Merge pull request #1416 from bitcoinjs/signTxb

Migrate to stricter type checks during sign

src/transaction_builder.js

@@ -13,6 +13,33 @@ const transaction_1 = require('./transaction');
 const types = require('./types');
 const typeforce = require('typeforce');
 const SCRIPT_TYPES = classify.types;
+const PREVOUT_TYPES = new Set([
+  // Raw
+  'p2pkh',
+  'p2pk',
+  'p2wpkh',
+  'p2ms',
+  // P2SH wrapped
+  'p2sh-p2pkh',
+  'p2sh-p2pk',
+  'p2sh-p2wpkh',
+  'p2sh-p2ms',
+  // P2WSH wrapped
+  'p2wsh-p2pkh',
+  'p2wsh-p2pk',
+  'p2wsh-p2ms',
+  // P2SH-P2WSH wrapper
+  'p2sh-p2wsh-p2pkh',
+  'p2sh-p2wsh-p2pk',
+  'p2sh-p2wsh-p2ms',
+]);
+function tfMessage(type, value, message) {
+  try {
+    typeforce(type, value);
+  } catch (err) {
+    throw new Error(message);
+  }
+}
 function txIsString(tx) {
   return typeof tx === 'string' || tx instanceof String;
 }
@@ -118,74 +145,29 @@ class TransactionBuilder {
   buildIncomplete() {
     return this.__build(true);
   }
-  sign(vin, keyPair, redeemScript, hashType, witnessValue, witnessScript) {
+  sign(
-    // TODO: remove keyPair.network matching in 4.0.0
+    signParams,
-    if (keyPair.network && keyPair.network !== this.network)
+    keyPair,
-      throw new TypeError('Inconsistent network');
-    if (!this.__INPUTS[vin]) throw new Error('No input at index: ' + vin);
-    hashType = hashType || transaction_1.Transaction.SIGHASH_ALL;
-    if (this.__needsOutputs(hashType))
-      throw new Error('Transaction needs outputs');
-    const input = this.__INPUTS[vin];
-    // if redeemScript was previously provided, enforce consistency
-    if (
-      input.redeemScript !== undefined &&
-      redeemScript &&
-      !input.redeemScript.equals(redeemScript)
-    ) {
-      throw new Error('Inconsistent redeemScript');
-    }
-    const ourPubKey = keyPair.publicKey || keyPair.getPublicKey();
-    if (!canSign(input)) {
-      if (witnessValue !== undefined) {
-        if (input.value !== undefined && input.value !== witnessValue)
-          throw new Error('Input did not match witnessValue');
-        typeforce(types.Satoshi, witnessValue);
-        input.value = witnessValue;
-      }
-      if (!canSign(input)) {
-        const prepared = prepareInput(
-          input,
-          ourPubKey,
     redeemScript,
+    hashType,
+    witnessValue,
     witnessScript,
-        );
+  ) {
-        // updates inline
+    trySign(
-        Object.assign(input, prepared);
+      getSigningData(
-      }
+        this.network,
-      if (!canSign(input)) throw Error(input.prevOutType + ' not supported');
+        this.__INPUTS,
-    }
+        this.__needsOutputs.bind(this),
-    // ready to sign
+        this.__TX,
-    let signatureHash;
+        signParams,
-    if (input.hasWitness) {
+        keyPair,
-      signatureHash = this.__TX.hashForWitnessV0(
+        redeemScript,
-        vin,
-        input.signScript,
-        input.value,
         hashType,
+        witnessValue,
+        witnessScript,
+        this.__USE_LOW_R,
+      ),
     );
-    } else {
-      signatureHash = this.__TX.hashForSignature(
-        vin,
-        input.signScript,
-        hashType,
-      );
-    }
-    // enforce in order signing of public keys
-    const signed = input.pubkeys.some((pubKey, i) => {
-      if (!ourPubKey.equals(pubKey)) return false;
-      if (input.signatures[i]) throw new Error('Signature already exists');
-      // TODO: add tests
-      if (ourPubKey.length !== 33 && input.hasWitness) {
-        throw new Error(
-          'BIP143 rejects uncompressed public keys in P2WPKH or P2WSH',
-        );
-      }
-      const signature = keyPair.sign(signatureHash, this.__USE_LOW_R);
-      input.signatures[i] = bscript.signature.encode(signature, hashType);
-      return true;
-    });
-    if (!signed) throw new Error('Key pair cannot sign for this input');
   }
   __addInputUnsafe(txHash, vout, options) {
     if (transaction_1.Transaction.isCoinbaseHash(txHash)) {
@@ -746,3 +728,331 @@ function canSign(input) {
 function signatureHashType(buffer) {
   return buffer.readUInt8(buffer.length - 1);
 }
+function checkSignArgs(inputs, signParams) {
+  if (!PREVOUT_TYPES.has(signParams.prevOutScriptType)) {
+    throw new TypeError(
+      `Unknown prevOutScriptType "${signParams.prevOutScriptType}"`,
+    );
+  }
+  tfMessage(
+    typeforce.Number,
+    signParams.vin,
+    `sign must include vin parameter as Number (input index)`,
+  );
+  tfMessage(
+    types.Signer,
+    signParams.keyPair,
+    `sign must include keyPair parameter as Signer interface`,
+  );
+  tfMessage(
+    typeforce.maybe(typeforce.Number),
+    signParams.hashType,
+    `sign hashType parameter must be a number`,
+  );
+  const prevOutType = (inputs[signParams.vin] || []).prevOutType;
+  const posType = signParams.prevOutScriptType;
+  switch (posType) {
+    case 'p2pkh':
+      if (prevOutType && prevOutType !== 'pubkeyhash') {
+        throw new TypeError(
+          `input #${signParams.vin} is not of type p2pkh: ${prevOutType}`,
+        );
+      }
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessScript,
+        `${posType} requires NO witnessScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.redeemScript,
+        `${posType} requires NO redeemScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessValue,
+        `${posType} requires NO witnessValue`,
+      );
+      break;
+    case 'p2pk':
+      if (prevOutType && prevOutType !== 'pubkey') {
+        throw new TypeError(
+          `input #${signParams.vin} is not of type p2pk: ${prevOutType}`,
+        );
+      }
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessScript,
+        `${posType} requires NO witnessScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.redeemScript,
+        `${posType} requires NO redeemScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessValue,
+        `${posType} requires NO witnessValue`,
+      );
+      break;
+    case 'p2wpkh':
+      if (prevOutType && prevOutType !== 'witnesspubkeyhash') {
+        throw new TypeError(
+          `input #${signParams.vin} is not of type p2wpkh: ${prevOutType}`,
+        );
+      }
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessScript,
+        `${posType} requires NO witnessScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.redeemScript,
+        `${posType} requires NO redeemScript`,
+      );
+      tfMessage(
+        types.Satoshi,
+        signParams.witnessValue,
+        `${posType} requires witnessValue`,
+      );
+      break;
+    case 'p2ms':
+      if (prevOutType && prevOutType !== 'multisig') {
+        throw new TypeError(
+          `input #${signParams.vin} is not of type p2ms: ${prevOutType}`,
+        );
+      }
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessScript,
+        `${posType} requires NO witnessScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.redeemScript,
+        `${posType} requires NO redeemScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessValue,
+        `${posType} requires NO witnessValue`,
+      );
+      break;
+    case 'p2sh-p2wpkh':
+      if (prevOutType && prevOutType !== 'scripthash') {
+        throw new TypeError(
+          `input #${signParams.vin} is not of type p2sh-p2wpkh: ${prevOutType}`,
+        );
+      }
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessScript,
+        `${posType} requires NO witnessScript`,
+      );
+      tfMessage(
+        typeforce.Buffer,
+        signParams.redeemScript,
+        `${posType} requires redeemScript`,
+      );
+      tfMessage(
+        types.Satoshi,
+        signParams.witnessValue,
+        `${posType} requires witnessValue`,
+      );
+      break;
+    case 'p2sh-p2ms':
+    case 'p2sh-p2pk':
+    case 'p2sh-p2pkh':
+      if (prevOutType && prevOutType !== 'scripthash') {
+        throw new TypeError(
+          `input #${signParams.vin} is not of type ${posType}: ${prevOutType}`,
+        );
+      }
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessScript,
+        `${posType} requires NO witnessScript`,
+      );
+      tfMessage(
+        typeforce.Buffer,
+        signParams.redeemScript,
+        `${posType} requires redeemScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessValue,
+        `${posType} requires NO witnessValue`,
+      );
+      break;
+    case 'p2wsh-p2ms':
+    case 'p2wsh-p2pk':
+    case 'p2wsh-p2pkh':
+      if (prevOutType && prevOutType !== 'witnessscripthash') {
+        throw new TypeError(
+          `input #${signParams.vin} is not of type ${posType}: ${prevOutType}`,
+        );
+      }
+      tfMessage(
+        typeforce.Buffer,
+        signParams.witnessScript,
+        `${posType} requires witnessScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.redeemScript,
+        `${posType} requires NO redeemScript`,
+      );
+      tfMessage(
+        types.Satoshi,
+        signParams.witnessValue,
+        `${posType} requires witnessValue`,
+      );
+      break;
+    case 'p2sh-p2wsh-p2ms':
+    case 'p2sh-p2wsh-p2pk':
+    case 'p2sh-p2wsh-p2pkh':
+      if (prevOutType && prevOutType !== 'scripthash') {
+        throw new TypeError(
+          `input #${signParams.vin} is not of type ${posType}: ${prevOutType}`,
+        );
+      }
+      tfMessage(
+        typeforce.Buffer,
+        signParams.witnessScript,
+        `${posType} requires witnessScript`,
+      );
+      tfMessage(
+        typeforce.Buffer,
+        signParams.redeemScript,
+        `${posType} requires witnessScript`,
+      );
+      tfMessage(
+        types.Satoshi,
+        signParams.witnessValue,
+        `${posType} requires witnessScript`,
+      );
+      break;
+  }
+}
+function trySign({
+  input,
+  ourPubKey,
+  keyPair,
+  signatureHash,
+  hashType,
+  useLowR,
+}) {
+  // enforce in order signing of public keys
+  let signed = false;
+  for (const [i, pubKey] of input.pubkeys.entries()) {
+    if (!ourPubKey.equals(pubKey)) continue;
+    if (input.signatures[i]) throw new Error('Signature already exists');
+    // TODO: add tests
+    if (ourPubKey.length !== 33 && input.hasWitness) {
+      throw new Error(
+        'BIP143 rejects uncompressed public keys in P2WPKH or P2WSH',
+      );
+    }
+    const signature = keyPair.sign(signatureHash, useLowR);
+    input.signatures[i] = bscript.signature.encode(signature, hashType);
+    signed = true;
+  }
+  if (!signed) throw new Error('Key pair cannot sign for this input');
+}
+function getSigningData(
+  network,
+  inputs,
+  needsOutputs,
+  tx,
+  signParams,
+  keyPair,
+  redeemScript,
+  hashType,
+  witnessValue,
+  witnessScript,
+  useLowR,
+) {
+  let vin;
+  if (typeof signParams === 'number') {
+    console.warn(
+      'DEPRECATED: TransactionBuilder sign method arguments ' +
+        'will change in v6, please use the TxbSignArg interface',
+    );
+    vin = signParams;
+  } else if (typeof signParams === 'object') {
+    checkSignArgs(inputs, signParams);
+    ({
+      vin,
+      keyPair,
+      redeemScript,
+      hashType,
+      witnessValue,
+      witnessScript,
+    } = signParams);
+  } else {
+    throw new TypeError(
+      'TransactionBuilder sign first arg must be TxbSignArg or number',
+    );
+  }
+  if (keyPair === undefined) {
+    throw new Error('sign requires keypair');
+  }
+  // TODO: remove keyPair.network matching in 4.0.0
+  if (keyPair.network && keyPair.network !== network)
+    throw new TypeError('Inconsistent network');
+  if (!inputs[vin]) throw new Error('No input at index: ' + vin);
+  hashType = hashType || transaction_1.Transaction.SIGHASH_ALL;
+  if (needsOutputs(hashType)) throw new Error('Transaction needs outputs');
+  const input = inputs[vin];
+  // if redeemScript was previously provided, enforce consistency
+  if (
+    input.redeemScript !== undefined &&
+    redeemScript &&
+    !input.redeemScript.equals(redeemScript)
+  ) {
+    throw new Error('Inconsistent redeemScript');
+  }
+  const ourPubKey =
+    keyPair.publicKey || (keyPair.getPublicKey && keyPair.getPublicKey());
+  if (!canSign(input)) {
+    if (witnessValue !== undefined) {
+      if (input.value !== undefined && input.value !== witnessValue)
+        throw new Error('Input did not match witnessValue');
+      typeforce(types.Satoshi, witnessValue);
+      input.value = witnessValue;
+    }
+    if (!canSign(input)) {
+      const prepared = prepareInput(
+        input,
+        ourPubKey,
+        redeemScript,
+        witnessScript,
+      );
+      // updates inline
+      Object.assign(input, prepared);
+    }
+    if (!canSign(input)) throw Error(input.prevOutType + ' not supported');
+  }
+  // ready to sign
+  let signatureHash;
+  if (input.hasWitness) {
+    signatureHash = tx.hashForWitnessV0(
+      vin,
+      input.signScript,
+      input.value,
+      hashType,
+    );
+  } else {
+    signatureHash = tx.hashForSignature(vin, input.signScript, hashType);
+  }
+  return {
+    input,
+    ourPubKey,
+    keyPair,
+    signatureHash,
+    hashType,
+    useLowR: !!useLowR,
+  };
+}

src/types.js

@@ -13,6 +13,14 @@ exports.BIP32Path = BIP32Path;
 BIP32Path.toJSON = () => {
   return 'BIP32 derivation path';
 };
+function Signer(obj) {
+  return (
+    (typeforce.Buffer(obj.publicKey) ||
+      typeof obj.getPublicKey === 'function') &&
+    typeof obj.sign === 'function'
+  );
+}
+exports.Signer = Signer;
 const SATOSHI_MAX = 21 * 1e14;
 function Satoshi(value) {
   return typeforce.UInt53(value) && value <= SATOSHI_MAX;

test/integration/_regtest.js

@@ -92,7 +92,11 @@ async function faucetComplex (output, value) {
   const txvb = new bitcoin.TransactionBuilder(NETWORK)
   txvb.addInput(unspent.txId, unspent.vout, null, p2pkh.output)
   txvb.addOutput(output, value)
-  txvb.sign(0, keyPair)
+  txvb.sign({
+    prevOutScriptType: 'p2pkh',
+    vin: 0,
+    keyPair
+  })
   const txv = txvb.build()
 
   await broadcast(txv.toHex())

test/integration/payments.js

@@ -15,12 +15,29 @@ async function buildAndSign (depends, prevOutput, redeemScript, witnessScript) {
   txb.addInput(unspent.txId, unspent.vout, null, prevOutput)
   txb.addOutput(regtestUtils.RANDOM_ADDRESS, 2e4)
 
+  const posType = depends.prevOutScriptType
+  const needsValue = !!witnessScript || posType.slice(-6) === 'p2wpkh'
+
   if (depends.signatures) {
     keyPairs.forEach(keyPair => {
-      txb.sign(0, keyPair, redeemScript, null, unspent.value, witnessScript)
+      txb.sign({
+        prevOutScriptType: posType,
+        vin: 0,
+        keyPair,
+        redeemScript,
+        witnessValue: needsValue ? unspent.value : undefined,
+        witnessScript,
+      })
     })
   } else if (depends.signature) {
-    txb.sign(0, keyPairs[0], redeemScript, null, unspent.value, witnessScript)
+    txb.sign({
+      prevOutScriptType: posType,
+      vin: 0,
+      keyPair: keyPairs[0],
+      redeemScript,
+      witnessValue: needsValue ? unspent.value : undefined,
+      witnessScript,
+    })
   }
 
   return regtestUtils.broadcast(txb.build().toHex())
@@ -41,12 +58,14 @@ async function buildAndSign (depends, prevOutput, redeemScript, witnessScript) {
 
   describe('bitcoinjs-lib (payments - ' + k + ')', () => {
     it('can broadcast as an output, and be spent as an input', async () => {
-      await buildAndSign(depends, output, null, null)
+      Object.assign(depends, { prevOutScriptType: k })
+      await buildAndSign(depends, output, undefined, undefined)
     })
 
     it('can (as P2SH(' + k + ')) broadcast as an output, and be spent as an input', async () => {
       const p2sh = bitcoin.payments.p2sh({ redeem: { output }, network: NETWORK })
-      await buildAndSign(depends, p2sh.output, p2sh.redeem.output, null)
+      Object.assign(depends, { prevOutScriptType: 'p2sh-' + k })
+      await buildAndSign(depends, p2sh.output, p2sh.redeem.output, undefined)
     })
 
     // NOTE: P2WPKH cannot be wrapped in P2WSH, consensus fail
@@ -54,13 +73,15 @@ async function buildAndSign (depends, prevOutput, redeemScript, witnessScript) {
 
     it('can (as P2WSH(' + k + ')) broadcast as an output, and be spent as an input', async () => {
       const p2wsh = bitcoin.payments.p2wsh({ redeem: { output }, network: NETWORK })
-      await buildAndSign(depends, p2wsh.output, null, p2wsh.redeem.output)
+      Object.assign(depends, { prevOutScriptType: 'p2wsh-' + k })
+      await buildAndSign(depends, p2wsh.output, undefined, p2wsh.redeem.output)
     })
 
     it('can (as P2SH(P2WSH(' + k + '))) broadcast as an output, and be spent as an input', async () => {
       const p2wsh = bitcoin.payments.p2wsh({ redeem: { output }, network: NETWORK })
       const p2sh = bitcoin.payments.p2sh({ redeem: { output: p2wsh.output }, network: NETWORK })
 
+      Object.assign(depends, { prevOutScriptType: 'p2sh-p2wsh-' + k })
       await buildAndSign(depends, p2sh.output, p2sh.redeem.output, p2wsh.redeem.output)
     })
   })

test/integration/transactions.js

@@ -18,7 +18,11 @@ describe('bitcoinjs-lib (transactions)', () => {
     txb.addOutput('1cMh228HTCiwS8ZsaakH8A8wze1JR5ZsP', 12000)
     // (in)15000 - (out)12000 = (fee)3000, this is the miner fee
 
-    txb.sign(0, alice)
+    txb.sign({
+      prevOutScriptType: 'p2pkh',
+      vin: 0,
+      keyPair: alice
+    })
 
     // prepare for broadcast to the Bitcoin network, see "can broadcast a Transaction" below
     assert.strictEqual(txb.build().toHex(), '01000000019d344070eac3fe6e394a16d06d7704a7d5c0a10eb2a2c16bc98842b7cc20d561000000006b48304502210088828c0bdfcdca68d8ae0caeb6ec62cd3fd5f9b2191848edae33feb533df35d302202e0beadd35e17e7f83a733f5277028a9b453d525553e3f5d2d7a7aa8010a81d60121029f50f51d63b345039a290c94bffd3180c99ed659ff6ea6b1242bca47eb93b59fffffffff01e02e0000000000001976a91406afd46bcdfd22ef94ac122aa11f241244a37ecc88ac00000000')
@@ -36,8 +40,16 @@ describe('bitcoinjs-lib (transactions)', () => {
     txb.addOutput('1JtK9CQw1syfWj1WtFMWomrYdV3W2tWBF9', 170000)
     // (in)(200000 + 300000) - (out)(180000 + 170000) = (fee)150000, this is the miner fee
 
-    txb.sign(1, bob) // Bob signs his input, which was the second input (1th)
+    txb.sign({
-    txb.sign(0, alice) // Alice signs her input, which was the first input (0th)
+      prevOutScriptType: 'p2pkh',
+      vin: 1,
+      keyPair: bob
+    }) // Bob signs his input, which was the second input (1th)
+    txb.sign({
+      prevOutScriptType: 'p2pkh',
+      vin: 0,
+      keyPair: alice
+    }) // Alice signs her input, which was the first input (0th)
 
     // prepare for broadcast to the Bitcoin network, see "can broadcast a Transaction" below
     assert.strictEqual(txb.build().toHex(), '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')
@@ -65,8 +77,16 @@ describe('bitcoinjs-lib (transactions)', () => {
     // (in)(5e4 + 7e4) - (out)(8e4 + 1e4) = (fee)3e4 = 30000, this is the miner fee
 
     // Alice signs each input with the respective private keys
-    txb.sign(0, alice1)
+    txb.sign({
-    txb.sign(1, alice2)
+      prevOutScriptType: 'p2pkh',
+      vin: 0,
+      keyPair: alice1
+    })
+    txb.sign({
+      prevOutScriptType: 'p2pkh',
+      vin: 1,
+      keyPair: alice2
+    })
 
     // build and broadcast our RegTest network
     await regtestUtils.broadcast(txb.build().toHex())
@@ -85,7 +105,11 @@ describe('bitcoinjs-lib (transactions)', () => {
     txb.addInput(unspent.txId, unspent.vout)
     txb.addOutput(embed.output, 1000)
     txb.addOutput(regtestUtils.RANDOM_ADDRESS, 1e5)
-    txb.sign(0, keyPair)
+    txb.sign({
+      prevOutScriptType: 'p2pkh',
+      vin: 0,
+      keyPair,
+    })
 
     // build and broadcast to the RegTest network
     await regtestUtils.broadcast(txb.build().toHex())
@@ -108,8 +132,18 @@ describe('bitcoinjs-lib (transactions)', () => {
     txb.addInput(unspent.txId, unspent.vout)
     txb.addOutput(regtestUtils.RANDOM_ADDRESS, 1e4)
 
-    txb.sign(0, keyPairs[0], p2sh.redeem.output)
+    txb.sign({
-    txb.sign(0, keyPairs[2], p2sh.redeem.output)
+      prevOutScriptType: 'p2sh-p2ms',
+      vin: 0,
+      keyPair: keyPairs[0],
+      redeemScript: p2sh.redeem.output,
+    })
+    txb.sign({
+      prevOutScriptType: 'p2sh-p2ms',
+      vin: 0,
+      keyPair: keyPairs[2],
+      redeemScript: p2sh.redeem.output,
+    })
     const tx = txb.build()
 
     // build and broadcast to the Bitcoin RegTest network
@@ -133,7 +167,13 @@ describe('bitcoinjs-lib (transactions)', () => {
     const txb = new bitcoin.TransactionBuilder(regtest)
     txb.addInput(unspent.txId, unspent.vout)
     txb.addOutput(regtestUtils.RANDOM_ADDRESS, 2e4)
-    txb.sign(0, keyPair, p2sh.redeem.output, null, unspent.value)
+    txb.sign({
+      prevOutScriptType: 'p2sh-p2wpkh',
+      vin: 0,
+      keyPair: keyPair,
+      redeemScript: p2sh.redeem.output,
+      witnessValue: unspent.value,
+    })
 
     const tx = txb.build()
 
@@ -158,7 +198,12 @@ describe('bitcoinjs-lib (transactions)', () => {
     const txb = new bitcoin.TransactionBuilder(regtest)
     txb.addInput(unspent.txId, unspent.vout, null, p2wpkh.output) // NOTE: provide the prevOutScript!
     txb.addOutput(regtestUtils.RANDOM_ADDRESS, 2e4)
-    txb.sign(0, keyPair, null, null, unspent.value) // NOTE: no redeem script
+    txb.sign({
+      prevOutScriptType: 'p2wpkh',
+      vin: 0,
+      keyPair: keyPair,
+      witnessValue: unspent.value,
+    }) // NOTE: no redeem script
     const tx = txb.build()
 
     // build and broadcast (the P2WPKH transaction) to the Bitcoin RegTest network
@@ -183,7 +228,13 @@ describe('bitcoinjs-lib (transactions)', () => {
     const txb = new bitcoin.TransactionBuilder(regtest)
     txb.addInput(unspent.txId, unspent.vout, null, p2wsh.output) // NOTE: provide the prevOutScript!
     txb.addOutput(regtestUtils.RANDOM_ADDRESS, 2e4)
-    txb.sign(0, keyPair, null, null, 5e4, p2wsh.redeem.output) // NOTE: provide a witnessScript!
+    txb.sign({
+      prevOutScriptType: 'p2wsh-p2pk',
+      vin: 0,
+      keyPair: keyPair,
+      witnessValue: 5e4,
+      witnessScript: p2wsh.redeem.output,
+    }) // NOTE: provide a witnessScript!
     const tx = txb.build()
 
     // build and broadcast (the P2WSH transaction) to the Bitcoin RegTest network
@@ -215,9 +266,30 @@ describe('bitcoinjs-lib (transactions)', () => {
     const txb = new bitcoin.TransactionBuilder(regtest)
     txb.addInput(unspent.txId, unspent.vout, null, p2sh.output)
     txb.addOutput(regtestUtils.RANDOM_ADDRESS, 3e4)
-    txb.sign(0, keyPairs[0], p2sh.redeem.output, null, unspent.value, p2wsh.redeem.output)
+    txb.sign({
-    txb.sign(0, keyPairs[2], p2sh.redeem.output, null, unspent.value, p2wsh.redeem.output)
+      prevOutScriptType: 'p2sh-p2wsh-p2ms',
-    txb.sign(0, keyPairs[3], p2sh.redeem.output, null, unspent.value, p2wsh.redeem.output)
+      vin: 0,
+      keyPair: keyPairs[0],
+      redeemScript: p2sh.redeem.output,
+      witnessValue: unspent.value,
+      witnessScript: p2wsh.redeem.output,
+    })
+    txb.sign({
+      prevOutScriptType: 'p2sh-p2wsh-p2ms',
+      vin: 0,
+      keyPair: keyPairs[2],
+      redeemScript: p2sh.redeem.output,
+      witnessValue: unspent.value,
+      witnessScript: p2wsh.redeem.output,
+    })
+    txb.sign({
+      prevOutScriptType: 'p2sh-p2wsh-p2ms',
+      vin: 0,
+      keyPair: keyPairs[3],
+      redeemScript: p2sh.redeem.output,
+      witnessValue: unspent.value,
+      witnessScript: p2wsh.redeem.output,
+    })
 
     const tx = txb.build()
 

test/transaction_builder.js

@@ -11,7 +11,7 @@ const NETWORKS = require('../src/networks')
 
 const fixtures = require('./fixtures/transaction_builder')
 
-function constructSign (f, txb) {
+function constructSign (f, txb, useOldSignArgs) {
   const network = NETWORKS[f.network]
   const stages = f.stages && f.stages.concat()
 
@@ -21,21 +21,36 @@ function constructSign (f, txb) {
       const keyPair = ECPair.fromWIF(sign.keyPair, network)
       let redeemScript
       let witnessScript
-      let value
+      let witnessValue
 
       if (sign.redeemScript) {
         redeemScript = bscript.fromASM(sign.redeemScript)
       }
 
       if (sign.value) {
-        value = sign.value
+        witnessValue = sign.value
       }
 
       if (sign.witnessScript) {
         witnessScript = bscript.fromASM(sign.witnessScript)
       }
 
-      txb.sign(index, keyPair, redeemScript, sign.hashType, value, witnessScript)
+      if (useOldSignArgs) {
+        // DEPRECATED: v6 will remove this interface
+        txb.sign(index, keyPair, redeemScript, sign.hashType, witnessValue, witnessScript)
+      } else {
+        // prevOutScriptType is required, see /ts_src/transaction_builder.ts
+        // The PREVOUT_TYPES constant is a Set with all possible values.
+        txb.sign({
+          prevOutScriptType: sign.prevOutScriptType,
+          vin: index,
+          keyPair,
+          redeemScript,
+          hashType: sign.hashType,
+          witnessValue,
+          witnessScript,
+        })
+      }
 
       if (sign.stage) {
         const tx = txb.buildIncomplete()
@@ -48,7 +63,7 @@ function constructSign (f, txb) {
   return txb
 }
 
-function construct (f, dontSign) {
+function construct (f, dontSign, useOldSignArgs) {
   const network = NETWORKS[f.network]
   const txb = new TransactionBuilder(network)
 
@@ -84,10 +99,20 @@ function construct (f, dontSign) {
   })
 
   if (dontSign) return txb
-  return constructSign(f, txb)
+  return constructSign(f, txb, useOldSignArgs)
 }
 
-describe('TransactionBuilder', () => {
+// TODO: Remove loop in v6
+for (const useOldSignArgs of [ false, true ]) {
+  // Search for "useOldSignArgs"
+  // to find the second part of this console.warn replace
+  let consoleWarn;
+  if (useOldSignArgs) {
+    consoleWarn = console.warn;
+    // Silence console.warn during these tests
+    console.warn = () => undefined;
+  }
+  describe(`TransactionBuilder: useOldSignArgs === ${useOldSignArgs}`, () => {
     // constants
     const keyPair = ECPair.fromPrivateKey(Buffer.from('0000000000000000000000000000000000000000000000000000000000000001', 'hex'))
     const scripts = [
@@ -149,7 +174,7 @@ describe('TransactionBuilder', () => {
             assert.strictEqual(bscript.toASM(input.script), f.inputs[i].scriptSig)
           })
 
-        constructSign(f, txb)
+          constructSign(f, txb, useOldSignArgs)
           const txAfter = f.incomplete ? txb.buildIncomplete() : txb.build()
 
           txAfter.ins.forEach((input, i) => {
@@ -232,7 +257,11 @@ describe('TransactionBuilder', () => {
       it('throws if SIGHASH_ALL has been used to sign any existing scriptSigs', () => {
         txb.addInput(txHash, 0)
         txb.addOutput(scripts[0], 1000)
-      txb.sign(0, keyPair)
+        txb.sign({
+          prevOutScriptType: 'p2pkh',
+          vin: 0,
+          keyPair,
+        })
 
         assert.throws(() => {
           txb.addInput(txHash, 0)
@@ -274,26 +303,46 @@ describe('TransactionBuilder', () => {
       it('add second output after signed first input with SIGHASH_NONE', () => {
         txb.addInput(txHash, 0)
         txb.addOutput(scripts[0], 2000)
-      txb.sign(0, keyPair, undefined, Transaction.SIGHASH_NONE)
+        txb.sign({
+          prevOutScriptType: 'p2pkh',
+          vin: 0,
+          keyPair,
+          hashType: Transaction.SIGHASH_NONE,
+        })
         assert.strictEqual(txb.addOutput(scripts[1], 9000), 1)
       })
 
       it('add first output after signed first input with SIGHASH_NONE', () => {
         txb.addInput(txHash, 0)
-      txb.sign(0, keyPair, undefined, Transaction.SIGHASH_NONE)
+        txb.sign({
+          prevOutScriptType: 'p2pkh',
+          vin: 0,
+          keyPair,
+          hashType: Transaction.SIGHASH_NONE,
+        })
         assert.strictEqual(txb.addOutput(scripts[0], 2000), 0)
       })
 
       it('add second output after signed first input with SIGHASH_SINGLE', () => {
         txb.addInput(txHash, 0)
         txb.addOutput(scripts[0], 2000)
-      txb.sign(0, keyPair, undefined, Transaction.SIGHASH_SINGLE)
+        txb.sign({
+          prevOutScriptType: 'p2pkh',
+          vin: 0,
+          keyPair,
+          hashType: Transaction.SIGHASH_SINGLE,
+        })
         assert.strictEqual(txb.addOutput(scripts[1], 9000), 1)
       })
 
       it('add first output after signed first input with SIGHASH_SINGLE', () => {
         txb.addInput(txHash, 0)
-      txb.sign(0, keyPair, undefined, Transaction.SIGHASH_SINGLE)
+        txb.sign({
+          prevOutScriptType: 'p2pkh',
+          vin: 0,
+          keyPair,
+          hashType: Transaction.SIGHASH_SINGLE,
+        })
         assert.throws(() => {
           txb.addOutput(scripts[0], 2000)
         }, /No, this would invalidate signatures/)
@@ -302,7 +351,11 @@ describe('TransactionBuilder', () => {
       it('throws if SIGHASH_ALL has been used to sign any existing scriptSigs', () => {
         txb.addInput(txHash, 0)
         txb.addOutput(scripts[0], 2000)
-      txb.sign(0, keyPair)
+        txb.sign({
+          prevOutScriptType: 'p2pkh',
+          vin: 0,
+          keyPair,
+        })
 
         assert.throws(() => {
           txb.addOutput(scripts[1], 9000)
@@ -315,7 +368,11 @@ describe('TransactionBuilder', () => {
         const txb = new TransactionBuilder()
         txb.addInput(txHash, 0)
         txb.addOutput(scripts[0], 100)
-      txb.sign(0, keyPair)
+        txb.sign({
+          prevOutScriptType: 'p2pkh',
+          vin: 0,
+          keyPair,
+        })
 
         assert.throws(() => {
           txb.setLockTime(65535)
@@ -334,7 +391,11 @@ describe('TransactionBuilder', () => {
         txb.setVersion(1)
         txb.addInput('ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff', 1)
         txb.addOutput('1111111111111111111114oLvT2', 100000)
-      txb.sign(0, keyPair)
+        txb.sign({
+          prevOutScriptType: 'p2pkh',
+          vin: 0,
+          keyPair,
+        })
         assert.strictEqual(txb.build().toHex(), '0100000001ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff010000006a47304402205f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f02205f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f5f0121031b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078fffffffff01a0860100000000001976a914000000000000000000000000000000000000000088ac00000000')
       })
 
@@ -343,7 +404,11 @@ describe('TransactionBuilder', () => {
         txb.setVersion(1)
         txb.addInput('ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff', 1)
         txb.addOutput('1111111111111111111114oLvT2', 100000)
-      txb.sign(0, keyPair)
+        txb.sign({
+          prevOutScriptType: 'p2pkh',
+          vin: 0,
+          keyPair,
+        })
         // high R
         assert.strictEqual(txb.build().toHex(), '0100000001ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff010000006b483045022100b872677f35c9c14ad9c41d83649fb049250f32574e0b2547d67e209ed14ff05d022059b36ad058be54e887a1a311d5c393cb4941f6b93a0b090845ec67094de8972b01210279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798ffffffff01a0860100000000001976a914000000000000000000000000000000000000000088ac00000000')
 
@@ -352,11 +417,58 @@ describe('TransactionBuilder', () => {
         txb.addInput('ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff', 1)
         txb.addOutput('1111111111111111111114oLvT2', 100000)
         txb.setLowR()
-      txb.sign(0, keyPair)
+        txb.sign({
+          prevOutScriptType: 'p2pkh',
+          vin: 0,
+          keyPair,
+        })
         // low R
         assert.strictEqual(txb.build().toHex(), '0100000001ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff010000006a473044022012a601efa8756ebe83e9ac7a7db061c3147e3b49d8be67685799fe51a4c8c62f02204d568d301d5ce14af390d566d4fd50e7b8ee48e71ec67786c029e721194dae3601210279be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798ffffffff01a0860100000000001976a914000000000000000000000000000000000000000088ac00000000')
       })
 
+      it('fails when missing required arguments', () => {
+        let txb = new TransactionBuilder()
+        txb.setVersion(1)
+        txb.addInput('ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff', 1)
+        txb.addOutput('1111111111111111111114oLvT2', 100000)
+        assert.throws(() => {
+          txb.sign()
+        }, /TransactionBuilder sign first arg must be TxbSignArg or number/)
+        assert.throws(() => {
+          txb.sign({
+            prevOutScriptType: 'p2pkh',
+            vin: 1,
+            keyPair,
+          })
+        }, /No input at index: 1/)
+        assert.throws(() => {
+          txb.sign({
+            prevOutScriptType: 'p2pkh',
+            keyPair,
+          })
+        }, /sign must include vin parameter as Number \(input index\)/)
+        assert.throws(() => {
+          txb.sign({
+            prevOutScriptType: 'p2pkh',
+            vin: 0,
+            keyPair: {},
+          })
+        }, /sign must include keyPair parameter as Signer interface/)
+        assert.throws(() => {
+          txb.sign({
+            prevOutScriptType: 'p2pkh',
+            vin: 0,
+            keyPair,
+            hashType: 'string',
+          })
+        }, /sign hashType parameter must be a number/)
+        if (useOldSignArgs) {
+          assert.throws(() => {
+            txb.sign(0)
+          }, /sign requires keypair/)
+        }
+      })
+
       fixtures.invalid.sign.forEach(f => {
         it('throws ' + f.exception + (f.description ? ' (' + f.description + ')' : ''), () => {
           const txb = construct(f, true)
@@ -379,11 +491,27 @@ describe('TransactionBuilder', () => {
 
               if (sign.throws) {
                 assert.throws(() => {
-                txb.sign(index, keyPair2, redeemScript, sign.hashType, sign.value, witnessScript)
+                  txb.sign({
+                    prevOutScriptType: sign.prevOutScriptType,
+                    vin: index,
+                    keyPair: keyPair2,
+                    redeemScript,
+                    hashType: sign.hashType,
+                    witnessValue: sign.value,
+                    witnessScript,
+                  })
                 }, new RegExp(f.exception))
                 threw = true
               } else {
-              txb.sign(index, keyPair2, redeemScript, sign.hashType, sign.value, witnessScript)
+                txb.sign({
+                  prevOutScriptType: sign.prevOutScriptType,
+                  vin: index,
+                  keyPair: keyPair2,
+                  redeemScript,
+                  hashType: sign.hashType,
+                  witnessValue: sign.value,
+                  witnessScript,
+                })
               }
             })
           })
@@ -396,7 +524,7 @@ describe('TransactionBuilder', () => {
     describe('build', () => {
       fixtures.valid.build.forEach(f => {
         it('builds "' + f.description + '"', () => {
-        const txb = construct(f)
+          const txb = construct(f, undefined, useOldSignArgs)
           const tx = f.incomplete ? txb.buildIncomplete() : txb.build()
 
           assert.strictEqual(tx.toHex(), f.txHex)
@@ -412,7 +540,7 @@ describe('TransactionBuilder', () => {
               if (f.txHex) {
                 txb = TransactionBuilder.fromTransaction(Transaction.fromHex(f.txHex))
               } else {
-              txb = construct(f)
+                txb = construct(f, undefined, useOldSignArgs)
               }
 
               txb.build()
@@ -427,7 +555,7 @@ describe('TransactionBuilder', () => {
                 if (f.txHex) {
                   txb = TransactionBuilder.fromTransaction(Transaction.fromHex(f.txHex))
                 } else {
-                txb = construct(f)
+                  txb = construct(f, undefined, useOldSignArgs)
                 }
 
                 txb.buildIncomplete()
@@ -439,7 +567,7 @@ describe('TransactionBuilder', () => {
               if (f.txHex) {
                 txb = TransactionBuilder.fromTransaction(Transaction.fromHex(f.txHex))
               } else {
-              txb = construct(f)
+                txb = construct(f, undefined, useOldSignArgs)
               }
 
               txb.buildIncomplete()
@@ -516,7 +644,13 @@ describe('TransactionBuilder', () => {
               }
 
               const keyPair2 = ECPair.fromWIF(sign.keyPair, network)
-            txb.sign(i, keyPair2, redeemScript, sign.hashType)
+              txb.sign({
+                prevOutScriptType: sign.prevOutScriptType,
+                vin: i,
+                keyPair: keyPair2,
+                redeemScript,
+                hashType: sign.hashType,
+              })
 
               // update the tx
               tx = txb.buildIncomplete()
@@ -571,7 +705,14 @@ describe('TransactionBuilder', () => {
         txb.setVersion(1)
         txb.addInput('a4696c4b0cd27ec2e173ab1fa7d1cc639a98ee237cec95a77ca7ff4145791529', 1, 0xffffffff, scriptPubKey)
         txb.addOutput(scriptPubKey, 99000)
-      txb.sign(0, keyPair, redeemScript, null, 100000, witnessScript)
+        txb.sign({
+          prevOutScriptType: 'p2sh-p2wsh-p2ms',
+          vin: 0,
+          keyPair,
+          redeemScript,
+          witnessValue: 100000,
+          witnessScript,
+        })
 
         // 2-of-2 signed only once
         const tx = txb.buildIncomplete()
@@ -596,7 +737,12 @@ describe('TransactionBuilder', () => {
         const txb = TransactionBuilder.fromTransaction(tx, NETWORKS.testnet)
 
         const keyPair2 = ECPair.fromWIF('91avARGdfge8E4tZfYLoxeJ5sGBdNJQH4kvjJoQFacbgx3cTMqe', network)
-      txb.sign(0, keyPair2, redeemScript)
+        txb.sign({
+          prevOutScriptType: 'p2sh-p2ms',
+          vin: 0,
+          keyPair: keyPair2,
+          redeemScript,
+        })
 
         const tx2 = txb.build()
         assert.strictEqual(tx2.getId(), 'eab59618a564e361adef6d918bd792903c3d41bcf1220137364fb847880467f9')
@@ -613,16 +759,29 @@ describe('TransactionBuilder', () => {
 
         // sign, as expected
         txb.addOutput('1Gokm82v6DmtwKEB8AiVhm82hyFSsEvBDK', 15000)
-      txb.sign(0, keyPair)
+        txb.sign({
+          prevOutScriptType: 'p2pkh',
+          vin: 0,
+          keyPair,
+        })
         const txId = txb.build().getId()
         assert.strictEqual(txId, '54f097315acbaedb92a95455da3368eb45981cdae5ffbc387a9afc872c0f29b3')
 
         // and, repeat
         txb = TransactionBuilder.fromTransaction(Transaction.fromHex(incomplete))
         txb.addOutput('1Gokm82v6DmtwKEB8AiVhm82hyFSsEvBDK', 15000)
-      txb.sign(0, keyPair)
+        txb.sign({
+          prevOutScriptType: 'p2pkh',
+          vin: 0,
+          keyPair,
+        })
         const txId2 = txb.build().getId()
         assert.strictEqual(txId, txId2)
+        // TODO: Remove me in v6
+        if (useOldSignArgs) {
+          console.warn = consoleWarn;
+        }
       })
     })
   })
+}

ts_src/ecpair.ts

@@ -19,15 +19,26 @@ interface ECPairOptions {
   rng?(arg0: number): Buffer;
 }
 
-export interface ECPairInterface {
+export interface Signer {
+  publicKey: Buffer;
+  network?: Network;
+  sign(hash: Buffer, lowR?: boolean): Buffer;
+  getPublicKey?(): Buffer;
+}
+
+export interface SignerAsync {
+  publicKey: Buffer;
+  network?: Network;
+  sign(hash: Buffer, lowR?: boolean): Promise<Buffer>;
+  getPublicKey?(): Buffer;
+}
+
+export interface ECPairInterface extends Signer {
   compressed: boolean;
   network: Network;
-  publicKey: Buffer;
   privateKey?: Buffer;
   toWIF(): string;
-  sign(hash: Buffer, lowR?: boolean): Buffer;
   verify(hash: Buffer, signature: Buffer): boolean;
-  getPublicKey?(): Buffer;
 }
 
 class ECPair implements ECPairInterface {

ts_src/index.ts

@@ -14,7 +14,7 @@ export { Transaction } from './transaction';
 export { TransactionBuilder } from './transaction_builder';
 
 export { BIP32Interface } from 'bip32';
-export { ECPairInterface } from './ecpair';
+export { ECPairInterface, Signer, SignerAsync } from './ecpair';
 export { Network } from './networks';
 export { Payment, PaymentOpts, Stack, StackElement } from './payments';
 export { OpCode } from './script';

ts_src/transaction_builder.ts

@@ -2,7 +2,7 @@ import * as baddress from './address';
 import { reverseBuffer } from './bufferutils';
 import * as classify from './classify';
 import * as bcrypto from './crypto';
-import { ECPairInterface } from './ecpair';
+import { Signer } from './ecpair';
 import * as ECPair from './ecpair';
 import { Network } from './networks';
 import * as networks from './networks';
@@ -16,6 +16,27 @@ const typeforce = require('typeforce');
 
 const SCRIPT_TYPES = classify.types;
 
+const PREVOUT_TYPES: Set<string> = new Set([
+  // Raw
+  'p2pkh',
+  'p2pk',
+  'p2wpkh',
+  'p2ms',
+  // P2SH wrapped
+  'p2sh-p2pkh',
+  'p2sh-p2pk',
+  'p2sh-p2wpkh',
+  'p2sh-p2ms',
+  // P2WSH wrapped
+  'p2wsh-p2pkh',
+  'p2wsh-p2pk',
+  'p2wsh-p2ms',
+  // P2SH-P2WSH wrapper
+  'p2sh-p2wsh-p2pkh',
+  'p2sh-p2wsh-p2pk',
+  'p2sh-p2wsh-p2ms',
+]);
+
 type MaybeBuffer = Buffer | undefined;
 type TxbSignatures = Buffer[] | MaybeBuffer[];
 type TxbPubkeys = MaybeBuffer[];
@@ -50,6 +71,24 @@ interface TxbOutput {
   maxSignatures?: number;
 }
 
+interface TxbSignArg {
+  prevOutScriptType: string;
+  vin: number;
+  keyPair: Signer;
+  redeemScript?: Buffer;
+  hashType?: number;
+  witnessValue?: number;
+  witnessScript?: Buffer;
+}
+
+function tfMessage(type: any, value: any, message: string): void {
+  try {
+    typeforce(type, value);
+  } catch (err) {
+    throw new Error(message);
+  }
+}
+
 function txIsString(tx: Buffer | string | Transaction): tx is string {
   return typeof tx === 'string' || tx instanceof String;
 }
@@ -197,92 +236,28 @@ export class TransactionBuilder {
   }
 
   sign(
-    vin: number,
+    signParams: number | TxbSignArg,
-    keyPair: ECPairInterface,
+    keyPair?: Signer,
     redeemScript?: Buffer,
     hashType?: number,
     witnessValue?: number,
     witnessScript?: Buffer,
   ): void {
-    // TODO: remove keyPair.network matching in 4.0.0
+    trySign(
-    if (keyPair.network && keyPair.network !== this.network)
+      getSigningData(
-      throw new TypeError('Inconsistent network');
+        this.network,
-    if (!this.__INPUTS[vin]) throw new Error('No input at index: ' + vin);
+        this.__INPUTS,
-
+        this.__needsOutputs.bind(this),
-    hashType = hashType || Transaction.SIGHASH_ALL;
+        this.__TX,
-    if (this.__needsOutputs(hashType))
+        signParams,
-      throw new Error('Transaction needs outputs');
+        keyPair,
-
-    const input = this.__INPUTS[vin];
-
-    // if redeemScript was previously provided, enforce consistency
-    if (
-      input.redeemScript !== undefined &&
-      redeemScript &&
-      !input.redeemScript.equals(redeemScript)
-    ) {
-      throw new Error('Inconsistent redeemScript');
-    }
-
-    const ourPubKey = keyPair.publicKey || keyPair.getPublicKey!();
-    if (!canSign(input)) {
-      if (witnessValue !== undefined) {
-        if (input.value !== undefined && input.value !== witnessValue)
-          throw new Error('Input did not match witnessValue');
-        typeforce(types.Satoshi, witnessValue);
-        input.value = witnessValue;
-      }
-
-      if (!canSign(input)) {
-        const prepared = prepareInput(
-          input,
-          ourPubKey,
         redeemScript,
+        hashType,
+        witnessValue,
         witnessScript,
+        this.__USE_LOW_R,
+      ),
     );
-
-        // updates inline
-        Object.assign(input, prepared);
-      }
-
-      if (!canSign(input)) throw Error(input.prevOutType + ' not supported');
-    }
-
-    // ready to sign
-    let signatureHash: Buffer;
-    if (input.hasWitness) {
-      signatureHash = this.__TX.hashForWitnessV0(
-        vin,
-        input.signScript as Buffer,
-        input.value as number,
-        hashType,
-      );
-    } else {
-      signatureHash = this.__TX.hashForSignature(
-        vin,
-        input.signScript as Buffer,
-        hashType,
-      );
-    }
-
-    // enforce in order signing of public keys
-    const signed = input.pubkeys!.some((pubKey, i) => {
-      if (!ourPubKey.equals(pubKey!)) return false;
-      if (input.signatures![i]) throw new Error('Signature already exists');
-
-      // TODO: add tests
-      if (ourPubKey.length !== 33 && input.hasWitness) {
-        throw new Error(
-          'BIP143 rejects uncompressed public keys in P2WPKH or P2WSH',
-        );
-      }
-
-      const signature = keyPair.sign(signatureHash, this.__USE_LOW_R);
-      input.signatures![i] = bscript.signature.encode(signature, hashType!);
-      return true;
-    });
-
-    if (!signed) throw new Error('Key pair cannot sign for this input');
   }
 
   private __addInputUnsafe(
@@ -976,3 +951,361 @@ function canSign(input: TxbInput): boolean {
 function signatureHashType(buffer: Buffer): number {
   return buffer.readUInt8(buffer.length - 1);
 }
+
+function checkSignArgs(inputs: TxbInput[], signParams: TxbSignArg): void {
+  if (!PREVOUT_TYPES.has(signParams.prevOutScriptType)) {
+    throw new TypeError(
+      `Unknown prevOutScriptType "${signParams.prevOutScriptType}"`,
+    );
+  }
+  tfMessage(
+    typeforce.Number,
+    signParams.vin,
+    `sign must include vin parameter as Number (input index)`,
+  );
+  tfMessage(
+    types.Signer,
+    signParams.keyPair,
+    `sign must include keyPair parameter as Signer interface`,
+  );
+  tfMessage(
+    typeforce.maybe(typeforce.Number),
+    signParams.hashType,
+    `sign hashType parameter must be a number`,
+  );
+  const prevOutType = (inputs[signParams.vin] || []).prevOutType;
+  const posType = signParams.prevOutScriptType;
+  switch (posType) {
+    case 'p2pkh':
+      if (prevOutType && prevOutType !== 'pubkeyhash') {
+        throw new TypeError(
+          `input #${signParams.vin} is not of type p2pkh: ${prevOutType}`,
+        );
+      }
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessScript,
+        `${posType} requires NO witnessScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.redeemScript,
+        `${posType} requires NO redeemScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessValue,
+        `${posType} requires NO witnessValue`,
+      );
+      break;
+    case 'p2pk':
+      if (prevOutType && prevOutType !== 'pubkey') {
+        throw new TypeError(
+          `input #${signParams.vin} is not of type p2pk: ${prevOutType}`,
+        );
+      }
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessScript,
+        `${posType} requires NO witnessScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.redeemScript,
+        `${posType} requires NO redeemScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessValue,
+        `${posType} requires NO witnessValue`,
+      );
+      break;
+    case 'p2wpkh':
+      if (prevOutType && prevOutType !== 'witnesspubkeyhash') {
+        throw new TypeError(
+          `input #${signParams.vin} is not of type p2wpkh: ${prevOutType}`,
+        );
+      }
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessScript,
+        `${posType} requires NO witnessScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.redeemScript,
+        `${posType} requires NO redeemScript`,
+      );
+      tfMessage(
+        types.Satoshi,
+        signParams.witnessValue,
+        `${posType} requires witnessValue`,
+      );
+      break;
+    case 'p2ms':
+      if (prevOutType && prevOutType !== 'multisig') {
+        throw new TypeError(
+          `input #${signParams.vin} is not of type p2ms: ${prevOutType}`,
+        );
+      }
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessScript,
+        `${posType} requires NO witnessScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.redeemScript,
+        `${posType} requires NO redeemScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessValue,
+        `${posType} requires NO witnessValue`,
+      );
+      break;
+    case 'p2sh-p2wpkh':
+      if (prevOutType && prevOutType !== 'scripthash') {
+        throw new TypeError(
+          `input #${signParams.vin} is not of type p2sh-p2wpkh: ${prevOutType}`,
+        );
+      }
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessScript,
+        `${posType} requires NO witnessScript`,
+      );
+      tfMessage(
+        typeforce.Buffer,
+        signParams.redeemScript,
+        `${posType} requires redeemScript`,
+      );
+      tfMessage(
+        types.Satoshi,
+        signParams.witnessValue,
+        `${posType} requires witnessValue`,
+      );
+      break;
+    case 'p2sh-p2ms':
+    case 'p2sh-p2pk':
+    case 'p2sh-p2pkh':
+      if (prevOutType && prevOutType !== 'scripthash') {
+        throw new TypeError(
+          `input #${signParams.vin} is not of type ${posType}: ${prevOutType}`,
+        );
+      }
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessScript,
+        `${posType} requires NO witnessScript`,
+      );
+      tfMessage(
+        typeforce.Buffer,
+        signParams.redeemScript,
+        `${posType} requires redeemScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.witnessValue,
+        `${posType} requires NO witnessValue`,
+      );
+      break;
+    case 'p2wsh-p2ms':
+    case 'p2wsh-p2pk':
+    case 'p2wsh-p2pkh':
+      if (prevOutType && prevOutType !== 'witnessscripthash') {
+        throw new TypeError(
+          `input #${signParams.vin} is not of type ${posType}: ${prevOutType}`,
+        );
+      }
+      tfMessage(
+        typeforce.Buffer,
+        signParams.witnessScript,
+        `${posType} requires witnessScript`,
+      );
+      tfMessage(
+        typeforce.value(undefined),
+        signParams.redeemScript,
+        `${posType} requires NO redeemScript`,
+      );
+      tfMessage(
+        types.Satoshi,
+        signParams.witnessValue,
+        `${posType} requires witnessValue`,
+      );
+      break;
+    case 'p2sh-p2wsh-p2ms':
+    case 'p2sh-p2wsh-p2pk':
+    case 'p2sh-p2wsh-p2pkh':
+      if (prevOutType && prevOutType !== 'scripthash') {
+        throw new TypeError(
+          `input #${signParams.vin} is not of type ${posType}: ${prevOutType}`,
+        );
+      }
+      tfMessage(
+        typeforce.Buffer,
+        signParams.witnessScript,
+        `${posType} requires witnessScript`,
+      );
+      tfMessage(
+        typeforce.Buffer,
+        signParams.redeemScript,
+        `${posType} requires witnessScript`,
+      );
+      tfMessage(
+        types.Satoshi,
+        signParams.witnessValue,
+        `${posType} requires witnessScript`,
+      );
+      break;
+  }
+}
+
+function trySign({
+  input,
+  ourPubKey,
+  keyPair,
+  signatureHash,
+  hashType,
+  useLowR,
+}: SigningData): void {
+  // enforce in order signing of public keys
+  let signed = false;
+  for (const [i, pubKey] of input.pubkeys!.entries()) {
+    if (!ourPubKey.equals(pubKey!)) continue;
+    if (input.signatures![i]) throw new Error('Signature already exists');
+
+    // TODO: add tests
+    if (ourPubKey.length !== 33 && input.hasWitness) {
+      throw new Error(
+        'BIP143 rejects uncompressed public keys in P2WPKH or P2WSH',
+      );
+    }
+
+    const signature = keyPair.sign(signatureHash, useLowR);
+    input.signatures![i] = bscript.signature.encode(signature, hashType);
+    signed = true;
+  }
+
+  if (!signed) throw new Error('Key pair cannot sign for this input');
+}
+
+interface SigningData {
+  input: TxbInput;
+  ourPubKey: Buffer;
+  keyPair: Signer;
+  signatureHash: Buffer;
+  hashType: number;
+  useLowR: boolean;
+}
+
+type HashTypeCheck = (hashType: number) => boolean;
+
+function getSigningData(
+  network: Network,
+  inputs: TxbInput[],
+  needsOutputs: HashTypeCheck,
+  tx: Transaction,
+  signParams: number | TxbSignArg,
+  keyPair?: Signer,
+  redeemScript?: Buffer,
+  hashType?: number,
+  witnessValue?: number,
+  witnessScript?: Buffer,
+  useLowR?: boolean,
+): SigningData {
+  let vin: number;
+  if (typeof signParams === 'number') {
+    console.warn(
+      'DEPRECATED: TransactionBuilder sign method arguments ' +
+        'will change in v6, please use the TxbSignArg interface',
+    );
+    vin = signParams;
+  } else if (typeof signParams === 'object') {
+    checkSignArgs(inputs, signParams);
+    ({
+      vin,
+      keyPair,
+      redeemScript,
+      hashType,
+      witnessValue,
+      witnessScript,
+    } = signParams);
+  } else {
+    throw new TypeError(
+      'TransactionBuilder sign first arg must be TxbSignArg or number',
+    );
+  }
+  if (keyPair === undefined) {
+    throw new Error('sign requires keypair');
+  }
+  // TODO: remove keyPair.network matching in 4.0.0
+  if (keyPair.network && keyPair.network !== network)
+    throw new TypeError('Inconsistent network');
+  if (!inputs[vin]) throw new Error('No input at index: ' + vin);
+
+  hashType = hashType || Transaction.SIGHASH_ALL;
+  if (needsOutputs(hashType)) throw new Error('Transaction needs outputs');
+
+  const input = inputs[vin];
+
+  // if redeemScript was previously provided, enforce consistency
+  if (
+    input.redeemScript !== undefined &&
+    redeemScript &&
+    !input.redeemScript.equals(redeemScript)
+  ) {
+    throw new Error('Inconsistent redeemScript');
+  }
+
+  const ourPubKey =
+    keyPair.publicKey || (keyPair.getPublicKey && keyPair.getPublicKey());
+  if (!canSign(input)) {
+    if (witnessValue !== undefined) {
+      if (input.value !== undefined && input.value !== witnessValue)
+        throw new Error('Input did not match witnessValue');
+      typeforce(types.Satoshi, witnessValue);
+      input.value = witnessValue;
+    }
+
+    if (!canSign(input)) {
+      const prepared = prepareInput(
+        input,
+        ourPubKey,
+        redeemScript,
+        witnessScript,
+      );
+
+      // updates inline
+      Object.assign(input, prepared);
+    }
+
+    if (!canSign(input)) throw Error(input.prevOutType + ' not supported');
+  }
+
+  // ready to sign
+  let signatureHash: Buffer;
+  if (input.hasWitness) {
+    signatureHash = tx.hashForWitnessV0(
+      vin,
+      input.signScript as Buffer,
+      input.value as number,
+      hashType,
+    );
+  } else {
+    signatureHash = tx.hashForSignature(
+      vin,
+      input.signScript as Buffer,
+      hashType,
+    );
+  }
+
+  return {
+    input,
+    ourPubKey,
+    keyPair,
+    signatureHash,
+    hashType,
+    useLowR: !!useLowR,
+  };
+}

ts_src/types.ts

@@ -12,6 +12,14 @@ BIP32Path.toJSON = (): string => {
   return 'BIP32 derivation path';
 };
 
+export function Signer(obj: any): boolean {
+  return (
+    (typeforce.Buffer(obj.publicKey) ||
+      typeof obj.getPublicKey === 'function') &&
+    typeof obj.sign === 'function'
+  );
+}
+
 const SATOSHI_MAX: number = 21 * 1e14;
 export function Satoshi(value: number): boolean {
   return typeforce.UInt53(value) && value <= SATOSHI_MAX;

types/ecpair.d.ts

@@ -5,15 +5,24 @@ interface ECPairOptions {
     network?: Network;
     rng?(arg0: number): Buffer;
 }
-export interface ECPairInterface {
+export interface Signer {
+    publicKey: Buffer;
+    network?: Network;
+    sign(hash: Buffer, lowR?: boolean): Buffer;
+    getPublicKey?(): Buffer;
+}
+export interface SignerAsync {
+    publicKey: Buffer;
+    network?: Network;
+    sign(hash: Buffer, lowR?: boolean): Promise<Buffer>;
+    getPublicKey?(): Buffer;
+}
+export interface ECPairInterface extends Signer {
     compressed: boolean;
     network: Network;
-    publicKey: Buffer;
     privateKey?: Buffer;
     toWIF(): string;
-    sign(hash: Buffer, lowR?: boolean): Buffer;
     verify(hash: Buffer, signature: Buffer): boolean;
-    getPublicKey?(): Buffer;
 }
 declare class ECPair implements ECPairInterface {
     private __D?;

types/index.d.ts

@@ -11,7 +11,7 @@ export { OPS as opcodes } from './script';
 export { Transaction } from './transaction';
 export { TransactionBuilder } from './transaction_builder';
 export { BIP32Interface } from 'bip32';
-export { ECPairInterface } from './ecpair';
+export { ECPairInterface, Signer, SignerAsync } from './ecpair';
 export { Network } from './networks';
 export { Payment, PaymentOpts, Stack, StackElement } from './payments';
 export { OpCode } from './script';

types/transaction_builder.d.ts

@@ -1,7 +1,16 @@
 /// <reference types="node" />
-import { ECPairInterface } from './ecpair';
+import { Signer } from './ecpair';
 import { Network } from './networks';
 import { Transaction } from './transaction';
+interface TxbSignArg {
+    prevOutScriptType: string;
+    vin: number;
+    keyPair: Signer;
+    redeemScript?: Buffer;
+    hashType?: number;
+    witnessValue?: number;
+    witnessScript?: Buffer;
+}
 export declare class TransactionBuilder {
     network: Network;
     maximumFeeRate: number;
@@ -18,7 +27,7 @@ export declare class TransactionBuilder {
     addOutput(scriptPubKey: string | Buffer, value: number): number;
     build(): Transaction;
     buildIncomplete(): Transaction;
-    sign(vin: number, keyPair: ECPairInterface, redeemScript?: Buffer, hashType?: number, witnessValue?: number, witnessScript?: Buffer): void;
+    sign(signParams: number | TxbSignArg, keyPair?: Signer, redeemScript?: Buffer, hashType?: number, witnessValue?: number, witnessScript?: Buffer): void;
     private __addInputUnsafe;
     private __build;
     private __canModifyInputs;
@@ -26,3 +35,4 @@ export declare class TransactionBuilder {
     private __canModifyOutputs;
     private __overMaximumFees;
 }
+export {};

types/types.d.ts

@@ -3,6 +3,7 @@ export declare function BIP32Path(value: string): boolean;
 export declare namespace BIP32Path {
     var toJSON: () => string;
 }
+export declare function Signer(obj: any): boolean;
 export declare function Satoshi(value: number): boolean;
 export declare const ECPoint: any;
 export declare const Network: any;