From 27c3f90650c9d8647e8adcc756eb6bce06f82e0c Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Tue, 25 Jun 2024 13:46:33 +0200
Subject: [PATCH] QCryptographicHash: copy SHA-3 context outside sha3Finish()

This matches what other algorithms do.

This is in preparation of separating the state copying from the
algorithm finishing, to eventually establish code paths that do not
need to copy (e.g. static hash()/hashInto()).

Pick-to: 6.7 6.5
Change-Id: If674cae6b7b3fc3abd3b72f2162532321decadff
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
(cherry picked from commit 37e360a13f14f19ac0d3ea9ca5d18ca222f3b5a7)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
---
 src/corelib/tools/qcryptographichash.cpp | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/src/corelib/tools/qcryptographichash.cpp b/src/corelib/tools/qcryptographichash.cpp
index 3788361ea85..1c122d5620f 100644
--- a/src/corelib/tools/qcryptographichash.cpp
+++ b/src/corelib/tools/qcryptographichash.cpp
@@ -386,7 +386,7 @@ public:
         SHA3Context sha3Context;
 
         enum class Sha3Variant { Sha3, Keccak };
-        void sha3Finish(HashResult &result, int bitCount, Sha3Variant sha3Variant);
+        static void sha3Finish(SHA3Context &ctx, HashResult &result, int bitCount, Sha3Variant sha3Variant);
         blake2b_state blake2bContext;
         blake2s_state blake2sContext;
 #endif
@@ -399,8 +399,8 @@ public:
 };
 
 #ifndef QT_CRYPTOGRAPHICHASH_ONLY_SHA1
-void QCryptographicHashPrivate::State::sha3Finish(HashResult &result, int bitCount,
-                                                  Sha3Variant sha3Variant)
+void QCryptographicHashPrivate::State::sha3Finish(SHA3Context &ctx, HashResult &result,
+                                                  int bitCount, Sha3Variant sha3Variant)
 {
     /*
         FIPS 202 §6.1 defines SHA-3 in terms of calculating the Keccak function
@@ -426,17 +426,15 @@ void QCryptographicHashPrivate::State::sha3Finish(HashResult &result, int bitCou
 
     result.resizeForOverwrite(bitCount / 8);
 
-    SHA3Context copy = sha3Context;
-
     switch (sha3Variant) {
     case Sha3Variant::Sha3:
-        sha3Update(&copy, reinterpret_cast<const BitSequence *>(&sha3FinalSuffix), 2);
+        sha3Update(&ctx, reinterpret_cast<const BitSequence *>(&sha3FinalSuffix), 2);
         break;
     case Sha3Variant::Keccak:
         break;
     }
 
-    sha3Final(&copy, result.data());
+    sha3Final(&ctx, result.data());
 }
 #endif
 
@@ -1034,7 +1032,8 @@ void QCryptographicHashPrivate::State::finalizeUnchecked(QCryptographicHash::Alg
         method == QCryptographicHash::Keccak_256 ||
         method == QCryptographicHash::Keccak_384 ||
         method == QCryptographicHash::Keccak_512) {
-        sha3Finish(result, 8 * hashLengthInternal(method), Sha3Variant::Keccak);
+        SHA3Context copy = sha3Context;
+        sha3Finish(copy, result, 8 * hashLengthInternal(method), Sha3Variant::Keccak);
     } else if (method == QCryptographicHash::Blake2b_160 ||
                method == QCryptographicHash::Blake2b_256 ||
                method == QCryptographicHash::Blake2b_384) {
@@ -1123,14 +1122,16 @@ void QCryptographicHashPrivate::State::finalizeUnchecked(QCryptographicHash::Alg
     case QCryptographicHash::RealSha3_256:
     case QCryptographicHash::RealSha3_384:
     case QCryptographicHash::RealSha3_512: {
-        sha3Finish(result, 8 * hashLengthInternal(method), Sha3Variant::Sha3);
+        SHA3Context copy = sha3Context;
+        sha3Finish(copy, result, 8 * hashLengthInternal(method), Sha3Variant::Sha3);
         break;
     }
     case QCryptographicHash::Keccak_224:
     case QCryptographicHash::Keccak_256:
     case QCryptographicHash::Keccak_384:
     case QCryptographicHash::Keccak_512: {
-        sha3Finish(result, 8 * hashLengthInternal(method), Sha3Variant::Keccak);
+        SHA3Context copy = sha3Context;
+        sha3Finish(copy, result, 8 * hashLengthInternal(method), Sha3Variant::Keccak);
         break;
     }
     case QCryptographicHash::Blake2b_160: