From b1d80b35af1d05e0fff8ce3da76f58dd5b5a4fd0 Mon Sep 17 00:00:00 2001
From: stelar7 <dudedbz@gmail.com>
Date: Mon, 3 Apr 2023 18:53:29 +0200
Subject: [PATCH] LibCrypto: Add ability to rewrite current tag kind

This is used for IMPLICIT tags where the expected kind is overriden
by the encoding instructions.
---
 Userland/Libraries/LibCrypto/ASN1/DER.h | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/Userland/Libraries/LibCrypto/ASN1/DER.h b/Userland/Libraries/LibCrypto/ASN1/DER.h
index d4333e5b94..63829c95b2 100644
--- a/Userland/Libraries/LibCrypto/ASN1/DER.h
+++ b/Userland/Libraries/LibCrypto/ASN1/DER.h
@@ -58,6 +58,25 @@ public:
         ValueType value;
     };
 
+    ErrorOr<void> rewrite_tag(Kind kind)
+    {
+        if (m_stack.is_empty())
+            return Error::from_string_view("Nothing on stack to rewrite"sv);
+
+        if (eof())
+            return Error::from_string_view("Stream is empty"sv);
+
+        if (m_current_tag.has_value()) {
+            m_current_tag->kind = kind;
+            return {};
+        }
+
+        auto tag = TRY(read_tag());
+        m_current_tag = tag;
+        m_current_tag->kind = kind;
+        return {};
+    }
+
     ErrorOr<void> drop()
     {
         if (m_stack.is_empty())