https_server: Fix use of open_fn from application level

https-server uses the open_fn() callback and potentially overwrites user defined callback. This commit adds the user defined open_fn() to https-server's context and calls it upon openning a session

components/esp_https_server/src/https_server.c

@@ -20,6 +20,11 @@
 
 const static char *TAG = "esp_https_server";
 
+typedef struct httpd_ssl_ctx {
+    esp_tls_cfg_server_t *tls_cfg;
+    httpd_open_func_t open_fn;
+} httpd_ssl_ctx_t;
+
 /**
  * SSL socket close handler
  *
@@ -93,7 +98,7 @@ static esp_err_t httpd_ssl_open(httpd_handle_t server, int sockfd)
     assert(server != NULL);
 
     // Retrieve the SSL context from the global context field (set in config)
-    esp_tls_cfg_server_t *global_ctx = httpd_get_global_transport_ctx(server);
+    httpd_ssl_ctx_t *global_ctx = httpd_get_global_transport_ctx(server);
     assert(global_ctx != NULL);
 
     esp_tls_t *tls = (esp_tls_t *)calloc(1, sizeof(esp_tls_t));
@@ -101,7 +106,7 @@ static esp_err_t httpd_ssl_open(httpd_handle_t server, int sockfd)
         return ESP_ERR_NO_MEM;
     }
     ESP_LOGI(TAG, "performing session handshake");
-    int ret = esp_tls_server_session_create(global_ctx, sockfd, tls);
+    int ret = esp_tls_server_session_create(global_ctx->tls_cfg, sockfd, tls);
     if (ret != 0) {
         ESP_LOGE(TAG, "esp_tls_create_server_session failed");
         goto fail;
@@ -119,6 +124,9 @@ static esp_err_t httpd_ssl_open(httpd_handle_t server, int sockfd)
 
     ESP_LOGD(TAG, "Secure socket open");
 
+    if (global_ctx->open_fn) {
+        (global_ctx->open_fn)(server, sockfd);
+    }
     return ESP_OK;
 fail:
     esp_tls_server_session_delete(tls);
@@ -133,7 +141,8 @@ fail:
 static void free_secure_context(void *ctx)
 {
     assert(ctx != NULL);
-    esp_tls_cfg_server_t *cfg = (esp_tls_cfg_server_t *)ctx;
+    httpd_ssl_ctx_t *ssl_ctx = ctx;
+    esp_tls_cfg_server_t *cfg = ssl_ctx->tls_cfg;
     ESP_LOGI(TAG, "Server shuts down, releasing SSL context");
     if (cfg->cacert_buf) {
         free((void *)cfg->cacert_buf);
@@ -145,14 +154,21 @@ static void free_secure_context(void *ctx)
         free((void *)cfg->serverkey_buf);
     }
     free(cfg);
+    free(ssl_ctx);
 }
 
-static esp_tls_cfg_server_t *create_secure_context(const struct httpd_ssl_config *config)
+static httpd_ssl_ctx_t *create_secure_context(const struct httpd_ssl_config *config)
 {
+    httpd_ssl_ctx_t *ssl_ctx = calloc(1, sizeof(httpd_ssl_ctx_t));
+    if (!ssl_ctx) {
+        return NULL;
+    }
     esp_tls_cfg_server_t *cfg = (esp_tls_cfg_server_t *)calloc(1, sizeof(esp_tls_cfg_server_t));
     if (!cfg) {
+        free(ssl_ctx);
         return NULL;
     }
+    ssl_ctx->tls_cfg = cfg;
 /* cacert = CA which signs client cert, or client cert itself , which is mapped to client_verify_cert_pem */
     if(config->client_verify_cert_pem != NULL) {
         cfg->cacert_buf = (unsigned char *)malloc(config->client_verify_cert_len);
@@ -186,7 +202,7 @@ static esp_tls_cfg_server_t *create_secure_context(const struct httpd_ssl_config
     memcpy((char *)cfg->serverkey_buf, config->prvtkey_pem, config->prvtkey_len);
     cfg->serverkey_bytes = config->prvtkey_len;
 
-    return cfg;
+    return ssl_ctx;
 }
 
 /** Start the server */
@@ -199,16 +215,21 @@ esp_err_t httpd_ssl_start(httpd_handle_t *pHandle, struct httpd_ssl_config *conf
 
     if (HTTPD_SSL_TRANSPORT_SECURE == config->transport_mode) {
 
-        esp_tls_cfg_server_t *esp_tls_cfg = create_secure_context(config);
-        if (!esp_tls_cfg) {
+        httpd_ssl_ctx_t *ssl_ctx = create_secure_context(config);
+        if (!ssl_ctx) {
             return -1;
         }
 
         ESP_LOGD(TAG, "SSL context ready");
 
         // set SSL specific config
-        config->httpd.global_transport_ctx = esp_tls_cfg;
+        config->httpd.global_transport_ctx = ssl_ctx;
         config->httpd.global_transport_ctx_free_fn = free_secure_context;
+        if (config->httpd.open_fn) {
+            // since the httpd's open_fn is used for opening the SSL session, we save the configured
+            // user pointer and call it upon opening the ssl socket
+            ssl_ctx->open_fn = config->httpd.open_fn;
+        }
         config->httpd.open_fn = httpd_ssl_open; // the open function configures the created SSL sessions
 
         config->httpd.server_port = config->port_secure;