Restore compatibility with pre-5.9 Keccak calculation

Commit 12c5264d9add1826d543c36d893db77262195fc6 fixed the calculation of
SHA-3 in QCryptographicHash: we were previously calculating Keccak.
Unfortunately, turns out that replacing the algorithm wasn't the best
idea: there are people who need to compare with the result obtained from
a previous version of Qt and stored somewhere. This commit restores the
enum values 7 through 10 to mean Keccak and moves SHA-3 to 12 through
15. The "Sha3_nnn" enums will switch between the two according to the
QT_SHA3_KECCAK_COMPAT macro.

[ChangeLog][Important Behavior Changes] This version of Qt restores
compatibility with pre-5.9.0 calculation of QCryptographicHash
algorithms that were labelled "Sha3_nnn": that is, applications compiled
with old versions of Qt will continue using the Keccak algorithm.
Applications recompiled with this version will use SHA-3, unless
QT_SHA3_KECCAK_COMPAT is #define'd prior to #include
<QCryptographicHash>.

[ChangeLog][Binary Compatibility Note] This version of Qt changes the
values assigned to enumerations QCryptographicHash::Sha3_nnn.
Applications compiled with this version and using those enumerations
will not work with Qt 5.9.0 and 5.9.1, unless QT_SHA3_KECCAK_COMPAT is
defined.

Task-number: QTBUG-62025
Discussed-at: http://lists.qt-project.org/pipermail/development/2017-September/030818.html
Change-Id: I6e1fe42ae4b742a7b811fffd14e418fc04f096c3
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 8 insertions, 4 deletions

diff --git a/src/corelib/tools/qmessageauthenticationcode.cpp b/src/corelib/tools/qmessageauthenticationcode.cpp
index 9a84191452..40a1193622 100644
--- a/src/corelib/tools/qmessageauthenticationcode.cpp
+++ b/src/corelib/tools/qmessageauthenticationcode.cpp
@@ -99,13 +99,17 @@ static int qt_hash_block_size(QCryptographicHash::Algorithm method)
         return SHA384_Message_Block_Size;
     case QCryptographicHash::Sha512:
         return SHA512_Message_Block_Size;
-    case QCryptographicHash::Sha3_224:
+    case QCryptographicHash::RealSha3_224:
+    case QCryptographicHash::Keccak_224:
         return 144;
-    case QCryptographicHash::Sha3_256:
+    case QCryptographicHash::RealSha3_256:
+    case QCryptographicHash::Keccak_256:
         return 136;
-    case QCryptographicHash::Sha3_384:
+    case QCryptographicHash::RealSha3_384:
+    case QCryptographicHash::Keccak_384:
         return 104;
-    case QCryptographicHash::Sha3_512:
+    case QCryptographicHash::RealSha3_512:
+    case QCryptographicHash::Keccak_512:
         return 72;
     }
     return 0;