wifi_prov: Exposed events for secure session establishment

components/protocomm/include/security/protocomm_security.h

@@ -7,11 +7,25 @@
 #pragma once
 
 #include <esp_err.h>
+#include "esp_event.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+ESP_EVENT_DECLARE_BASE(PROTOCOMM_SECURITY_SESSION_EVENT);
+
+/**
+ * @brief   Events generated by the protocomm security layer
+ *
+ * These events are generated while establishing secured session.
+ */
+typedef enum {
+    PROTOCOMM_SECURITY_SESSION_SETUP_OK,                 /**< Secured session established successfully */
+    PROTOCOMM_SECURITY_SESSION_INVALID_SECURITY_PARAMS,  /**< Received invalid (NULL) security parameters (username / client public-key) */
+    PROTOCOMM_SECURITY_SESSION_CREDENTIALS_MISMATCH,     /**< Received incorrect credentials (username / PoP) */
+} protocomm_security_session_event_t;
+
 /**
  * @brief   Protocomm Security 1 parameters: Proof Of Possession
  */

components/protocomm/src/security/security1.c

@@ -42,6 +42,13 @@
 
 static const char* TAG = "security1";
 
+/*NOTE: As both the security schemes share the events,
+ * we need to define the event base only once.
+ */
+#ifndef CONFIG_ESP_PROTOCOMM_SUPPORT_SECURITY_VERSION_2
+ESP_EVENT_DEFINE_BASE(PROTOCOMM_SECURITY_SESSION_EVENT);
+#endif
+
 #define PUBLIC_KEY_LEN  32
 #define SZ_RANDOM       16
 
@@ -127,6 +134,9 @@ static esp_err_t handle_session_command1(session_t *cur_session,
                                  sizeof(cur_session->device_pubkey)) != 0) {
         ESP_LOGE(TAG, "Key mismatch. Close connection");
         mbedtls_aes_free(&cur_session->ctx_aes);
+        if (esp_event_post(PROTOCOMM_SECURITY_SESSION_EVENT, PROTOCOMM_SECURITY_SESSION_CREDENTIALS_MISMATCH, NULL, 0, portMAX_DELAY) != ESP_OK) {
+            ESP_LOGE(TAG, "Failed to post credential mismatch event");
+        }
         return ESP_FAIL;
     }
 
@@ -178,6 +188,10 @@ static esp_err_t handle_session_command1(session_t *cur_session,
     resp->sec1 = out;
 
     cur_session->state = SESSION_STATE_DONE;
+    if (esp_event_post(PROTOCOMM_SECURITY_SESSION_EVENT, PROTOCOMM_SECURITY_SESSION_SETUP_OK, NULL, 0, portMAX_DELAY) != ESP_OK) {
+        ESP_LOGE(TAG, "Failed to post secure session setup success event");
+    }
+
     ESP_LOGD(TAG, "Secure session established successfully");
     return ESP_OK;
 }
@@ -202,6 +216,9 @@ static esp_err_t handle_session_command0(session_t *cur_session,
 
     if (in->sc0->client_pubkey.len != PUBLIC_KEY_LEN) {
         ESP_LOGE(TAG, "Invalid public key length");
+        if (esp_event_post(PROTOCOMM_SECURITY_SESSION_EVENT, PROTOCOMM_SECURITY_SESSION_INVALID_SECURITY_PARAMS, NULL, 0, portMAX_DELAY) != ESP_OK) {
+            ESP_LOGE(TAG, "Failed to post secure session invalid security params event");
+        }
         return ESP_ERR_INVALID_ARG;
     }
 

components/protocomm/src/security/security2.c

@@ -27,6 +27,8 @@
 
 static const char *TAG = "security2";
 
+ESP_EVENT_DEFINE_BASE(PROTOCOMM_SECURITY_SESSION_EVENT);
+
 #define SALT_LEN                    (16)
 #define PUBLIC_KEY_LEN              (384)
 #define CLIENT_PROOF_LEN            (64)
@@ -81,11 +83,17 @@ static esp_err_t handle_session_command0(session_t *cur_session,
 
     if (in->sc0->client_pubkey.len != PUBLIC_KEY_LEN) {
         ESP_LOGE(TAG, "Invalid public key length");
+        if (esp_event_post(PROTOCOMM_SECURITY_SESSION_EVENT, PROTOCOMM_SECURITY_SESSION_INVALID_SECURITY_PARAMS, NULL, 0, portMAX_DELAY) != ESP_OK) {
+            ESP_LOGE(TAG, "Failed to post secure session invalid security params event");
+        }
         return ESP_ERR_INVALID_ARG;
     }
 
     if (in->sc0->client_username.len <= 0) {
         ESP_LOGE(TAG, "Invalid username");
+        if (esp_event_post(PROTOCOMM_SECURITY_SESSION_EVENT, PROTOCOMM_SECURITY_SESSION_INVALID_SECURITY_PARAMS, NULL, 0, portMAX_DELAY) != ESP_OK) {
+            ESP_LOGE(TAG, "Failed to post secure session invalid security params event");
+        }
         return ESP_ERR_INVALID_ARG;
     }
 
@@ -214,6 +222,9 @@ static esp_err_t handle_session_command1(session_t *cur_session,
     if (esp_srp_exchange_proofs(cur_session->srp_hd, cur_session->username, cur_session->username_len, (char * ) in->sc1->client_proof.data, device_proof) != ESP_OK) {
         ESP_LOGE(TAG, "Failed to authenticate client proof!");
         free(device_proof);
+        if (esp_event_post(PROTOCOMM_SECURITY_SESSION_EVENT, PROTOCOMM_SECURITY_SESSION_CREDENTIALS_MISMATCH, NULL, 0, portMAX_DELAY) != ESP_OK) {
+            ESP_LOGE(TAG, "Failed to post credential mismatch event");
+        }
         return ESP_FAIL;
     }
     hexdump("Device proof", device_proof, CLIENT_PROOF_LEN);
@@ -265,6 +276,9 @@ static esp_err_t handle_session_command1(session_t *cur_session,
     resp->sec2 = out;
 
     cur_session->state = SESSION_STATE_DONE;
+    if (esp_event_post(PROTOCOMM_SECURITY_SESSION_EVENT, PROTOCOMM_SECURITY_SESSION_SETUP_OK, NULL, 0, portMAX_DELAY) != ESP_OK) {
+            ESP_LOGE(TAG, "Failed to post secure session setup success event");
+    }
     ESP_LOGD(TAG, "Secure session established successfully");
     return ESP_OK;
 }

examples/provisioning/wifi_prov_mgr/main/app_main.c

@@ -194,6 +194,20 @@ static void event_handler(void* arg, esp_event_base_t event_base,
                 break;
         }
 #endif
+    } else if (event_base == PROTOCOMM_SECURITY_SESSION_EVENT) {
+        switch (event_id) {
+            case PROTOCOMM_SECURITY_SESSION_SETUP_OK:
+                ESP_LOGI(TAG, "Secured session established!");
+                break;
+            case PROTOCOMM_SECURITY_SESSION_INVALID_SECURITY_PARAMS:
+                ESP_LOGE(TAG, "Received invalid security parameters for establishing secure session!");
+                break;
+            case PROTOCOMM_SECURITY_SESSION_CREDENTIALS_MISMATCH:
+                ESP_LOGE(TAG, "Received incorrect username and/or PoP for establishing secure session!");
+                break;
+            default:
+                break;
+        }
     }
 }
 
@@ -289,6 +303,7 @@ void app_main(void)
 #ifdef CONFIG_EXAMPLE_PROV_TRANSPORT_BLE
     ESP_ERROR_CHECK(esp_event_handler_register(PROTOCOMM_TRANSPORT_BLE_EVENT, ESP_EVENT_ANY_ID, &event_handler, NULL));
 #endif
+    ESP_ERROR_CHECK(esp_event_handler_register(PROTOCOMM_SECURITY_SESSION_EVENT, ESP_EVENT_ANY_ID, &event_handler, NULL));
     ESP_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &event_handler, NULL));
     ESP_ERROR_CHECK(esp_event_handler_register(IP_EVENT, IP_EVENT_STA_GOT_IP, &event_handler, NULL));