1 files changed, 18 insertions, 22 deletions

diff --git a/src/plugins/tls/shared/qasn1element.cpp b/src/plugins/tls/shared/qasn1element.cpp
index cbf038f569..97be46866d 100644
--- a/src/plugins/tls/shared/qasn1element.cpp
+++ b/src/plugins/tls/shared/qasn1element.cpp
@@ -6,13 +6,17 @@
 
 #include <QtCore/qdatastream.h>
 #include <QtCore/qdatetime.h>
+#include <QtCore/qtimezone.h>
 #include <QtCore/qlist.h>
 #include <QDebug>
+#include <private/qtools_p.h>
 
 #include <limits>
 
 QT_BEGIN_NAMESPACE
 
+using namespace QtMiscUtils;
+
 typedef QMap<QByteArray, QByteArray> OidNameMap;
 static OidNameMap createOidMap()
 {
@@ -213,11 +217,6 @@ QDateTime QAsn1Element::toDateTime() const
 
     // QDateTime::fromString is lenient and accepts +- signs in front
     // of the year; but ASN.1 doesn't allow them.
-    const auto isAsciiDigit = [](char c)
-    {
-        return c >= '0' && c <= '9';
-    };
-
     if (!isAsciiDigit(mValue[0]))
         return result;
 
@@ -226,31 +225,28 @@ QDateTime QAsn1Element::toDateTime() const
         return result;
 
     if (mType == UtcTimeType && mValue.size() == 13) {
-        result = QDateTime::fromString(QString::fromLatin1(mValue),
-                                       QStringLiteral("yyMMddHHmmsst"));
-        if (!result.isValid())
-            return result;
-
-        Q_ASSERT(result.timeSpec() == Qt::UTC);
-
-        QDate date = result.date();
-
         // RFC 2459:
         //   Where YY is greater than or equal to 50, the year shall be
         //   interpreted as 19YY; and
         //
         //   Where YY is less than 50, the year shall be interpreted as 20YY.
         //
-        // QDateTime interprets the 'yy' format as 19yy, so we may need to adjust
-        // the year (bring it in the [1950, 2049] range).
-        if (date.year() < 1950)
-            result.setDate(date.addYears(100));
+        // so use 1950 as base year.
+        constexpr int rfc2459CenturyStart = 1950;
+        const QLatin1StringView inputView(mValue);
+        QDate date = QDate::fromString(inputView.first(6), u"yyMMdd", rfc2459CenturyStart);
+        if (!date.isValid())
+            return result;
 
-        Q_ASSERT(result.date().year() >= 1950);
-        Q_ASSERT(result.date().year() <= 2049);
+        Q_ASSERT(date.year() >= rfc2459CenturyStart);
+        Q_ASSERT(date.year() < 100 + rfc2459CenturyStart);
+
+        QTime time = QTime::fromString(inputView.sliced(6, 6), u"HHmmss");
+        if (!time.isValid())
+            return result;
+        result = QDateTime(date, time, QTimeZone::UTC);
     } else if (mType == GeneralizedTimeType && mValue.size() == 15) {
-        result = QDateTime::fromString(QString::fromLatin1(mValue),
-                                       QStringLiteral("yyyyMMddHHmmsst"));
+        result = QDateTime::fromString(QString::fromLatin1(mValue), u"yyyyMMddHHmmsst");
     }
 
     return result;