Added validation to image download

CoviDok/BLL/Storage/StorageHandler.cs

@@ -41,7 +41,12 @@ namespace CoviDok.BLL.Storage
 
         public async Task GetImage(string bucketName, string ImageId, Action<Stream> callback)
         {
-            await storageProvider.Download(bucketName, ImageId, callback);
+            if (await storageProvider.ObjectExists(bucketName, ImageId))
+            {
+                await storageProvider.Download(bucketName, ImageId, callback);
+            }
+            else throw new KeyNotFoundException();
+            
         }
 
         public async Task<bool> ImageExists(string bucketName, string ImageId)

CoviDok/Controllers/ImagesController.cs

@@ -67,15 +67,22 @@ namespace CoviDok.Controllers
                 response.Body["reason"] = "unauthorized";
                 return response;
             }
+            try {
+                string res = null;
+                await MinioHandler.GetImage(BucketName, imageGet.ImageId, (stream) => {
+                    StreamReader reader = new StreamReader(stream);
+                    res = reader.ReadToEnd();
+                });
 
-            string res = null; ;
-            await MinioHandler.GetImage(BucketName, imageGet.ImageId, (stream) => {
-                StreamReader reader = new StreamReader(stream);
-                res = reader.ReadToEnd();
-            });
-            
-            response.Body["image"] = res;
-            return response;
+                response.Body["image"] = res;
+                return response;
+            }
+            catch (KeyNotFoundException)
+            {
+                response.Status = Status.Error;
+                response.Body["reason"] = "Image not found!";
+                return response;
+            }
         }
     }
 }