miniscript.cpp
1 // Copyright (c) 2019-present 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 #include <limits> 6 #include <vector> 7 8 #include <primitives/transaction.h> 9 #include <script/miniscript.h> 10 #include <script/script.h> 11 #include <script/solver.h> 12 #include <span.h> 13 #include <util/check.h> 14 #include <util/vector.h> 15 16 namespace miniscript { 17 namespace internal { 18 19 Type SanitizeType(Type e) { 20 int num_types = (e << "K"_mst) + (e << "V"_mst) + (e << "B"_mst) + (e << "W"_mst); 21 if (num_types == 0) return ""_mst; // No valid type, don't care about the rest 22 CHECK_NONFATAL(num_types == 1); // K, V, B, W all conflict with each other 23 CHECK_NONFATAL(!(e << "z"_mst) || !(e << "o"_mst)); // z conflicts with o 24 CHECK_NONFATAL(!(e << "n"_mst) || !(e << "z"_mst)); // n conflicts with z 25 CHECK_NONFATAL(!(e << "n"_mst) || !(e << "W"_mst)); // n conflicts with W 26 CHECK_NONFATAL(!(e << "V"_mst) || !(e << "d"_mst)); // V conflicts with d 27 CHECK_NONFATAL(!(e << "K"_mst) || (e << "u"_mst)); // K implies u 28 CHECK_NONFATAL(!(e << "V"_mst) || !(e << "u"_mst)); // V conflicts with u 29 CHECK_NONFATAL(!(e << "e"_mst) || !(e << "f"_mst)); // e conflicts with f 30 CHECK_NONFATAL(!(e << "e"_mst) || (e << "d"_mst)); // e implies d 31 CHECK_NONFATAL(!(e << "V"_mst) || !(e << "e"_mst)); // V conflicts with e 32 CHECK_NONFATAL(!(e << "d"_mst) || !(e << "f"_mst)); // d conflicts with f 33 CHECK_NONFATAL(!(e << "V"_mst) || (e << "f"_mst)); // V implies f 34 CHECK_NONFATAL(!(e << "K"_mst) || (e << "s"_mst)); // K implies s 35 CHECK_NONFATAL(!(e << "z"_mst) || (e << "m"_mst)); // z implies m 36 return e; 37 } 38 39 Type ComputeType(Fragment fragment, Type x, Type y, Type z, const std::vector<Type>& sub_types, uint32_t k, 40 size_t data_size, size_t n_subs, size_t n_keys, MiniscriptContext ms_ctx) { 41 // Sanity check on data 42 if (fragment == Fragment::SHA256 || fragment == Fragment::HASH256) { 43 CHECK_NONFATAL(data_size == 32); 44 } else if (fragment == Fragment::RIPEMD160 || fragment == Fragment::HASH160) { 45 CHECK_NONFATAL(data_size == 20); 46 } else { 47 CHECK_NONFATAL(data_size == 0); 48 } 49 // Sanity check on k 50 if (fragment == Fragment::OLDER || fragment == Fragment::AFTER) { 51 CHECK_NONFATAL(k >= 1 && k < 0x80000000UL); 52 } else if (fragment == Fragment::MULTI || fragment == Fragment::MULTI_A) { 53 CHECK_NONFATAL(k >= 1 && k <= n_keys); 54 } else if (fragment == Fragment::THRESH) { 55 CHECK_NONFATAL(k >= 1 && k <= n_subs); 56 } else { 57 CHECK_NONFATAL(k == 0); 58 } 59 // Sanity check on subs 60 if (fragment == Fragment::AND_V || fragment == Fragment::AND_B || fragment == Fragment::OR_B || 61 fragment == Fragment::OR_C || fragment == Fragment::OR_I || fragment == Fragment::OR_D) { 62 CHECK_NONFATAL(n_subs == 2); 63 } else if (fragment == Fragment::ANDOR) { 64 CHECK_NONFATAL(n_subs == 3); 65 } else if (fragment == Fragment::WRAP_A || fragment == Fragment::WRAP_S || fragment == Fragment::WRAP_C || 66 fragment == Fragment::WRAP_D || fragment == Fragment::WRAP_V || fragment == Fragment::WRAP_J || 67 fragment == Fragment::WRAP_N) { 68 CHECK_NONFATAL(n_subs == 1); 69 } else if (fragment != Fragment::THRESH) { 70 CHECK_NONFATAL(n_subs == 0); 71 } 72 // Sanity check on keys 73 if (fragment == Fragment::PK_K || fragment == Fragment::PK_H) { 74 CHECK_NONFATAL(n_keys == 1); 75 } else if (fragment == Fragment::MULTI) { 76 CHECK_NONFATAL(n_keys >= 1 && n_keys <= MAX_PUBKEYS_PER_MULTISIG); 77 CHECK_NONFATAL(!IsTapscript(ms_ctx)); 78 } else if (fragment == Fragment::MULTI_A) { 79 CHECK_NONFATAL(n_keys >= 1 && n_keys <= MAX_PUBKEYS_PER_MULTI_A); 80 CHECK_NONFATAL(IsTapscript(ms_ctx)); 81 } else { 82 CHECK_NONFATAL(n_keys == 0); 83 } 84 85 // Below is the per-fragment logic for computing the expression types. 86 // It heavily relies on Type's << operator (where "X << a_mst" means 87 // "X has all properties listed in a"). 88 switch (fragment) { 89 case Fragment::PK_K: return "Konudemsxk"_mst; 90 case Fragment::PK_H: return "Knudemsxk"_mst; 91 case Fragment::OLDER: return 92 "g"_mst.If(k & CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG) | 93 "h"_mst.If(!(k & CTxIn::SEQUENCE_LOCKTIME_TYPE_FLAG)) | 94 "Bzfmxk"_mst; 95 case Fragment::AFTER: return 96 "i"_mst.If(k >= LOCKTIME_THRESHOLD) | 97 "j"_mst.If(k < LOCKTIME_THRESHOLD) | 98 "Bzfmxk"_mst; 99 case Fragment::SHA256: return "Bonudmk"_mst; 100 case Fragment::RIPEMD160: return "Bonudmk"_mst; 101 case Fragment::HASH256: return "Bonudmk"_mst; 102 case Fragment::HASH160: return "Bonudmk"_mst; 103 case Fragment::JUST_1: return "Bzufmxk"_mst; 104 case Fragment::JUST_0: return "Bzudemsxk"_mst; 105 case Fragment::WRAP_A: return 106 "W"_mst.If(x << "B"_mst) | // W=B_x 107 (x & "ghijk"_mst) | // g=g_x, h=h_x, i=i_x, j=j_x, k=k_x 108 (x & "udfems"_mst) | // u=u_x, d=d_x, f=f_x, e=e_x, m=m_x, s=s_x 109 "x"_mst; // x 110 case Fragment::WRAP_S: return 111 "W"_mst.If(x << "Bo"_mst) | // W=B_x*o_x 112 (x & "ghijk"_mst) | // g=g_x, h=h_x, i=i_x, j=j_x, k=k_x 113 (x & "udfemsx"_mst); // u=u_x, d=d_x, f=f_x, e=e_x, m=m_x, s=s_x, x=x_x 114 case Fragment::WRAP_C: return 115 "B"_mst.If(x << "K"_mst) | // B=K_x 116 (x & "ghijk"_mst) | // g=g_x, h=h_x, i=i_x, j=j_x, k=k_x 117 (x & "ondfem"_mst) | // o=o_x, n=n_x, d=d_x, f=f_x, e=e_x, m=m_x 118 "us"_mst; // u, s 119 case Fragment::WRAP_D: return 120 "B"_mst.If(x << "Vz"_mst) | // B=V_x*z_x 121 "o"_mst.If(x << "z"_mst) | // o=z_x 122 "e"_mst.If(x << "f"_mst) | // e=f_x 123 (x & "ghijk"_mst) | // g=g_x, h=h_x, i=i_x, j=j_x, k=k_x 124 (x & "ms"_mst) | // m=m_x, s=s_x 125 // NOTE: 'd:' is 'u' under Tapscript but not P2WSH as MINIMALIF is only a policy rule there. 126 "u"_mst.If(IsTapscript(ms_ctx)) | 127 "ndx"_mst; // n, d, x 128 case Fragment::WRAP_V: return 129 "V"_mst.If(x << "B"_mst) | // V=B_x 130 (x & "ghijk"_mst) | // g=g_x, h=h_x, i=i_x, j=j_x, k=k_x 131 (x & "zonms"_mst) | // z=z_x, o=o_x, n=n_x, m=m_x, s=s_x 132 "fx"_mst; // f, x 133 case Fragment::WRAP_J: return 134 "B"_mst.If(x << "Bn"_mst) | // B=B_x*n_x 135 "e"_mst.If(x << "f"_mst) | // e=f_x 136 (x & "ghijk"_mst) | // g=g_x, h=h_x, i=i_x, j=j_x, k=k_x 137 (x & "oums"_mst) | // o=o_x, u=u_x, m=m_x, s=s_x 138 "ndx"_mst; // n, d, x 139 case Fragment::WRAP_N: return 140 (x & "ghijk"_mst) | // g=g_x, h=h_x, i=i_x, j=j_x, k=k_x 141 (x & "Bzondfems"_mst) | // B=B_x, z=z_x, o=o_x, n=n_x, d=d_x, f=f_x, e=e_x, m=m_x, s=s_x 142 "ux"_mst; // u, x 143 case Fragment::AND_V: return 144 (y & "KVB"_mst).If(x << "V"_mst) | // B=V_x*B_y, V=V_x*V_y, K=V_x*K_y 145 (x & "n"_mst) | (y & "n"_mst).If(x << "z"_mst) | // n=n_x+z_x*n_y 146 ((x | y) & "o"_mst).If((x | y) << "z"_mst) | // o=o_x*z_y+z_x*o_y 147 (x & y & "mz"_mst) | // m=m_x*m_y, z=z_x*z_y 148 ((x | y) & "s"_mst) | // s=s_x+s_y 149 "f"_mst.If((y << "f"_mst) || (x << "s"_mst)) | // f=f_y+s_x 150 (y & "ux"_mst) | // u=u_y, x=x_y 151 ((x | y) & "ghij"_mst) | // g=g_x+g_y, h=h_x+h_y, i=i_x+i_y, j=j_x+j_y 152 "k"_mst.If(((x & y) << "k"_mst) && 153 !(((x << "g"_mst) && (y << "h"_mst)) || 154 ((x << "h"_mst) && (y << "g"_mst)) || 155 ((x << "i"_mst) && (y << "j"_mst)) || 156 ((x << "j"_mst) && (y << "i"_mst)))); // k=k_x*k_y*!(g_x*h_y + h_x*g_y + i_x*j_y + j_x*i_y) 157 case Fragment::AND_B: return 158 (x & "B"_mst).If(y << "W"_mst) | // B=B_x*W_y 159 ((x | y) & "o"_mst).If((x | y) << "z"_mst) | // o=o_x*z_y+z_x*o_y 160 (x & "n"_mst) | (y & "n"_mst).If(x << "z"_mst) | // n=n_x+z_x*n_y 161 (x & y & "e"_mst).If((x & y) << "s"_mst) | // e=e_x*e_y*s_x*s_y 162 (x & y & "dzm"_mst) | // d=d_x*d_y, z=z_x*z_y, m=m_x*m_y 163 "f"_mst.If(((x & y) << "f"_mst) || (x << "sf"_mst) || (y << "sf"_mst)) | // f=f_x*f_y + f_x*s_x + f_y*s_y 164 ((x | y) & "s"_mst) | // s=s_x+s_y 165 "ux"_mst | // u, x 166 ((x | y) & "ghij"_mst) | // g=g_x+g_y, h=h_x+h_y, i=i_x+i_y, j=j_x+j_y 167 "k"_mst.If(((x & y) << "k"_mst) && 168 !(((x << "g"_mst) && (y << "h"_mst)) || 169 ((x << "h"_mst) && (y << "g"_mst)) || 170 ((x << "i"_mst) && (y << "j"_mst)) || 171 ((x << "j"_mst) && (y << "i"_mst)))); // k=k_x*k_y*!(g_x*h_y + h_x*g_y + i_x*j_y + j_x*i_y) 172 case Fragment::OR_B: return 173 "B"_mst.If(x << "Bd"_mst && y << "Wd"_mst) | // B=B_x*d_x*W_x*d_y 174 ((x | y) & "o"_mst).If((x | y) << "z"_mst) | // o=o_x*z_y+z_x*o_y 175 (x & y & "m"_mst).If((x | y) << "s"_mst && (x & y) << "e"_mst) | // m=m_x*m_y*e_x*e_y*(s_x+s_y) 176 (x & y & "zse"_mst) | // z=z_x*z_y, s=s_x*s_y, e=e_x*e_y 177 "dux"_mst | // d, u, x 178 ((x | y) & "ghij"_mst) | // g=g_x+g_y, h=h_x+h_y, i=i_x+i_y, j=j_x+j_y 179 (x & y & "k"_mst); // k=k_x*k_y 180 case Fragment::OR_D: return 181 (y & "B"_mst).If(x << "Bdu"_mst) | // B=B_y*B_x*d_x*u_x 182 (x & "o"_mst).If(y << "z"_mst) | // o=o_x*z_y 183 (x & y & "m"_mst).If(x << "e"_mst && (x | y) << "s"_mst) | // m=m_x*m_y*e_x*(s_x+s_y) 184 (x & y & "zs"_mst) | // z=z_x*z_y, s=s_x*s_y 185 (y & "ufde"_mst) | // u=u_y, f=f_y, d=d_y, e=e_y 186 "x"_mst | // x 187 ((x | y) & "ghij"_mst) | // g=g_x+g_y, h=h_x+h_y, i=i_x+i_y, j=j_x+j_y 188 (x & y & "k"_mst); // k=k_x*k_y 189 case Fragment::OR_C: return 190 (y & "V"_mst).If(x << "Bdu"_mst) | // V=V_y*B_x*u_x*d_x 191 (x & "o"_mst).If(y << "z"_mst) | // o=o_x*z_y 192 (x & y & "m"_mst).If(x << "e"_mst && (x | y) << "s"_mst) | // m=m_x*m_y*e_x*(s_x+s_y) 193 (x & y & "zs"_mst) | // z=z_x*z_y, s=s_x*s_y 194 "fx"_mst | // f, x 195 ((x | y) & "ghij"_mst) | // g=g_x+g_y, h=h_x+h_y, i=i_x+i_y, j=j_x+j_y 196 (x & y & "k"_mst); // k=k_x*k_y 197 case Fragment::OR_I: return 198 (x & y & "VBKufs"_mst) | // V=V_x*V_y, B=B_x*B_y, K=K_x*K_y, u=u_x*u_y, f=f_x*f_y, s=s_x*s_y 199 "o"_mst.If((x & y) << "z"_mst) | // o=z_x*z_y 200 ((x | y) & "e"_mst).If((x | y) << "f"_mst) | // e=e_x*f_y+f_x*e_y 201 (x & y & "m"_mst).If((x | y) << "s"_mst) | // m=m_x*m_y*(s_x+s_y) 202 ((x | y) & "d"_mst) | // d=d_x+d_y 203 "x"_mst | // x 204 ((x | y) & "ghij"_mst) | // g=g_x+g_y, h=h_x+h_y, i=i_x+i_y, j=j_x+j_y 205 (x & y & "k"_mst); // k=k_x*k_y 206 case Fragment::ANDOR: return 207 (y & z & "BKV"_mst).If(x << "Bdu"_mst) | // B=B_x*d_x*u_x*B_y*B_z, K=B_x*d_x*u_x*K_y*K_z, V=B_x*d_x*u_x*V_y*V_z 208 (x & y & z & "z"_mst) | // z=z_x*z_y*z_z 209 ((x | (y & z)) & "o"_mst).If((x | (y & z)) << "z"_mst) | // o=o_x*z_y*z_z+z_x*o_y*o_z 210 (y & z & "u"_mst) | // u=u_y*u_z 211 (z & "f"_mst).If((x << "s"_mst) || (y << "f"_mst)) | // f=(s_x+f_y)*f_z 212 (z & "d"_mst) | // d=d_z 213 (z & "e"_mst).If(x << "s"_mst || y << "f"_mst) | // e=e_z*(s_x+f_y) 214 (x & y & z & "m"_mst).If(x << "e"_mst && (x | y | z) << "s"_mst) | // m=m_x*m_y*m_z*e_x*(s_x+s_y+s_z) 215 (z & (x | y) & "s"_mst) | // s=s_z*(s_x+s_y) 216 "x"_mst | // x 217 ((x | y | z) & "ghij"_mst) | // g=g_x+g_y+g_z, h=h_x+h_y+h_z, i=i_x+i_y+i_z, j=j_x+j_y_j_z 218 "k"_mst.If(((x & y & z) << "k"_mst) && 219 !(((x << "g"_mst) && (y << "h"_mst)) || 220 ((x << "h"_mst) && (y << "g"_mst)) || 221 ((x << "i"_mst) && (y << "j"_mst)) || 222 ((x << "j"_mst) && (y << "i"_mst)))); // k=k_x*k_y*k_z* !(g_x*h_y + h_x*g_y + i_x*j_y + j_x*i_y) 223 case Fragment::MULTI: { 224 return "Bnudemsk"_mst; 225 } 226 case Fragment::MULTI_A: { 227 return "Budemsk"_mst; 228 } 229 case Fragment::THRESH: { 230 bool all_e = true; 231 bool all_m = true; 232 uint32_t args = 0; 233 uint32_t num_s = 0; 234 Type acc_tl = "k"_mst; 235 for (size_t i = 0; i < sub_types.size(); ++i) { 236 Type t = sub_types[i]; 237 if (!(t << (i ? "Wdu"_mst : "Bdu"_mst))) return ""_mst; // Require Bdu, Wdu, Wdu, ... 238 if (!(t << "e"_mst)) all_e = false; 239 if (!(t << "m"_mst)) all_m = false; 240 if (t << "s"_mst) num_s += 1; 241 args += (t << "z"_mst) ? 0 : (t << "o"_mst) ? 1 : 2; 242 acc_tl = ((acc_tl | t) & "ghij"_mst) | 243 // Thresh contains a combination of timelocks if it has threshold > 1 and 244 // it contains two different children that have different types of timelocks 245 // Note how if any of the children don't have "k", the parent also does not have "k" 246 "k"_mst.If(((acc_tl & t) << "k"_mst) && ((k <= 1) || 247 ((k > 1) && !(((acc_tl << "g"_mst) && (t << "h"_mst)) || 248 ((acc_tl << "h"_mst) && (t << "g"_mst)) || 249 ((acc_tl << "i"_mst) && (t << "j"_mst)) || 250 ((acc_tl << "j"_mst) && (t << "i"_mst)))))); 251 } 252 return "Bdu"_mst | 253 "z"_mst.If(args == 0) | // z=all z 254 "o"_mst.If(args == 1) | // o=all z except one o 255 "e"_mst.If(all_e && num_s == n_subs) | // e=all e and all s 256 "m"_mst.If(all_e && all_m && num_s >= n_subs - k) | // m=all e, >=(n-k) s 257 "s"_mst.If(num_s >= n_subs - k + 1) | // s= >=(n-k+1) s 258 acc_tl; // timelock info 259 } 260 } 261 assert(false); 262 } 263 264 size_t ComputeScriptLen(Fragment fragment, Type sub0typ, size_t subsize, uint32_t k, size_t n_subs, 265 size_t n_keys, MiniscriptContext ms_ctx) { 266 switch (fragment) { 267 case Fragment::JUST_1: 268 case Fragment::JUST_0: return 1; 269 case Fragment::PK_K: return IsTapscript(ms_ctx) ? 33 : 34; 270 case Fragment::PK_H: return 3 + 21; 271 case Fragment::OLDER: 272 case Fragment::AFTER: return 1 + BuildScript(k).size(); 273 case Fragment::HASH256: 274 case Fragment::SHA256: return 4 + 2 + 33; 275 case Fragment::HASH160: 276 case Fragment::RIPEMD160: return 4 + 2 + 21; 277 case Fragment::MULTI: return 1 + BuildScript(n_keys).size() + BuildScript(k).size() + 34 * n_keys; 278 case Fragment::MULTI_A: return (1 + 32 + 1) * n_keys + BuildScript(k).size() + 1; 279 case Fragment::AND_V: return subsize; 280 case Fragment::WRAP_V: return subsize + (sub0typ << "x"_mst); 281 case Fragment::WRAP_S: 282 case Fragment::WRAP_C: 283 case Fragment::WRAP_N: 284 case Fragment::AND_B: 285 case Fragment::OR_B: return subsize + 1; 286 case Fragment::WRAP_A: 287 case Fragment::OR_C: return subsize + 2; 288 case Fragment::WRAP_D: 289 case Fragment::OR_D: 290 case Fragment::OR_I: 291 case Fragment::ANDOR: return subsize + 3; 292 case Fragment::WRAP_J: return subsize + 4; 293 case Fragment::THRESH: return subsize + n_subs + BuildScript(k).size(); 294 } 295 assert(false); 296 } 297 298 InputStack& InputStack::SetAvailable(Availability avail) { 299 available = avail; 300 if (avail == Availability::NO) { 301 stack.clear(); 302 size = std::numeric_limits<size_t>::max(); 303 has_sig = false; 304 malleable = false; 305 non_canon = false; 306 } 307 return *this; 308 } 309 310 InputStack& InputStack::SetWithSig() { 311 has_sig = true; 312 return *this; 313 } 314 315 InputStack& InputStack::SetNonCanon() { 316 non_canon = true; 317 return *this; 318 } 319 320 InputStack& InputStack::SetMalleable(bool x) { 321 malleable = x; 322 return *this; 323 } 324 325 InputStack operator+(InputStack a, InputStack b) { 326 a.stack = Cat(std::move(a.stack), std::move(b.stack)); 327 if (a.available != Availability::NO && b.available != Availability::NO) a.size += b.size; 328 a.has_sig |= b.has_sig; 329 a.malleable |= b.malleable; 330 a.non_canon |= b.non_canon; 331 if (a.available == Availability::NO || b.available == Availability::NO) { 332 a.SetAvailable(Availability::NO); 333 } else if (a.available == Availability::MAYBE || b.available == Availability::MAYBE) { 334 a.SetAvailable(Availability::MAYBE); 335 } 336 return a; 337 } 338 339 InputStack operator|(InputStack a, InputStack b) { 340 // If only one is invalid, pick the other one. If both are invalid, pick an arbitrary one. 341 if (a.available == Availability::NO) return b; 342 if (b.available == Availability::NO) return a; 343 // If only one of the solutions has a signature, we must pick the other one. 344 if (!a.has_sig && b.has_sig) return a; 345 if (!b.has_sig && a.has_sig) return b; 346 if (!a.has_sig && !b.has_sig) { 347 // If neither solution requires a signature, the result is inevitably malleable. 348 a.malleable = true; 349 b.malleable = true; 350 } else { 351 // If both options require a signature, prefer the non-malleable one. 352 if (b.malleable && !a.malleable) return a; 353 if (a.malleable && !b.malleable) return b; 354 } 355 // Between two malleable or two non-malleable solutions, pick the smaller one between 356 // YESes, and the bigger ones between MAYBEs. Prefer YES over MAYBE. 357 if (a.available == Availability::YES && b.available == Availability::YES) { 358 return std::move(a.size <= b.size ? a : b); 359 } else if (a.available == Availability::MAYBE && b.available == Availability::MAYBE) { 360 return std::move(a.size >= b.size ? a : b); 361 } else if (a.available == Availability::YES) { 362 return a; 363 } else { 364 return b; 365 } 366 } 367 368 std::optional<std::vector<Opcode>> DecomposeScript(const CScript& script) 369 { 370 std::vector<Opcode> out; 371 CScript::const_iterator it = script.begin(), itend = script.end(); 372 while (it != itend) { 373 std::vector<unsigned char> push_data; 374 opcodetype opcode; 375 if (!script.GetOp(it, opcode, push_data)) { 376 return {}; 377 } else if (opcode >= OP_1 && opcode <= OP_16) { 378 // Deal with OP_n (GetOp does not turn them into pushes). 379 push_data.assign(1, CScript::DecodeOP_N(opcode)); 380 } else if (opcode == OP_CHECKSIGVERIFY) { 381 // Decompose OP_CHECKSIGVERIFY into OP_CHECKSIG OP_VERIFY 382 out.emplace_back(OP_CHECKSIG, std::vector<unsigned char>()); 383 opcode = OP_VERIFY; 384 } else if (opcode == OP_CHECKMULTISIGVERIFY) { 385 // Decompose OP_CHECKMULTISIGVERIFY into OP_CHECKMULTISIG OP_VERIFY 386 out.emplace_back(OP_CHECKMULTISIG, std::vector<unsigned char>()); 387 opcode = OP_VERIFY; 388 } else if (opcode == OP_EQUALVERIFY) { 389 // Decompose OP_EQUALVERIFY into OP_EQUAL OP_VERIFY 390 out.emplace_back(OP_EQUAL, std::vector<unsigned char>()); 391 opcode = OP_VERIFY; 392 } else if (opcode == OP_NUMEQUALVERIFY) { 393 // Decompose OP_NUMEQUALVERIFY into OP_NUMEQUAL OP_VERIFY 394 out.emplace_back(OP_NUMEQUAL, std::vector<unsigned char>()); 395 opcode = OP_VERIFY; 396 } else if (IsPushdataOp(opcode)) { 397 if (!CheckMinimalPush(push_data, opcode)) return {}; 398 } else if (it != itend && (opcode == OP_CHECKSIG || opcode == OP_CHECKMULTISIG || opcode == OP_EQUAL || opcode == OP_NUMEQUAL) && (*it == OP_VERIFY)) { 399 // Rule out non minimal VERIFY sequences 400 return {}; 401 } 402 out.emplace_back(opcode, std::move(push_data)); 403 } 404 std::reverse(out.begin(), out.end()); 405 return out; 406 } 407 408 std::optional<int64_t> ParseScriptNumber(const Opcode& in) { 409 if (in.first == OP_0) { 410 return 0; 411 } 412 if (!in.second.empty()) { 413 if (IsPushdataOp(in.first) && !CheckMinimalPush(in.second, in.first)) return {}; 414 try { 415 return CScriptNum(in.second, true).GetInt64(); 416 } catch(const scriptnum_error&) {} 417 } 418 return {}; 419 } 420 421 int FindNextChar(std::span<const char> sp, const char m) 422 { 423 for (int i = 0; i < (int)sp.size(); ++i) { 424 if (sp[i] == m) return i; 425 // We only search within the current parentheses 426 if (sp[i] == ')') break; 427 } 428 return -1; 429 } 430 431 } // namespace internal 432 } // namespace miniscript