tst_QSslCertificate - improve code coverage

Some code-paths were never executed by auto-test, thus giving us LCOV's
diagnostic. Extend existing tests and add new ones.

Pick-to: 5.15
Change-Id: I648747547f0525a482216b1e1972fcc698c73f65
Reviewed-by: Mårten Nordheim <[email protected]>

tests/auto/network/ssl/qsslcertificate/more-certificates/aspiriniks.ca.crt

@@ -0,0 +1,22 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

tests/auto/network/ssl/qsslcertificate/more-certificates/cert-cn.pem

@@ -0,0 +1,32 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

tests/auto/network/ssl/qsslcertificate/more-certificates/cert-noname.pem

@@ -0,0 +1,32 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

tests/auto/network/ssl/qsslcertificate/more-certificates/cert-on.pem

@@ -0,0 +1,31 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

tests/auto/network/ssl/qsslcertificate/more-certificates/cert-oun.pem

@@ -0,0 +1,31 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

tests/auto/network/ssl/qsslcertificate/tst_qsslcertificate.cpp

@@ -80,6 +80,9 @@ private slots:
     void subjectAlternativeNames_data();
     void utf8SubjectNames();
     void subjectAlternativeNames();
+    void subjectInfoToString();
+    void subjectIssuerDisplayName_data();
+    void subjectIssuerDisplayName();
     void publicKey_data();
     void publicKey();
     void toPemOrDer_data();
@@ -437,6 +440,63 @@ void tst_QSslCertificate::subjectAlternativeNames()
     }
 }
 
+void tst_QSslCertificate::subjectInfoToString()
+{
+    QFile certFile(testDataDir + "more-certificates/aspiriniks.ca.crt");
+    const bool ok = certFile.open(QIODevice::ReadOnly);
+    QVERIFY(ok);
+    const auto chain = QSslCertificate::fromDevice(&certFile, QSsl::Pem);
+    QCOMPARE(chain.size(), 1);
+    const auto cert = chain.at(0);
+    QVERIFY(!cert.isNull());
+
+    const auto testInfo = [&cert](QSslCertificate::SubjectInfo info, const QString &expected) {
+        const auto infoAsList = cert.subjectInfo(info);
+        if (infoAsList.size())
+            return expected == infoAsList.at(0);
+        return expected == QString();
+    };
+
+    QVERIFY(testInfo(QSslCertificate::Organization, QStringLiteral("TT ASA")));
+    QVERIFY(testInfo(QSslCertificate::CommonName, QStringLiteral("aspiriniks.troll.no")));
+    QVERIFY(testInfo(QSslCertificate::LocalityName, QStringLiteral("Oslo")));
+    QVERIFY(testInfo(QSslCertificate::OrganizationalUnitName, QStringLiteral("QT SW")));
+    QVERIFY(testInfo(QSslCertificate::CountryName, QStringLiteral("NO")));
+    QVERIFY(testInfo(QSslCertificate::StateOrProvinceName, QStringLiteral("Oslo")));
+    QVERIFY(testInfo(QSslCertificate::DistinguishedNameQualifier, QString()));
+    QVERIFY(testInfo(QSslCertificate::SerialNumber, QString()));
+#ifndef QT_NO_OPENSSL
+    // TODO: check why generic code does not handle this!
+    QVERIFY(testInfo(QSslCertificate::EmailAddress, QStringLiteral("[email protected]")));
+#endif
+}
+
+void tst_QSslCertificate::subjectIssuerDisplayName_data()
+{
+    QTest::addColumn<QString>("certName");
+    QTest::addColumn<QString>("expectedName");
+
+    QTest::addRow("CommonName") << QStringLiteral("more-certificates/cert-cn.pem") << QStringLiteral("YOUR name");
+    QTest::addRow("OrganizationName") << QStringLiteral("more-certificates/cert-on.pem") << QStringLiteral("R&D");
+    QTest::addRow("OrganizationUnitName") << QStringLiteral("more-certificates/cert-oun.pem") << QStringLiteral("Foundations");
+#ifndef QT_NO_OPENSSL
+    QTest::addRow("NoSubjectName") << QStringLiteral("more-certificates/cert-noname.pem") << QString();
+#endif
+}
+
+void tst_QSslCertificate::subjectIssuerDisplayName()
+{
+    QFETCH(const QString, certName);
+    QFETCH(const QString, expectedName);
+
+    const auto chain = QSslCertificate::fromPath(testDataDir + certName);
+    QCOMPARE(chain.size(), 1);
+    const auto cert = chain.at(0);
+    QVERIFY(!cert.isNull());
+    QCOMPARE(cert.subjectDisplayName(), expectedName);
+    QCOMPARE(cert.issuerDisplayName(), expectedName);
+}
+
 void tst_QSslCertificate::utf8SubjectNames()
 {
     QSslCertificate cert = QSslCertificate::fromPath(testDataDir + "certificates/cert-ss-san-utf8.pem", QSsl::Pem,
@@ -545,8 +605,15 @@ void tst_QSslCertificate::toPemOrDer()
 void tst_QSslCertificate::fromDevice()
 {
     QTest::ignoreMessage(QtWarningMsg, "QSslCertificate::fromDevice: cannot read from a null device");
-    QList<QSslCertificate> certs = QSslCertificate::fromDevice(0); // don't crash
+    QList<QSslCertificate> certs = QSslCertificate::fromDevice(nullptr); // don't crash
     QVERIFY(certs.isEmpty());
+
+    QFile certFile(testDataDir + "certificates/cert.der");
+    const bool ok = certFile.open(QIODevice::ReadOnly);
+    QVERIFY(ok);
+    const auto chain = QSslCertificate::fromDevice(&certFile, QSsl::Der);
+    QCOMPARE(chain.size(), 1);
+    QVERIFY(!chain.at(0).isNull());
 }
 
 void tst_QSslCertificate::fromPath_qregularexpression_data()