bitcoinjs-lib/src/esm/payments/p2ms.js

Client-side Bitcoin JavaScript library

import { bitcoin as BITCOIN_NETWORK } from '../networks.js';
import * as bscript from '../script.js';
import * as scriptNumber from '../script_number.js';
import { BufferSchema, isPoint, stacksEqual } from '../types.js';
import * as lazy from './lazy.js';
import * as v from 'valibot';
const OPS = bscript.OPS;
const OP_INT_BASE = OPS.OP_RESERVED; // OP_1 - 1
function encodeSmallOrScriptNum(n) {
  return n <= 16 ? OP_INT_BASE + n : scriptNumber.encode(n);
}
function decodeSmallOrScriptNum(chunk) {
  if (typeof chunk === 'number') {
    const val = chunk - OP_INT_BASE;
    if (val < 1 || val > 16)
      throw new TypeError(`Invalid opcode: expected OP_1–OP_16, got ${chunk}`);
    return val;
  } else return scriptNumber.decode(chunk);
}
function isSmallOrScriptNum(chunk) {
  if (typeof chunk === 'number')
    return chunk - OP_INT_BASE >= 1 && chunk - OP_INT_BASE <= 16;
  else return Number.isInteger(scriptNumber.decode(chunk));
}
// input: OP_0 [signatures ...]
// output: m [pubKeys ...] n OP_CHECKMULTISIG
/**
 * Represents a function that creates a Pay-to-Multisig (P2MS) payment object.
 * @param a - The payment object.
 * @param opts - Optional payment options.
 * @returns The created payment object.
 * @throws {TypeError} If the provided data is not valid.
 */
export function p2ms(a, opts) {
  if (
    !a.input &&
    !a.output &&
    !(a.pubkeys && a.m !== undefined) &&
    !a.signatures
  )
    throw new TypeError('Not enough data');
  opts = Object.assign({ validate: true }, opts || {});
  function isAcceptableSignature(x) {
    return (
      bscript.isCanonicalScriptSignature(x) ||
      (opts.allowIncomplete && x === OPS.OP_0) !== undefined
    );
  }
  v.parse(
    v.partial(
      v.object({
        network: v.object({}),
        m: v.number(),
        n: v.number(),
        output: BufferSchema,
        pubkeys: v.array(v.custom(isPoint), 'Received invalid pubkey'),
        signatures: v.array(
          v.custom(isAcceptableSignature),
          'Expected signature to be of type isAcceptableSignature',
        ),
        input: BufferSchema,
      }),
    ),
    a,
  );
  const network = a.network || BITCOIN_NETWORK;
  const o = { network };
  let chunks = [];
  let decoded = false;
  function decode(output) {
    if (decoded) return;
    decoded = true;
    chunks = bscript.decompile(output);
    if (chunks.length < 3) throw new TypeError('Output is invalid');
    o.m = decodeSmallOrScriptNum(chunks[0]);
    o.n = decodeSmallOrScriptNum(chunks[chunks.length - 2]);
    o.pubkeys = chunks.slice(1, -2);
  }
  lazy.prop(o, 'output', () => {
    if (!a.m) return;
    if (!o.n) return;
    if (!a.pubkeys) return;
    return bscript.compile(
      [].concat(
        encodeSmallOrScriptNum(a.m),
        a.pubkeys,
        encodeSmallOrScriptNum(o.n),
        OPS.OP_CHECKMULTISIG,
      ),
    );
  });
  lazy.prop(o, 'm', () => {
    if (!o.output) return;
    decode(o.output);
    return o.m;
  });
  lazy.prop(o, 'n', () => {
    if (!o.pubkeys) return;
    return o.pubkeys.length;
  });
  lazy.prop(o, 'pubkeys', () => {
    if (!a.output) return;
    decode(a.output);
    return o.pubkeys;
  });
  lazy.prop(o, 'signatures', () => {
    if (!a.input) return;
    return bscript.decompile(a.input).slice(1);
  });
  lazy.prop(o, 'input', () => {
    if (!a.signatures) return;
    return bscript.compile([OPS.OP_0].concat(a.signatures));
  });
  lazy.prop(o, 'witness', () => {
    if (!o.input) return;
    return [];
  });
  lazy.prop(o, 'name', () => {
    if (!o.m || !o.n) return;
    return `p2ms(${o.m} of ${o.n})`;
  });
  // extended validation
  if (opts.validate) {
    if (a.output) {
      decode(a.output);
      if (!isSmallOrScriptNum(chunks[0]))
        throw new TypeError('Output is invalid');
      if (!isSmallOrScriptNum(chunks[chunks.length - 2]))
        throw new TypeError('Output is invalid');
      if (chunks[chunks.length - 1] !== OPS.OP_CHECKMULTISIG)
        throw new TypeError('Output is invalid');
      if (o.m <= 0 || o.n > 20 || o.m > o.n || o.n !== chunks.length - 3)
        throw new TypeError('Output is invalid');
      if (!o.pubkeys.every(x => isPoint(x)))
        throw new TypeError('Output is invalid');
      if (a.m !== undefined && a.m !== o.m) throw new TypeError('m mismatch');
      if (a.n !== undefined && a.n !== o.n) throw new TypeError('n mismatch');
      if (a.pubkeys && !stacksEqual(a.pubkeys, o.pubkeys))
        throw new TypeError('Pubkeys mismatch');
    }
    if (a.pubkeys) {
      if (a.n !== undefined && a.n !== a.pubkeys.length)
        throw new TypeError('Pubkey count mismatch');
      o.n = a.pubkeys.length;
      if (o.n < o.m) throw new TypeError('Pubkey count cannot be less than m');
    }
    if (a.signatures) {
      if (a.signatures.length < o.m)
        throw new TypeError('Not enough signatures provided');
      if (a.signatures.length > o.m)
        throw new TypeError('Too many signatures provided');
    }
    if (a.input) {
      if (a.input[0] !== OPS.OP_0) throw new TypeError('Input is invalid');
      if (
        o.signatures.length === 0 ||
        !o.signatures.every(isAcceptableSignature)
      )
        throw new TypeError('Input has invalid signature(s)');
      if (a.signatures && !stacksEqual(a.signatures, o.signatures))
        throw new TypeError('Signature mismatch');
      if (a.m !== undefined && a.m !== a.signatures.length)
        throw new TypeError('Signature count mismatch');
    }
  }
  return Object.assign(o, a);
}