From 41e236aa5995297d6f47f5e3e11897a45cd71e72 Mon Sep 17 00:00:00 2001
From: Jonas Oreland <jonaso@webrtc.org>
Date: Thu, 21 Mar 2024 14:04:45 +0100
Subject: [PATCH] Fix ubsan warning in ParseError testcase
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The parse error testcase creates a random byte string
and tries to parse it as a delta attribute expecting it to fail.

Ubsan detected that there was "unsafe" static_cast<>, where
a value from network is static_casted:ed into a enum.
That enum was then *checked* for validity, so I think it was
same before aswell.

This fix changes to do the check/convering as one step.

Bug: webrtc:15392
Change-Id: Ie2534deef8988bc3c3179e194155cfd48b0ee6e5
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/343980
Reviewed-by: Jonas Oreland <jonaso@webrtc.org>
Reviewed-by: Björn Terelius <terelius@webrtc.org>
Commit-Queue: Jonas Oreland <jonaso@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#41942}
---
 p2p/base/stun_dictionary.cc | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/p2p/base/stun_dictionary.cc b/p2p/base/stun_dictionary.cc
index aabb8c394f..4ace8265af 100644
--- a/p2p/base/stun_dictionary.cc
+++ b/p2p/base/stun_dictionary.cc
@@ -18,6 +18,31 @@
 
 namespace cricket {
 
+namespace {
+
+StunAttributeValueType GetStunAttributeValueType(int value_type) {
+  switch (value_type) {
+    case STUN_VALUE_ADDRESS:
+      return STUN_VALUE_ADDRESS;
+    case STUN_VALUE_XOR_ADDRESS:
+      return STUN_VALUE_XOR_ADDRESS;
+    case STUN_VALUE_UINT32:
+      return STUN_VALUE_UINT32;
+    case STUN_VALUE_UINT64:
+      return STUN_VALUE_UINT64;
+    case STUN_VALUE_BYTE_STRING:
+      return STUN_VALUE_BYTE_STRING;
+    case STUN_VALUE_ERROR_CODE:
+      return STUN_VALUE_ERROR_CODE;
+    case STUN_VALUE_UINT16_LIST:
+      return STUN_VALUE_UINT16_LIST;
+    default:
+      return STUN_VALUE_UNKNOWN;
+  }
+}
+
+}  // namespace
+
 const StunAddressAttribute* StunDictionaryView::GetAddress(int key) const {
   const StunAttribute* attr = GetOrNull(key, STUN_VALUE_ADDRESS);
   if (attr == nullptr) {
@@ -120,7 +145,7 @@ StunDictionaryView::ParseDelta(const StunByteStringAttribute& delta) {
     }
 
     StunAttributeValueType value_type_enum =
-        static_cast<StunAttributeValueType>(value_type);
+        GetStunAttributeValueType(value_type);
     std::unique_ptr<StunAttribute> attr(
         StunAttribute::Create(value_type_enum, key, length, nullptr));
     if (!attr) {