@salesforce/core/lib/secureBuffer.js

"use strict";
/*
 * Copyright (c) 2018, salesforce.com, inc.
 * All rights reserved.
 * SPDX-License-Identifier: BSD-3-Clause
 * For full license text, see the LICENSE file in the repo root or https://opensource.org/licenses/BSD-3-Clause
 */
Object.defineProperty(exports, "__esModule", { value: true });
const ts_types_1 = require("@salesforce/ts-types");
const crypto = require("crypto");
const cipherName = 'aes-256-cbc';
const cipherSize = 32;
/**
 * Used to store and retrieve a sensitive information in memory. This is not meant for at rest encryption.
 *
 * ```
 * const sString: SecureBuffer<string> = new SecureBuffer();
 * sString.consume(secretTextBuffer);
 * const value: string = sString.value((buffer: Buffer): string => {
 *     const password: string = buffer.toString('utf8');
 *     // doSomething with the password
 *     // returns something of type <T>
 *     return testReturnValue;
 * });
 * ```
 */
class SecureBuffer {
    constructor() {
        this.key = crypto.randomBytes(cipherSize);
        this.iv = crypto.randomBytes(16);
    }
    /**
     * Invokes a callback with a decrypted version of the buffer.
     * @param cb The callback containing the decrypted buffer parameter that returns a desired.
     * typed object. It's important to understand that once the callback goes out of scope the buffer parameters is
     * overwritten with random data. Do not make a copy of this buffer and persist it!
     */
    value(cb) {
        if (cb) {
            const cipher = crypto.createDecipheriv(cipherName, this.key, this.iv);
            const a = cipher.update(ts_types_1.ensure(this.secret));
            const b = cipher.final();
            const c = Buffer.concat([a, b]);
            try {
                return cb(c);
            }
            finally {
                crypto.randomFillSync(a);
                crypto.randomFillSync(b);
                crypto.randomFillSync(c);
            }
        }
    }
    /**
     * Overwrites the value of the encrypted secret with random data.
     */
    clear() {
        if (this.secret) {
            crypto.randomFillSync(this.secret);
        }
        const cipher = crypto.createCipheriv(cipherName, this.key, this.iv);
        this.secret = Buffer.concat([cipher.update(Buffer.from('')), cipher.final()]);
    }
    /**
     * Consumes a buffer of data that's intended to be secret.
     * @param buffer Data to encrypt. The input buffer is overwritten with random data after it's encrypted
     * and assigned internally.
     */
    consume(buffer) {
        let targetBuffer = buffer;
        if (!targetBuffer) {
            targetBuffer = Buffer.from('');
        }
        const cipher = crypto.createCipheriv(cipherName, this.key, this.iv);
        this.secret = Buffer.concat([cipher.update(targetBuffer), cipher.final()]);
        crypto.randomFillSync(targetBuffer);
    }
}
exports.SecureBuffer = SecureBuffer;
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