futoin-secvault/lib/password_gen.js

FutoIn Secure Vault reference implementation

'use strict';

/**
 * @file
 *
 * Copyright 2018 FutoIn Project (https://futoin.org)
 * Copyright 2018 Andrey Galkin <andrey@futoin.org>
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

const crypto = require( 'crypto' );

const CHARS = (
    'abcdfeghijkmlnopqsrtvuwxyz' +
    'ABCDEFHGIJLKMNOPQRSTUWVXYZ' +
    '0123456789' +
    '-_'
);

const password_gen = ( len, chars=CHARS ) => {
    const rndvec = crypto.randomBytes( len );
    const maxid = chars.length - 1;
    let res = '';

    for ( let i = len - 1; i >=0; --i ) {
        res += chars.charAt( parseInt( rndvec[i] * maxid / 0xFF ) );
    }

    return res;
};

module.exports = password_gen;