bitcore/ScriptInterpreter.js at master · FrictionlessCoin/bitcore · GitHub

Repository navigation

History

1068 lines (924 loc) · 30.5 KB

Raw

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

452

453

454

455

456

457

458

459

460

461

462

463

464

465

466

467

468

469

470

471

472

473

474

475

476

477

478

479

480

481

482

483

484

485

486

487

488

489

490

491

492

493

494

495

496

497

498

499

500

501

502

503

504

505

506

507

508

509

510

511

512

513

514

515

516

517

518

519

520

521

522

523

524

525

526

527

528

529

530

531

532

533

534

535

536

537

538

539

540

541

542

543

544

545

546

547

548

549

550

551

552

553

554

555

556

557

558

559

560

561

562

563

564

565

566

567

568

569

570

571

572

573

574

575

576

577

578

579

580

581

582

583

584

585

586

587

588

589

590

591

592

593

594

595

596

597

598

599

600

601

602

603

604

605

606

607

608

609

610

611

612

613

614

615

616

617

618

619

620

621

622

623

624

625

626

627

628

629

630

631

632

633

634

635

636

637

638

639

640

641

642

643

644

645

646

647

648

649

650

651

652

653

654

655

656

657

658

659

660

661

662

663

664

665

666

667

668

669

670

671

672

673

674

675

676

677

678

679

680

681

682

683

684

685

686

687

688

689

690

691

692

693

694

695

696

697

698

699

700

701

702

703

704

705

706

707

708

709

710

711

712

713

714

715

716

717

718

719

720

721

722

723

724

725

726

727

728

729

730

731

732

733

734

735

736

737

738

739

740

741

742

743

744

745

746

747

748

749

750

751

752

753

754

755

756

757

758

759

760

761

762

763

764

765

766

767

768

769

770

771

772

773

774

775

776

777

778

779

780

781

782

783

784

785

786

787

788

789

790

791

792

793

794

795

796

797

798

799

800

801

802

803

804

805

806

807

808

809

810

811

812

813

814

815

816

817

818

819

820

821

822

823

824

825

826

827

828

829

830

831

832

833

834

835

836

837

838

839

840

841

842

843

844

845

846

847

848

849

850

851

852

853

854

855

856

857

858

859

860

861

862

863

864

865

866

867

868

869

870

871

872

873

874

875

876

877

878

879

880

881

882

883

884

885

886

887

888

889

890

891

892

893

894

895

896

897

898

899

900

901

902

903

904

905

906

907

908

909

910

911

912

913

914

915

916

917

918

919

920

921

922

923

924

925

926

927

928

929

930

931

932

933

934

935

936

937

938

939

940

941

942

943

944

945

946

947

948

949

950

951

952

953

954

955

956

957

958

959

960

961

962

963

964

965

966

967

968

969

970

971

972

973

974

975

976

977

978

979

980

981

982

983

984

985

986

987

988

989

990

991

992

993

994

995

996

997

998

999

1000

var imports = require('soop').imports();

var config = imports.config || require('./config');

var log = imports.log || require('./util/log');

var util = imports.util || require('./util/util');

var Opcode = imports.Opcode || require('./Opcode');

var buffertools = imports.buffertools || require('buffertools');

var bignum = imports.bignum || require('bignum');

var Util = imports.Util || require('./util/util');

var Script = require('./Script');

var Key = require('./Key');

var SIGHASH_ALL = 1;

var SIGHASH_NONE = 2;

var SIGHASH_SINGLE = 3;

var SIGHASH_ANYONECANPAY = 80;

// Make opcodes available as pseudo-constants

for (var i in Opcode.map) {

eval(i + " = " + Opcode.map[i] + ";");

}

var intToBufferSM = Util.intToBufferSM

var bufferSMToInt = Util.bufferSMToInt;

function ScriptInterpreter(opts) {

this.opts = opts || {};

this.stack = [];

this.disableUnsafeOpcodes = true;

};

ScriptInterpreter.prototype.eval = function eval(script, tx, inIndex, hashType, callback) {

if ("function" !== typeof callback) {

throw new Error("ScriptInterpreter.eval() requires a callback");

}

var pc = 0;

var execStack = [];

var altStack = [];

var hashStart = 0;

var opCount = 0;

if (script.buffer.length > 10000) {

callback(new Error("Oversized script (> 10k bytes)"));

return this;

}

// Start execution by running the first step

executeStep.call(this, callback);

function executeStep(cb) {

// Once all chunks have been processed, execution ends

if (pc >= script.chunks.length) {

// Execution stack must be empty at the end of the script

if (execStack.length) {

cb(new Error("Execution stack ended non-empty"));

return;

}

// Execution successful (Note that we still have to check whether the

// final stack contains a truthy value.)

cb(null);

return;

}

// The execution bit is true if there are no "false" values in the

// execution stack. (A "false" value indicates that we're in the

// inactive branch of an if statement.)

var exec = !~execStack.indexOf(false);

var opcode = script.chunks[pc++];

if (opcode.length > 520) {

throw new Error("Max push value size exceeded (>520)");

}

if (opcode > OP_16 && ++opCount > 201) {

throw new Error("Opcode limit exceeded (>200)");

}

if (this.disableUnsafeOpcodes &&

"number" === typeof opcode &&

(opcode === OP_CAT ||

opcode === OP_SUBSTR ||

opcode === OP_LEFT ||

opcode === OP_RIGHT ||

opcode === OP_INVERT ||

opcode === OP_AND ||

opcode === OP_OR ||

opcode === OP_XOR ||

opcode === OP_2MUL ||

opcode === OP_2DIV ||

opcode === OP_MUL ||

opcode === OP_DIV ||

opcode === OP_MOD ||

opcode === OP_LSHIFT ||

opcode === OP_RSHIFT)) {

throw new Error("Encountered a disabled opcode");

}

if (exec && Buffer.isBuffer(opcode)) {

this.stack.push(opcode);

} else if (exec || (OP_IF <= opcode && opcode <= OP_ENDIF))

switch (opcode) {

case OP_0:

this.stack.push(new Buffer([]));

break;

case OP_1NEGATE:

case OP_1:

case OP_2:

case OP_3:

case OP_4:

case OP_5:

case OP_6:

case OP_7:

case OP_8:

case OP_9:

case OP_10:

case OP_11:

case OP_12:

case OP_13:

case OP_14:

case OP_15:

case OP_16:

var opint = opcode - OP_1 + 1;

var opbuf = intToBufferSM(opint);

this.stack.push(opbuf);

break;

case OP_NOP:

case OP_NOP1:

case OP_NOP2:

case OP_NOP3:

case OP_NOP4:

case OP_NOP5:

case OP_NOP6:

case OP_NOP7:

case OP_NOP8:

case OP_NOP9:

case OP_NOP10:

break;

case OP_IF:

case OP_NOTIF:

// <expression> if [statements] [else [statements]] endif

var value = false;

if (exec) {

value = castBool(this.stackPop());

if (opcode === OP_NOTIF) {

value = !value;

}

execStack.push(value);

break;

case OP_ELSE:

if (execStack.length < 1) {

throw new Error("Unmatched OP_ELSE");

}

execStack[execStack.length - 1] = !execStack[execStack.length - 1];

break;

case OP_ENDIF:

if (execStack.length < 1) {

throw new Error("Unmatched OP_ENDIF");

}

execStack.pop();

break;

case OP_VERIFY:

var value = castBool(this.stackTop());

if (value) {

this.stackPop();

} else {

throw new Error("OP_VERIFY negative");

}

break;

case OP_RETURN:

throw new Error("OP_RETURN");

case OP_TOALTSTACK:

altStack.push(this.stackPop());

break;

case OP_FROMALTSTACK:

if (altStack.length < 1) {

throw new Error("OP_FROMALTSTACK with alt stack empty");

}

this.stack.push(altStack.pop());

break;

case OP_2DROP:

// (x1 x2 -- )

this.stackPop();

break;

case OP_2DUP:

// (x1 x2 -- x1 x2 x1 x2)

var v1 = this.stackTop(2);

var v2 = this.stackTop(1);

this.stack.push(v1);

this.stack.push(v2);

break;

case OP_3DUP:

// (x1 x2 -- x1 x2 x1 x2)

var v1 = this.stackTop(3);

var v2 = this.stackTop(2);

var v3 = this.stackTop(1);

this.stack.push(v1);

this.stack.push(v2);

this.stack.push(v3);

break;

case OP_2OVER:

// (x1 x2 x3 x4 -- x1 x2 x3 x4 x1 x2)

var v1 = this.stackTop(4);

var v2 = this.stackTop(3);

this.stack.push(v1);

this.stack.push(v2);

break;

case OP_2ROT:

// (x1 x2 x3 x4 x5 x6 -- x3 x4 x5 x6 x1 x2)

var v1 = this.stackTop(6);

var v2 = this.stackTop(5);

this.stack.splice(this.stack.length - 6, 2);

this.stack.push(v1);

this.stack.push(v2);

break;

case OP_2SWAP:

// (x1 x2 x3 x4 -- x3 x4 x1 x2)

this.stackSwap(4, 2);

this.stackSwap(3, 1);

break;

case OP_IFDUP:

// (x - 0 | x x)

var value = this.stackTop();

if (castBool(value)) {

this.stack.push(value);

}

break;

case OP_DEPTH:

// -- stacksize

var value = bignum(this.stack.length);

this.stack.push(intToBufferSM(value));

break;

case OP_DROP:

// (x -- )

this.stackPop();

break;

case OP_DUP:

// (x -- x x)

this.stack.push(this.stackTop());

break;

case OP_NIP:

// (x1 x2 -- x2)

if (this.stack.length < 2) {

throw new Error("OP_NIP insufficient stack size");

}

this.stack.splice(this.stack.length - 2, 1);

break;

case OP_OVER:

// (x1 x2 -- x1 x2 x1)

this.stack.push(this.stackTop(2));

break;

case OP_PICK:

case OP_ROLL:

// (xn ... x2 x1 x0 n - xn ... x2 x1 x0 xn)

// (xn ... x2 x1 x0 n - ... x2 x1 x0 xn)

var n = castInt(this.stackPop());

if (n < 0 || n >= this.stack.length) {

throw new Error("OP_PICK/OP_ROLL insufficient stack size");

}

var value = this.stackTop(n + 1);

if (opcode === OP_ROLL) {

this.stack.splice(this.stack.length - n - 1, 1);

}

this.stack.push(value);

break;

case OP_ROT:

// (x1 x2 x3 -- x2 x3 x1)

// x2 x1 x3 after first swap

// x2 x3 x1 after second swap

this.stackSwap(3, 2);

this.stackSwap(2, 1);

break;

case OP_SWAP:

// (x1 x2 -- x2 x1)

this.stackSwap(2, 1);

break;

case OP_TUCK:

// (x1 x2 -- x2 x1 x2)

if (this.stack.length < 2) {

throw new Error("OP_TUCK insufficient stack size");

}

this.stack.splice(this.stack.length - 2, 0, this.stackTop());

break;

case OP_CAT:

// (x1 x2 -- out)

var v1 = this.stackTop(2);

var v2 = this.stackTop(1);

this.stackPop();

this.stack.push(Buffer.concat([v1, v2]));

break;

case OP_SUBSTR:

// (in begin size -- out)

var buf = this.stackTop(3);

var start = castInt(this.stackTop(2));

var len = castInt(this.stackTop(1));

if (start < 0 || len < 0) {

throw new Error("OP_SUBSTR start < 0 or len < 0");

}

if ((start + len) >= buf.length) {

throw new Error("OP_SUBSTR range out of bounds");

}

this.stackPop();

this.stack[this.stack.length - 1] = buf.slice(start, start + len);

break;

case OP_LEFT:

case OP_RIGHT:

// (in size -- out)

var buf = this.stackTop(2);

var size = castInt(this.stackTop(1));

if (size < 0) {

throw new Error("OP_LEFT/OP_RIGHT size < 0");

}

if (size > buf.length) {

size = buf.length;

}

this.stackPop();

if (opcode === OP_LEFT) {

this.stack[this.stack.length - 1] = buf.slice(0, size);

} else {

this.stack[this.stack.length - 1] = buf.slice(buf.length - size);

}

break;

case OP_SIZE:

// (in -- in size)

var value = bignum(this.stackTop().length);

this.stack.push(intToBufferSM(value));

break;

case OP_INVERT:

// (in - out)

var buf = this.stackTop();

for (var i = 0, l = buf.length; i < l; i++) {

buf[i] = ~buf[i];

}

break;

case OP_AND:

case OP_OR:

case OP_XOR:

// (x1 x2 - out)

var v1 = this.stackTop(2);

var v2 = this.stackTop(1);

this.stackPop();

var out = new Buffer(Math.max(v1.length, v2.length));

if (opcode === OP_AND) {

for (var i = 0, l = out.length; i < l; i++) {

out[i] = v1[i] & v2[i];

}

} else if (opcode === OP_OR) {

for (var i = 0, l = out.length; i < l; i++) {

out[i] = v1[i] | v2[i];

}

} else if (opcode === OP_XOR) {

for (var i = 0, l = out.length; i < l; i++) {

out[i] = v1[i] ^ v2[i];

}

this.stack.push(out);

break;

case OP_EQUAL:

case OP_EQUALVERIFY:

//case OP_NOTEQUAL: // use OP_NUMNOTEQUAL

// (x1 x2 - bool)

var v1 = this.stackTop(2);

var v2 = this.stackTop(1);

var value = buffertools.compare(v1, v2) === 0;

// OP_NOTEQUAL is disabled because it would be too easy to say

// something like n != 1 and have some wiseguy pass in 1 with extra

// zero bytes after it (numerically, 0x01 == 0x0001 == 0x000001)

//if (opcode == OP_NOTEQUAL)

// fEqual = !fEqual;

this.stackPop();

this.stack.push(new Buffer([value ? 1 : 0]));

if (opcode === OP_EQUALVERIFY) {

if (value) {

this.stackPop();

} else {

throw new Error("OP_EQUALVERIFY negative");

}

break;

case OP_1ADD:

case OP_1SUB:

case OP_2MUL:

case OP_2DIV:

case OP_NEGATE:

case OP_ABS:

case OP_NOT:

case OP_0NOTEQUAL:

// (in -- out)

var num = bufferSMToInt(this.stackTop());

switch (opcode) {

case OP_1ADD:

num = num.add(bignum(1));

break;

case OP_1SUB:

num = num.sub(bignum(1));

break;

case OP_2MUL:

num = num.mul(bignum(2));

break;

case OP_2DIV:

num = num.div(bignum(2));

break;

case OP_NEGATE:

num = num.neg();

break;

case OP_ABS:

num = num.abs();

break;

case OP_NOT:

num = bignum(num.cmp(0) == 0 ? 1 : 0);

break;

case OP_0NOTEQUAL:

num = bignum(num.cmp(0) == 0 ? 0 : 1);

break;

}

this.stack[this.stack.length - 1] = intToBufferSM(num);

break;

case OP_ADD:

case OP_SUB:

case OP_MUL:

case OP_DIV:

case OP_MOD:

case OP_LSHIFT:

case OP_RSHIFT:

case OP_BOOLAND:

case OP_BOOLOR:

case OP_NUMEQUAL:

case OP_NUMEQUALVERIFY:

case OP_NUMNOTEQUAL:

case OP_LESSTHAN:

case OP_GREATERTHAN:

case OP_LESSTHANOREQUAL:

case OP_GREATERTHANOREQUAL:

case OP_MIN:

case OP_MAX:

// (x1 x2 -- out)

var v1 = bufferSMToInt(this.stackTop(2));

var v2 = bufferSMToInt(this.stackTop(1));

var num;

switch (opcode) {

case OP_ADD:

num = v1.add(v2);

break;

case OP_SUB:

num = v1.sub(v2);

break;

case OP_MUL:

num = v1.mul(v2);

break;

case OP_DIV:

num = v1.div(v2);

break;

case OP_MOD:

num = v1.mod(v2);

break;

case OP_LSHIFT:

if (v2.cmp(0) < 0 || v2.cmp(2048) > 0) {

throw new Error("OP_LSHIFT parameter out of bounds");

}

num = v1.shiftLeft(v2);

break;

case OP_RSHIFT:

if (v2.cmp(0) < 0 || v2.cmp(2048) > 0) {

throw new Error("OP_RSHIFT parameter out of bounds");

}

num = v1.shiftRight(v2);

break;

case OP_BOOLAND:

num = bignum((v1.cmp(0) != 0 && v2.cmp(0) != 0) ? 1 : 0);

break;

case OP_BOOLOR:

num = bignum((v1.cmp(0) != 0 || v2.cmp(0) != 0) ? 1 : 0);

break;

case OP_NUMEQUAL:

case OP_NUMEQUALVERIFY:

num = bignum(v1.cmp(v2) == 0 ? 1 : 0);

break;

case OP_NUMNOTEQUAL:

;

num = bignum(v1.cmp(v2) != 0 ? 1 : 0);

break;

case OP_LESSTHAN:

num = bignum(v1.lt(v2) ? 1 : 0);

break;

case OP_GREATERTHAN:

num = bignum(v1.gt(v2) ? 1 : 0);

break;

case OP_LESSTHANOREQUAL:

num = bignum(v1.gt(v2) ? 0 : 1);

break;

case OP_GREATERTHANOREQUAL:

num = bignum(v1.lt(v2) ? 0 : 1);

break;

case OP_MIN:

num = (v1.lt(v2) ? v1 : v2);

break;

case OP_MAX:

num = (v1.gt(v2) ? v1 : v2);

break;

}

this.stackPop();

this.stack.push(intToBufferSM(num));

if (opcode === OP_NUMEQUALVERIFY) {

if (castBool(this.stackTop())) {

this.stackPop();

} else {

throw new Error("OP_NUMEQUALVERIFY negative");

}

break;

case OP_WITHIN:

// (x min max -- out)

var v1 = bufferSMToInt(this.stackTop(3));

var v2 = bufferSMToInt(this.stackTop(2));

var v3 = bufferSMToInt(this.stackTop(1));

this.stackPop();

var value = v1.cmp(v2) >= 0 && v1.cmp(v3) < 0;

this.stack.push(intToBufferSM(value ? 1 : 0));

break;

case OP_RIPEMD160:

case OP_SHA1:

case OP_SHA256:

case OP_HASH160:

case OP_HASH256:

// (in -- hash)

var value = this.stackPop();

var hash;

if (opcode === OP_RIPEMD160) {

hash = Util.ripe160(value);

} else if (opcode === OP_SHA1) {

hash = Util.sha1(value);

} else if (opcode === OP_SHA256) {

hash = Util.sha256(value);

} else if (opcode === OP_HASH160) {

hash = Util.sha256ripe160(value);

} else if (opcode === OP_HASH256) {

hash = Util.twoSha256(value);

}

this.stack.push(hash);

break;

case OP_CODESEPARATOR:

// Hash starts after the code separator

hashStart = pc;

break;

case OP_CHECKSIG:

case OP_CHECKSIGVERIFY:

// (sig pubkey -- bool)

var sig = this.stackTop(2);

var pubkey = this.stackTop(1);

// Get the part of this script since the last OP_CODESEPARATOR

var scriptChunks = script.chunks.slice(hashStart);

// Convert to binary

var scriptCode = Script.fromChunks(scriptChunks);

// Remove signature if present (a signature can't sign itself)

scriptCode.findAndDelete(sig);

// check canonical signature

this.isCanonicalSignature(new Buffer(sig));

// Verify signature

checkSig(sig, pubkey, scriptCode, tx, inIndex, hashType, function(e, result) {

var success;

if (e) {

// We intentionally ignore errors during signature verification and

// treat these cases as an invalid signature.

success = false;

} else {

success = result;

}

// Update stack

this.stackPop();

this.stack.push(new Buffer([success ? 1 : 0]));

if (opcode === OP_CHECKSIGVERIFY) {

if (success) {

this.stackPop();

} else {

throw new Error("OP_CHECKSIGVERIFY negative");

}

// Run next step

executeStep.call(this, cb);

}.bind(this));

// Note that for asynchronous opcodes we have to return here to prevent

// the next opcode from being executed.

return;

case OP_CHECKMULTISIG:

case OP_CHECKMULTISIGVERIFY:

// ([sig ...] num_of_signatures [pubkey ...] num_of_pubkeys -- bool)

var keysCount = castInt(this.stackPop());

if (keysCount < 0 || keysCount > 20) {

throw new Error("OP_CHECKMULTISIG keysCount out of bounds");

}

opCount += keysCount;

if (opCount > 201) {

throw new Error("Opcode limit exceeded (>200)");

}

var keys = [];

for (var i = 0, l = keysCount; i < l; i++) {

keys.push(this.stackPop());

}

var sigsCount = castInt(this.stackPop());

if (sigsCount < 0 || sigsCount > keysCount) {

throw new Error("OP_CHECKMULTISIG sigsCount out of bounds");

}

var sigs = [];

for (var i = 0, l = sigsCount; i < l; i++) {

sigs.push(this.stackPop());

}

// The original client has a bug where it pops an extra element off the

// stack. It can't be fixed without causing a chain split and we need to

// imitate this behavior as well.

this.stackPop();

// Get the part of this script since the last OP_CODESEPARATOR

var scriptChunks = script.chunks.slice(hashStart);

// Convert to binary

var scriptCode = Script.fromChunks(scriptChunks);

// Drop the signatures, since a signature can't sign itself

var that = this;

sigs.forEach(function(sig) {

that.isCanonicalSignature(new Buffer(sig));

scriptCode.findAndDelete(sig);

});

var success = true,

isig = 0,

ikey = 0;

checkMultiSigStep.call(this);

function checkMultiSigStep() {

if (success && sigsCount > 0) {

var sig = sigs[isig];

var key = keys[ikey];

checkSig(sig, key, scriptCode, tx, inIndex, hashType, function(e, result) {

if (!e && result) {

isig++;

sigsCount--;

} else {

ikey++;

keysCount--;

// If there are more signatures than keys left, then too many

// signatures have failed

if (sigsCount > keysCount) {

success = false;

}

checkMultiSigStep.call(this);

}.bind(this));

} else {

this.stack.push(new Buffer([success ? 1 : 0]));

if (opcode === OP_CHECKMULTISIGVERIFY) {

if (success) {

this.stackPop();

} else {

throw new Error("OP_CHECKMULTISIGVERIFY negative");

}

// Run next step

executeStep.call(this, cb);

}

};

// Note that for asynchronous opcodes we have to return here to prevent

// the next opcode from being executed.

return;

default:

throw new Error("Unknown opcode encountered");

}

// Size limits

if ((this.stack.length + altStack.length) > 1000) {

throw new Error("Maximum stack size exceeded");

}

// Run next step

if (false && pc % 100) {

// V8 allows for much deeper stacks than Bitcoin's scripting language,

// but just to be safe, we'll reset the stack every 100 steps

process.nextTick(executeStep.bind(this, cb));

} else {

executeStep.call(this, cb);

}

};

ScriptInterpreter.prototype.evalTwo =

function evalTwo(scriptSig, scriptPubkey, tx, n, hashType, callback) {

var self = this;

self.eval(scriptSig, tx, n, hashType, function(e) {

if (e) {

callback(e)

return;

}

self.eval(scriptPubkey, tx, n, hashType, callback);

});

};

/**

* Get the top element of the stack.

* Using the offset parameter this function can also access lower elements

* from the stack.

ScriptInterpreter.prototype.stackTop = function stackTop(offset) {

offset = +offset || 1;

if (offset < 1) offset = 1;

if (offset > this.stack.length) {

throw new Error('ScriptInterpreter.stackTop(): Stack underrun');

}

return this.stack[this.stack.length - offset];

};

ScriptInterpreter.prototype.stackBack = function stackBack() {

return this.stack[this.stack.length - 1];

};

/**

* Pop the top element off the stack and return it.

ScriptInterpreter.prototype.stackPop = function stackPop() {

if (this.stack.length < 1) {

throw new Error('ScriptInterpreter.stackTop(): Stack underrun');

}

return this.stack.pop();

};

ScriptInterpreter.prototype.stackSwap = function stackSwap(a, b) {

if (this.stack.length < a || this.stack.length < b) {

throw new Error('ScriptInterpreter.stackTop(): Stack underrun');

}

var s = this.stack,

l = s.length;

var tmp = s[l - a];

s[l - a] = s[l - b];

s[l - b] = tmp;

};

/**

* Returns a version of the stack with only primitive types.

* The return value is an array. Any single byte buffer is converted to an

* integer. Any longer Buffer is converted to a hex string.

ScriptInterpreter.prototype.getPrimitiveStack = function getPrimitiveStack() {

return this.stack.map(function(chunk) {

if (chunk.length > 2) {

return buffertools.toHex(chunk.slice(0));

}

var num = bufferSMToInt(chunk);

if (num.cmp(-128) >= 0 && num.cmp(127) <= 0) {

return num.toNumber();

} else {

return buffertools.toHex(chunk.slice(0));

}

});

};

var castBool = ScriptInterpreter.castBool = function castBool(v) {

for (var i = 0, l = v.length; i < l; i++) {

if (v[i] != 0) {

// Negative zero is still zero

if (i == (l - 1) && v[i] == 0x80) {

return false;

}

return true;

}

return false;

};

var castInt = ScriptInterpreter.castInt = function castInt(v) {

return bufferSMToInt(v).toNumber();

};

ScriptInterpreter.prototype.getResult = function getResult() {

if (this.stack.length === 0) {

throw new Error("Empty stack after script evaluation");

}

return castBool(this.stack[this.stack.length - 1]);

};

// Use ScriptInterpreter.verifyFull instead

ScriptInterpreter.verify =

function verify(scriptSig, scriptPubKey, txTo, n, hashType, callback) {

if ("function" !== typeof callback) {

throw new Error("ScriptInterpreter.verify() requires a callback");

}

// Create execution environment

var si = new ScriptInterpreter();

// Evaluate scripts

si.evalTwo(scriptSig, scriptPubKey, txTo, n, hashType, function(err) {

if (err) {

callback(err);

return;

}

// Cast result to bool

var result = si.getResult();

callback(null, result);

});

return si;

};

ScriptInterpreter.prototype.verifyStep4 = function(scriptSig, scriptPubKey,

txTo, nIn, hashType, callback, siCopy) {

if (siCopy.stack.length == 0) {

callback(null, false);

return;

}

callback(null, castBool(siCopy.stackBack()));

}

ScriptInterpreter.prototype.verifyStep3 = function(scriptSig,

scriptPubKey, txTo, nIn, hashType, callback, siCopy) {

if (this.stack.length == 0) {

callback(null, false);

return;

}

if (castBool(this.stackBack()) == false) {

callback(null, false);

return;

}

// if not P2SH, we're done

if (!this.opts.verifyP2SH || !scriptPubKey.isP2SH()) {

callback(null, true);

return;

}

if (!scriptSig.isPushOnly()) {

callback(null, false);

return;

}

if (siCopy.length === 0)

throw new Error('siCopy should have length != 0');

var subscript = new Script(siCopy.stackPop());

var that = this;

siCopy.eval(subscript, txTo, nIn, hashType, function(err) {

if (err) callback(err);

else that.verifyStep4(scriptSig, scriptPubKey, txTo, nIn,

hashType, callback, siCopy);

});

};

ScriptInterpreter.prototype.verifyStep2 = function(scriptSig, scriptPubKey,

txTo, nIn, hashType, callback, siCopy) {

if (this.opts.verifyP2SH) {

this.stack.forEach(function(item) {

siCopy.stack.push(item);

});

}

var that = this;

this.eval(scriptPubKey, txTo, nIn, hashType, function(err) {

if (err) callback(err);

else that.verifyStep3(scriptSig, scriptPubKey, txTo, nIn,

hashType, callback, siCopy);

});

};

ScriptInterpreter.verifyFull =

function verifyFull(scriptSig, scriptPubKey, txTo, nIn, hashType,

opts, callback) {

var si = new ScriptInterpreter(opts);

si.verifyFull(scriptSig, scriptPubKey,

txTo, nIn, hashType, callback);

};

ScriptInterpreter.prototype.verifyFull = function(scriptSig, scriptPubKey,

txTo, nIn, hashType, callback) {

var siCopy = new ScriptInterpreter(this.opts);

var that = this;

this.eval(scriptSig, txTo, nIn, hashType, function(err) {

if (err) callback(err);

else {

that.verifyStep2(scriptSig, scriptPubKey, txTo, nIn,

hashType, callback, siCopy);

}

});

};

var checkSig = ScriptInterpreter.checkSig =

function(sig, pubkey, scriptCode, tx, n, hashType, callback) {

if (!sig.length) {

callback(null, false);

return;

}

if (hashType == 0) {

hashType = sig[sig.length - 1];

} else if (hashType != sig[sig.length - 1]) {

callback(null, false);

return;

}

sig = sig.slice(0, sig.length - 1);

// Signature verification requires a special hash procedure

var hash = tx.hashForSignature(scriptCode, n, hashType);

// Verify signature

var key = new Key();

key.public = pubkey;

key.verifySignature(hash, sig, callback);

};

View remainder of file in raw view

bitcore/ScriptInterpreter.js at master · FrictionlessCoin/bitcore · GitHub

Repository navigation

Expand file tree

Breadcrumbs

ScriptInterpreter.js

Latest commit

History

Breadcrumbs

ScriptInterpreter.js

File metadata and controls