Authentication Helpers

Demonstrates how to authenticate requests using Bearer / JWT tokens, HTTP Basic Auth, and custom API Key headers.

Source: examples/AuthHelpers/AuthHelpers.ino

---

Overview

The client provides dedicated helpers that configure persistent authorization headers for all subsequent requests:

Helper Method	Header Generated	Description
client.bearer(token)	Authorization: Bearer <token>	For JWT and OAuth2 Bearer tokens.
client.basic(user, pass)	Authorization: Basic <base64>	Automatically encodes credentials into Base64.
client.apiKey(name, key)	<name>: <key>	Sets any API Key header (e.g., X-API-Key).
client.setHeader(name, val)	<name>: <val>	Sets any generic persistent HTTP header.

---

Full Sketch

#include <Arduino.h>
#include <WiFi.h>
#include "ESP32HTTPClient.h"

const char* ssid     = "YOUR_SSID";
const char* password = "YOUR_PASSWORD";

ESP32HTTPClient client("https://httpbin.org");

void setup() {
    Serial.begin(115200);

    WiFi.begin(ssid, password);
    while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        Serial.print(".");
    }
    Serial.println("\nConnected to WiFi");
}

void loop() {
    char authHeader[128] = {0};

    // 1. Bearer Token Authentication
    Serial.println("\n--- [1] Testing Bearer Token ---");
    client.bearer("eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.sampleToken");
    client.get("/bearer").getBody("token", authHeader, sizeof(authHeader));

    if (client.isSuccess()) {
        Serial.printf("Bearer Authenticated -> Token verified by server\n");
    }

    // 2. HTTP Basic Authentication (Username + Password)
    Serial.println("\n--- [2] Testing HTTP Basic Auth ---");
    client.basic("admin", "secret123");
    client.get("/basic-auth/admin/secret123");

    if (client.isSuccess()) {
        Serial.println("Basic Auth Success -> 200 OK");
    }

    // 3. API Key Header Authentication
    Serial.println("\n--- [3] Testing API Key Header ---");
    client.apiKey("X-API-KEY", "my-super-secret-api-key-9988");
    client.get("/headers").getBody("headers.X-Api-Key", authHeader, sizeof(authHeader));

    if (client.isSuccess()) {
        Serial.printf("API Key Sent -> Server received: %s\n", authHeader);
    }

    delay(15000);
}

---

Expected Serial Output

Connected to WiFi

--- [1] Testing Bearer Token ---
Bearer Authenticated -> Token verified by server

--- [2] Testing HTTP Basic Auth ---
Basic Auth Success -> 200 OK

--- [3] Testing API Key Header ---
API Key Sent -> Server received: my-super-secret-api-key-9988

---

Key Takeaways

• Authentication headers configured via bearer(), basic(), apiKey(), or setHeader() persist across all requests made by that client instance.
• client.basic() encodes username and password on the fly, eliminating the need for manual Base64 encoding.