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, 20 insertions, 4 deletions

diff --git a/src/corelib/tools/qcryptographichash.h b/src/corelib/tools/qcryptographichash.h
index 0f17baa036..2f74d42405 100644
--- a/src/corelib/tools/qcryptographichash.h
+++ b/src/corelib/tools/qcryptographichash.h
@@ -65,10 +65,26 @@ public:
         Sha256,
         Sha384,
         Sha512,
-        Sha3_224,
-        Sha3_256,
-        Sha3_384,
-        Sha3_512
+
+        Keccak_224 = 7,
+        Keccak_256,
+        Keccak_384,
+        Keccak_512,
+        RealSha3_224 = 11,
+        RealSha3_256,
+        RealSha3_384,
+        RealSha3_512,
+#  ifndef QT_SHA3_KECCAK_COMPAT
+        Sha3_224 = RealSha3_224,
+        Sha3_256 = RealSha3_256,
+        Sha3_384 = RealSha3_384,
+        Sha3_512 = RealSha3_512
+#  else
+        Sha3_224 = Keccak_224,
+        Sha3_256 = Keccak_256,
+        Sha3_384 = Keccak_384,
+        Sha3_512 = Keccak_512
+#  endif
 #endif
     };
     Q_ENUM(Algorithm)