example/http_server: add basic authenticated example to HTTP server

Closes https://github.com/espressif/esp-idf/issues/5646

examples/protocols/http_server/simple/main/Kconfig.projbuild

@@ -0,0 +1,29 @@
+menu "Example Configuration"
+
+    config EXAMPLE_BASIC_AUTH
+        bool "Basic Authentication"
+        default n
+        help
+            Basic Authentication is a method for an HTTP user agent (e.g. a web browser)
+            to provide a user name and password when making a request. It is the simplest
+            technique for enforcing access controls to web resources. because it doesn't
+            require cookies, session identifiers, or login pages; rather, it uses standard
+            fields in the HTTP header.
+            Note that, Basic Authentication is not encrypted channel and also easy to retrieve
+            credentials as they are sent in plain text format.
+
+    config EXAMPLE_BASIC_AUTH_USERNAME
+        string "Basic Authenticate User Name"
+        depends on EXAMPLE_BASIC_AUTH
+        default "ESP32"
+        help
+            The client's user name which used for basic authenticate.
+
+    config EXAMPLE_BASIC_AUTH_PASSWORD
+        string "Basic Authenticate Password"
+        depends on EXAMPLE_BASIC_AUTH
+        default "ESP32Webserver"
+        help
+            The client's password which used for basic authenticate.
+
+endmenu

examples/protocols/http_server/simple/main/main.c

@@ -17,7 +17,7 @@
 #include "esp_netif.h"
 #include "esp_eth.h"
 #include "protocol_examples_common.h"
-
+#include "esp_tls_crypto.h"
 #include <esp_http_server.h>
 
 /* A simple example that demonstrates how to create GET and POST
@@ -26,6 +26,125 @@
 
 static const char *TAG = "example";
 
+#if CONFIG_EXAMPLE_BASIC_AUTH
+
+typedef struct {
+    char    *username;
+    char    *password;
+} basic_auth_info_t;
+
+#define HTTPD_401      "401 UNAUTHORIZED"           /*!< HTTP Response 401 */
+
+static char *http_auth_basic(const char *username, const char *password)
+{
+    int out;
+    char *user_info = NULL;
+    char *digest = NULL;
+    size_t n = 0;
+    asprintf(&user_info, "%s:%s", username, password);
+    if (!user_info) {
+        ESP_LOGE(TAG, "No enough memory for user information");
+        return NULL;
+    }
+    esp_crypto_base64_encode(NULL, 0, &n, (const unsigned char *)user_info, strlen(user_info));
+
+    /* 6: The length of the "Basic " string
+     * n: Number of bytes for a base64 encode format
+     * 1: Number of bytes for a reserved which be used to fill zero
+    */
+    digest = calloc(1, 6 + n + 1);
+    if (digest) {
+        strcpy(digest, "Basic ");
+        esp_crypto_base64_encode((unsigned char *)digest + 6, n, (size_t *)&out, (const unsigned char *)user_info, strlen(user_info));
+    }
+    free(user_info);
+    return digest;
+}
+
+/* An HTTP GET handler */
+static esp_err_t basic_auth_get_handler(httpd_req_t *req)
+{
+    char *buf = NULL;
+    size_t buf_len = 0;
+    basic_auth_info_t *basic_auth_info = req->user_ctx;
+
+    buf_len = httpd_req_get_hdr_value_len(req, "Authorization") + 1;
+    if (buf_len > 1) {
+        buf = calloc(1, buf_len);
+        if (!buf) {
+            ESP_LOGE(TAG, "No enough memory for basic authorization");
+            return ESP_ERR_NO_MEM;
+        }
+
+        if (httpd_req_get_hdr_value_str(req, "Authorization", buf, buf_len) == ESP_OK) {
+            ESP_LOGI(TAG, "Found header => Authorization: %s", buf);
+        } else {
+            ESP_LOGE(TAG, "No auth value received");
+        }
+
+        char *auth_credentials = http_auth_basic(basic_auth_info->username, basic_auth_info->password);
+        if (!auth_credentials) {
+            ESP_LOGE(TAG, "No enough memory for basic authorization credentials");
+            free(buf);
+            return ESP_ERR_NO_MEM;
+        }
+
+        if (strncmp(auth_credentials, buf, buf_len)) {
+            ESP_LOGE(TAG, "Not authenticated");
+            httpd_resp_set_status(req, HTTPD_401);
+            httpd_resp_set_type(req, "application/json");
+            httpd_resp_set_hdr(req, "Connection", "keep-alive");
+            httpd_resp_set_hdr(req, "WWW-Authenticate", "Basic realm=\"Hello\"");
+            httpd_resp_send(req, NULL, 0);
+        } else {
+            ESP_LOGI(TAG, "Authenticated!");
+            char *basic_auth_resp = NULL;
+            httpd_resp_set_status(req, HTTPD_200);
+            httpd_resp_set_type(req, "application/json");
+            httpd_resp_set_hdr(req, "Connection", "keep-alive");
+            asprintf(&basic_auth_resp, "{\"authenticated\": true,\"user\": \"%s\"}", basic_auth_info->username);
+            if (!basic_auth_resp) {
+                ESP_LOGE(TAG, "No enough memory for basic authorization response");
+                free(auth_credentials);
+                free(buf);
+                return ESP_ERR_NO_MEM;
+            }
+            httpd_resp_send(req, basic_auth_resp, strlen(basic_auth_resp));
+            free(basic_auth_resp);
+        }
+        free(auth_credentials);
+        free(buf);
+    } else {
+        ESP_LOGE(TAG, "No auth header received");
+        httpd_resp_set_status(req, HTTPD_401);
+        httpd_resp_set_type(req, "application/json");
+        httpd_resp_set_hdr(req, "Connection", "keep-alive");
+        httpd_resp_set_hdr(req, "WWW-Authenticate", "Basic realm=\"Hello\"");
+        httpd_resp_send(req, NULL, 0);
+    }
+
+    return ESP_OK;
+}
+
+static httpd_uri_t basic_auth = {
+    .uri       = "/basic_auth",
+    .method    = HTTP_GET,
+    .handler   = basic_auth_get_handler,
+};
+
+static void httpd_register_basic_auth(httpd_handle_t server)
+{
+    basic_auth_info_t *basic_auth_info = calloc(1, sizeof(basic_auth_info_t));
+    if (basic_auth_info) {
+        basic_auth_info->username = CONFIG_EXAMPLE_BASIC_AUTH_USERNAME;
+        basic_auth_info->password = CONFIG_EXAMPLE_BASIC_AUTH_PASSWORD;
+
+        basic_auth.user_ctx = basic_auth_info;
+        httpd_register_uri_handler(server, &basic_auth);
+    }
+}
+#endif
+
 /* An HTTP GET handler */
 static esp_err_t hello_get_handler(httpd_req_t *req)
 {
@@ -233,6 +352,9 @@ static httpd_handle_t start_webserver(void)
         httpd_register_uri_handler(server, &hello);
         httpd_register_uri_handler(server, &echo);
         httpd_register_uri_handler(server, &ctrl);
+        #if CONFIG_EXAMPLE_BASIC_AUTH
+        httpd_register_basic_auth(server);
+        #endif
         return server;
     }
 

examples/protocols/http_server/simple/sdkconfig.ci.basic_auth

@@ -0,0 +1 @@
+CONFIG_EXAMPLE_BASIC_AUTH=y