libchrome_tools/patches/backward-compatibility-0500-Restore-old-UngessableToken-Deserialize.patch

From 6b47f434f8d3f63f61abc034e11d2fba7fd99906 Mon Sep 17 00:00:00 2001
From: Grace Cham <hscham@chromium.org>
Date: Mon, 30 Jan 2023 15:35:07 +0900
Subject: [PATCH] Revert "Remove the old UnguessableToken::Deserialize"

Clean-up bug: b/267117536

This reverts commit a150dbb23e71f80c06a04707223571b9e68a5fd9.
---
 base/unguessable_token.cc | 11 +++++++++++
 base/unguessable_token.h  | 15 ++++++++++++---
 2 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/base/unguessable_token.cc b/base/unguessable_token.cc
index db7a36144729..af8afb24367d 100644
--- a/base/unguessable_token.cc
+++ b/base/unguessable_token.cc
@@ -32,6 +32,17 @@ const UnguessableToken& UnguessableToken::Null() {
   return null_token;
 }
 
+// static
+UnguessableToken UnguessableToken::Deserialize(uint64_t high, uint64_t low) {
+  // Receiving a zeroed out UnguessableToken from another process means that it
+  // was never initialized via Create(). The real check for this is in the
+  // StructTraits in mojo/public/cpp/base/unguessable_token_mojom_traits.cc
+  // where a zero-ed out token will fail to deserialize. This DCHECK is a
+  // backup check.
+  DCHECK(!(high == 0 && low == 0));
+  return UnguessableToken(Token{high, low});
+}
+
 // static
 absl::optional<UnguessableToken> UnguessableToken::Deserialize2(uint64_t high,
                                                                 uint64_t low) {
diff --git a/base/unguessable_token.h b/base/unguessable_token.h
index 121f92d07a60..f35749ddfc22 100644
--- a/base/unguessable_token.h
+++ b/base/unguessable_token.h
@@ -56,11 +56,20 @@ class BASE_EXPORT UnguessableToken {
   // default constructor.
   static const UnguessableToken& Null();
 
-  // Return an UnguessableToken built from the high/low bytes provided.
+  // NOTE: This method is deprecated and will soon be replaced by the one below.
+  // Return a UnguessableToken built from the high/low bytes provided.
   // It should only be used in deserialization scenarios.
   //
-  // NOTE: If the returned `absl::optional` does not have a value, it means that
-  // `high` and `low` correspond to an `UnguesssableToken` that was never
+  // NOTE: If the deserialized token is empty, it means that it was never
+  // initialized via Create(). This is a security issue, and should be handled.
+  static UnguessableToken Deserialize(uint64_t high, uint64_t low);
+
+  // Return a UnguessableToken built from the high/low bytes provided.
+  // It should only be used in deserialization scenarios.
+  //
+  // NOTE: Once `Deserialize` above is removed, this will be renamed to that.
+  //
+  // NOTE: If the deserialized token is empty, it means that it was never
   // initialized via Create(). This is a security issue, and should be handled.
   static absl::optional<UnguessableToken> Deserialize2(uint64_t high,
                                                        uint64_t low);
-- 
2.39.1.456.gfc5497dd1b-goog