cognito-srp/dist/lib/Session.js

Secure Remote Password protocol implementation compatible with Amazon Cognito.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
const crypto = require("crypto");
const util_1 = require("./util");
const constants_1 = require("./constants");
class Session {
    constructor(poolname, username, keyOrHkdf, scramblingParameter) {
        this.poolname = poolname;
        this.username = username;
        this.scramblingParameter = scramblingParameter;
        if (keyOrHkdf instanceof Buffer) {
            this.key = keyOrHkdf;
            this.hkdf = this.calculateHkdf();
        }
        else {
            this.hkdf = Buffer.from(keyOrHkdf, 'hex');
        }
    }
    calculateSignature(secretBlock, timestamp) {
        return crypto
            .createHmac(util_1.HASH_TYPE, this.hkdf)
            .update(this.poolname)
            .update(this.username)
            .update(Buffer.from(secretBlock, 'base64'))
            .update(timestamp)
            .digest('base64');
    }
    getHkdf() {
        return this.hkdf.toString('hex');
    }
    calculateHkdf() {
        const prk = crypto
            .createHmac(util_1.HASH_TYPE, Buffer.from(util_1.padHex(this.scramblingParameter), 'hex'))
            .update(Buffer.from(util_1.padHex(this.key), 'hex'))
            .digest();
        const hmac = crypto
            .createHmac(util_1.HASH_TYPE, prk)
            .update(constants_1.infoBits)
            .digest();
        return hmac.slice(0, 16);
    }
}
exports.Session = Session;