fix: use env-agnostic std libraries

Author: lukashroch

src/client.ts

@@ -6,7 +6,6 @@
 import axios, { AxiosInstance } from 'axios';
 import https from 'https';
 import { SignJWT, jwtVerify } from 'jose';
-import { URL, URLSearchParams } from 'url';
 import * as constants from './constants';
 import { DuoException } from './duo-exception';
 import {
@@ -89,9 +88,8 @@ export class Client {
       throw new DuoException(constants.INVALID_CLIENT_SECRET_ERROR);
 
     if (apiHost === '') throw new DuoException(constants.PARSING_CONFIG_ERROR);
-
     try {
-      new URL(redirectUrl);
+      new globalThis.URL(redirectUrl);
     } catch {
       throw new DuoException(constants.PARSING_CONFIG_ERROR);
     }
@@ -214,7 +212,7 @@ export class Client {
     try {
       const { data } = await this.axios.post<HealthCheckResponse>(
         this.HEALTH_CHECK_ENDPOINT,
-        new URLSearchParams(request),
+        new globalThis.URLSearchParams(request),
       );
       const { stat } = data;
 
@@ -271,7 +269,7 @@ export class Client {
       scope: 'openid',
     };
 
-    return `${this.baseURL}${this.AUTHORIZE_ENDPOINT}?${new URLSearchParams(query).toString()}`;
+    return `${this.baseURL}${this.AUTHORIZE_ENDPOINT}?${new globalThis.URLSearchParams(query).toString()}`;
   }
 
   /**
@@ -307,7 +305,7 @@ export class Client {
     try {
       const { data } = await this.axios.post<TokenResponse>(
         this.TOKEN_ENDPOINT,
-        new URLSearchParams(request),
+        new globalThis.URLSearchParams(request),
         {
           headers: {
             'user-agent': `${constants.USER_AGENT} node/${process.versions.node} v8/${process.versions.v8}`,

src/duo-exception.ts

@@ -8,7 +8,6 @@ export class DuoException extends Error {
     super(message);
 
     this.name = 'DuoException';
-    Error.captureStackTrace(this, this.constructor);
 
     if (error) this.inner = error;
   }

src/util.ts

@@ -3,14 +3,12 @@
 //
 // SPDX-License-Identifier: MIT
 
-import { randomBytes } from 'crypto';
-
-function bytesToBase64url(s: Buffer): string {
-  return s.toString('base64url');
-}
-
-export const generateRandomString = (length: number): string => {
-  return bytesToBase64url(randomBytes(length)).substring(0, length);
+export const generateRandomString = (length: number) => {
+  const arr = new Uint8Array((length % 2 ? length + 1 : length) / 2);
+  globalThis.crypto.getRandomValues(arr);
+  return Array.from(arr, (dec) => dec.toString(16).padStart(2, '0'))
+    .join('')
+    .slice(0, length);
 };
 
 export const getTimeInSeconds = (date = new Date(Date.now())): number =>