/** * @author mikecat * @copyright Crown Copyright 2022 * @license Apache-2.0 */ import Operation from "../Operation.mjs"; import Utils from "../Utils.mjs"; import { toHexFast } from "../lib/Hex.mjs"; import forge from "node-forge"; import OperationError from "../errors/OperationError.mjs"; /** * AES Key Wrap operation */ class AESKeyWrap extends Operation { /** * AESKeyWrap constructor */ constructor() { super(); this.name = "AES Key Wrap"; this.module = "Ciphers"; this.description = "A key wrapping algorithm defined in RFC3394, which is used to protect keys in untrusted storage or communications, using AES.

This algorithm uses an AES key (KEK: key-encryption key) and a 64-bit IV to encrypt 64-bit blocks."; this.infoURL = "https://wikipedia.org/wiki/Key_wrap"; this.inputType = "string"; this.outputType = "string"; this.args = [ { "name": "Key (KEK)", "type": "toggleString", "value": "", "toggleValues": ["Hex", "UTF8", "Latin1", "Base64"] }, { "name": "IV", "type": "toggleString", "value": "a6a6a6a6a6a6a6a6", "toggleValues": ["Hex", "UTF8", "Latin1", "Base64"] }, { "name": "Input", "type": "option", "value": ["Hex", "Raw"] }, { "name": "Output", "type": "option", "value": ["Hex", "Raw"] }, ]; } /** * @param {string} input * @param {Object[]} args * @returns {string} */ run(input, args) { const kek = Utils.convertToByteString(args[0].string, args[0].option), iv = Utils.convertToByteString(args[1].string, args[1].option), inputType = args[2], outputType = args[3]; if (kek.length !== 16 && kek.length !== 24 && kek.length !== 32) { throw new OperationError("KEK must be either 16, 24, or 32 bytes (currently " + kek.length + " bytes)"); } if (iv.length !== 8) { throw new OperationError("IV must be 8 bytes (currently " + iv.length + " bytes)"); } const inputData = Utils.convertToByteString(input, inputType); if (inputData.length % 8 !== 0 || inputData.length < 16) { throw new OperationError("input must be 8n (n>=2) bytes (currently " + inputData.length + " bytes)"); } const cipher = forge.cipher.createCipher("AES-ECB", kek); let A = iv; const R = []; for (let i = 0; i < inputData.length; i += 8) { R.push(inputData.substring(i, i + 8)); } let cntLower = 1, cntUpper = 0; for (let j = 0; j < 6; j++) { for (let i = 0; i < R.length; i++) { cipher.start(); cipher.update(forge.util.createBuffer(A + R[i])); cipher.finish(); const B = cipher.output.getBytes(); const msbBuffer = Utils.strToArrayBuffer(B.substring(0, 8)); const msbView = new DataView(msbBuffer); msbView.setUint32(0, msbView.getUint32(0) ^ cntUpper); msbView.setUint32(4, msbView.getUint32(4) ^ cntLower); A = Utils.arrayBufferToStr(msbBuffer, false); R[i] = B.substring(8, 16); cntLower++; if (cntLower > 0xffffffff) { cntUpper++; cntLower = 0; } } } const C = A + R.join(""); if (outputType === "Hex") { return toHexFast(Utils.strToArrayBuffer(C)); } return C; } } export default AESKeyWrap;