lss-mqtt/src/lib/coder.ts

LSS-MQTT framework in NodeJS implementation"

import {
    CipherCCM,
    createCipheriv,
    createDecipheriv,
    DecipherCCM,
    HexBase64BinaryEncoding,
    Utf8AsciiBinaryEncoding
} from "crypto";

export class Coder {
    private readonly algorithm = 'chacha20-poly1305';
    private iv = Buffer.alloc(12, 0);
    private cipher: CipherCCM;
    private decipher: DecipherCCM;

    constructor(private password: string,
                private textCoding: Utf8AsciiBinaryEncoding = 'ascii',
                private cipherCoding: HexBase64BinaryEncoding = 'hex') {
        this.cipher = createCipheriv(this.algorithm, this.password, this.iv, {authTagLength: 16});
        this.decipher = createDecipheriv(this.algorithm, this.password, this.iv, {authTagLength: 16});
    }

    public encode(data: string) {
        this.cipher = createCipheriv(this.algorithm, this.password, this.iv, {authTagLength: 16});
        return this.cipher.update(data, this.textCoding, this.cipherCoding);
    }

    public decode(cipher: string) {
        this.decipher = createDecipheriv(this.algorithm, this.password, this.iv, {authTagLength: 16});
        return this.decipher.update(cipher, this.cipherCoding, this.textCoding)
    }
}