"use strict"; //See: https://github.com/ethereum/wiki/wiki/RLP import { arrayify, hexlify, isBytesLike } from "@ethersproject/bytes"; import { Logger } from "@ethersproject/logger"; import { version } from "./_version"; const logger = new Logger(version); function arrayifyInteger(value) { const result = []; while (value) { result.unshift(value & 0xff); value >>= 8; } return result; } function unarrayifyInteger(data, offset, length) { let result = 0; for (let i = 0; i < length; i++) { result = (result * 256) + data[offset + i]; } return result; } function _encode(object) { if (Array.isArray(object)) { let payload = []; object.forEach(function (child) { payload = payload.concat(_encode(child)); }); if (payload.length <= 55) { payload.unshift(0xc0 + payload.length); return payload; } const length = arrayifyInteger(payload.length); length.unshift(0xf7 + length.length); return length.concat(payload); } if (!isBytesLike(object)) { logger.throwArgumentError("RLP object must be BytesLike", "object", object); } const data = Array.prototype.slice.call(arrayify(object)); if (data.length === 1 && data[0] <= 0x7f) { return data; } else if (data.length <= 55) { data.unshift(0x80 + data.length); return data; } const length = arrayifyInteger(data.length); length.unshift(0xb7 + length.length); return length.concat(data); } export function encode(object) { return hexlify(_encode(object)); } function _decodeChildren(data, offset, childOffset, length) { const result = []; while (childOffset < offset + 1 + length) { const decoded = _decode(data, childOffset); result.push(decoded.result); childOffset += decoded.consumed; if (childOffset > offset + 1 + length) { logger.throwError("child data too short", Logger.errors.BUFFER_OVERRUN, {}); } } return { consumed: (1 + length), result: result }; } // returns { consumed: number, result: Object } function _decode(data, offset) { if (data.length === 0) { logger.throwError("data too short", Logger.errors.BUFFER_OVERRUN, {}); } // Array with extra length prefix if (data[offset] >= 0xf8) { const lengthLength = data[offset] - 0xf7; if (offset + 1 + lengthLength > data.length) { logger.throwError("data short segment too short", Logger.errors.BUFFER_OVERRUN, {}); } const length = unarrayifyInteger(data, offset + 1, lengthLength); if (offset + 1 + lengthLength + length > data.length) { logger.throwError("data long segment too short", Logger.errors.BUFFER_OVERRUN, {}); } return _decodeChildren(data, offset, offset + 1 + lengthLength, lengthLength + length); } else if (data[offset] >= 0xc0) { const length = data[offset] - 0xc0; if (offset + 1 + length > data.length) { logger.throwError("data array too short", Logger.errors.BUFFER_OVERRUN, {}); } return _decodeChildren(data, offset, offset + 1, length); } else if (data[offset] >= 0xb8) { const lengthLength = data[offset] - 0xb7; if (offset + 1 + lengthLength > data.length) { logger.throwError("data array too short", Logger.errors.BUFFER_OVERRUN, {}); } const length = unarrayifyInteger(data, offset + 1, lengthLength); if (offset + 1 + lengthLength + length > data.length) { logger.throwError("data array too short", Logger.errors.BUFFER_OVERRUN, {}); } const result = hexlify(data.slice(offset + 1 + lengthLength, offset + 1 + lengthLength + length)); return { consumed: (1 + lengthLength + length), result: result }; } else if (data[offset] >= 0x80) { const length = data[offset] - 0x80; if (offset + 1 + length > data.length) { logger.throwError("data too short", Logger.errors.BUFFER_OVERRUN, {}); } const result = hexlify(data.slice(offset + 1, offset + 1 + length)); return { consumed: (1 + length), result: result }; } return { consumed: 1, result: hexlify(data[offset]) }; } export function decode(data) { const bytes = arrayify(data); const decoded = _decode(bytes, 0); if (decoded.consumed !== bytes.length) { logger.throwArgumentError("invalid rlp data", "data", data); } return decoded.result; }