment::OLDER:
925 : 0 : case Fragment::AFTER: return {1, 0, {}};
926 : : case Fragment::SHA256:
927 : : case Fragment::RIPEMD160:
928 : : case Fragment::HASH256:
929 : 0 : case Fragment::HASH160: return {4, 0, {}};
930 : 0 : case Fragment::AND_V: return {subs[0]->ops.count + subs[1]->ops.count, subs[0]->ops.sat + subs[1]->ops.sat, {}};
931 : : case Fragment::AND_B: {
932 : 0 : const auto count{1 + subs[0]->ops.count + subs[1]->ops.count};
933 : 0 : const auto sat{subs[0]->ops.sat + subs[1]->ops.sat};
934 : 0 : const auto dsat{subs[0]->ops.dsat + subs[1]->ops.dsat};
935 : 0 : return {count, sat, dsat};
936 : : }
937 : : case Fragment::OR_B: {
938 : 0 : const auto count{1 + subs[0]->ops.count + subs[1]->ops.count};
939 : 0 : const auto sat{(subs[0]->ops.sat + subs[1]->ops.dsat) | (subs[1]->ops.sat + subs[0]->ops.dsat)};
940 : 0 : const auto dsat{subs[0]->ops.dsat + subs[1]->ops.dsat};
941 : 0 : return {count, sat, dsat};
942 : : }
943 : : case Fragment::OR_D: {
944 : 0 : const auto count{3 + subs[0]->ops.count + subs[1]->ops.count};
945 : 0 : const auto sat{subs[0]->ops.sat | (subs[1]->ops.sat + subs[0]->ops.dsat)};
946 : 0 : const auto dsat{subs[0]->ops.dsat + subs[1]->ops.dsat};
947 : 0 : return {count, sat, dsat};
948 : : }
949 : : case Fragment::OR_C: {
950 : 0 : const auto count{2 + subs[0]->ops.count + subs[1]->ops.count};
951 : 0 : const auto sat{subs[0]->ops.sat | (subs[1]->ops.sat + subs[0]->ops.dsat)};
952 : 0 : return {count, sat, {}};
953 : : }
954 : : case Fragment::OR_I: {
955 : 0 : const auto count{3 + subs[0]->ops.count + subs[1]->ops.count};
956 : 0 : const auto sat{subs[0]->ops.sat | subs[1]->ops.sat};
957 : 0 : const auto dsat{subs[0]->ops.dsat | subs[1]->ops.dsat};
958 : 0 : return {count, sat, dsat};
959 : : }
960 : : case Fragment::ANDOR: {
961 : 0 : const auto count{3 + subs[0]->ops.count + subs[1]->ops.count + subs[2]->ops.count};
962 : 0 : const auto sat{(subs[1]->ops.sat + subs[0]->ops.sat) | (subs[0]->ops.dsat + subs[2]->ops.sat)};
963 : 0 : const auto dsat{subs[0]->ops.dsat + subs[2]->ops.dsat};
964 : 0 : return {count, sat, dsat};
965 : : }
966 : 0 : case Fragment::MULTI: return {1, (uint32_t)keys.size(), (uint32_t)keys.size()};
967 : 0 : case Fragment::MULTI_A: return {(uint32_t)keys.size() + 1, 0, 0};
968 : : case Fragment::WRAP_S:
969 : : case Fragment::WRAP_C:
970 : 0 : case Fragment::WRAP_N: return {1 + subs[0]->ops.count, subs[0]->ops.sat, subs[0]->ops.dsat};
971 : 0 : case Fragment::WRAP_A: return {2 + subs[0]->ops.count, subs[0]->ops.sat, subs[0]->ops.dsat};
972 : 0 : case Fragment::WRAP_D: return {3 + subs[0]->ops.count, subs[0]->ops.sat, 0};
973 : 0 : case Fragment::WRAP_J: return {4 + subs[0]->ops.count, subs[0]->ops.sat, 0};
974 : 0 : case Fragment::WRAP_V: return {subs[0]->ops.count + (subs[0]->GetType() << "x"_mst), subs[0]->ops.sat, {}};
975 : : case Fragment::THRESH: {
976 : 0 : uint32_t count = 0;
977 : 0 : auto sats = Vector(internal::MaxInt<uint32_t>(0));
978 [ # # ][ # # ]: 0 : for (const auto& sub : subs) {
979 : 0 : count += sub->ops.count + 1;
980 [ # # ][ # # ]: 0 : auto next_sats = Vector(sats[0] + sub->ops.dsat);
[ # # ][ # # ]
981 [ # # ][ # # ]: 0 : for (size_t j = 1; j < sats.size(); ++j) next_sats.push_back((sats[j] + sub->ops.dsat) | (sats[j - 1] + sub->ops.sat));
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
982 [ # # ][ # # ]: 0 : next_sats.push_back(sats[sats.size() - 1] + sub->ops.sat);
[ # # ][ # # ]
983 : 0 : sats = std::move(next_sats);
984 : 0 : }
985 [ # # ][ # # ]: 0 : assert(k <= sats.size());
986 [ # # ][ # # ]: 0 : return {count, sats[k], sats[0]};
987 : 0 : }
988 : : }
989 : 0 : assert(false);
990 : 0 : }
991 : :
992 : 0 : internal::StackSize CalcStackSize() const {
993 : : using namespace internal;
994 [ # # # # : 0 : switch (fragment) {
# # # # #
# # # # #
# # # # #
# # # ][ #
# # # # #
# # # # #
# # # # #
# # # # #
# ]
995 : 0 : case Fragment::JUST_0: return {{}, SatInfo::Push()};
996 : 0 : case Fragment::JUST_1: return {SatInfo::Push(), {}};
997 : : case Fragment::OLDER:
998 : 0 : case Fragment::AFTER: return {SatInfo::Push() + SatInfo::Nop(), {}};
999 : 0 : case Fragment::PK_K: return {SatInfo::Push()};
1000 : 0 : case Fragment::PK_H: return {SatInfo::OP_DUP() + SatInfo::Hash() + SatInfo::Push() + SatInfo::OP_EQUALVERIFY()};
1001 : : case Fragment::SHA256:
1002 : : case Fragment::RIPEMD160:
1003 : : case Fragment::HASH256:
1004 : 0 : case Fragment::HASH160: return {
1005 : 0 : SatInfo::OP_SIZE() + SatInfo::Push() + SatInfo::OP_EQUALVERIFY() + SatInfo::Hash() + SatInfo::Push() + SatInfo::OP_EQUAL(),
1006 : 0 : {}
1007 : : };
1008 : : case Fragment::ANDOR: {
1009 : 0 : const auto& x{subs[0]->ss};
1010 : 0 : const auto& y{subs[1]->ss};
1011 : 0 : const auto& z{subs[2]->ss};
1012 : 0 : return {
1013 : 0 : (x.sat + SatInfo::If() + y.sat) | (x.dsat + SatInfo::If() + z.sat),
1014 : 0 : x.dsat + SatInfo::If() + z.dsat
1015 : : };
1016 : : }
1017 : : case Fragment::AND_V: {
1018 : 0 : const auto& x{subs[0]->ss};
1019 : 0 : const auto& y{subs[1]->ss};
1020 : 0 : return {x.sat + y.sat, {}};
1021 : : }
1022 : : case Fragment::AND_B: {
1023 : 0 : const auto& x{subs[0]->ss};
1024 : 0 : const auto& y{subs[1]->ss};
1025 : 0 : return {x.sat + y.sat + SatInfo::BinaryOp(), x.dsat + y.dsat + SatInfo::BinaryOp()};
1026 : : }
1027 : : case Fragment::OR_B: {
1028 : 0 : const auto& x{subs[0]->ss};
1029 : 0 : const auto& y{subs[1]->ss};
1030 : 0 : return {
1031 : 0 : ((x.sat + y.dsat) | (x.dsat + y.sat)) + SatInfo::BinaryOp(),
1032 : 0 : x.dsat + y.dsat + SatInfo::BinaryOp()
1033 : : };
1034 : : }
1035 : : case Fragment::OR_C: {
1036 : 0 : const auto& x{subs[0]->ss};
1037 : 0 : const auto& y{subs[1]->ss};
1038 : 0 : return {(x.sat + SatInfo::If()) | (x.dsat + SatInfo::If() + y.sat), {}};
1039 : : }
1040 : : case Fragment::OR_D: {
1041 : 0 : const auto& x{subs[0]->ss};
1042 : 0 : const auto& y{subs[1]->ss};
1043 : 0 : return {
1044 : 0 : (x.sat + SatInfo::OP_IFDUP(true) + SatInfo::If()) | (x.dsat + SatInfo::OP_IFDUP(false) + SatInfo::If() + y.sat),
1045 : 0 : x.dsat + SatInfo::OP_IFDUP(false) + SatInfo::If() + y.dsat
1046 : : };
1047 : : }
1048 : : case Fragment::OR_I: {
1049 : 0 : const auto& x{subs[0]->ss};
1050 : 0 : const auto& y{subs[1]->ss};
1051 : 0 : return {SatInfo::If() + (x.sat | y.sat), SatInfo::If() + (x.dsat | y.dsat)};
1052 : : }
1053 : : // multi(k, key1, key2, ..., key_n) starts off with k+1 stack elements (a 0, plus k
1054 : : // signatures), then reaches n+k+3 stack elements after pushing the n keys, plus k and
1055 : : // n itself, and ends with 1 stack element (success or failure). Thus, it net removes
1056 : : // k elements (from k+1 to 1), while reaching k+n+2 more than it ends with.
1057 : 0 : case Fragment::MULTI: return {SatInfo(k, k + keys.size() + 2)};
1058 : : // multi_a(k, key1, key2, ..., key_n) starts off with n stack elements (the
1059 : : // signatures), reaches 1 more (after the first key push), and ends with 1. Thus it net
1060 : : // removes n-1 elements (from n to 1) while reaching n more than it ends with.
1061 : 0 : case Fragment::MULTI_A: return {SatInfo(keys.size() - 1, keys.size())};
1062 : : case Fragment::WRAP_A:
1063 : : case Fragment::WRAP_N:
1064 : 0 : case Fragment::WRAP_S: return subs[0]->ss;
1065 : 0 : case Fragment::WRAP_C: return {
1066 : 0 : subs[0]->ss.sat + SatInfo::OP_CHECKSIG(),
1067 : 0 : subs[0]->ss.dsat + SatInfo::OP_CHECKSIG()
1068 : : };
1069 : 0 : case Fragment::WRAP_D: return {
1070 : 0 : SatInfo::OP_DUP() + SatInfo::If() + subs[0]->ss.sat,
1071 : 0 : SatInfo::OP_DUP() + SatInfo::If()
1072 : : };
1073 : 0 : case Fragment::WRAP_V: return {subs[0]->ss.sat + SatInfo::OP_VERIFY(), {}};
1074 : 0 : case Fragment::WRAP_J: return {
1075 : 0 : SatInfo::OP_SIZE() + SatInfo::OP_0NOTEQUAL() + SatInfo::If() + subs[0]->ss.sat,
1076 : 0 : SatInfo::OP_SIZE() + SatInfo::OP_0NOTEQUAL() + SatInfo::If()
1077 : : };
1078 : : case Fragment::THRESH: {
1079 : : // sats[j] is the SatInfo corresponding to all traces reaching j satisfactions.
1080 : 0 : auto sats = Vector(SatInfo::Empty());
1081 [ # # ][ # # ]: 0 : for (size_t i = 0; i < subs.size(); ++i) {
1082 : : // Loop over the subexpressions, processing them one by one. After adding
1083 : : // element i we need to add OP_ADD (if i>0).
1084 [ # # ][ # # ]: 0 : auto add = i ? SatInfo::BinaryOp() : SatInfo::Empty();
1085 : : // Construct a variable that will become the next sats, starting with index 0.
1086 [ # # ][ # # ]: 0 : auto next_sats = Vector(sats[0] + subs[i]->ss.dsat + add);
1087 : : // Then loop to construct next_sats[1..i].
1088 [ # # ][ # # ]: 0 : for (size_t j = 1; j < sats.size(); ++j) {
1089 [ # # ][ # # ]: 0 : next_sats.push_back(((sats[j] + subs[i]->ss.dsat) | (sats[j - 1] + subs[i]->ss.sat)) + add);
1090 : 0 : }
1091 : : // Finally construct next_sats[i+1].
1092 [ # # ][ # # ]: 0 : next_sats.push_back(sats[sats.size() - 1] + subs[i]->ss.sat + add);
1093 : : // Switch over.
1094 : 0 : sats = std::move(next_sats);
1095 : 0 : }
1096 : : // To satisfy thresh we need k satisfactions; to dissatisfy we need 0. In both
1097 : : // cases a push of k and an OP_EQUAL follow.
1098 : 0 : return {
1099 : 0 : sats[k] + SatInfo::Push() + SatInfo::OP_EQUAL(),
1100 : 0 : sats[0] + SatInfo::Push() + SatInfo::OP_EQUAL()
1101 : : };
1102 : 0 : }
1103 : : }
1104 : 0 : assert(false);
1105 : 0 : }
1106 : :
1107 : 0 : internal::WitnessSize CalcWitnessSize() const {
1108 : 0 : const uint32_t sig_size = IsTapscript(m_script_ctx) ? 1 + 65 : 1 + 72;
1109 : 0 : const uint32_t pubkey_size = IsTapscript(m_script_ctx) ? 1 + 32 : 1 + 33;
1110 [ # # # # : 0 : switch (fragment) {
# # # # #
# # # # #
# # # # #
# ][ # # #
# # # # #
# # # # #
# # # # #
# # ]
1111 : 0 : case Fragment::JUST_0: return {{}, 0};
1112 : : case Fragment::JUST_1:
1113 : : case Fragment::OLDER:
1114 : 0 : case Fragment::AFTER: return {0, {}};
1115 : 0 : case Fragment::PK_K: return {sig_size, 1};
1116 : 0 : case Fragment::PK_H: return {sig_size + pubkey_size, 1 + pubkey_size};
1117 : : case Fragment::SHA256:
1118 : : case Fragment::RIPEMD160:
1119 : : case Fragment::HASH256:
1120 : 0 : case Fragment::HASH160: return {1 + 32, {}};
1121 : : case Fragment::ANDOR: {
1122 : 0 : const auto sat{(subs[0]->ws.sat + subs[1]->ws.sat) | (subs[0]->ws.dsat + subs[2]->ws.sat)};
1123 : 0 : const auto dsat{subs[0]->ws.dsat + subs[2]->ws.dsat};
1124 : 0 : return {sat, dsat};
1125 : : }
1126 : 0 : case Fragment::AND_V: return {subs[0]->ws.sat + subs[1]->ws.sat, {}};
1127 : 0 : case Fragment::AND_B: return {subs[0]->ws.sat + subs[1]->ws.sat, subs[0]->ws.dsat + subs[1]->ws.dsat};
1128 : : case Fragment::OR_B: {
1129 : 0 : const auto sat{(subs[0]->ws.dsat + subs[1]->ws.sat) | (subs[0]->ws.sat + subs[1]->ws.dsat)};
1130 : 0 : const auto dsat{subs[0]->ws.dsat + subs[1]->ws.dsat};
1131 : 0 : return {sat, dsat};
1132 : : }
1133 : 0 : case Fragment::OR_C: return {subs[0]->ws.sat | (subs[0]->ws.dsat + subs[1]->ws.sat), {}};
1134 : 0 : case Fragment::OR_D: return {subs[0]->ws.sat | (subs[0]->ws.dsat + subs[1]->ws.sat), subs[0]->ws.dsat + subs[1]->ws.dsat};
1135 : 0 : case Fragment::OR_I: return {(subs[0]->ws.sat + 1 + 1) | (subs[1]->ws.sat + 1), (subs[0]->ws.dsat + 1 + 1) | (subs[1]->ws.dsat + 1)};
1136 : 0 : case Fragment::MULTI: return {k * sig_size + 1, k + 1};
1137 : 0 : case Fragment::MULTI_A: return {k * sig_size + static_cast<uint32_t>(keys.size()) - k, static_cast<uint32_t>(keys.size())};
1138 : : case Fragment::WRAP_A:
1139 : : case Fragment::WRAP_N:
1140 : : case Fragment::WRAP_S:
1141 : 0 : case Fragment::WRAP_C: return subs[0]->ws;
1142 : 0 : case Fragment::WRAP_D: return {1 + 1 + subs[0]->ws.sat, 1};
1143 : 0 : case Fragment::WRAP_V: return {subs[0]->ws.sat, {}};
1144 : 0 : case Fragment::WRAP_J: return {subs[0]->ws.sat, 1};
1145 : : case Fragment::THRESH: {
1146 : 0 : auto sats = Vector(internal::MaxInt<uint32_t>(0));
1147 [ # # ][ # # ]: 0 : for (const auto& sub : subs) {
1148 [ # # ][ # # ]: 0 : auto next_sats = Vector(sats[0] + sub->ws.dsat);
[ # # ][ # # ]
1149 [ # # ][ # # ]: 0 : for (size_t j = 1; j < sats.size(); ++j) next_sats.push_back((sats[j] + sub->ws.dsat) | (sats[j - 1] + sub->ws.sat));
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1150 [ # # ][ # # ]: 0 : next_sats.push_back(sats[sats.size() - 1] + sub->ws.sat);
[ # # ][ # # ]
1151 : 0 : sats = std::move(next_sats);
1152 : 0 : }
1153 [ # # ][ # # ]: 0 : assert(k <= sats.size());
1154 [ # # ][ # # ]: 0 : return {sats[k], sats[0]};
1155 : 0 : }
1156 : : }
1157 : 0 : assert(false);
1158 : 0 : }
1159 : :
1160 : : template<typename Ctx>
1161 : 0 : internal::InputResult ProduceInput(const Ctx& ctx) const {
1162 : : using namespace internal;
1163 : :
1164 : : // Internal function which is invoked for every tree node, constructing satisfaction/dissatisfactions
1165 : : // given those of its subnodes.
1166 : 0 : auto helper = [&ctx](const Node& node, Span<InputResult> subres) -> InputResult {
1167 [ # # # # : 0 : switch (node.fragment) {
# # # # #
# # # # #
# # # # #
# # # # #
# ][ # # #
# # # # #
# # # # #
# # # # #
# # # # #
# # ]
1168 : : case Fragment::PK_K: {
1169 : 0 : std::vector<unsigned char> sig;
1170 [ # # ][ # # ]: 0 : Availability avail = ctx.Sign(node.keys[0], sig);
1171 [ # # ][ # # ]: 0 : return {ZERO, InputStack(std::move(sig)).SetWithSig().SetAvailable(avail)};
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1172 : 0 : }
1173 : : case Fragment::PK_H: {
1174 : 0 : std::vector<unsigned char> key = ctx.ToPKBytes(node.keys[0]), sig;
1175 [ # # ][ # # ]: 0 : Availability avail = ctx.Sign(node.keys[0], sig);
1176 [ # # ][ # # ]: 0 : return {ZERO + InputStack(key), (InputStack(std::move(sig)).SetWithSig() + InputStack(key)).SetAvailable(avail)};
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1177 : 0 : }
1178 : : case Fragment::MULTI_A: {
1179 : : // sats[j] represents the best stack containing j valid signatures (out of the first i keys).
1180 : : // In the loop below, these stacks are built up using a dynamic programming approach.
1181 : 0 : std::vector<InputStack> sats = Vector(EMPTY);
1182 [ # # ][ # # ]: 0 : for (size_t i = 0; i < node.keys.size(); ++i) {
1183 : : // Get the signature for the i'th key in reverse order (the signature for the first key needs to
1184 : : // be at the top of the stack, contrary to CHECKMULTISIG's satisfaction).
1185 : 0 : std::vector<unsigned char> sig;
1186 [ # # ][ # # ]: 0 : Availability avail = ctx.Sign(node.keys[node.keys.size() - 1 - i], sig);
1187 : : // Compute signature stack for just this key.
1188 [ # # ][ # # ]: 0 : auto sat = InputStack(std::move(sig)).SetWithSig().SetAvailable(avail);
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1189 : : // Compute the next sats vector: next_sats[0] is a copy of sats[0] (no signatures). All further
1190 : : // next_sats[j] are equal to either the existing sats[j] + ZERO, or sats[j-1] plus a signature
1191 : : // for the current (i'th) key. The very last element needs all signatures filled.
1192 : 0 : std::vector<InputStack> next_sats;
1193 [ # # ][ # # ]: 0 : next_sats.push_back(sats[0] + ZERO);
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1194 [ # # ][ # # ]: 0 : for (size_t j = 1; j < sats.size(); ++j) next_sats.push_back((sats[j] + ZERO) | (std::move(sats[j - 1]) + sat));
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1195 [ # # ][ # # ]: 0 : next_sats.push_back(std::move(sats[sats.size() - 1]) + std::move(sat));
[ # # ][ # # ]
1196 : : // Switch over.
1197 : 0 : sats = std::move(next_sats);
1198 : 0 : }
1199 : : // The dissatisfaction consists of as many empty vectors as there are keys, which is the same as
1200 : : // satisfying 0 keys.
1201 : 0 : auto& nsat{sats[0]};
1202 [ # # ][ # # ]: 0 : assert(node.k != 0);
1203 [ # # ][ # # ]: 0 : assert(node.k <= sats.size());
1204 [ # # ][ # # ]: 0 : return {std::move(nsat), std::move(sats[node.k])};
1205 : 0 : }
1206 : : case Fragment::MULTI: {
1207 : : // sats[j] represents the best stack containing j valid signatures (out of the first i keys).
1208 : : // In the loop below, these stacks are built up using a dynamic programming approach.
1209 : : // sats[0] starts off being {0}, due to the CHECKMULTISIG bug that pops off one element too many.
1210 : 0 : std::vector<InputStack> sats = Vector(ZERO);
1211 [ # # ][ # # ]: 0 : for (size_t i = 0; i < node.keys.size(); ++i) {
1212 : 0 : std::vector<unsigned char> sig;
1213 [ # # ][ # # ]: 0 : Availability avail = ctx.Sign(node.keys[i], sig);
1214 : : // Compute signature stack for just the i'th key.
1215 [ # # ][ # # ]: 0 : auto sat = InputStack(std::move(sig)).SetWithSig().SetAvailable(avail);
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1216 : : // Compute the next sats vector: next_sats[0] is a copy of sats[0] (no signatures). All further
1217 : : // next_sats[j] are equal to either the existing sats[j], or sats[j-1] plus a signature for the
1218 : : // current (i'th) key. The very last element needs all signatures filled.
1219 : 0 : std::vector<InputStack> next_sats;
1220 [ # # ][ # # ]: 0 : next_sats.push_back(sats[0]);
1221 [ # # ][ # # ]: 0 : for (size_t j = 1; j < sats.size(); ++j) next_sats.push_back(sats[j] | (std::move(sats[j - 1]) + sat));
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1222 [ # # ][ # # ]: 0 : next_sats.push_back(std::move(sats[sats.size() - 1]) + std::move(sat));
[ # # ][ # # ]
1223 : : // Switch over.
1224 : 0 : sats = std::move(next_sats);
1225 : 0 : }
1226 : : // The dissatisfaction consists of k+1 stack elements all equal to 0.
1227 [ # # ][ # # ]: 0 : InputStack nsat = ZERO;
1228 [ # # ][ # # ]: 0 : for (size_t i = 0; i < node.k; ++i) nsat = std::move(nsat) + ZERO;
[ # # ][ # # ]
[ # # ][ # # ]
1229 [ # # ][ # # ]: 0 : assert(node.k <= sats.size());
1230 [ # # ][ # # ]: 0 : return {std::move(nsat), std::move(sats[node.k])};
1231 : 0 : }
1232 : : case Fragment::THRESH: {
1233 : : // sats[k] represents the best stack that satisfies k out of the *last* i subexpressions.
1234 : : // In the loop below, these stacks are built up using a dynamic programming approach.
1235 : : // sats[0] starts off empty.
1236 : 0 : std::vector<InputStack> sats = Vector(EMPTY);
1237 [ # # ][ # # ]: 0 : for (size_t i = 0; i < subres.size(); ++i) {
1238 : : // Introduce an alias for the i'th last satisfaction/dissatisfaction.
1239 : 0 : auto& res = subres[subres.size() - i - 1];
1240 : : // Compute the next sats vector: next_sats[0] is sats[0] plus res.nsat (thus containing all dissatisfactions
1241 : : // so far. next_sats[j] is either sats[j] + res.nsat (reusing j earlier satisfactions) or sats[j-1] + res.sat
1242 : : // (reusing j-1 earlier satisfactions plus a new one). The very last next_sats[j] is all satisfactions.
1243 : 0 : std::vector<InputStack> next_sats;
1244 [ # # ][ # # ]: 0 : next_sats.push_back(sats[0] + res.nsat);
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1245 [ # # ][ # # ]: 0 : for (size_t j = 1; j < sats.size(); ++j) next_sats.push_back((sats[j] + res.nsat) | (std::move(sats[j - 1]) + res.sat));
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1246 [ # # ][ # # ]: 0 : next_sats.push_back(std::move(sats[sats.size() - 1]) + std::move(res.sat));
[ # # ][ # # ]
1247 : : // Switch over.
1248 : 0 : sats = std::move(next_sats);
1249 : 0 : }
1250 : : // At this point, sats[k].sat is the best satisfaction for the overall thresh() node. The best dissatisfaction
1251 : : // is computed by gathering all sats[i].nsat for i != k.
1252 [ # # ][ # # ]: 0 : InputStack nsat = INVALID;
1253 [ # # ][ # # ]: 0 : for (size_t i = 0; i < sats.size(); ++i) {
1254 : : // i==k is the satisfaction; i==0 is the canonical dissatisfaction;
1255 : : // the rest are non-canonical (a no-signature dissatisfaction - the i=0
1256 : : // form - is always available) and malleable (due to overcompleteness).
1257 : : // Marking the solutions malleable here is not strictly necessary, as they
1258 : : // should already never be picked in non-malleable solutions due to the
1259 : : // availability of the i=0 form.
1260 [ # # ][ # # ]: 0 : if (i != 0 && i != node.k) sats[i].SetMalleable().SetNonCanon();
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1261 : : // Include all dissatisfactions (even these non-canonical ones) in nsat.
1262 [ # # ][ # # ]: 0 : if (i != node.k) nsat = std::move(nsat) | std::move(sats[i]);
[ # # ][ # # ]
1263 : 0 : }
1264 [ # # ][ # # ]: 0 : assert(node.k <= sats.size());
1265 [ # # ][ # # ]: 0 : return {std::move(nsat), std::move(sats[node.k])};
1266 : 0 : }
1267 : : case Fragment::OLDER: {
1268 [ # # ][ # # ]: 0 : return {INVALID, ctx.CheckOlder(node.k) ? EMPTY : INVALID};
1269 : : }
1270 : : case Fragment::AFTER: {
1271 [ # # ][ # # ]: 0 : return {INVALID, ctx.CheckAfter(node.k) ? EMPTY : INVALID};
1272 : : }
1273 : : case Fragment::SHA256: {
1274 : 0 : std::vector<unsigned char> preimage;
1275 [ # # ][ # # ]: 0 : Availability avail = ctx.SatSHA256(node.data, preimage);
1276 [ # # ][ # # ]: 0 : return {ZERO32, InputStack(std::move(preimage)).SetAvailable(avail)};
[ # # ][ # # ]
[ # # ][ # # ]
1277 : 0 : }
1278 : : case Fragment::RIPEMD160: {
1279 : 0 : std::vector<unsigned char> preimage;
1280 [ # # ][ # # ]: 0 : Availability avail = ctx.SatRIPEMD160(node.data, preimage);
1281 [ # # ][ # # ]: 0 : return {ZERO32, InputStack(std::move(preimage)).SetAvailable(avail)};
[ # # ][ # # ]
[ # # ][ # # ]
1282 : 0 : }
1283 : : case Fragment::HASH256: {
1284 : 0 : std::vector<unsigned char> preimage;
1285 [ # # ][ # # ]: 0 : Availability avail = ctx.SatHASH256(node.data, preimage);
1286 [ # # ][ # # ]: 0 : return {ZERO32, InputStack(std::move(preimage)).SetAvailable(avail)};
[ # # ][ # # ]
[ # # ][ # # ]
1287 : 0 : }
1288 : : case Fragment::HASH160: {
1289 : 0 : std::vector<unsigned char> preimage;
1290 [ # # ][ # # ]: 0 : Availability avail = ctx.SatHASH160(node.data, preimage);
1291 [ # # ][ # # ]: 0 : return {ZERO32, InputStack(std::move(preimage)).SetAvailable(avail)};
[ # # ][ # # ]
[ # # ][ # # ]
1292 : 0 : }
1293 : : case Fragment::AND_V: {
1294 : 0 : auto& x = subres[0], &y = subres[1];
1295 : : // As the dissatisfaction here only consist of a single option, it doesn't
1296 : : // actually need to be listed (it's not required for reasoning about malleability of
1297 : : // other options), and is never required (no valid miniscript relies on the ability
1298 : : // to satisfy the type V left subexpression). It's still listed here for
1299 : : // completeness, as a hypothetical (not currently implemented) satisfier that doesn't
1300 : : // care about malleability might in some cases prefer it still.
1301 [ # # ][ # # ]: 0 : return {(y.nsat + x.sat).SetNonCanon(), y.sat + x.sat};
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1302 : : }
1303 : : case Fragment::AND_B: {
1304 : 0 : auto& x = subres[0], &y = subres[1];
1305 : : // Note that it is not strictly necessary to mark the 2nd and 3rd dissatisfaction here
1306 : : // as malleable. While they are definitely malleable, they are also non-canonical due
1307 : : // to the guaranteed existence of a no-signature other dissatisfaction (the 1st)
1308 : : // option. Because of that, the 2nd and 3rd option will never be chosen, even if they
1309 : : // weren't marked as malleable.
1310 [ # # ][ # # ]: 0 : return {(y.nsat + x.nsat) | (y.sat + x.nsat).SetMalleable().SetNonCanon() | (y.nsat + x.sat).SetMalleable().SetNonCanon(), y.sat + x.sat};
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1311 : : }
1312 : : case Fragment::OR_B: {
1313 : 0 : auto& x = subres[0], &z = subres[1];
1314 : : // The (sat(Z) sat(X)) solution is overcomplete (attacker can change either into dsat).
1315 [ # # ][ # # ]: 0 : return {z.nsat + x.nsat, (z.nsat + x.sat) | (z.sat + x.nsat) | (z.sat + x.sat).SetMalleable().SetNonCanon()};
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1316 : : }
1317 : : case Fragment::OR_C: {
1318 : 0 : auto& x = subres[0], &z = subres[1];
1319 [ # # ][ # # ]: 0 : return {INVALID, std::move(x.sat) | (z.sat + x.nsat)};
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1320 : : }
1321 : : case Fragment::OR_D: {
1322 : 0 : auto& x = subres[0], &z = subres[1];
1323 [ # # ][ # # ]: 0 : return {z.nsat + x.nsat, std::move(x.sat) | (z.sat + x.nsat)};
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1324 : : }
1325 : : case Fragment::OR_I: {
1326 : 0 : auto& x = subres[0], &z = subres[1];
1327 [ # # ][ # # ]: 0 : return {(x.nsat + ONE) | (z.nsat + ZERO), (x.sat + ONE) | (z.sat + ZERO)};
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1328 : : }
1329 : : case Fragment::ANDOR: {
1330 : 0 : auto& x = subres[0], &y = subres[1], &z = subres[2];
1331 [ # # ][ # # ]: 0 : return {(y.nsat + x.sat).SetNonCanon() | (z.nsat + x.nsat), (y.sat + x.sat) | (z.sat + x.nsat)};
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1332 : : }
1333 : : case Fragment::WRAP_A:
1334 : : case Fragment::WRAP_S:
1335 : : case Fragment::WRAP_C:
1336 : : case Fragment::WRAP_N:
1337 : 0 : return std::move(subres[0]);
1338 : : case Fragment::WRAP_D: {
1339 : 0 : auto &x = subres[0];
1340 [ # # ][ # # ]: 0 : return {ZERO, x.sat + ONE};
[ # # ][ # # ]
[ # # ][ # # ]
1341 : : }
1342 : : case Fragment::WRAP_J: {
1343 : 0 : auto &x = subres[0];
1344 : : // If a dissatisfaction with a nonzero top stack element exists, an alternative dissatisfaction exists.
1345 : : // As the dissatisfaction logic currently doesn't keep track of this nonzeroness property, and thus even
1346 : : // if a dissatisfaction with a top zero element is found, we don't know whether another one with a
1347 : : // nonzero top stack element exists. Make the conservative assumption that whenever the subexpression is weakly
1348 : : // dissatisfiable, this alternative dissatisfaction exists and leads to malleability.
1349 [ # # ][ # # ]: 0 : return {InputStack(ZERO).SetMalleable(x.nsat.available != Availability::NO && !x.nsat.has_sig), std::move(x.sat)};
[ # # ][ # # ]
[ # # ][ # # ]
1350 : : }
1351 : : case Fragment::WRAP_V: {
1352 : 0 : auto &x = subres[0];
1353 : 0 : return {INVALID, std::move(x.sat)};
1354 : : }
1355 : 0 : case Fragment::JUST_0: return {EMPTY, INVALID};
1356 : 0 : case Fragment::JUST_1: return {INVALID, EMPTY};
1357 : : }
1358 : 0 : assert(false);
1359 : : return {INVALID, INVALID};
1360 : 0 : };
1361 : :
1362 : 0 : auto tester = [&helper](const Node& node, Span<InputResult> subres) -> InputResult {
1363 : 0 : auto ret = helper(node, subres);
1364 : :
1365 : : // Do a consistency check between the satisfaction code and the type checker
1366 : : // (the actual satisfaction code in ProduceInputHelper does not use GetType)
1367 : :
1368 : : // For 'z' nodes, available satisfactions/dissatisfactions must have stack size 0.
1369 [ # # ][ # # ]: 0 : if (node.GetType() << "z"_mst && ret.nsat.available != Availability::NO) assert(ret.nsat.stack.size() == 0);
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1370 [ # # ][ # # ]: 0 : if (node.GetType() << "z"_mst && ret.sat.available != Availability::NO) assert(ret.sat.stack.size() == 0);
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1371 : :
1372 : : // For 'o' nodes, available satisfactions/dissatisfactions must have stack size 1.
1373 [ # # ][ # # ]: 0 : if (node.GetType() << "o"_mst && ret.nsat.available != Availability::NO) assert(ret.nsat.stack.size() == 1);
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1374 [ # # ][ # # ]: 0 : if (node.GetType() << "o"_mst && ret.sat.available != Availability::NO) assert(ret.sat.stack.size() == 1);
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1375 : :
1376 : : // For 'n' nodes, available satisfactions/dissatisfactions must have stack size 1 or larger. For satisfactions,
1377 : : // the top element cannot be 0.
1378 [ # # ][ # # ]: 0 : if (node.GetType() << "n"_mst && ret.sat.available != Availability::NO) assert(ret.sat.stack.size() >= 1);
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1379 [ # # ][ # # ]: 0 : if (node.GetType() << "n"_mst && ret.nsat.available != Availability::NO) assert(ret.nsat.stack.size() >= 1);
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1380 [ # # ][ # # ]: 0 : if (node.GetType() << "n"_mst && ret.sat.available != Availability::NO) assert(!ret.sat.stack.back().empty());
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1381 : :
1382 : : // For 'd' nodes, a dissatisfaction must exist, and they must not need a signature. If it is non-malleable,
1383 : : // it must be canonical.
1384 [ # # ][ # # ]: 0 : if (node.GetType() << "d"_mst) assert(ret.nsat.available != Availability::NO);
[ # # ][ # # ]
[ # # ][ # # ]
1385 [ # # ][ # # ]: 0 : if (node.GetType() << "d"_mst) assert(!ret.nsat.has_sig);
[ # # ][ # # ]
[ # # ][ # # ]
1386 [ # # ][ # # ]: 0 : if (node.GetType() << "d"_mst && !ret.nsat.malleable) assert(!ret.nsat.non_canon);
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1387 : :
1388 : : // For 'f'/'s' nodes, dissatisfactions/satisfactions must have a signature.
1389 [ # # ][ # # ]: 0 : if (node.GetType() << "f"_mst && ret.nsat.available != Availability::NO) assert(ret.nsat.has_sig);
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1390 [ # # ][ # # ]: 0 : if (node.GetType() << "s"_mst && ret.sat.available != Availability::NO) assert(ret.sat.has_sig);
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1391 : :
1392 : : // For non-malleable 'e' nodes, a non-malleable dissatisfaction must exist.
1393 [ # # ][ # # ]: 0 : if (node.GetType() << "me"_mst) assert(ret.nsat.available != Availability::NO);
[ # # ][ # # ]
[ # # ][ # # ]
1394 [ # # ][ # # ]: 0 : if (node.GetType() << "me"_mst) assert(!ret.nsat.malleable);
[ # # ][ # # ]
[ # # ][ # # ]
1395 : :
1396 : : // For 'm' nodes, if a satisfaction exists, it must be non-malleable.
1397 [ # # ][ # # ]: 0 : if (node.GetType() << "m"_mst && ret.sat.available != Availability::NO) assert(!ret.sat.malleable);
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1398 : :
1399 : : // If a non-malleable satisfaction exists, it must be canonical.
1400 [ # # ][ # # ]: 0 : if (ret.sat.available != Availability::NO && !ret.sat.malleable) assert(!ret.sat.non_canon);
[ # # ][ # # ]
[ # # ][ # # ]
1401 : :
1402 : 0 : return ret;
1403 [ # # ][ # # ]: 0 : };
1404 : :
1405 : 0 : return TreeEval<InputResult>(tester);
1406 : : }
1407 : :
1408 : : public:
1409 : : /** Update duplicate key information in this Node.
1410 : : *
1411 : : * This uses a custom key comparator provided by the context in order to still detect duplicates
1412 : : * for more complicated types.
1413 : : */
1414 : 0 : template<typename Ctx> void DuplicateKeyCheck(const Ctx& ctx) const
1415 : : {
1416 : : // We cannot use a lambda here, as lambdas are non assignable, and the set operations
1417 : : // below require moving the comparators around.
1418 : : struct Comp {
1419 : : const Ctx* ctx_ptr;
1420 : 0 : Comp(const Ctx& ctx) : ctx_ptr(&ctx) {}
1421 : 0 : bool operator()(const Key& a, const Key& b) const { return ctx_ptr->KeyCompare(a, b); }
1422 : : };
1423 : :
1424 : : // state in the recursive computation:
1425 : : // - std::nullopt means "this node has duplicates"
1426 : : // - an std::set means "this node has no duplicate keys, and they are: ...".
1427 : : using keyset = std::set<Key, Comp>;
1428 : : using state = std::optional<keyset>;
1429 : :
1430 : 0 : auto upfn = [&ctx](const Node& node, Span<state> subs) -> state {
1431 : : // If this node is already known to have duplicates, nothing left to do.
1432 [ # # ][ # # ]: 0 : if (node.has_duplicate_keys.has_value() && *node.has_duplicate_keys) return {};
[ # # ][ # # ]
[ # # ][ # # ]
1433 : :
1434 : : // Check if one of the children is already known to have duplicates.
1435 [ # # ][ # # ]: 0 : for (auto& sub : subs) {
[ # # ]
1436 [ # # ][ # # ]: 0 : if (!sub.has_value()) {
[ # # ]
1437 : 0 : node.has_duplicate_keys = true;
1438 : 0 : return {};
1439 : : }
1440 : : }
1441 : :
1442 : : // Start building the set of keys involved in this node and children.
1443 : : // Start by keys in this node directly.
1444 : 0 : size_t keys_count = node.keys.size();
1445 [ # # ][ # # ]: 0 : keyset key_set{node.keys.begin(), node.keys.end(), Comp(ctx)};
[ # # ]
1446 [ # # ][ # # ]: 0 : if (key_set.size() != keys_count) {
[ # # ]
1447 : : // It already has duplicates; bail out.
1448 : 0 : node.has_duplicate_keys = true;
1449 : 0 : return {};
1450 : : }
1451 : :
1452 : : // Merge the keys from the children into this set.
1453 [ # # ][ # # ]: 0 : for (auto& sub : subs) {
[ # # ]
1454 : 0 : keys_count += sub->size();
1455 : : // Small optimization: std::set::merge is linear in the size of the second arg but
1456 : : // logarithmic in the size of the first.
1457 [ # # ][ # # ]: 0 : if (key_set.size() < sub->size()) std::swap(key_set, *sub);
[ # # ]
1458 [ # # ][ # # ]: 0 : key_set.merge(*sub);
[ # # ]
1459 [ # # ][ # # ]: 0 : if (key_set.size() != keys_count) {
[ # # ]
1460 : 0 : node.has_duplicate_keys = true;
1461 : 0 : return {};
1462 : : }
1463 : : }
1464 : :
1465 : 0 : node.has_duplicate_keys = false;
1466 : 0 : return key_set;
1467 : 0 : };
1468 : :
1469 : 0 : TreeEval<state>(upfn);
1470 : 0 : }
1471 : :
1472 : : //! Return the size of the script for this expression (faster than ToScript().size()).
1473 : 0 : size_t ScriptSize() const { return scriptlen; }
1474 : :
1475 : : //! Return the maximum number of ops needed to satisfy this script non-malleably.
1476 : 0 : std::optional<uint32_t> GetOps() const {
1477 [ # # ]: 0 : if (!ops.sat.valid) return {};
1478 : 0 : return ops.count + ops.sat.value;
1479 : 0 : }
1480 : :
1481 : : //! Return the number of ops in the script (not counting the dynamic ones that depend on execution).
1482 : 0 : uint32_t GetStaticOps() const { return ops.count; }
1483 : :
1484 : : //! Check the ops limit of this script against the consensus limit.
1485 : 0 : bool CheckOpsLimit() const {
1486 [ # # ]: 0 : if (IsTapscript(m_script_ctx)) return true;
1487 [ # # ]: 0 : if (const auto ops = GetOps()) return *ops <= MAX_OPS_PER_SCRIPT;
1488 : 0 : return true;
1489 : 0 : }
1490 : :
1491 : : /** Whether this node is of type B, K or W. (That is, anything but V.) */
1492 : 0 : bool IsBKW() const {
1493 : 0 : return !((GetType() & "BKW"_mst) == ""_mst);
1494 : : }
1495 : :
1496 : : /** Return the maximum number of stack elements needed to satisfy this script non-malleably. */
1497 : 0 : std::optional<uint32_t> GetStackSize() const {
1498 [ # # ]: 0 : if (!ss.sat.valid) return {};
1499 : 0 : return ss.sat.netdiff + static_cast<int32_t>(IsBKW());
1500 : 0 : }
1501 : :
1502 : : //! Return the maximum size of the stack during execution of this script.
1503 : 0 : std::optional<uint32_t> GetExecStackSize() const {
1504 [ # # ]: 0 : if (!ss.sat.valid) return {};
1505 : 0 : return ss.sat.exec + static_cast<int32_t>(IsBKW());
1506 : 0 : }
1507 : :
1508 : : //! Check the maximum stack size for this script against the policy limit.
1509 : 0 : bool CheckStackSize() const {
1510 : : // Since in Tapscript there is no standardness limit on the script and witness sizes, we may run
1511 : : // into the maximum stack size while executing the script. Make sure it doesn't happen.
1512 [ # # ]: 0 : if (IsTapscript(m_script_ctx)) {
1513 [ # # ]: 0 : if (const auto exec_ss = GetExecStackSize()) return exec_ss <= MAX_STACK_SIZE;
1514 : 0 : return true;
1515 : : }
1516 [ # # ]: 0 : if (const auto ss = GetStackSize()) return *ss <= MAX_STANDARD_P2WSH_STACK_ITEMS;
1517 : 0 : return true;
1518 : 0 : }
1519 : :
1520 : : //! Whether no satisfaction exists for this node.
1521 : 0 : bool IsNotSatisfiable() const { return !GetStackSize(); }
1522 : :
1523 : : /** Return the maximum size in bytes of a witness to satisfy this script non-malleably. Note this does
1524 : : * not include the witness script push. */
1525 : 0 : std::optional<uint32_t> GetWitnessSize() const {
1526 [ # # ]: 0 : if (!ws.sat.valid) return {};
1527 : 0 : return ws.sat.value;
1528 : 0 : }
1529 : :
1530 : : //! Return the expression type.
1531 : 0 : Type GetType() const { return typ; }
1532 : :
1533 : : //! Return the script context for this node.
1534 : 0 : MiniscriptContext GetMsCtx() const { return m_script_ctx; }
1535 : :
1536 : : //! Find an insane subnode which has no insane children. Nullptr if there is none.
1537 : 0 : const Node* FindInsaneSub() const {
1538 : 0 : return TreeEval<const Node*>([](const Node& node, Span<const Node*> subs) -> const Node* {
1539 [ # # ][ # # ]: 0 : for (auto& sub: subs) if (sub) return sub;
1540 [ # # ]: 0 : if (!node.IsSaneSubexpression()) return &node;
1541 : 0 : return nullptr;
1542 : 0 : });
1543 : : }
1544 : :
1545 : : //! Determine whether a Miniscript node is satisfiable. fn(node) will be invoked for all
1546 : : //! key, time, and hashing nodes, and should return their satisfiability.
1547 : : template<typename F>
1548 : 0 : bool IsSatisfiable(F fn) const
1549 : : {
1550 : : // TreeEval() doesn't support bool as NodeType, so use int instead.
1551 : 0 : return TreeEval<int>([&fn](const Node& node, Span<int> subs) -> bool {
1552 [ # # # # : 0 : switch (node.fragment) {
# # # # ]
1553 : : case Fragment::JUST_0:
1554 : 0 : return false;
1555 : : case Fragment::JUST_1:
1556 : 0 : return true;
1557 : : case Fragment::PK_K:
1558 : : case Fragment::PK_H:
1559 : : case Fragment::MULTI:
1560 : : case Fragment::MULTI_A:
1561 : : case Fragment::AFTER:
1562 : : case Fragment::OLDER:
1563 : : case Fragment::HASH256:
1564 : : case Fragment::HASH160:
1565 : : case Fragment::SHA256:
1566 : : case Fragment::RIPEMD160:
1567 : 0 : return bool{fn(node)};
1568 : : case Fragment::ANDOR:
1569 [ # # ][ # # ]: 0 : return (subs[0] && subs[1]) || subs[2];
1570 : : case Fragment::AND_V:
1571 : : case Fragment::AND_B:
1572 [ # # ]: 0 : return subs[0] && subs[1];
1573 : : case Fragment::OR_B:
1574 : : case Fragment::OR_C:
1575 : : case Fragment::OR_D:
1576 : : case Fragment::OR_I:
1577 [ # # ]: 0 : return subs[0] || subs[1];
1578 : : case Fragment::THRESH:
1579 : 0 : return static_cast<uint32_t>(std::count(subs.begin(), subs.end(), true)) >= node.k;
1580 : : default: // wrappers
1581 [ # # ]: 0 : assert(subs.size() == 1);
1582 : 0 : return subs[0];
1583 : : }
1584 : 0 : });
1585 : : }
1586 : :
1587 : : //! Check whether this node is valid at all.
1588 : 0 : bool IsValid() const {
1589 [ # # ][ # # ]: 0 : if (GetType() == ""_mst) return false;
1590 : 0 : return ScriptSize() <= internal::MaxScriptSize(m_script_ctx);
1591 : 0 : }
1592 : :
1593 : : //! Check whether this node is valid as a script on its own.
1594 [ # # ][ # # ]: 0 : bool IsValidTopLevel() const { return IsValid() && GetType() << "B"_mst; }
1595 : :
1596 : : //! Check whether this script can always be satisfied in a non-malleable way.
1597 : 0 : bool IsNonMalleable() const { return GetType() << "m"_mst; }
1598 : :
1599 : : //! Check whether this script always needs a signature.
1600 : 0 : bool NeedsSignature() const { return GetType() << "s"_mst; }
1601 : :
1602 : : //! Check whether there is no satisfaction path that contains both timelocks and heightlocks
1603 : 0 : bool CheckTimeLocksMix() const { return GetType() << "k"_mst; }
1604 : :
1605 : : //! Check whether there is no duplicate key across this fragment and all its sub-fragments.
1606 [ # # ]: 0 : bool CheckDuplicateKey() const { return has_duplicate_keys && !*has_duplicate_keys; }
1607 : :
1608 : : //! Whether successful non-malleable satisfactions are guaranteed to be valid.
1609 [ # # ][ # # ]: 0 : bool ValidSatisfactions() const { return IsValid() && CheckOpsLimit() && CheckStackSize(); }
1610 : :
1611 : : //! Whether the apparent policy of this node matches its script semantics. Doesn't guarantee it is a safe script on its own.
1612 [ # # ][ # # ]: 0 : bool IsSaneSubexpression() const { return ValidSatisfactions() && IsNonMalleable() && CheckTimeLocksMix() && CheckDuplicateKey(); }
[ # # ]
1613 : :
1614 : : //! Check whether this node is safe as a script on its own.
1615 [ # # ][ # # ]: 0 : bool IsSane() const { return IsValidTopLevel() && IsSaneSubexpression() && NeedsSignature(); }
1616 : :
1617 : : //! Produce a witness for this script, if possible and given the information available in the context.
1618 : : //! The non-malleable satisfaction is guaranteed to be valid if it exists, and ValidSatisfaction()
1619 : : //! is true. If IsSane() holds, this satisfaction is guaranteed to succeed in case the node's
1620 : : //! conditions are satisfied (private keys and hash preimages available, locktimes satsified).
1621 : : template<typename Ctx>
1622 : 0 : Availability Satisfy(const Ctx& ctx, std::vector<std::vector<unsigned char>>& stack, bool nonmalleable = true) const {
1623 : 0 : auto ret = ProduceInput(ctx);
1624 [ # # ][ # # ]: 0 : if (nonmalleable && (ret.sat.malleable || !ret.sat.has_sig)) return Availability::NO;
[ # # ][ # # ]
[ # # ][ # # ]
1625 : 0 : stack = std::move(ret.sat.stack);
1626 : 0 : return ret.sat.available;
1627 : 0 : }
1628 : :
1629 : : //! Equality testing.
1630 : 0 : bool operator==(const Node<Key>& arg) const { return Compare(*this, arg) == 0; }
1631 : :
1632 : : // Constructors with various argument combinations, which bypass the duplicate key check.
1633 : 0 : Node(internal::NoDupCheck, MiniscriptContext script_ctx, Fragment nt, std::vector<NodeRef<Key>> sub, std::vector<unsigned char> arg, uint32_t val = 0)
1634 [ # # ][ # # ]: 0 : : fragment(nt), k(val), data(std::move(arg)), subs(std::move(sub)), m_script_ctx{script_ctx}, ops(CalcOps()), ss(CalcStackSize()), ws(CalcWitnessSize()), typ(CalcType()), scriptlen(CalcScriptLen()) {}
[ # # ][ # # ]
[ # # ][ # # ]
1635 : 0 : Node(internal::NoDupCheck, MiniscriptContext script_ctx, Fragment nt, std::vector<unsigned char> arg, uint32_t val = 0)
1636 [ # # ][ # # ]: 0 : : fragment(nt), k(val), data(std::move(arg)), m_script_ctx{script_ctx}, ops(CalcOps()), ss(CalcStackSize()), ws(CalcWitnessSize()), typ(CalcType()), scriptlen(CalcScriptLen()) {}
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1637 : : Node(internal::NoDupCheck, MiniscriptContext script_ctx, Fragment nt, std::vector<NodeRef<Key>> sub, std::vector<Key> key, uint32_t val = 0)
1638 : : : fragment(nt), k(val), keys(std::move(key)), m_script_ctx{script_ctx}, subs(std::move(sub)), ops(CalcOps()), ss(CalcStackSize()), ws(CalcWitnessSize()), typ(CalcType()), scriptlen(CalcScriptLen()) {}
1639 : 0 : Node(internal::NoDupCheck, MiniscriptContext script_ctx, Fragment nt, std::vector<Key> key, uint32_t val = 0)
1640 [ # # ][ # # ]: 0 : : fragment(nt), k(val), keys(std::move(key)), m_script_ctx{script_ctx}, ops(CalcOps()), ss(CalcStackSize()), ws(CalcWitnessSize()), typ(CalcType()), scriptlen(CalcScriptLen()) {}
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1641 : 0 : Node(internal::NoDupCheck, MiniscriptContext script_ctx, Fragment nt, std::vector<NodeRef<Key>> sub, uint32_t val = 0)
1642 [ # # ][ # # ]: 0 : : fragment(nt), k(val), subs(std::move(sub)), m_script_ctx{script_ctx}, ops(CalcOps()), ss(CalcStackSize()), ws(CalcWitnessSize()), typ(CalcType()), scriptlen(CalcScriptLen()) {}
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1643 : 0 : Node(internal::NoDupCheck, MiniscriptContext script_ctx, Fragment nt, uint32_t val = 0)
1644 [ # # ][ # # ]: 0 : : fragment(nt), k(val), m_script_ctx{script_ctx}, ops(CalcOps()), ss(CalcStackSize()), ws(CalcWitnessSize()), typ(CalcType()), scriptlen(CalcScriptLen()) {}
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1645 : :
1646 : : // Constructors with various argument combinations, which do perform the duplicate key check.
1647 : : template <typename Ctx> Node(const Ctx& ctx, Fragment nt, std::vector<NodeRef<Key>> sub, std::vector<unsigned char> arg, uint32_t val = 0)
1648 : : : Node(internal::NoDupCheck{}, ctx.MsContext(), nt, std::move(sub), std::move(arg), val) { DuplicateKeyCheck(ctx); }
1649 : : template <typename Ctx> Node(const Ctx& ctx, Fragment nt, std::vector<unsigned char> arg, uint32_t val = 0)
1650 : : : Node(internal::NoDupCheck{}, ctx.MsContext(), nt, std::move(arg), val) { DuplicateKeyCheck(ctx);}
1651 : : template <typename Ctx> Node(const Ctx& ctx, Fragment nt, std::vector<NodeRef<Key>> sub, std::vector<Key> key, uint32_t val = 0)
1652 : : : Node(internal::NoDupCheck{}, ctx.MsContext(), nt, std::move(sub), std::move(key), val) { DuplicateKeyCheck(ctx); }
1653 : : template <typename Ctx> Node(const Ctx& ctx, Fragment nt, std::vector<Key> key, uint32_t val = 0)
1654 : : : Node(internal::NoDupCheck{}, ctx.MsContext(), nt, std::move(key), val) { DuplicateKeyCheck(ctx); }
1655 : : template <typename Ctx> Node(const Ctx& ctx, Fragment nt, std::vector<NodeRef<Key>> sub, uint32_t val = 0)
1656 : : : Node(internal::NoDupCheck{}, ctx.MsContext(), nt, std::move(sub), val) { DuplicateKeyCheck(ctx); }
1657 : : template <typename Ctx> Node(const Ctx& ctx, Fragment nt, uint32_t val = 0)
1658 : : : Node(internal::NoDupCheck{}, ctx.MsContext(), nt, val) { DuplicateKeyCheck(ctx); }
1659 : : };
1660 : :
1661 : : namespace internal {
1662 : :
1663 : : enum class ParseContext {
1664 : : /** An expression which may be begin with wrappers followed by a colon. */
1665 : : WRAPPED_EXPR,
1666 : : /** A miniscript expression which does not begin with wrappers. */
1667 : : EXPR,
1668 : :
1669 : : /** SWAP wraps the top constructed node with s: */
1670 : : SWAP,
1671 : : /** ALT wraps the top constructed node with a: */
1672 : : ALT,
1673 : : /** CHECK wraps the top constructed node with c: */
1674 : : CHECK,
1675 : : /** DUP_IF wraps the top constructed node with d: */
1676 : : DUP_IF,
1677 : : /** VERIFY wraps the top constructed node with v: */
1678 : : VERIFY,
1679 : : /** NON_ZERO wraps the top constructed node with j: */
1680 : : NON_ZERO,
1681 : : /** ZERO_NOTEQUAL wraps the top constructed node with n: */
1682 : : ZERO_NOTEQUAL,
1683 : : /** WRAP_U will construct an or_i(X,0) node from the top constructed node. */
1684 : : WRAP_U,
1685 : : /** WRAP_T will construct an and_v(X,1) node from the top constructed node. */
1686 : : WRAP_T,
1687 : :
1688 : : /** AND_N will construct an andor(X,Y,0) node from the last two constructed nodes. */
1689 : : AND_N,
1690 : : /** AND_V will construct an and_v node from the last two constructed nodes. */
1691 : : AND_V,
1692 : : /** AND_B will construct an and_b node from the last two constructed nodes. */
1693 : : AND_B,
1694 : : /** ANDOR will construct an andor node from the last three constructed nodes. */
1695 : : ANDOR,
1696 : : /** OR_B will construct an or_b node from the last two constructed nodes. */
1697 : : OR_B,
1698 : : /** OR_C will construct an or_c node from the last two constructed nodes. */
1699 : : OR_C,
1700 : : /** OR_D will construct an or_d node from the last two constructed nodes. */
1701 : : OR_D,
1702 : : /** OR_I will construct an or_i node from the last two constructed nodes. */
1703 : : OR_I,
1704 : :
1705 : : /** THRESH will read a wrapped expression, and then look for a COMMA. If
1706 : : * no comma follows, it will construct a thresh node from the appropriate
1707 : : * number of constructed children. Otherwise, it will recurse with another
1708 : : * THRESH. */
1709 : : THRESH,
1710 : :
1711 : : /** COMMA expects the next element to be ',' and fails if not. */
1712 : : COMMA,
1713 : : /** CLOSE_BRACKET expects the next element to be ')' and fails if not. */
1714 : : CLOSE_BRACKET,
1715 : : };
1716 : :
1717 : : int FindNextChar(Span<const char> in, const char m);
1718 : :
1719 : : /** Parse a key string ending at the end of the fragment's text representation. */
1720 : : template<typename Key, typename Ctx>
1721 : 0 : std::optional<std::pair<Key, int>> ParseKeyEnd(Span<const char> in, const Ctx& ctx)
1722 : : {
1723 : 0 : int key_size = FindNextChar(in, ')');
1724 [ # # ]: 0 : if (key_size < 1) return {};
1725 : 0 : auto key = ctx.FromString(in.begin(), in.begin() + key_size);
1726 [ # # ]: 0 : if (!key) return {};
1727 : 0 : return {{std::move(*key), key_size}};
1728 : 0 : }
1729 : :
1730 : : /** Parse a hex string ending at the end of the fragment's text representation. */
1731 : : template<typename Ctx>
1732 : 0 : std::optional<std::pair<std::vector<unsigned char>, int>> ParseHexStrEnd(Span<const char> in, const size_t expected_size,
1733 : : const Ctx& ctx)
1734 : : {
1735 : 0 : int hash_size = FindNextChar(in, ')');
1736 [ # # ]: 0 : if (hash_size < 1) return {};
1737 [ # # ]: 0 : std::string val = std::string(in.begin(), in.begin() + hash_size);
1738 [ # # ][ # # ]: 0 : if (!IsHex(val)) return {};
1739 [ # # ]: 0 : auto hash = ParseHex(val);
1740 [ # # ]: 0 : if (hash.size() != expected_size) return {};
1741 [ # # ]: 0 : return {{std::move(hash), hash_size}};
1742 : 0 : }
1743 : :
1744 : : /** BuildBack pops the last two elements off `constructed` and wraps them in the specified Fragment */
1745 : : template<typename Key>
1746 : 0 : void BuildBack(const MiniscriptContext script_ctx, Fragment nt, std::vector<NodeRef<Key>>& constructed, const bool reverse = false)
1747 : : {
1748 : 0 : NodeRef<Key> child = std::move(constructed.back());
1749 : 0 : constructed.pop_back();
1750 [ # # ][ # # ]: 0 : if (reverse) {
1751 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, script_ctx, nt, Vector(std::move(child), std::move(constructed.back())));
[ # # ][ # # ]
1752 : 0 : } else {
1753 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, script_ctx, nt, Vector(std::move(constructed.back()), std::move(child)));
[ # # ][ # # ]
1754 : : }
1755 : 0 : }
1756 : :
1757 : : /**
1758 : : * Parse a miniscript from its textual descriptor form.
1759 : : * This does not check whether the script is valid, let alone sane. The caller is expected to use
1760 : : * the `IsValidTopLevel()` and `IsSaneTopLevel()` to check for these properties on the node.
1761 : : */
1762 : : template<typename Key, typename Ctx>
1763 : 0 : inline NodeRef<Key> Parse(Span<const char> in, const Ctx& ctx)
1764 : : {
1765 : : using namespace spanparsing;
1766 : :
1767 : : // Account for the minimum script size for all parsed fragments so far. It "borrows" 1
1768 : : // script byte from all leaf nodes, counting it instead whenever a space for a recursive
1769 : : // expression is added (through andor, and_*, or_*, thresh). This guarantees that all fragments
1770 : : // increment the script_size by at least one, except for:
1771 : : // - "0", "1": these leafs are only a single byte, so their subtracted-from increment is 0.
1772 : : // This is not an issue however, as "space" for them has to be created by combinators,
1773 : : // which do increment script_size.
1774 : : // - "v:": the v wrapper adds nothing as in some cases it results in no opcode being added
1775 : : // (instead transforming another opcode into its VERIFY form). However, the v: wrapper has
1776 : : // to be interleaved with other fragments to be valid, so this is not a concern.
1777 : 0 : size_t script_size{1};
1778 : 0 : size_t max_size{internal::MaxScriptSize(ctx.MsContext())};
1779 : :
1780 : : // The two integers are used to hold state for thresh()
1781 : 0 : std::vector<std::tuple<ParseContext, int64_t, int64_t>> to_parse;
1782 : 0 : std::vector<NodeRef<Key>> constructed;
1783 : :
1784 [ # # ]: 0 : to_parse.emplace_back(ParseContext::WRAPPED_EXPR, -1, -1);
1785 : :
1786 : : // Parses a multi() or multi_a() from its string representation. Returns false on parsing error.
1787 : 0 : const auto parse_multi_exp = [&](Span<const char>& in, const bool is_multi_a) -> bool {
1788 : 0 : const auto max_keys{is_multi_a ? MAX_PUBKEYS_PER_MULTI_A : MAX_PUBKEYS_PER_MULTISIG};
1789 : 0 : const auto required_ctx{is_multi_a ? MiniscriptContext::TAPSCRIPT : MiniscriptContext::P2WSH};
1790 [ # # ]: 0 : if (ctx.MsContext() != required_ctx) return false;
1791 : : // Get threshold
1792 : 0 : int next_comma = FindNextChar(in, ',');
1793 [ # # ]: 0 : if (next_comma < 1) return false;
1794 : : int64_t k;
1795 [ # # ][ # # ]: 0 : if (!ParseInt64(std::string(in.begin(), in.begin() + next_comma), &k)) return false;
[ # # ]
1796 : 0 : in = in.subspan(next_comma + 1);
1797 : : // Get keys. It is compatible for both compressed and x-only keys.
1798 : 0 : std::vector<Key> keys;
1799 [ # # ]: 0 : while (next_comma != -1) {
1800 [ # # ]: 0 : next_comma = FindNextChar(in, ',');
1801 [ # # ][ # # ]: 0 : int key_length = (next_comma == -1) ? FindNextChar(in, ')') : next_comma;
1802 [ # # ]: 0 : if (key_length < 1) return false;
1803 [ # # ]: 0 : auto key = ctx.FromString(in.begin(), in.begin() + key_length);
1804 [ # # ]: 0 : if (!key) return false;
1805 [ # # ]: 0 : keys.push_back(std::move(*key));
1806 : 0 : in = in.subspan(key_length + 1);
1807 : : }
1808 [ # # ][ # # ]: 0 : if (keys.size() < 1 || keys.size() > max_keys) return false;
1809 [ # # ][ # # ]: 0 : if (k < 1 || k > (int64_t)keys.size()) return false;
1810 [ # # ]: 0 : if (is_multi_a) {
1811 : : // (push + xonly-key + CHECKSIG[ADD]) * n + k + OP_NUMEQUAL(VERIFY), minus one.
1812 [ # # ][ # # ]: 0 : script_size += (1 + 32 + 1) * keys.size() + BuildScript(k).size();
1813 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::MULTI_A, std::move(keys), k));
1814 : 0 : } else {
1815 : 0 : script_size += 2 + (keys.size() > 16) + (k > 16) + 34 * keys.size();
1816 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::MULTI, std::move(keys), k));
1817 : : }
1818 : 0 : return true;
1819 : 0 : };
1820 : :
1821 [ # # ]: 0 : while (!to_parse.empty()) {
1822 [ # # ]: 0 : if (script_size > max_size) return {};
1823 : :
1824 : : // Get the current context we are decoding within
1825 : 0 : auto [cur_context, n, k] = to_parse.back();
1826 : 0 : to_parse.pop_back();
1827 : :
1828 [ # # # # : 0 : switch (cur_context) {
# # # # #
# # # # #
# # # # #
# # # # ]
1829 : : case ParseContext::WRAPPED_EXPR: {
1830 : 0 : std::optional<size_t> colon_index{};
1831 [ # # ]: 0 : for (size_t i = 1; i < in.size(); ++i) {
1832 [ # # ]: 0 : if (in[i] == ':') {
1833 : 0 : colon_index = i;
1834 : 0 : break;
1835 : : }
1836 [ # # ][ # # ]: 0 : if (in[i] < 'a' || in[i] > 'z') break;
1837 : 0 : }
1838 : : // If there is no colon, this loop won't execute
1839 : 0 : bool last_was_v{false};
1840 [ # # ][ # # ]: 0 : for (size_t j = 0; colon_index && j < *colon_index; ++j) {
1841 [ # # ]: 0 : if (script_size > max_size) return {};
1842 [ # # ]: 0 : if (in[j] == 'a') {
1843 : 0 : script_size += 2;
1844 [ # # ]: 0 : to_parse.emplace_back(ParseContext::ALT, -1, -1);
1845 [ # # ]: 0 : } else if (in[j] == 's') {
1846 : 0 : script_size += 1;
1847 [ # # ]: 0 : to_parse.emplace_back(ParseContext::SWAP, -1, -1);
1848 [ # # ]: 0 : } else if (in[j] == 'c') {
1849 : 0 : script_size += 1;
1850 [ # # ]: 0 : to_parse.emplace_back(ParseContext::CHECK, -1, -1);
1851 [ # # ]: 0 : } else if (in[j] == 'd') {
1852 : 0 : script_size += 3;
1853 [ # # ]: 0 : to_parse.emplace_back(ParseContext::DUP_IF, -1, -1);
1854 [ # # ]: 0 : } else if (in[j] == 'j') {
1855 : 0 : script_size += 4;
1856 [ # # ]: 0 : to_parse.emplace_back(ParseContext::NON_ZERO, -1, -1);
1857 [ # # ]: 0 : } else if (in[j] == 'n') {
1858 : 0 : script_size += 1;
1859 [ # # ]: 0 : to_parse.emplace_back(ParseContext::ZERO_NOTEQUAL, -1, -1);
1860 [ # # ]: 0 : } else if (in[j] == 'v') {
1861 : : // do not permit "...vv...:"; it's not valid, and also doesn't trigger early
1862 : : // failure as script_size isn't incremented.
1863 [ # # ]: 0 : if (last_was_v) return {};
1864 [ # # ]: 0 : to_parse.emplace_back(ParseContext::VERIFY, -1, -1);
1865 [ # # ]: 0 : } else if (in[j] == 'u') {
1866 : 0 : script_size += 4;
1867 [ # # ]: 0 : to_parse.emplace_back(ParseContext::WRAP_U, -1, -1);
1868 [ # # ]: 0 : } else if (in[j] == 't') {
1869 : 0 : script_size += 1;
1870 [ # # ]: 0 : to_parse.emplace_back(ParseContext::WRAP_T, -1, -1);
1871 [ # # ]: 0 : } else if (in[j] == 'l') {
1872 : : // The l: wrapper is equivalent to or_i(0,X)
1873 : 0 : script_size += 4;
1874 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::JUST_0));
[ # # ]
1875 [ # # ]: 0 : to_parse.emplace_back(ParseContext::OR_I, -1, -1);
1876 : 0 : } else {
1877 : 0 : return {};
1878 : : }
1879 : 0 : last_was_v = (in[j] == 'v');
1880 : 0 : }
1881 [ # # ]: 0 : to_parse.emplace_back(ParseContext::EXPR, -1, -1);
1882 [ # # ]: 0 : if (colon_index) in = in.subspan(*colon_index + 1);
1883 : 0 : break;
1884 : : }
1885 : : case ParseContext::EXPR: {
1886 [ # # ][ # # ]: 0 : if (Const("0", in)) {
[ # # ]
1887 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::JUST_0));
[ # # ]
1888 [ # # ][ # # ]: 0 : } else if (Const("1", in)) {
[ # # ]
1889 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::JUST_1));
[ # # ]
1890 [ # # ][ # # ]: 0 : } else if (Const("pk(", in)) {
[ # # ]
1891 [ # # ]: 0 : auto res = ParseKeyEnd<Key, Ctx>(in, ctx);
1892 [ # # ]: 0 : if (!res) return {};
1893 : 0 : auto& [key, key_size] = *res;
1894 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::WRAP_C, Vector(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::PK_K, Vector(std::move(key))))));
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1895 : 0 : in = in.subspan(key_size + 1);
1896 [ # # ][ # # ]: 0 : script_size += IsTapscript(ctx.MsContext()) ? 33 : 34;
1897 [ # # ][ # # ]: 0 : } else if (Const("pkh(", in)) {
[ # # ]
1898 [ # # ]: 0 : auto res = ParseKeyEnd<Key>(in, ctx);
1899 [ # # ]: 0 : if (!res) return {};
1900 : 0 : auto& [key, key_size] = *res;
1901 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::WRAP_C, Vector(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::PK_H, Vector(std::move(key))))));
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
1902 : 0 : in = in.subspan(key_size + 1);
1903 : 0 : script_size += 24;
1904 [ # # ][ # # ]: 0 : } else if (Const("pk_k(", in)) {
[ # # ]
1905 [ # # ]: 0 : auto res = ParseKeyEnd<Key>(in, ctx);
1906 [ # # ]: 0 : if (!res) return {};
1907 : 0 : auto& [key, key_size] = *res;
1908 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::PK_K, Vector(std::move(key))));
[ # # ][ # # ]
[ # # ]
1909 : 0 : in = in.subspan(key_size + 1);
1910 [ # # ][ # # ]: 0 : script_size += IsTapscript(ctx.MsContext()) ? 32 : 33;
1911 [ # # ][ # # ]: 0 : } else if (Const("pk_h(", in)) {
[ # # ]
1912 [ # # ]: 0 : auto res = ParseKeyEnd<Key>(in, ctx);
1913 [ # # ]: 0 : if (!res) return {};
1914 : 0 : auto& [key, key_size] = *res;
1915 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::PK_H, Vector(std::move(key))));
[ # # ][ # # ]
[ # # ]
1916 : 0 : in = in.subspan(key_size + 1);
1917 : 0 : script_size += 23;
1918 [ # # ][ # # ]: 0 : } else if (Const("sha256(", in)) {
[ # # ]
1919 [ # # ]: 0 : auto res = ParseHexStrEnd(in, 32, ctx);
1920 [ # # ]: 0 : if (!res) return {};
1921 : 0 : auto& [hash, hash_size] = *res;
1922 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::SHA256, std::move(hash)));
[ # # ][ # # ]
1923 : 0 : in = in.subspan(hash_size + 1);
1924 : 0 : script_size += 38;
1925 [ # # ][ # # ]: 0 : } else if (Const("ripemd160(", in)) {
[ # # ][ # # ]
1926 [ # # ]: 0 : auto res = ParseHexStrEnd(in, 20, ctx);
1927 [ # # ]: 0 : if (!res) return {};
1928 : 0 : auto& [hash, hash_size] = *res;
1929 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::RIPEMD160, std::move(hash)));
[ # # ][ # # ]
1930 : 0 : in = in.subspan(hash_size + 1);
1931 : 0 : script_size += 26;
1932 [ # # ][ # # ]: 0 : } else if (Const("hash256(", in)) {
[ # # ][ # # ]
1933 [ # # ]: 0 : auto res = ParseHexStrEnd(in, 32, ctx);
1934 [ # # ]: 0 : if (!res) return {};
1935 : 0 : auto& [hash, hash_size] = *res;
1936 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::HASH256, std::move(hash)));
[ # # ][ # # ]
1937 : 0 : in = in.subspan(hash_size + 1);
1938 : 0 : script_size += 38;
1939 [ # # ][ # # ]: 0 : } else if (Const("hash160(", in)) {
[ # # ][ # # ]
1940 [ # # ]: 0 : auto res = ParseHexStrEnd(in, 20, ctx);
1941 [ # # ]: 0 : if (!res) return {};
1942 : 0 : auto& [hash, hash_size] = *res;
1943 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::HASH160, std::move(hash)));
[ # # ][ # # ]
1944 : 0 : in = in.subspan(hash_size + 1);
1945 : 0 : script_size += 26;
1946 [ # # ][ # # ]: 0 : } else if (Const("after(", in)) {
[ # # ][ # # ]
1947 [ # # ]: 0 : int arg_size = FindNextChar(in, ')');
1948 [ # # ]: 0 : if (arg_size < 1) return {};
1949 : : int64_t num;
1950 [ # # ][ # # ]: 0 : if (!ParseInt64(std::string(in.begin(), in.begin() + arg_size), &num)) return {};
[ # # ]
1951 [ # # ][ # # ]: 0 : if (num < 1 || num >= 0x80000000L) return {};
1952 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::AFTER, num));
[ # # ]
1953 : 0 : in = in.subspan(arg_size + 1);
1954 : 0 : script_size += 1 + (num > 16) + (num > 0x7f) + (num > 0x7fff) + (num > 0x7fffff);
1955 [ # # ][ # # ]: 0 : } else if (Const("older(", in)) {
[ # # ]
1956 [ # # ]: 0 : int arg_size = FindNextChar(in, ')');
1957 [ # # ]: 0 : if (arg_size < 1) return {};
1958 : : int64_t num;
1959 [ # # ][ # # ]: 0 : if (!ParseInt64(std::string(in.begin(), in.begin() + arg_size), &num)) return {};
[ # # ]
1960 [ # # ][ # # ]: 0 : if (num < 1 || num >= 0x80000000L) return {};
1961 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::OLDER, num));
[ # # ]
1962 : 0 : in = in.subspan(arg_size + 1);
1963 : 0 : script_size += 1 + (num > 16) + (num > 0x7f) + (num > 0x7fff) + (num > 0x7fffff);
1964 [ # # ][ # # ]: 0 : } else if (Const("multi(", in)) {
[ # # ]
1965 [ # # ][ # # ]: 0 : if (!parse_multi_exp(in, /* is_multi_a = */false)) return {};
1966 [ # # ][ # # ]: 0 : } else if (Const("multi_a(", in)) {
[ # # ]
1967 [ # # ][ # # ]: 0 : if (!parse_multi_exp(in, /* is_multi_a = */true)) return {};
1968 [ # # ][ # # ]: 0 : } else if (Const("thresh(", in)) {
[ # # ]
1969 [ # # ]: 0 : int next_comma = FindNextChar(in, ',');
1970 [ # # ]: 0 : if (next_comma < 1) return {};
1971 [ # # ][ # # ]: 0 : if (!ParseInt64(std::string(in.begin(), in.begin() + next_comma), &k)) return {};
[ # # ][ # # ]
1972 [ # # ]: 0 : if (k < 1) return {};
1973 : 0 : in = in.subspan(next_comma + 1);
1974 : : // n = 1 here because we read the first WRAPPED_EXPR before reaching THRESH
1975 [ # # ][ # # ]: 0 : to_parse.emplace_back(ParseContext::THRESH, 1, k);
1976 [ # # ]: 0 : to_parse.emplace_back(ParseContext::WRAPPED_EXPR, -1, -1);
1977 : 0 : script_size += 2 + (k > 16) + (k > 0x7f) + (k > 0x7fff) + (k > 0x7fffff);
1978 [ # # ][ # # ]: 0 : } else if (Const("andor(", in)) {
[ # # ]
1979 [ # # ]: 0 : to_parse.emplace_back(ParseContext::ANDOR, -1, -1);
1980 [ # # ]: 0 : to_parse.emplace_back(ParseContext::CLOSE_BRACKET, -1, -1);
1981 [ # # ]: 0 : to_parse.emplace_back(ParseContext::WRAPPED_EXPR, -1, -1);
1982 [ # # ]: 0 : to_parse.emplace_back(ParseContext::COMMA, -1, -1);
1983 [ # # ]: 0 : to_parse.emplace_back(ParseContext::WRAPPED_EXPR, -1, -1);
1984 [ # # ]: 0 : to_parse.emplace_back(ParseContext::COMMA, -1, -1);
1985 [ # # ]: 0 : to_parse.emplace_back(ParseContext::WRAPPED_EXPR, -1, -1);
1986 : 0 : script_size += 5;
1987 : 0 : } else {
1988 [ # # ][ # # ]: 0 : if (Const("and_n(", in)) {
[ # # ]
1989 [ # # ]: 0 : to_parse.emplace_back(ParseContext::AND_N, -1, -1);
1990 : 0 : script_size += 5;
1991 [ # # ][ # # ]: 0 : } else if (Const("and_b(", in)) {
[ # # ]
1992 [ # # ]: 0 : to_parse.emplace_back(ParseContext::AND_B, -1, -1);
1993 : 0 : script_size += 2;
1994 [ # # ][ # # ]: 0 : } else if (Const("and_v(", in)) {
[ # # ]
1995 [ # # ]: 0 : to_parse.emplace_back(ParseContext::AND_V, -1, -1);
1996 : 0 : script_size += 1;
1997 [ # # ][ # # ]: 0 : } else if (Const("or_b(", in)) {
[ # # ]
1998 [ # # ]: 0 : to_parse.emplace_back(ParseContext::OR_B, -1, -1);
1999 : 0 : script_size += 2;
2000 [ # # ][ # # ]: 0 : } else if (Const("or_c(", in)) {
[ # # ]
2001 [ # # ]: 0 : to_parse.emplace_back(ParseContext::OR_C, -1, -1);
2002 : 0 : script_size += 3;
2003 [ # # ][ # # ]: 0 : } else if (Const("or_d(", in)) {
[ # # ]
2004 [ # # ]: 0 : to_parse.emplace_back(ParseContext::OR_D, -1, -1);
2005 : 0 : script_size += 4;
2006 [ # # ][ # # ]: 0 : } else if (Const("or_i(", in)) {
[ # # ]
2007 [ # # ]: 0 : to_parse.emplace_back(ParseContext::OR_I, -1, -1);
2008 : 0 : script_size += 4;
2009 : 0 : } else {
2010 : 0 : return {};
2011 : : }
2012 [ # # ]: 0 : to_parse.emplace_back(ParseContext::CLOSE_BRACKET, -1, -1);
2013 [ # # ]: 0 : to_parse.emplace_back(ParseContext::WRAPPED_EXPR, -1, -1);
2014 [ # # ]: 0 : to_parse.emplace_back(ParseContext::COMMA, -1, -1);
2015 [ # # ]: 0 : to_parse.emplace_back(ParseContext::WRAPPED_EXPR, -1, -1);
2016 : : }
2017 : 0 : break;
2018 : : }
2019 : : case ParseContext::ALT: {
2020 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::WRAP_A, Vector(std::move(constructed.back())));
[ # # ]
2021 : 0 : break;
2022 : : }
2023 : : case ParseContext::SWAP: {
2024 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::WRAP_S, Vector(std::move(constructed.back())));
[ # # ]
2025 : 0 : break;
2026 : : }
2027 : : case ParseContext::CHECK: {
2028 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::WRAP_C, Vector(std::move(constructed.back())));
[ # # ]
2029 : 0 : break;
2030 : : }
2031 : : case ParseContext::DUP_IF: {
2032 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::WRAP_D, Vector(std::move(constructed.back())));
[ # # ]
2033 : 0 : break;
2034 : : }
2035 : : case ParseContext::NON_ZERO: {
2036 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::WRAP_J, Vector(std::move(constructed.back())));
[ # # ]
2037 : 0 : break;
2038 : : }
2039 : : case ParseContext::ZERO_NOTEQUAL: {
2040 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::WRAP_N, Vector(std::move(constructed.back())));
[ # # ]
2041 : 0 : break;
2042 : : }
2043 : : case ParseContext::VERIFY: {
2044 [ # # ][ # # ]: 0 : script_size += (constructed.back()->GetType() << "x"_mst);
[ # # ]
2045 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::WRAP_V, Vector(std::move(constructed.back())));
[ # # ]
2046 : 0 : break;
2047 : : }
2048 : : case ParseContext::WRAP_U: {
2049 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::OR_I, Vector(std::move(constructed.back()), MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::JUST_0)));
[ # # ][ # # ]
[ # # ]
2050 : 0 : break;
2051 : : }
2052 : : case ParseContext::WRAP_T: {
2053 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::AND_V, Vector(std::move(constructed.back()), MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::JUST_1)));
[ # # ][ # # ]
[ # # ]
2054 : 0 : break;
2055 : : }
2056 : : case ParseContext::AND_B: {
2057 [ # # ][ # # ]: 0 : BuildBack(ctx.MsContext(), Fragment::AND_B, constructed);
2058 : 0 : break;
2059 : : }
2060 : : case ParseContext::AND_N: {
2061 : 0 : auto mid = std::move(constructed.back());
2062 : 0 : constructed.pop_back();
2063 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::ANDOR, Vector(std::move(constructed.back()), std::move(mid), MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::JUST_0)));
[ # # ][ # # ]
[ # # ]
2064 : : break;
2065 : 0 : }
2066 : : case ParseContext::AND_V: {
2067 [ # # ][ # # ]: 0 : BuildBack(ctx.MsContext(), Fragment::AND_V, constructed);
2068 : 0 : break;
2069 : : }
2070 : : case ParseContext::OR_B: {
2071 [ # # ][ # # ]: 0 : BuildBack(ctx.MsContext(), Fragment::OR_B, constructed);
2072 : 0 : break;
2073 : : }
2074 : : case ParseContext::OR_C: {
2075 [ # # ][ # # ]: 0 : BuildBack(ctx.MsContext(), Fragment::OR_C, constructed);
2076 : 0 : break;
2077 : : }
2078 : : case ParseContext::OR_D: {
2079 [ # # ][ # # ]: 0 : BuildBack(ctx.MsContext(), Fragment::OR_D, constructed);
2080 : 0 : break;
2081 : : }
2082 : : case ParseContext::OR_I: {
2083 [ # # ][ # # ]: 0 : BuildBack(ctx.MsContext(), Fragment::OR_I, constructed);
2084 : 0 : break;
2085 : : }
2086 : : case ParseContext::ANDOR: {
2087 : 0 : auto right = std::move(constructed.back());
2088 : 0 : constructed.pop_back();
2089 : 0 : auto mid = std::move(constructed.back());
2090 : 0 : constructed.pop_back();
2091 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::ANDOR, Vector(std::move(constructed.back()), std::move(mid), std::move(right)));
[ # # ]
2092 : : break;
2093 : 0 : }
2094 : : case ParseContext::THRESH: {
2095 [ # # ]: 0 : if (in.size() < 1) return {};
2096 [ # # ]: 0 : if (in[0] == ',') {
2097 : 0 : in = in.subspan(1);
2098 [ # # ][ # # ]: 0 : to_parse.emplace_back(ParseContext::THRESH, n+1, k);
[ # # ]
2099 [ # # ]: 0 : to_parse.emplace_back(ParseContext::WRAPPED_EXPR, -1, -1);
2100 : 0 : script_size += 2;
2101 [ # # ]: 0 : } else if (in[0] == ')') {
2102 [ # # ][ # # ]: 0 : if (k > n) return {};
2103 : 0 : in = in.subspan(1);
2104 : : // Children are constructed in reverse order, so iterate from end to beginning
2105 : 0 : std::vector<NodeRef<Key>> subs;
2106 [ # # ][ # # ]: 0 : for (int i = 0; i < n; ++i) {
2107 [ # # ]: 0 : subs.push_back(std::move(constructed.back()));
2108 : 0 : constructed.pop_back();
2109 : 0 : }
2110 [ # # ]: 0 : std::reverse(subs.begin(), subs.end());
2111 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::THRESH, std::move(subs), k));
[ # # ][ # # ]
2112 : 0 : } else {
2113 : 0 : return {};
2114 : : }
2115 : 0 : break;
2116 : : }
2117 : : case ParseContext::COMMA: {
2118 [ # # ][ # # ]: 0 : if (in.size() < 1 || in[0] != ',') return {};
2119 : 0 : in = in.subspan(1);
2120 : 0 : break;
2121 : : }
2122 : : case ParseContext::CLOSE_BRACKET: {
2123 [ # # ][ # # ]: 0 : if (in.size() < 1 || in[0] != ')') return {};
2124 : 0 : in = in.subspan(1);
2125 : 0 : break;
2126 : : }
2127 : : }
2128 : : }
2129 : :
2130 : : // Sanity checks on the produced miniscript
2131 [ # # ]: 0 : assert(constructed.size() == 1);
2132 [ # # ][ # # ]: 0 : assert(constructed[0]->ScriptSize() == script_size);
2133 [ # # ]: 0 : if (in.size() > 0) return {};
2134 : 0 : NodeRef<Key> tl_node = std::move(constructed.front());
2135 [ # # ]: 0 : tl_node->DuplicateKeyCheck(ctx);
2136 : 0 : return tl_node;
2137 [ # # ]: 0 : }
2138 : :
2139 : : /** Decode a script into opcode/push pairs.
2140 : : *
2141 : : * Construct a vector with one element per opcode in the script, in reverse order.
2142 : : * Each element is a pair consisting of the opcode, as well as the data pushed by
2143 : : * the opcode (including OP_n), if any. OP_CHECKSIGVERIFY, OP_CHECKMULTISIGVERIFY,
2144 : : * OP_NUMEQUALVERIFY and OP_EQUALVERIFY are decomposed into OP_CHECKSIG, OP_CHECKMULTISIG,
2145 : : * OP_EQUAL and OP_NUMEQUAL respectively, plus OP_VERIFY.
2146 : : */
2147 : : std::optional<std::vector<Opcode>> DecomposeScript(const CScript& script);
2148 : :
2149 : : /** Determine whether the passed pair (created by DecomposeScript) is pushing a number. */
2150 : : std::optional<int64_t> ParseScriptNumber(const Opcode& in);
2151 : :
2152 : : enum class DecodeContext {
2153 : : /** A single expression of type B, K, or V. Specifically, this can't be an
2154 : : * and_v or an expression of type W (a: and s: wrappers). */
2155 : : SINGLE_BKV_EXPR,
2156 : : /** Potentially multiple SINGLE_BKV_EXPRs as children of (potentially multiple)
2157 : : * and_v expressions. Syntactic sugar for MAYBE_AND_V + SINGLE_BKV_EXPR. */
2158 : : BKV_EXPR,
2159 : : /** An expression of type W (a: or s: wrappers). */
2160 : : W_EXPR,
2161 : :
2162 : : /** SWAP expects the next element to be OP_SWAP (inside a W-type expression that
2163 : : * didn't end with FROMALTSTACK), and wraps the top of the constructed stack
2164 : : * with s: */
2165 : : SWAP,
2166 : : /** ALT expects the next element to be TOALTSTACK (we must have already read a
2167 : : * FROMALTSTACK earlier), and wraps the top of the constructed stack with a: */
2168 : : ALT,
2169 : : /** CHECK wraps the top constructed node with c: */
2170 : : CHECK,
2171 : : /** DUP_IF wraps the top constructed node with d: */
2172 : : DUP_IF,
2173 : : /** VERIFY wraps the top constructed node with v: */
2174 : : VERIFY,
2175 : : /** NON_ZERO wraps the top constructed node with j: */
2176 : : NON_ZERO,
2177 : : /** ZERO_NOTEQUAL wraps the top constructed node with n: */
2178 : : ZERO_NOTEQUAL,
2179 : :
2180 : : /** MAYBE_AND_V will check if the next part of the script could be a valid
2181 : : * miniscript sub-expression, and if so it will push AND_V and SINGLE_BKV_EXPR
2182 : : * to decode it and construct the and_v node. This is recursive, to deal with
2183 : : * multiple and_v nodes inside each other. */
2184 : : MAYBE_AND_V,
2185 : : /** AND_V will construct an and_v node from the last two constructed nodes. */
2186 : : AND_V,
2187 : : /** AND_B will construct an and_b node from the last two constructed nodes. */
2188 : : AND_B,
2189 : : /** ANDOR will construct an andor node from the last three constructed nodes. */
2190 : : ANDOR,
2191 : : /** OR_B will construct an or_b node from the last two constructed nodes. */
2192 : : OR_B,
2193 : : /** OR_C will construct an or_c node from the last two constructed nodes. */
2194 : : OR_C,
2195 : : /** OR_D will construct an or_d node from the last two constructed nodes. */
2196 : : OR_D,
2197 : :
2198 : : /** In a thresh expression, all sub-expressions other than the first are W-type,
2199 : : * and end in OP_ADD. THRESH_W will check for this OP_ADD and either push a W_EXPR
2200 : : * or a SINGLE_BKV_EXPR and jump to THRESH_E accordingly. */
2201 : : THRESH_W,
2202 : : /** THRESH_E constructs a thresh node from the appropriate number of constructed
2203 : : * children. */
2204 : : THRESH_E,
2205 : :
2206 : : /** ENDIF signals that we are inside some sort of OP_IF structure, which could be
2207 : : * or_d, or_c, or_i, andor, d:, or j: wrapper, depending on what follows. We read
2208 : : * a BKV_EXPR and then deal with the next opcode case-by-case. */
2209 : : ENDIF,
2210 : : /** If, inside an ENDIF context, we find an OP_NOTIF before finding an OP_ELSE,
2211 : : * we could either be in an or_d or an or_c node. We then check for IFDUP to
2212 : : * distinguish these cases. */
2213 : : ENDIF_NOTIF,
2214 : : /** If, inside an ENDIF context, we find an OP_ELSE, then we could be in either an
2215 : : * or_i or an andor node. Read the next BKV_EXPR and find either an OP_IF or an
2216 : : * OP_NOTIF. */
2217 : : ENDIF_ELSE,
2218 : : };
2219 : :
2220 : : //! Parse a miniscript from a bitcoin script
2221 : : template<typename Key, typename Ctx, typename I>
2222 : 0 : inline NodeRef<Key> DecodeScript(I& in, I last, const Ctx& ctx)
2223 : : {
2224 : : // The two integers are used to hold state for thresh()
2225 : 0 : std::vector<std::tuple<DecodeContext, int64_t, int64_t>> to_parse;
2226 : 0 : std::vector<NodeRef<Key>> constructed;
2227 : :
2228 : : // This is the top level, so we assume the type is B
2229 : : // (in particular, disallowing top level W expressions)
2230 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::BKV_EXPR, -1, -1);
2231 : :
2232 [ # # ][ # # ]: 0 : while (!to_parse.empty()) {
2233 : : // Exit early if the Miniscript is not going to be valid.
2234 [ # # ][ # # ]: 0 : if (!constructed.empty() && !constructed.back()->IsValid()) return {};
[ # # ][ # # ]
[ # # ][ # # ]
2235 : :
2236 : : // Get the current context we are decoding within
2237 : 0 : auto [cur_context, n, k] = to_parse.back();
2238 : 0 : to_parse.pop_back();
2239 : :
2240 [ # # # # : 0 : switch(cur_context) {
# # # # #
# # # # #
# # # # #
# # # # ]
[ # # # #
# # # # #
# # # # #
# # # # #
# # # # ]
2241 : : case DecodeContext::SINGLE_BKV_EXPR: {
2242 [ # # ][ # # ]: 0 : if (in >= last) return {};
2243 : :
2244 : : // Constants
2245 [ # # ][ # # ]: 0 : if (in[0].first == OP_1) {
2246 : 0 : ++in;
2247 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::JUST_1));
[ # # ][ # # ]
2248 : 0 : break;
2249 : : }
2250 [ # # ][ # # ]: 0 : if (in[0].first == OP_0) {
2251 : 0 : ++in;
2252 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::JUST_0));
[ # # ][ # # ]
2253 : 0 : break;
2254 : : }
2255 : : // Public keys
2256 [ # # ][ # # ]: 0 : if (in[0].second.size() == 33 || in[0].second.size() == 32) {
[ # # ][ # # ]
2257 [ # # ][ # # ]: 0 : auto key = ctx.FromPKBytes(in[0].second.begin(), in[0].second.end());
2258 [ # # ][ # # ]: 0 : if (!key) return {};
2259 : 0 : ++in;
2260 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::PK_K, Vector(std::move(*key))));
[ # # ][ # # ]
[ # # ][ # # ]
2261 : 0 : break;
2262 [ # # ]: 0 : }
2263 [ # # ][ # # ]: 0 : if (last - in >= 5 && in[0].first == OP_VERIFY && in[1].first == OP_EQUAL && in[3].first == OP_HASH160 && in[4].first == OP_DUP && in[2].second.size() == 20) {
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
2264 [ # # ][ # # ]: 0 : auto key = ctx.FromPKHBytes(in[2].second.begin(), in[2].second.end());
2265 [ # # ][ # # ]: 0 : if (!key) return {};
2266 : 0 : in += 5;
2267 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::PK_H, Vector(std::move(*key))));
[ # # ][ # # ]
[ # # ][ # # ]
2268 : 0 : break;
2269 : 0 : }
2270 : : // Time locks
2271 : 0 : std::optional<int64_t> num;
2272 [ # # ][ # # ]: 0 : if (last - in >= 2 && in[0].first == OP_CHECKSEQUENCEVERIFY && (num = ParseScriptNumber(in[1]))) {
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
2273 : 0 : in += 2;
2274 [ # # ][ # # ]: 0 : if (*num < 1 || *num > 0x7FFFFFFFL) return {};
[ # # ][ # # ]
2275 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::OLDER, *num));
[ # # ][ # # ]
2276 : 0 : break;
2277 : : }
2278 [ # # ][ # # ]: 0 : if (last - in >= 2 && in[0].first == OP_CHECKLOCKTIMEVERIFY && (num = ParseScriptNumber(in[1]))) {
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
2279 : 0 : in += 2;
2280 [ # # ][ # # ]: 0 : if (num < 1 || num > 0x7FFFFFFFL) return {};
[ # # ][ # # ]
[ # # ][ # # ]
2281 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::AFTER, *num));
[ # # ][ # # ]
2282 : 0 : break;
2283 : : }
2284 : : // Hashes
2285 [ # # ][ # # ]: 0 : if (last - in >= 7 && in[0].first == OP_EQUAL && in[3].first == OP_VERIFY && in[4].first == OP_EQUAL && (num = ParseScriptNumber(in[5])) && num == 32 && in[6].first == OP_SIZE) {
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ]
2286 [ # # ][ # # ]: 0 : if (in[2].first == OP_SHA256 && in[1].second.size() == 32) {
[ # # ][ # # ]
2287 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::SHA256, in[1].second));
[ # # ][ # # ]
2288 : 0 : in += 7;
2289 : 0 : break;
2290 [ # # ][ # # ]: 0 : } else if (in[2].first == OP_RIPEMD160 && in[1].second.size() == 20) {
[ # # ][ # # ]
2291 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::RIPEMD160, in[1].second));
[ # # ][ # # ]
2292 : 0 : in += 7;
2293 : 0 : break;
2294 [ # # ][ # # ]: 0 : } else if (in[2].first == OP_HASH256 && in[1].second.size() == 32) {
[ # # ][ # # ]
2295 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::HASH256, in[1].second));
[ # # ][ # # ]
2296 : 0 : in += 7;
2297 : 0 : break;
2298 [ # # ][ # # ]: 0 : } else if (in[2].first == OP_HASH160 && in[1].second.size() == 20) {
[ # # ][ # # ]
2299 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::HASH160, in[1].second));
[ # # ][ # # ]
2300 : 0 : in += 7;
2301 : 0 : break;
2302 : : }
2303 : 0 : }
2304 : : // Multi
2305 [ # # ][ # # ]: 0 : if (last - in >= 3 && in[0].first == OP_CHECKMULTISIG) {
[ # # ][ # # ]
2306 [ # # ][ # # ]: 0 : if (IsTapscript(ctx.MsContext())) return {};
2307 : 0 : std::vector<Key> keys;
2308 [ # # ][ # # ]: 0 : const auto n = ParseScriptNumber(in[1]);
2309 [ # # ][ # # ]: 0 : if (!n || last - in < 3 + *n) return {};
[ # # ][ # # ]
2310 [ # # ][ # # ]: 0 : if (*n < 1 || *n > 20) return {};
[ # # ][ # # ]
2311 [ # # ][ # # ]: 0 : for (int i = 0; i < *n; ++i) {
2312 [ # # ][ # # ]: 0 : if (in[2 + i].second.size() != 33) return {};
2313 [ # # ][ # # ]: 0 : auto key = ctx.FromPKBytes(in[2 + i].second.begin(), in[2 + i].second.end());
2314 [ # # ][ # # ]: 0 : if (!key) return {};
2315 [ # # ][ # # ]: 0 : keys.push_back(std::move(*key));
2316 [ # # ]: 0 : }
2317 [ # # ][ # # ]: 0 : const auto k = ParseScriptNumber(in[2 + *n]);
2318 [ # # ][ # # ]: 0 : if (!k || *k < 1 || *k > *n) return {};
[ # # ][ # # ]
[ # # ][ # # ]
2319 : 0 : in += 3 + *n;
2320 [ # # ][ # # ]: 0 : std::reverse(keys.begin(), keys.end());
2321 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::MULTI, std::move(keys), *k));
[ # # ][ # # ]
2322 : 0 : break;
2323 : 0 : }
2324 : : // Tapscript's equivalent of multi
2325 [ # # ][ # # ]: 0 : if (last - in >= 4 && in[0].first == OP_NUMEQUAL) {
[ # # ][ # # ]
2326 [ # # ][ # # ]: 0 : if (!IsTapscript(ctx.MsContext())) return {};
2327 : : // The necessary threshold of signatures.
2328 [ # # ][ # # ]: 0 : const auto k = ParseScriptNumber(in[1]);
2329 [ # # ][ # # ]: 0 : if (!k) return {};
2330 [ # # ][ # # ]: 0 : if (*k < 1 || *k > MAX_PUBKEYS_PER_MULTI_A) return {};
[ # # ][ # # ]
2331 [ # # ][ # # ]: 0 : if (last - in < 2 + *k * 2) return {};
2332 : 0 : std::vector<Key> keys;
2333 [ # # ][ # # ]: 0 : keys.reserve(*k);
2334 : : // Walk through the expected (pubkey, CHECKSIG[ADD]) pairs.
2335 : 0 : for (int pos = 2;; pos += 2) {
2336 [ # # ][ # # ]: 0 : if (last - in < pos + 2) return {};
2337 : : // Make sure it's indeed an x-only pubkey and a CHECKSIG[ADD], then parse the key.
2338 [ # # ][ # # ]: 0 : if (in[pos].first != OP_CHECKSIGADD && in[pos].first != OP_CHECKSIG) return {};
[ # # ][ # # ]
2339 [ # # ][ # # ]: 0 : if (in[pos + 1].second.size() != 32) return {};
2340 [ # # ][ # # ]: 0 : auto key = ctx.FromPKBytes(in[pos + 1].second.begin(), in[pos + 1].second.end());
2341 [ # # ][ # # ]: 0 : if (!key) return {};
2342 [ # # ][ # # ]: 0 : keys.push_back(std::move(*key));
2343 : : // Make sure early we don't parse an arbitrary large expression.
2344 [ # # ][ # # ]: 0 : if (keys.size() > MAX_PUBKEYS_PER_MULTI_A) return {};
2345 : : // OP_CHECKSIG means it was the last one to parse.
2346 [ # # ][ # # ]: 0 : if (in[pos].first == OP_CHECKSIG) break;
2347 [ # # # ]: 0 : }
2348 [ # # ][ # # ]: 0 : if (keys.size() < (size_t)*k) return {};
2349 : 0 : in += 2 + keys.size() * 2;
2350 [ # # ][ # # ]: 0 : std::reverse(keys.begin(), keys.end());
2351 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::MULTI_A, std::move(keys), *k));
[ # # ][ # # ]
2352 : 0 : break;
2353 : 0 : }
2354 : : /** In the following wrappers, we only need to push SINGLE_BKV_EXPR rather
2355 : : * than BKV_EXPR, because and_v commutes with these wrappers. For example,
2356 : : * c:and_v(X,Y) produces the same script as and_v(X,c:Y). */
2357 : : // c: wrapper
2358 [ # # ][ # # ]: 0 : if (in[0].first == OP_CHECKSIG) {
2359 : 0 : ++in;
2360 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::CHECK, -1, -1);
2361 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::SINGLE_BKV_EXPR, -1, -1);
2362 : 0 : break;
2363 : : }
2364 : : // v: wrapper
2365 [ # # ][ # # ]: 0 : if (in[0].first == OP_VERIFY) {
2366 : 0 : ++in;
2367 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::VERIFY, -1, -1);
2368 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::SINGLE_BKV_EXPR, -1, -1);
2369 : 0 : break;
2370 : : }
2371 : : // n: wrapper
2372 [ # # ][ # # ]: 0 : if (in[0].first == OP_0NOTEQUAL) {
2373 : 0 : ++in;
2374 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::ZERO_NOTEQUAL, -1, -1);
2375 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::SINGLE_BKV_EXPR, -1, -1);
2376 : 0 : break;
2377 : : }
2378 : : // Thresh
2379 [ # # ][ # # ]: 0 : if (last - in >= 3 && in[0].first == OP_EQUAL && (num = ParseScriptNumber(in[1]))) {
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
2380 [ # # ][ # # ]: 0 : if (*num < 1) return {};
2381 : 0 : in += 2;
2382 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::THRESH_W, 0, *num);
2383 : 0 : break;
2384 : : }
2385 : : // OP_ENDIF can be WRAP_J, WRAP_D, ANDOR, OR_C, OR_D, or OR_I
2386 [ # # ][ # # ]: 0 : if (in[0].first == OP_ENDIF) {
2387 : 0 : ++in;
2388 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::ENDIF, -1, -1);
2389 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::BKV_EXPR, -1, -1);
2390 : 0 : break;
2391 : : }
2392 : : /** In and_b and or_b nodes, we only look for SINGLE_BKV_EXPR, because
2393 : : * or_b(and_v(X,Y),Z) has script [X] [Y] [Z] OP_BOOLOR, the same as
2394 : : * and_v(X,or_b(Y,Z)). In this example, the former of these is invalid as
2395 : : * miniscript, while the latter is valid. So we leave the and_v "outside"
2396 : : * while decoding. */
2397 : : // and_b
2398 [ # # ][ # # ]: 0 : if (in[0].first == OP_BOOLAND) {
2399 : 0 : ++in;
2400 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::AND_B, -1, -1);
2401 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::SINGLE_BKV_EXPR, -1, -1);
2402 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::W_EXPR, -1, -1);
2403 : 0 : break;
2404 : : }
2405 : : // or_b
2406 [ # # ][ # # ]: 0 : if (in[0].first == OP_BOOLOR) {
2407 : 0 : ++in;
2408 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::OR_B, -1, -1);
2409 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::SINGLE_BKV_EXPR, -1, -1);
2410 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::W_EXPR, -1, -1);
2411 : 0 : break;
2412 : : }
2413 : : // Unrecognised expression
2414 : 0 : return {};
2415 : : }
2416 : : case DecodeContext::BKV_EXPR: {
2417 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::MAYBE_AND_V, -1, -1);
2418 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::SINGLE_BKV_EXPR, -1, -1);
2419 : 0 : break;
2420 : : }
2421 : : case DecodeContext::W_EXPR: {
2422 : : // a: wrapper
2423 [ # # ][ # # ]: 0 : if (in >= last) return {};
2424 [ # # ][ # # ]: 0 : if (in[0].first == OP_FROMALTSTACK) {
2425 : 0 : ++in;
2426 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::ALT, -1, -1);
2427 : 0 : } else {
2428 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::SWAP, -1, -1);
2429 : : }
2430 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::BKV_EXPR, -1, -1);
2431 : 0 : break;
2432 : : }
2433 : : case DecodeContext::MAYBE_AND_V: {
2434 : : // If we reach a potential AND_V top-level, check if the next part of the script could be another AND_V child
2435 : : // These op-codes cannot end any well-formed miniscript so cannot be used in an and_v node.
2436 [ # # ][ # # ]: 0 : if (in < last && in[0].first != OP_IF && in[0].first != OP_ELSE && in[0].first != OP_NOTIF && in[0].first != OP_TOALTSTACK && in[0].first != OP_SWAP) {
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
2437 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::AND_V, -1, -1);
2438 : : // BKV_EXPR can contain more AND_V nodes
2439 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::BKV_EXPR, -1, -1);
2440 : 0 : }
2441 : 0 : break;
2442 : : }
2443 : : case DecodeContext::SWAP: {
2444 [ # # ][ # # ]: 0 : if (in >= last || in[0].first != OP_SWAP || constructed.empty()) return {};
[ # # ][ # # ]
[ # # ][ # # ]
2445 : 0 : ++in;
2446 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::WRAP_S, Vector(std::move(constructed.back())));
[ # # ][ # # ]
2447 : 0 : break;
2448 : : }
2449 : : case DecodeContext::ALT: {
2450 [ # # ][ # # ]: 0 : if (in >= last || in[0].first != OP_TOALTSTACK || constructed.empty()) return {};
[ # # ][ # # ]
[ # # ][ # # ]
2451 : 0 : ++in;
2452 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::WRAP_A, Vector(std::move(constructed.back())));
[ # # ][ # # ]
2453 : 0 : break;
2454 : : }
2455 : : case DecodeContext::CHECK: {
2456 [ # # ][ # # ]: 0 : if (constructed.empty()) return {};
2457 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::WRAP_C, Vector(std::move(constructed.back())));
[ # # ][ # # ]
2458 : 0 : break;
2459 : : }
2460 : : case DecodeContext::DUP_IF: {
2461 [ # # ][ # # ]: 0 : if (constructed.empty()) return {};
2462 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::WRAP_D, Vector(std::move(constructed.back())));
[ # # ][ # # ]
2463 : 0 : break;
2464 : : }
2465 : : case DecodeContext::VERIFY: {
2466 [ # # ][ # # ]: 0 : if (constructed.empty()) return {};
2467 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::WRAP_V, Vector(std::move(constructed.back())));
[ # # ][ # # ]
2468 : 0 : break;
2469 : : }
2470 : : case DecodeContext::NON_ZERO: {
2471 [ # # ][ # # ]: 0 : if (constructed.empty()) return {};
2472 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::WRAP_J, Vector(std::move(constructed.back())));
[ # # ][ # # ]
2473 : 0 : break;
2474 : : }
2475 : : case DecodeContext::ZERO_NOTEQUAL: {
2476 [ # # ][ # # ]: 0 : if (constructed.empty()) return {};
2477 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::WRAP_N, Vector(std::move(constructed.back())));
[ # # ][ # # ]
2478 : 0 : break;
2479 : : }
2480 : : case DecodeContext::AND_V: {
2481 [ # # ][ # # ]: 0 : if (constructed.size() < 2) return {};
2482 [ # # ][ # # ]: 0 : BuildBack(ctx.MsContext(), Fragment::AND_V, constructed, /*reverse=*/true);
2483 : 0 : break;
2484 : : }
2485 : : case DecodeContext::AND_B: {
2486 [ # # ][ # # ]: 0 : if (constructed.size() < 2) return {};
2487 [ # # ][ # # ]: 0 : BuildBack(ctx.MsContext(), Fragment::AND_B, constructed, /*reverse=*/true);
2488 : 0 : break;
2489 : : }
2490 : : case DecodeContext::OR_B: {
2491 [ # # ][ # # ]: 0 : if (constructed.size() < 2) return {};
2492 [ # # ][ # # ]: 0 : BuildBack(ctx.MsContext(), Fragment::OR_B, constructed, /*reverse=*/true);
2493 : 0 : break;
2494 : : }
2495 : : case DecodeContext::OR_C: {
2496 [ # # ][ # # ]: 0 : if (constructed.size() < 2) return {};
2497 [ # # ][ # # ]: 0 : BuildBack(ctx.MsContext(), Fragment::OR_C, constructed, /*reverse=*/true);
2498 : 0 : break;
2499 : : }
2500 : : case DecodeContext::OR_D: {
2501 [ # # ][ # # ]: 0 : if (constructed.size() < 2) return {};
2502 [ # # ][ # # ]: 0 : BuildBack(ctx.MsContext(), Fragment::OR_D, constructed, /*reverse=*/true);
2503 : 0 : break;
2504 : : }
2505 : : case DecodeContext::ANDOR: {
2506 [ # # ][ # # ]: 0 : if (constructed.size() < 3) return {};
2507 : 0 : NodeRef<Key> left = std::move(constructed.back());
2508 : 0 : constructed.pop_back();
2509 : 0 : NodeRef<Key> right = std::move(constructed.back());
2510 : 0 : constructed.pop_back();
2511 : 0 : NodeRef<Key> mid = std::move(constructed.back());
2512 [ # # ][ # # ]: 0 : constructed.back() = MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::ANDOR, Vector(std::move(left), std::move(mid), std::move(right)));
[ # # ][ # # ]
2513 : : break;
2514 : 0 : }
2515 : : case DecodeContext::THRESH_W: {
2516 [ # # ][ # # ]: 0 : if (in >= last) return {};
2517 [ # # ][ # # ]: 0 : if (in[0].first == OP_ADD) {
2518 : 0 : ++in;
2519 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::THRESH_W, n+1, k);
[ # # ][ # # ]
[ # # ][ # # ]
2520 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::W_EXPR, -1, -1);
2521 : 0 : } else {
2522 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::THRESH_E, n+1, k);
[ # # ][ # # ]
[ # # ][ # # ]
2523 : : // All children of thresh have type modifier d, so cannot be and_v
2524 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::SINGLE_BKV_EXPR, -1, -1);
2525 : : }
2526 : 0 : break;
2527 : : }
2528 : : case DecodeContext::THRESH_E: {
2529 [ # # ][ # # ]: 0 : if (k < 1 || k > n || constructed.size() < static_cast<size_t>(n)) return {};
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
[ # # ][ # # ]
2530 : 0 : std::vector<NodeRef<Key>> subs;
2531 [ # # ][ # # ]: 0 : for (int i = 0; i < n; ++i) {
[ # # ][ # # ]
2532 : 0 : NodeRef<Key> sub = std::move(constructed.back());
2533 : 0 : constructed.pop_back();
2534 [ # # ][ # # ]: 0 : subs.push_back(std::move(sub));
2535 : 0 : }
2536 [ # # ][ # # ]: 0 : constructed.push_back(MakeNodeRef<Key>(internal::NoDupCheck{}, ctx.MsContext(), Fragment::THRESH, std::move(subs), k));
[ # # ][ # # ]
[ # # ][ # # ]
2537 : : break;
2538 : 0 : }
2539 : : case DecodeContext::ENDIF: {
2540 [ # # ][ # # ]: 0 : if (in >= last) return {};
2541 : :
2542 : : // could be andor or or_i
2543 [ # # ][ # # ]: 0 : if (in[0].first == OP_ELSE) {
2544 : 0 : ++in;
2545 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::ENDIF_ELSE, -1, -1);
2546 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::BKV_EXPR, -1, -1);
2547 : 0 : }
2548 : : // could be j: or d: wrapper
2549 [ # # ][ # # ]: 0 : else if (in[0].first == OP_IF) {
2550 [ # # ][ # # ]: 0 : if (last - in >= 2 && in[1].first == OP_DUP) {
[ # # ][ # # ]
2551 : 0 : in += 2;
2552 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::DUP_IF, -1, -1);
2553 [ # # ][ # # ]: 0 : } else if (last - in >= 3 && in[1].first == OP_0NOTEQUAL && in[2].first == OP_SIZE) {
[ # # ][ # # ]
[ # # ][ # # ]
2554 : 0 : in += 3;
2555 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::NON_ZERO, -1, -1);
2556 : 0 : }
2557 : : else {
2558 : 0 : return {};
2559 : : }
2560 : : // could be or_c or or_d
2561 [ # # ][ # # ]: 0 : } else if (in[0].first == OP_NOTIF) {
2562 : 0 : ++in;
2563 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::ENDIF_NOTIF, -1, -1);
2564 : 0 : }
2565 : : else {
2566 : 0 : return {};
2567 : : }
2568 : 0 : break;
2569 : : }
2570 : : case DecodeContext::ENDIF_NOTIF: {
2571 [ # # ][ # # ]: 0 : if (in >= last) return {};
2572 [ # # ][ # # ]: 0 : if (in[0].first == OP_IFDUP) {
2573 : 0 : ++in;
2574 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::OR_D, -1, -1);
2575 : 0 : } else {
2576 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::OR_C, -1, -1);
2577 : : }
2578 : : // or_c and or_d both require X to have type modifier d so, can't contain and_v
2579 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::SINGLE_BKV_EXPR, -1, -1);
2580 : 0 : break;
2581 : : }
2582 : : case DecodeContext::ENDIF_ELSE: {
2583 [ # # ][ # # ]: 0 : if (in >= last) return {};
2584 [ # # ][ # # ]: 0 : if (in[0].first == OP_IF) {
2585 : 0 : ++in;
2586 [ # # ][ # # ]: 0 : BuildBack(ctx.MsContext(), Fragment::OR_I, constructed, /*reverse=*/true);
2587 [ # # ][ # # ]: 0 : } else if (in[0].first == OP_NOTIF) {
2588 : 0 : ++in;
2589 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::ANDOR, -1, -1);
2590 : : // andor requires X to have type modifier d, so it can't be and_v
2591 [ # # ][ # # ]: 0 : to_parse.emplace_back(DecodeContext::SINGLE_BKV_EXPR, -1, -1);
2592 : 0 : } else {
2593 : 0 : return {};
2594 : : }
2595 : 0 : break;
2596 : : }
2597 : : }
2598 : : }
2599 [ # # ][ # # ]: 0 : if (constructed.size() != 1) return {};
2600 : 0 : NodeRef<Key> tl_node = std::move(constructed.front());
2601 [ # # ][ # # ]: 0 : tl_node->DuplicateKeyCheck(ctx);
2602 : : // Note that due to how ComputeType works (only assign the type to the node if the
2603 : : // subs' types are valid) this would fail if any node of tree is badly typed.
2604 [ # # ][ # # ]: 0 : if (!tl_node->IsValidTopLevel()) return {};
[ # # ][ # # ]
2605 : 0 : return tl_node;
2606 : 0 : }
2607 : :
2608 : : } // namespace internal
2609 : :
2610 : : template<typename Ctx>
2611 : 0 : inline NodeRef<typename Ctx::Key> FromString(const std::string& str, const Ctx& ctx) {
2612 : 0 : return internal::Parse<typename Ctx::Key>(str, ctx);
2613 : : }
2614 : :
2615 : : template<typename Ctx>
2616 : 0 : inline NodeRef<typename Ctx::Key> FromScript(const CScript& script, const Ctx& ctx) {
2617 : : using namespace internal;
2618 : : // A too large Script is necessarily invalid, don't bother parsing it.
2619 [ # # ][ # # ]: 0 : if (script.size() > MaxScriptSize(ctx.MsContext())) return {};
2620 : 0 : auto decomposed = DecomposeScript(script);
2621 [ # # ][ # # ]: 0 : if (!decomposed) return {};
2622 : 0 : auto it = decomposed->begin();
2623 [ # # ][ # # ]: 0 : auto ret = DecodeScript<typename Ctx::Key>(it, decomposed->end(), ctx);
2624 [ # # ][ # # ]: 0 : if (!ret) return {};
2625 [ # # ][ # # ]: 0 : if (it != decomposed->end()) return {};
2626 : 0 : return ret;
2627 : 0 : }
2628 : :
2629 : : } // namespace miniscript
2630 : :
2631 : : #endif // BITCOIN_SCRIPT_MINISCRIPT_H
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