fix(esp_wifi): Code cleanup for PR#15550 PR#15551

Closes #15550
Closes #15551

Author: kapilkedawat

components/wpa_supplicant/esp_supplicant/include/esp_eap_client.h

@@ -327,28 +327,22 @@ esp_err_t esp_eap_client_use_default_cert_bundle(bool use_default_bundle);
 void esp_wifi_set_okc_support(bool enable);
 
 /**
- * @brief Set name for certificate domain name validation
+ * @brief Set the domain name for certificate validation
  *
- * Enabling this option will only accept certificate with the provided subject name
+ * This function sets the expected domain name for validating the certificate's subject name.
+ * If the provided domain name does not match the certificate's subject name, validation will fail.
  *
- * @param[in] domain_match The expected domain name
- * @param[in] len      Length of the domain name (limited to 1~127 bytes).
+ * @attention  1. The `domain_name` should be a NULL-terminated string.
+ *
+ * @param[in] domain_name The expected domain name. Pass `NULL` to clear the domain matching.
  *
  * @return
- *    - ESP_OK: The identity was set successfully.
- *    - ESP_ERR_INVALID_ARG: Invalid argument (len <= 0 or len >= 128).
+ *    - ESP_OK: The domain match was set successfully.
+ *    - ESP_ERR_INVALID_ARG: Invalid argument (length > 255).
  *    - ESP_ERR_NO_MEM: Memory allocation failure.
+ *    - ESP_ERR_NOT_SUPPORTED: Feature not supported.
  */
-esp_err_t esp_eap_client_set_domain_match(const char *domain_match);
-
-/**
- * @brief Clear the domain name for certificate validation
- *
- * This function clears the domain name that was previously set for the EAP client.
- * After calling this function, the EAP client will no longer use the previously
- * configured domain name during the authentication process.
- */
-void esp_eap_client_clear_domain_match(void);
+esp_err_t esp_eap_client_set_domain_name(const char *domain_name);
 
 #ifdef __cplusplus
 }

components/wpa_supplicant/esp_supplicant/src/crypto/tls_mbedtls.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2020-2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2020-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -520,18 +520,18 @@ static int set_client_config(const struct tls_connection_params *cfg, tls_contex
         }
     }
 
-    /* Usages of default ciphersuites can take a lot of time on low end device
-     * and can cause watchdog. Enabling the ciphers which are secured enough
-     * but doesn't take that much processing power */
+    /* The use of default ciphersuites may take a lot of time on low-end devices
+     * and may trigger the watchdog timer. Enable ciphers that are secure enough
+     * but require less processing power. */
     tls_set_ciphersuite(cfg, tls);
 
 #ifdef CONFIG_ESP_WIFI_DISABLE_KEY_USAGE_CHECK
     mbedtls_ssl_set_verify(&tls->ssl, tls_disable_key_usages, NULL);
 #endif /*CONFIG_ESP_WIFI_DISABLE_KEY_USAGE_CHECK*/
-
-    if (cfg->domain_match) {
-        mbedtls_ssl_conf_authmode(&tls->conf, MBEDTLS_SSL_VERIFY_REQUIRED);
-        mbedtls_ssl_set_hostname(&tls->ssl, cfg->domain_match);
+    ret = mbedtls_ssl_set_hostname(&tls->ssl, cfg->domain_match);
+    if (ret != 0) {
+        wpa_printf(MSG_ERROR, "Failed to set hostname");
+        return ret;
     }
 
 #ifdef CONFIG_MBEDTLS_CERTIFICATE_BUNDLE

components/wpa_supplicant/esp_supplicant/src/esp_eap_client.c

@@ -946,6 +946,9 @@ esp_err_t esp_eap_client_set_ca_cert(const unsigned char *ca_cert, int ca_cert_l
         g_wpa_ca_cert_len = ca_cert_len;
     }
 
+    /* CA certs Set/updated, flushing current PMK cache */
+    wpa_sm_pmksa_cache_flush(get_wpa_sm(), NULL);
+
     return ESP_OK;
 }
 
@@ -1206,32 +1209,36 @@ esp_err_t esp_eap_client_use_default_cert_bundle(bool use_default_bundle)
 #endif
 }
 
-#define MAX_DOMAIN_MATCH_LEN 128
-esp_err_t esp_eap_client_set_domain_match(const char *domain_match)
+#define MAX_DOMAIN_MATCH_LEN 255 /* Maximum host name defined in RFC 1035 */
+esp_err_t esp_eap_client_set_domain_name(const char *domain_name)
 {
+#ifdef CONFIG_TLS_INTERNAL_CLIENT
+    return ESP_ERR_NOT_SUPPORTED;
+#else
+    int len = domain_name ? os_strnlen(domain_name, MAX_DOMAIN_MATCH_LEN + 1) : 0;
+    if (len > MAX_DOMAIN_MATCH_LEN) {
+        return ESP_ERR_INVALID_ARG;
+    }
+    if (g_wpa_domain_match && domain_name && os_strcmp(g_wpa_domain_match, domain_name) == 0) {
+        return ESP_OK;
+    }
     if (g_wpa_domain_match) {
         os_free(g_wpa_domain_match);
         g_wpa_domain_match = NULL;
     }
 
-    int len = os_strlen(domain_match);
-    if (len > MAX_DOMAIN_MATCH_LEN) {
-        return ESP_ERR_INVALID_ARG;
+    if (!domain_name) {
+        return ESP_OK;
     }
-    g_wpa_domain_match = (char *)os_zalloc(len+1);
-    if (g_wpa_domain_match == NULL) {
+    g_wpa_domain_match = os_strdup(domain_name);
+    if (!g_wpa_domain_match) {
         return ESP_ERR_NO_MEM;
     }
 
-    os_strlcpy(g_wpa_domain_match, domain_match, len+1);
+    /* flushing the PMK only needed when going for a better security ie no-domain name to domain name
+     * or changing the domain name */
+    wpa_sm_pmksa_cache_flush(get_wpa_sm(), NULL);
 
     return ESP_OK;
+#endif
 }
-
-void esp_eap_client_clear_domain_match(void)
-{
-    if (g_wpa_domain_match) {
-        os_free(g_wpa_domain_match);
-    }
-    g_wpa_domain_match = NULL;
-}

components/wpa_supplicant/port/include/os.h

@@ -261,6 +261,9 @@ char * ets_strdup(const char *s);
 #ifndef os_strlen
 #define os_strlen(s) strlen(s)
 #endif
+#ifndef os_strnlen
+#define os_strnlen(s, n) strnlen((s), (n))
+#endif
 #ifndef os_strcasecmp
 #ifdef _MSC_VER
 #define os_strcasecmp(s1, s2) _stricmp((s1), (s2))

components/wpa_supplicant/src/eap_peer/eap.c

@@ -67,7 +67,9 @@ bool g_wpa_suiteb_certification;
 bool g_wpa_default_cert_bundle;
 int (*esp_crt_bundle_attach_fn)(void *conf);
 #endif
+#ifndef CONFIG_TLS_INTERNAL_CLIENT
 char *g_wpa_domain_match;
+#endif
 
 void eap_peer_config_deinit(struct eap_sm *sm);
 void eap_peer_blob_deinit(struct eap_sm *sm);
@@ -530,7 +532,9 @@ int eap_peer_config_init(
 	sm->config.identity = NULL;
 	sm->config.password = NULL;
 	sm->config.new_password = NULL;
+#ifndef CONFIG_TLS_INTERNAL_CLIENT
 	sm->config.domain_match = g_wpa_domain_match;
+#endif
 	sm->config.private_key_passwd = private_key_passwd;
 	sm->config.client_cert = (u8 *)sm->blob[0].name;
 	sm->config.private_key = (u8 *)sm->blob[1].name;
@@ -593,7 +597,6 @@ int eap_peer_config_init(
 		sm->config.flags |= TLS_CONN_USE_DEFAULT_CERT_BUNDLE;
 	}
 #endif
-
 	/* To be used only for EAP-FAST */
 	if (g_wpa_phase1_options) {
 		sm->config.phase1 = g_wpa_phase1_options;

components/wpa_supplicant/src/eap_peer/eap.h

@@ -49,7 +49,9 @@ extern bool g_wpa_suiteb_certification;
 extern bool g_wpa_default_cert_bundle;
 extern int (*esp_crt_bundle_attach_fn)(void *conf);
 
+#ifndef CONFIG_TLS_INTERNAL_CLIENT
 extern char *g_wpa_domain_match;
+#endif
 
 const u8 * eap_get_eapKeyData(struct eap_sm *sm, size_t *len);
 void eap_deinit_prev_method(struct eap_sm *sm, const char *txt);

examples/wifi/wifi_enterprise/main/Kconfig.projbuild

@@ -100,15 +100,18 @@ menu "Example Configuration"
         help
             Use default CA certificate bundle for WiFi enterprise connection
 
-    config EXAMPLE_USE_SERVER_DOMAIN_MATCH
-        bool "Validate server cert domain"
+    config EXAMPLE_VALIDATE_SERVER_CERT_DOMAIN
+        bool "Enable server certificate domain validation"
+        depends on EXAMPLE_VALIDATE_SERVER_CERT
+        default n
         help
-            Validate the certificate domain
+            Enable validation of the server certificate's domain name.
 
-    config EXAMPLE_SERVER_DOMAIN_MATCH_VALUE
-        string "Server cert domain"
-        depends on EXAMPLE_USE_SERVER_DOMAIN_MATCH
+    config EXAMPLE_SERVER_CERT_DOMAIN
+        string "Expected server certificate domain"
+        depends on EXAMPLE_VALIDATE_SERVER_CERT_DOMAIN
         default "espressif.com"
         help
-            Accept only server certificates matching this domain
+            Specify the expected domain name for the server certificate.
+            The connection will be accepted only if the server certificate matches this domain.
 endmenu

examples/wifi/wifi_enterprise/main/wifi_enterprise_main.c

@@ -1,6 +1,6 @@
 /*
  * SPDX-FileCopyrightText: 2006-2016 ARM Limited
- * SPDX-FileCopyrightText: 2015-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -33,6 +33,7 @@
 #define EXAMPLE_EAP_ID CONFIG_EXAMPLE_EAP_ID
 #define EXAMPLE_EAP_USERNAME CONFIG_EXAMPLE_EAP_USERNAME
 #define EXAMPLE_EAP_PASSWORD CONFIG_EXAMPLE_EAP_PASSWORD
+#define EXAMPLE_SERVER_CERT_DOMAIN CONFIG_EXAMPLE_SERVER_CERT_DOMAIN
 
 /* FreeRTOS event group to signal when we are connected & ready to make a request */
 static EventGroupHandle_t wifi_event_group;
@@ -156,8 +157,8 @@ static void initialise_wifi(void)
 #ifdef CONFIG_EXAMPLE_USE_DEFAULT_CERT_BUNDLE
     ESP_ERROR_CHECK(esp_eap_client_use_default_cert_bundle(true));
 #endif
-#ifdef CONFIG_EXAMPLE_USE_SERVER_DOMAIN_MATCH
-    ESP_ERROR_CHECK(esp_eap_client_set_domain_match(CONFIG_EXAMPLE_SERVER_DOMAIN_MATCH_VALUE));
+#ifdef CONFIG_EXAMPLE_VALIDATE_SERVER_CERT_DOMAIN
+    ESP_ERROR_CHECK(esp_eap_client_set_domain_name(EXAMPLE_SERVER_CERT_DOMAIN));
 #endif
     ESP_ERROR_CHECK(esp_wifi_sta_enterprise_enable());
     ESP_ERROR_CHECK(esp_wifi_start());