From 59f79847c264b2a8623f3eabb999efa0ee77bd08 Mon Sep 17 00:00:00 2001
From: ruti <>
Date: Sat, 15 Mar 2025 14:38:01 +0300
Subject: [PATCH] Ignore extra bytes after tlsrec in fake payload

---
 packets.c | 13 ++++++-------
 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/packets.c b/packets.c
index 04a7957..208370f 100644
--- a/packets.c
+++ b/packets.c
@@ -118,14 +118,13 @@ static size_t find_ext_block(const char *data, size_t size)
 }
 
 
-static int merge_tls_records(char *buffer, ssize_t n)
+static void merge_tls_records(char *buffer, ssize_t n)
 {
     if (n < 5) {
-        return 0;
+        return;
     }
     uint16_t full_sz = 0;
     uint16_t r_sz = ANTOHS(buffer, 3);
-    int i = 0;
     
     while (1) {
         full_sz += r_sz;
@@ -140,11 +139,9 @@ static int merge_tls_records(char *buffer, ssize_t n)
         }
         memmove(buffer + 5 + full_sz, 
             buffer + 10 + full_sz, n - (10 + full_sz));
-        i++;
     }
     SHTONA(buffer, 3, full_sz);
     SHTONA(buffer, 7, full_sz - 4);
-    return i * 5;
 }
 
 
@@ -228,8 +225,8 @@ static void resize_sni(char *buffer, ssize_t n,
 
 int change_tls_sni(const char *host, char *buffer, ssize_t n, ssize_t nn)
 {
-    int avail = merge_tls_records(buffer, n);
-    avail += (nn - n);
+    merge_tls_records(buffer, n);
+    int avail = nn < n ? nn - n : 0;
     
     uint16_t r_sz = ANTOHS(buffer, 3);
     r_sz += avail;
@@ -285,6 +282,8 @@ int change_tls_sni(const char *host, char *buffer, ssize_t n, ssize_t nn)
     copy_name(buffer + sni_offs + 9, host, new_sz);
     
     if (avail >= 4) {
+        avail += remove_tls_ext(buffer, n, skip, 0x0015);
+        
         SHTONA(buffer, 5 + r_sz - avail, 0x0015);
         SHTONA(buffer, 5 + r_sz - avail + 2, avail - 4);
         memset(buffer + 5 + r_sz - avail + 4, 0, avail - 4);