qt: Prevent u32 overflow when calculating expiration date

* lang/qt/src/qgpgmesignkeyjob.cpp (sign_key): Change maxAllowedDate to
2106-02-05. Change log-level from warning to debug.
* lang/qt/tests/t-various.cpp (TestVarious::testSignKeyWithExpiration):
Remove check for warning. Adapt assertion.
--

Capping the expiration date at 2106-02-05 prevents a u32 overflow when
adding the number of days until the maximal date to the current time.

GnuPG-bug-id: 5991

2 files changed, 4 insertions, 4 deletions

diff --git a/lang/qt/src/qgpgmesignkeyjob.cpp b/lang/qt/src/qgpgmesignkeyjob.cpp
index 5036a9b9..506d64a1 100644
--- a/lang/qt/src/qgpgmesignkeyjob.cpp
+++ b/lang/qt/src/qgpgmesignkeyjob.cpp
@@ -127,11 +127,11 @@ static QGpgMESignKeyJob::result_type sign_key(Context *ctx, const Key &key, cons
 
     if (expirationDate.isValid()) {
         // on 2106-02-07, the Unix time will reach 0xFFFFFFFF; since gpg uses uint32 internally
-        // for the expiration date clip it at 2106-02-06
-        static const QDate maxAllowedDate{2106, 2, 6};
+        // for the expiration date clip it at 2106-02-05 to avoid problems with negative time zones
+        static const QDate maxAllowedDate{2106, 2, 5};
         const auto clippedExpirationDate = expirationDate <= maxAllowedDate ? expirationDate : maxAllowedDate;
         if (clippedExpirationDate != expirationDate) {
-            qCWarning(QGPGME_LOG) << "Expiration of certification has been changed to" << clippedExpirationDate;
+            qCDebug(QGPGME_LOG) << "Expiration of certification has been changed to" << clippedExpirationDate;
         }
         // use the "days from now" format to specify the expiration date of the certification;
         // this format is the most appropriate regardless of the local timezone
diff --git a/lang/qt/src/signkeyjob.h b/lang/qt/src/signkeyjob.h
index f4b3ed8f..d0e90c22 100644
--- a/lang/qt/src/signkeyjob.h
+++ b/lang/qt/src/signkeyjob.h
@@ -149,7 +149,7 @@ public:
      * Sets the expiration date of the key signature to @a expiration. By default,
      * key signatures do not expire.
      *
-     * Note: Expiration dates after 2106-02-06 will be set to 2106-02-06.
+     * Note: Expiration dates after 2106-02-05 will be set to 2106-02-05.
      *
      * Not pure virtual for ABI compatibility.
      **/