example: use decrypt_user_ctx in decryption callback

examples/system/ota/pre_encrypted_ota/main/idf_component.yml

@@ -1,3 +1,2 @@
 dependencies:
-  idf: ">=4.4"
   espressif/esp_encrypted_img: "^2.0.1"

examples/system/ota/pre_encrypted_ota/main/pre_encrypted_ota.c

@@ -39,15 +39,17 @@ extern const char rsa_private_pem_end[]   asm("_binary_private_pem_end");
 
 #define OTA_URL_SIZE 256
 
-static esp_decrypt_handle_t decrypt_handle;
-
 static esp_err_t _decrypt_cb(decrypt_cb_arg_t *args, void *user_ctx)
 {
+    if (args == NULL || user_ctx == NULL) {
+        ESP_LOGE(TAG, "_decrypt_cb: Invalid argument");
+        return ESP_ERR_INVALID_ARG;
+    }
     esp_err_t err;
     pre_enc_decrypt_arg_t pargs = {};
-    pargs.data_in = (char *) args->data_in;
+    pargs.data_in = args->data_in;
     pargs.data_in_len = args->data_in_len;
-    err = esp_encrypted_img_decrypt_data(decrypt_handle, &pargs);
+    err = esp_encrypted_img_decrypt_data((esp_decrypt_handle_t *)user_ctx, &pargs);
     if (err != ESP_OK && err != ESP_ERR_NOT_FINISHED) {
         return err;
     }
@@ -75,7 +77,7 @@ void pre_encrypted_ota_task(void *pvParameter)
     esp_decrypt_cfg_t cfg = {};
     cfg.rsa_pub_key = rsa_private_pem_start;
     cfg.rsa_pub_key_len = rsa_private_pem_end - rsa_private_pem_start;
-    decrypt_handle = esp_encrypted_img_decrypt_start(&cfg);
+    esp_decrypt_handle_t decrypt_handle = esp_encrypted_img_decrypt_start(&cfg);
     if (!decrypt_handle) {
         ESP_LOGE(TAG, "OTA upgrade failed");
         vTaskDelete(NULL);
@@ -106,7 +108,7 @@ void pre_encrypted_ota_task(void *pvParameter)
         .max_http_request_size = CONFIG_EXAMPLE_HTTP_REQUEST_SIZE,
 #endif
         .decrypt_cb = _decrypt_cb,
-        .decrypt_user_ctx = NULL
+        .decrypt_user_ctx = (void *)decrypt_handle,
     };
 
     esp_https_ota_handle_t https_ota_handle = NULL;