From 859980af026f163ca112170589bf49de9f206299 Mon Sep 17 00:00:00 2001
From: gamer147 <gamer147@gmail.com>
Date: Wed, 27 May 2026 14:11:47 -0400
Subject: [PATCH] wire: echo UDID in DataHeaders on every response
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SignUpTask.Parse validates data_headers.udid against Certification.Udid;
mismatch discards the response. Sourced from the same mappedUdid the
translation middleware uses to decrypt — never controller state. Other
endpoints carry the extra key; SignUpTask is the only reader.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
---
 .../Middlewares/ShadowverseTranslationMiddleware.cs |  6 +++++-
 .../Models/Dtos/Internal/DataHeaders.cs             | 13 ++++++++++++-
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/SVSim.EmulatedEntrypoint/Middlewares/ShadowverseTranslationMiddleware.cs b/SVSim.EmulatedEntrypoint/Middlewares/ShadowverseTranslationMiddleware.cs
index 230406f..2ffc0e6 100644
--- a/SVSim.EmulatedEntrypoint/Middlewares/ShadowverseTranslationMiddleware.cs
+++ b/SVSim.EmulatedEntrypoint/Middlewares/ShadowverseTranslationMiddleware.cs
@@ -166,7 +166,11 @@ public class ShadowverseTranslationMiddleware : IMiddleware
                 // populated (prod sends real numbers for the title check too, but 0 / 0 satisfies
                 // the client's BaseTask.Parse which only reads result_code + servertime here).
                 ShortUdid = viewer?.ShortUdid ?? 0,
-                ViewerId = viewer?.Id ?? 0
+                ViewerId = viewer?.Id ?? 0,
+                // Echo the decrypted-against UDID. Most clients ignore this field; SignUpTask.Parse
+                // requires it (validates against Certification.Udid on the response). Comes from
+                // mappedUdid (the value used for AES); never from controller state.
+                Udid = mappedUdid?.ToString() ?? ""
             }
         };
 
diff --git a/SVSim.EmulatedEntrypoint/Models/Dtos/Internal/DataHeaders.cs b/SVSim.EmulatedEntrypoint/Models/Dtos/Internal/DataHeaders.cs
index 5cac025..e39bd61 100644
--- a/SVSim.EmulatedEntrypoint/Models/Dtos/Internal/DataHeaders.cs
+++ b/SVSim.EmulatedEntrypoint/Models/Dtos/Internal/DataHeaders.cs
@@ -21,4 +21,15 @@ public class DataHeaders
     [JsonPropertyName("result_code")]
     [Key("result_code")]
     public int ResultCode { get; set; }
-}
\ No newline at end of file
+
+    /// <summary>
+    /// Echoed UDID. Read by <c>SignUpTask.Parse</c> to validate response identity (client logs
+    /// <c>udid一致しません</c> and discards the response on mismatch); ignored by every other
+    /// client task. Always set by <c>ShadowverseTranslationMiddleware</c> from the request's
+    /// resolved UDID — never from controller state. Empty string when the SID→UDID lookup misses
+    /// (request without UDID/SID headers).
+    /// </summary>
+    [JsonPropertyName("udid")]
+    [Key("udid")]
+    public string Udid { get; set; } = "";
+}