QtNetwork: convert some QDateTime::currentDateTime() to currentDateTimeUtc()

The latter is much faster as it doesn't have to deal with
time zones.

This change is safe, because the QDateTimes are only used for
comparison with other QDateTimes, which, from a quick glance around,
seem to be mostly, if not exclusively, in UTC. Comparsions work
across time zones, but the comparison between UTC date-times is
fastest.

Credits to Milian Wolff, from whose QtWS15 talk this advice is
taken.

Change-Id: I6859d886d8dc8e0a52fbe394fbb7b93a87b4739a
Reviewed-by: Milian Wolff <milian.wolff@kdab.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

4 files changed, 8 insertions, 5 deletions

diff --git a/src/network/access/qnetworkcookiejar.cpp b/src/network/access/qnetworkcookiejar.cpp
index 3cefb28f68..39f94a451f 100644
--- a/src/network/access/qnetworkcookiejar.cpp
+++ b/src/network/access/qnetworkcookiejar.cpp
@@ -216,7 +216,7 @@ QList<QNetworkCookie> QNetworkCookieJar::cookiesForUrl(const QUrl &url) const
 //     It does not implement a very good cross-domain verification yet.
 
     Q_D(const QNetworkCookieJar);
-    QDateTime now = QDateTime::currentDateTime();
+    const QDateTime now = QDateTime::currentDateTimeUtc();
     QList<QNetworkCookie> result;
     bool isEncrypted = url.scheme().toLower() == QLatin1String("https");
 
@@ -265,7 +265,7 @@ QList<QNetworkCookie> QNetworkCookieJar::cookiesForUrl(const QUrl &url) const
 bool QNetworkCookieJar::insertCookie(const QNetworkCookie &cookie)
 {
     Q_D(QNetworkCookieJar);
-    QDateTime now = QDateTime::currentDateTime();
+    const QDateTime now = QDateTime::currentDateTimeUtc();
     bool isDeletion = !cookie.isSessionCookie() &&
                       cookie.expirationDate() < now;
 
diff --git a/src/network/ssl/qsslcertificate.h b/src/network/ssl/qsslcertificate.h
index af605b0629..d58cfcf5d1 100644
--- a/src/network/ssl/qsslcertificate.h
+++ b/src/network/ssl/qsslcertificate.h
@@ -97,7 +97,7 @@ public:
     bool isNull() const;
 #if QT_DEPRECATED_SINCE(5,0)
     QT_DEPRECATED inline bool isValid() const {
-        const QDateTime currentTime = QDateTime::currentDateTime();
+        const QDateTime currentTime = QDateTime::currentDateTimeUtc();
         return currentTime >= effectiveDate() &&
                currentTime <= expiryDate() &&
                !isBlacklisted();
diff --git a/src/network/ssl/qsslcontext_openssl.cpp b/src/network/ssl/qsslcontext_openssl.cpp
index b88ab54038..68caaeb6dc 100644
--- a/src/network/ssl/qsslcontext_openssl.cpp
+++ b/src/network/ssl/qsslcontext_openssl.cpp
@@ -215,6 +215,8 @@ init_context:
         return sslContext;
     }
 
+    const QDateTime now = QDateTime::currentDateTimeUtc();
+
     // Add all our CAs to this store.
     foreach (const QSslCertificate &caCertificate, sslContext->sslConfiguration.caCertificates()) {
         // From https://www.openssl.org/docs/ssl/SSL_CTX_load_verify_locations.html:
@@ -228,7 +230,7 @@ init_context:
         // certificates mixed with valid ones.
         //
         // See also: QSslSocketBackendPrivate::verify()
-        if (caCertificate.expiryDate() >= QDateTime::currentDateTime()) {
+        if (caCertificate.expiryDate() >= now) {
             q_X509_STORE_add_cert(q_SSL_CTX_get_cert_store(sslContext->ctx), (X509 *)caCertificate.handle());
         }
     }
diff --git a/src/network/ssl/qsslsocket_openssl.cpp b/src/network/ssl/qsslsocket_openssl.cpp
index a8e4c61e9a..dd47dfc45f 100644
--- a/src/network/ssl/qsslsocket_openssl.cpp
+++ b/src/network/ssl/qsslsocket_openssl.cpp
@@ -1660,6 +1660,7 @@ QList<QSslError> QSslSocketBackendPrivate::verify(const QList<QSslCertificate> &
         setDefaultCaCertificates(defaultCaCertificates() + systemCaCertificates());
     }
 
+    const QDateTime now = QDateTime::currentDateTimeUtc();
     foreach (const QSslCertificate &caCertificate, QSslConfiguration::defaultConfiguration().caCertificates()) {
         // From https://www.openssl.org/docs/ssl/SSL_CTX_load_verify_locations.html:
         //
@@ -1672,7 +1673,7 @@ QList<QSslError> QSslSocketBackendPrivate::verify(const QList<QSslCertificate> &
         // certificates mixed with valid ones.
         //
         // See also: QSslContext::fromConfiguration()
-        if (caCertificate.expiryDate() >= QDateTime::currentDateTime()) {
+        if (caCertificate.expiryDate() >= now) {
             q_X509_STORE_add_cert(certStore, reinterpret_cast<X509 *>(caCertificate.handle()));
         }
     }