@trifrost/core/esm/middleware/Auth/Basic.js

Blazingly fast, runtime-agnostic server framework for modern edge and node environments

import { isNeString } from '@valkyriestudios/utils/string';
import { Sym_TriFrostDescription, Sym_TriFrostFingerPrint, Sym_TriFrostName } from '../../types/constants';
import { Sym_TriFrostMiddlewareAuth } from './types';
/* Specific symbol attached to auth mware to identify them by */
export const Sym_TriFrostMiddlewareBasicAuth = Symbol('TriFrost.Middleware.BasicAuth');
/**
 * HTTP Basic Authentication middleware.
 *
 * This middleware extracts the `Authorization` header using the Basic scheme,
 * decodes the base64-encoded username and password, and calls the provided
 * validate() function. If valid, the `$auth` state is set on the context.
 *
 * @see https://developer.mozilla.org/en-US/docs/Web/HTTP/Authentication#basic_authentication_scheme
 *
 * @example
 * .use(BasicAuth({
 *   validate: (ctx, {user, pass}) => user === 'admin' && pass === ctx.env.ADMIN_SECRET
 * }))
 */
export function BasicAuth(opts) {
    if (typeof opts?.validate !== 'function')
        throw new Error('TriFrostMiddleware@BasicAuth: A validate function must be provided');
    const realm = isNeString(opts.realm) ? opts.realm : 'Restricted Area';
    const NOT_AUTH = 'Basic realm="' + realm + '"';
    const mware = async function TriFrostBasicAuth(ctx) {
        const authHeader = ctx.headers.authorization;
        if (typeof authHeader !== 'string' || !authHeader.startsWith('Basic ')) {
            ctx.setHeader('www-authenticate', NOT_AUTH);
            return ctx.status(401);
        }
        let decoded = '';
        try {
            decoded = atob(authHeader.slice(6).trim());
        }
        catch {
            /* Nothing to do here */
        }
        const idx = decoded.indexOf(':');
        if (idx === -1) {
            ctx.setHeader('www-authenticate', NOT_AUTH);
            return ctx.status(401);
        }
        const user = decoded.slice(0, idx);
        const pass = decoded.slice(idx + 1);
        const result = await opts.validate(ctx, { user, pass });
        if (!result) {
            ctx.setHeader('www-authenticate', NOT_AUTH);
            return ctx.status(401);
        }
        const authenticated = result === true ? { user } : result;
        return ctx.setState({ $auth: authenticated });
    };
    /* Add symbols for introspection/use further down the line */
    Reflect.set(mware, Sym_TriFrostName, 'TriFrostBasicAuth');
    Reflect.set(mware, Sym_TriFrostDescription, 'HTTP Basic Authentication middleware');
    Reflect.set(mware, Sym_TriFrostMiddlewareAuth, true);
    Reflect.set(mware, Sym_TriFrostFingerPrint, Sym_TriFrostMiddlewareBasicAuth);
    return mware;
}