From c8435020a4e3998029abd14803e44f039de10c55 Mon Sep 17 00:00:00 2001
From: "ashutosh.nehete" <ashutosh.nehete@marcoaiot.com>
Date: Fri, 1 Aug 2025 18:22:31 +0530
Subject: [PATCH] Chnaged the function to chek if base64 is valid or not

---
 .../Controllers/TenantController.cs           | 46 ++++++++++++-------
 1 file changed, 29 insertions(+), 17 deletions(-)

diff --git a/Marco.Pms.Services/Controllers/TenantController.cs b/Marco.Pms.Services/Controllers/TenantController.cs
index 0b53f80..a922832 100644
--- a/Marco.Pms.Services/Controllers/TenantController.cs
+++ b/Marco.Pms.Services/Controllers/TenantController.cs
@@ -18,7 +18,6 @@ using Microsoft.AspNetCore.Mvc;
 using Microsoft.EntityFrameworkCore;
 using System.Net;
 using System.Text.Json;
-using System.Text.RegularExpressions;
 
 // For more information on enabling Web API for empty projects, visit https://go.microsoft.com/fwlink/?LinkID=397860
 
@@ -243,7 +242,8 @@ namespace Marco.Pms.Services.Controllers
             {
                 if (!string.IsNullOrWhiteSpace(model.TaxId))
                 {
-                    return await _context.Tenants.AnyAsync(t => t.TaxId == model.TaxId);
+                    await using var context = await _dbContextFactory.CreateDbContextAsync();
+                    return await context.Tenants.AnyAsync(t => t.TaxId == model.TaxId);
 
                 }
                 return false;
@@ -252,7 +252,8 @@ namespace Marco.Pms.Services.Controllers
             {
                 if (!string.IsNullOrWhiteSpace(model.DomainName))
                 {
-                    return await _context.Tenants.AnyAsync(t => t.DomainName == model.DomainName);
+                    await using var context = await _dbContextFactory.CreateDbContextAsync();
+                    return await context.Tenants.AnyAsync(t => t.DomainName == model.DomainName);
 
                 }
                 return false;
@@ -474,29 +475,40 @@ namespace Marco.Pms.Services.Controllers
         private bool IsBase64String(string? input)
         {
             if (string.IsNullOrWhiteSpace(input))
+            {
                 return false;
+            }
 
-            // Normalize string
-            input = input.Trim();
+            string base64Data = input;
+            const string dataUriMarker = "base64,";
+            int markerIndex = input.IndexOf(dataUriMarker, StringComparison.Ordinal);
 
-            // Length must be multiple of 4
-            if (input.Length % 4 != 0)
-                return false;
-
-            // Valid Base64 characters with correct padding
-            var base64Regex = new Regex(@"^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$");
-            if (!base64Regex.IsMatch(input))
+            // If the marker is found, extract the actual Base64 data
+            if (markerIndex >= 0)
+            {
+                base64Data = input.Substring(markerIndex + dataUriMarker.Length);
+            }
+
+            // Now, validate the extracted payload
+            base64Data = base64Data.Trim();
+
+            // Check for valid length (must be a multiple of 4) and non-empty
+            if (base64Data.Length == 0 || base64Data.Length % 4 != 0)
+            {
                 return false;
+            }
 
+            // The most reliable test is to simply try to convert it.
+            // The .NET converter is strict and will throw a FormatException
+            // for invalid characters or incorrect padding.
             try
             {
-                // Decode and re-encode to confirm validity
-                var bytes = Convert.FromBase64String(input);
-                var reEncoded = Convert.ToBase64String(bytes);
-                return input == reEncoded;
+                Convert.FromBase64String(base64Data);
+                return true;
             }
-            catch
+            catch (FormatException)
             {
+                // The string is not a valid Base64 payload.
                 return false;
             }
         }