liquidjs-lib/src/script_signature.js

Client-side Liquid JavaScript library

'use strict';
var __createBinding =
  (this && this.__createBinding) ||
  (Object.create
    ? function (o, m, k, k2) {
        if (k2 === undefined) k2 = k;
        var desc = Object.getOwnPropertyDescriptor(m, k);
        if (
          !desc ||
          ('get' in desc ? !m.__esModule : desc.writable || desc.configurable)
        ) {
          desc = {
            enumerable: true,
            get: function () {
              return m[k];
            },
          };
        }
        Object.defineProperty(o, k2, desc);
      }
    : function (o, m, k, k2) {
        if (k2 === undefined) k2 = k;
        o[k2] = m[k];
      });
var __setModuleDefault =
  (this && this.__setModuleDefault) ||
  (Object.create
    ? function (o, v) {
        Object.defineProperty(o, 'default', { enumerable: true, value: v });
      }
    : function (o, v) {
        o['default'] = v;
      });
var __importStar =
  (this && this.__importStar) ||
  function (mod) {
    if (mod && mod.__esModule) return mod;
    var result = {};
    if (mod != null)
      for (var k in mod)
        if (k !== 'default' && Object.prototype.hasOwnProperty.call(mod, k))
          __createBinding(result, mod, k);
    __setModuleDefault(result, mod);
    return result;
  };
Object.defineProperty(exports, '__esModule', { value: true });
exports.encode = exports.decode = void 0;
const bip66 = __importStar(require('./bip66'));
const types = __importStar(require('./types'));
const { typeforce } = types;
const ZERO = Buffer.alloc(1, 0);
function toDER(x) {
  let i = 0;
  while (x[i] === 0) ++i;
  if (i === x.length) return ZERO;
  x = x.slice(i);
  if (x[0] & 0x80) return Buffer.concat([ZERO, x], 1 + x.length);
  return x;
}
function fromDER(x) {
  if (x[0] === 0x00) x = x.slice(1);
  const buffer = Buffer.alloc(32, 0);
  const bstart = Math.max(0, 32 - x.length);
  x.copy(buffer, bstart);
  return buffer;
}
// BIP62: 1 byte hashType flag (only 0x01, 0x02, 0x03, 0x81, 0x82 and 0x83 are allowed)
function decode(buffer) {
  const hashType = buffer.readUInt8(buffer.length - 1);
  const hashTypeMod = hashType & ~0x80;
  if (hashTypeMod <= 0 || hashTypeMod >= 4)
    throw new Error('Invalid hashType ' + hashType);
  const decoded = bip66.decode(buffer.slice(0, -1));
  const r = fromDER(decoded.r);
  const s = fromDER(decoded.s);
  const signature = Buffer.concat([r, s], 64);
  return { signature, hashType };
}
exports.decode = decode;
function encode(signature, hashType) {
  typeforce(
    {
      signature: types.BufferN(64),
      hashType: types.UInt8,
    },
    { signature, hashType },
  );
  const hashTypeMod = hashType & ~0x80;
  if (hashTypeMod <= 0 || hashTypeMod >= 4)
    throw new Error('Invalid hashType ' + hashType);
  const hashTypeBuffer = Buffer.allocUnsafe(1);
  hashTypeBuffer.writeUInt8(hashType, 0);
  const r = toDER(signature.slice(0, 32));
  const s = toDER(signature.slice(32, 64));
  return Buffer.concat([bip66.encode(r, s), hashTypeBuffer]);
}
exports.encode = encode;