src/hasher/md2.mjs

'use strict';

import Hasher8 from "./hasher8";

/**
 * Constants from Pi
 * @link https://github.com/e-sushi/MD2-S-box-creator
 * @type {number[]}
 */
const SBOX = [
  0x29, 0x2e, 0x43, 0xc9, 0xa2, 0xd8, 0x7c, 0x01, 0x3d, 0x36, 0x54, 0xa1,
  0xec, 0xf0, 0x06, 0x13, 0x62, 0xa7, 0x05, 0xf3, 0xc0, 0xc7, 0x73, 0x8c,
  0x98, 0x93, 0x2b, 0xd9, 0xbc, 0x4c, 0x82, 0xca, 0x1e, 0x9b, 0x57, 0x3c,
  0xfd, 0xd4, 0xe0, 0x16, 0x67, 0x42, 0x6f, 0x18, 0x8a, 0x17, 0xe5, 0x12,
  0xbe, 0x4e, 0xc4, 0xd6, 0xda, 0x9e, 0xde, 0x49, 0xa0, 0xfb, 0xf5, 0x8e,
  0xbb, 0x2f, 0xee, 0x7a, 0xa9, 0x68, 0x79, 0x91, 0x15, 0xb2, 0x07, 0x3f,
  0x94, 0xc2, 0x10, 0x89, 0x0b, 0x22, 0x5f, 0x21, 0x80, 0x7f, 0x5d, 0x9a,
  0x5a, 0x90, 0x32, 0x27, 0x35, 0x3e, 0xcc, 0xe7, 0xbf, 0xf7, 0x97, 0x03,
  0xff, 0x19, 0x30, 0xb3, 0x48, 0xa5, 0xb5, 0xd1, 0xd7, 0x5e, 0x92, 0x2a,
  0xac, 0x56, 0xaa, 0xc6, 0x4f, 0xb8, 0x38, 0xd2, 0x96, 0xa4, 0x7d, 0xb6,
  0x76, 0xfc, 0x6b, 0xe2, 0x9c, 0x74, 0x04, 0xf1, 0x45, 0x9d, 0x70, 0x59,
  0x64, 0x71, 0x87, 0x20, 0x86, 0x5b, 0xcf, 0x65, 0xe6, 0x2d, 0xa8, 0x02,
  0x1b, 0x60, 0x25, 0xad, 0xae, 0xb0, 0xb9, 0xf6, 0x1c, 0x46, 0x61, 0x69,
  0x34, 0x40, 0x7e, 0x0f, 0x55, 0x47, 0xa3, 0x23, 0xdd, 0x51, 0xaf, 0x3a,
  0xc3, 0x5c, 0xf9, 0xce, 0xba, 0xc5, 0xea, 0x26, 0x2c, 0x53, 0x0d, 0x6e,
  0x85, 0x28, 0x84, 0x09, 0xd3, 0xdf, 0xcd, 0xf4, 0x41, 0x81, 0x4d, 0x52,
  0x6a, 0xdc, 0x37, 0xc8, 0x6c, 0xc1, 0xab, 0xfa, 0x24, 0xe1, 0x7b, 0x08,
  0x0c, 0xbd, 0xb1, 0x4a, 0x78, 0x88, 0x95, 0x8b, 0xe3, 0x63, 0xe8, 0x6d,
  0xe9, 0xcb, 0xd5, 0xfe, 0x3b, 0x00, 0x1d, 0x39, 0xf2, 0xef, 0xb7, 0x0e,
  0x66, 0x58, 0xd0, 0xe4, 0xa6, 0x77, 0x72, 0xf8, 0xeb, 0x75, 0x4b, 0x0a,
  0x31, 0x44, 0x50, 0xb4, 0x8f, 0xed, 0x1f, 0x1a, 0xdb, 0x99, 0x8d, 0x33,
  0x9f, 0x11, 0x83, 0x14
];

/**
 * Calculates [MD2](https://tools.ietf.org/html/rfc1319) hash
 *
 * @example <caption>Calculates MD2 hash from string "message" - ES6 style</caption>
 * import Md2 from "crypto-api/src/hasher/md2";
 * import {toHex} from "crypto-api/src/encoder/hex";
 *
 * let hasher = new Md2();
 * hasher.update('message');
 * console.log(toHex(hasher.finalize()));
 *
 * @example <caption>Calculates MD2 hash from UTF string "message" - ES6 style</caption>
 * import Md2 from "crypto-api/src/hasher/md2";
 * import {toHex} from "crypto-api/src/encoder/hex";
 * import {fromUtf} from "crypto-api/src/encoder/utf";
 *
 * let hasher = new Md2();
 * hasher.update(fromUtf('message'));
 * console.log(toHex(hasher.finalize()));
 *
 * @example <caption>Calculates MD2 hash from string "message" - ES5 style</caption>
 * <script src="https://nf404.github.io/crypto-api/crypto-api.min.js"></script>
 * <script>
 *   var hasher = CryptoApi.getHasher('md2');
 *   hasher.update('message');
 *   console.log(CryptoApi.encoder.toHex(hasher.finalize()));
 * </script>
 *
 * @example <caption>Calculates MD2 hash from UTF string "message" - ES5 style</caption>
 * <script src="https://nf404.github.io/crypto-api/crypto-api.min.js"></script>
 * <script>
 *   console.log(CryptoApi.hash('md2', 'message'));
 * </script>
 */
class Md2 extends Hasher8 {
  /**
   * @param {Object} [options]
   * @param {number} [options.rounds=18] - Number of rounds (Must be greater than 0)
   */
  constructor(options) {
    super(options);
    this.options.rounds = this.options.rounds || 18;
  }

  /**
   * Reset hasher to initial state
   */
  reset() {
    super.reset();
    this.state.hash = new Array(48);
    this.state.checksum = new Array(16);
  }

  /**
   * Process ready blocks
   *
   * @protected
   * @ignore
   * @param {number[]} block - Block
   */
  processBlock(block) {
    // Append hash
    for (let i = 0; i < 16; i++) {
      this.state.hash[16 + i] = block[i] | 0;
      this.state.hash[32 + i] = block[i] ^ this.state.hash[i];
    }

    // Rounds
    let t = 0;
    for (let i = 0; i < this.options.rounds; i++) {
      for (let j = 0; j < 48; j++) {
        t = this.state.hash[j] ^= SBOX[t];
      }
      t = (t + i) & 0xff;
    }

    // Append checksum
    t = this.state.checksum[15] & 0xff;
    for (let i = 0; i < 16; i++) {
      t = this.state.checksum[i] ^= SBOX[block[i] ^ t];
    }
  }

  /**
   * Finalize hash and return result
   *
   * @returns {string}
   */
  finalize() {
    this.addPaddingPKCS7(16 - (this.state.message.length & 0xf) | 0);
    this.process();

    // Process checksum
    for (let i = 0; i < 16; i++) {
      this.state.message += String.fromCharCode(this.state.checksum[i]);
    }
    this.process();

    // Return hash
    return this.getStateHash(16);
  }
}

export default Md2;