....

Back/Controllers/BaseController.cs

@@ -47,7 +47,13 @@ namespace Back.Controllers
         }
         [HttpPost("ReadPublicKeyFromCER")]
         public async Task<ActionResult<PublicKeyDTO>> ReadPublicKeyFromCER(string modelfromBase64)
-        => Ok(await _sBase.ReadPublicKeyFromCER(modelfromBase64));
+        {
+            var result = await _sBase.ReadPublicKeyFromCER(modelfromBase64);
+            if (result.type== "error")
+                return BadRequest();
+            
+           return Ok(result);
+        }
         
     }
 }

Back/Services/ServBase.cs

@@ -3,6 +3,7 @@ using Back.Data.Contracts;
 using Back.Data.Models;
 using Microsoft.EntityFrameworkCore;
 using Shared.DTOs;
+using System;
 using System.Diagnostics;
 using System.Text;
 
@@ -147,8 +148,12 @@ namespace Back.Services
 
             return taxTools;
         }
-        public async Task<PublicKeyDTO> ReadPublicKeyFromCER(string modelfromBase64)
+        public async Task<PublicKeyDTO?> ReadPublicKeyFromCER(string modelfromBase64)
         {
+            try
+            {
+
+           
             string name = $"{DateTime.Now.Year}{DateTime.Now.Month}{DateTime.Now.DayOfWeek}{DateTime.Now.Hour}{DateTime.Now.Minute}{DateTime.Now.Second}";
             string filePath = $"C:\\cer\\{name}.cer";
             Stream stream = System.IO.File.Open(filePath, FileMode.Create);
@@ -194,6 +199,15 @@ namespace Back.Services
                 PublicKeyBase64 = Convert.ToBase64String(buffer),
                 type = "txt"
             };
+            }
+            catch (Exception)
+            {
+                return new PublicKeyDTO
+                {
+                    PublicKeyBase64 = "error",
+                    type = "error"
+                };
+            }
         }
     }
 }