Security/Services/PreAuthService.cs

@@ -3,6 +3,7 @@ using Mirea.Api.Security.Common.Dto.Requests;
 using Mirea.Api.Security.Common.Dto.Responses;
 using Mirea.Api.Security.Common.Interfaces;
 using System;
+using System.Security;
 using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
@@ -43,4 +44,21 @@ public class PreAuthService(ICacheService cache)
             ExpiresIn = DateTime.UtcNow.Add(Lifetime)
         };
     }
+    public async Task<string> MatchToken(TokenRequest request, string preAuthToken, CancellationToken cancellation = default)
+    {
+        var preAuthTokenStruct = await cache.GetAsync<PreAuthToken>(GetPreAuthCacheKey(request.Fingerprint), cancellation)
+            ?? throw new SecurityException($"The token was not found using fingerprint \"{request.Fingerprint}\"");
+
+        if (preAuthTokenStruct == null ||
+            preAuthTokenStruct.Token != preAuthToken ||
+            (preAuthTokenStruct.UserAgent != request.UserAgent &&
+             preAuthTokenStruct.Ip != request.Ip))
+        {
+            throw new SecurityException("It was not possible to verify the authenticity of the token");
+        }
+
+        await cache.RemoveAsync(GetPreAuthCacheKey(request.Fingerprint), cancellation);
+
+        return preAuthTokenStruct.UserId;
+    }
 }