QSslCertificate: add fromFile() method

QSslCertificate::fromPath() does some extra work:
- matching wildcard glob or regular expression patterns
- checks if the string it's called on is a file or a dir

That extra work isn't needed when you already have the path to a
specific certificate file.
E.g. qtlsbackend_openssl.cpp:systemCaCertificates() used to call
fromPath() on *.pem/*.crt files that it got from iterating over system
certifcates dirs.

This also de-duplicates the code in fromPath().

[ChangeLog][QtNetwork][QSslCertificate] Added fromFile() method.

Change-Id: I92ab358e4711866dd4510da42c47905c7dae58b1
Reviewed-by: Ivan Solovev <ivan.solovev@qt.io>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>

src/network/ssl/qsslcertificate.cpp

@@ -633,6 +633,9 @@ QList<QSslCertificate> QSslCertificate::fromPath(const QString &path,
     if (path.isEmpty())
         return {};
 
+    if (syntax == PatternSyntax::FixedString && QFileInfo(path).isFile())
+        return fromFile(path, format);
+
     // $, (,), *, +, ., ?, [, ,], ^, {, | and }.
 
     // make sure to use the same path separators on Windows and Unix like systems.
@@ -665,15 +668,8 @@ QList<QSslCertificate> QSslCertificate::fromPath(const QString &path,
             pathPrefix = {};
     } else {
         // Check if the path is a file.
-        if (QFileInfo(sourcePath).isFile()) {
+        if (QFileInfo(sourcePath).isFile())
-            QFile file(sourcePath);
+            return fromFile(sourcePath, format);
-            QIODevice::OpenMode openMode = QIODevice::ReadOnly;
-            if (format == QSsl::Pem)
-                openMode |= QIODevice::Text;
-            if (file.open(openMode))
-                return QSslCertificate::fromData(file.readAll(), format);
-            return QList<QSslCertificate>();
-        }
     }
 
     // Special case - if the prefix ends up being nothing, use "." instead.
@@ -710,12 +706,7 @@ QList<QSslCertificate> QSslCertificate::fromPath(const QString &path,
             continue;
 #endif
 
-        QFile file(filePath);
+        certs += QSslCertificate::fromFile(filePath, format);
-        QIODevice::OpenMode openMode = QIODevice::ReadOnly;
-        if (format == QSsl::Pem)
-            openMode |= QIODevice::Text;
-        if (file.open(openMode))
-            certs += QSslCertificate::fromData(file.readAll(), format);
     }
     return certs;
 }
@@ -760,6 +751,30 @@ QList<QSslCertificate> QSslCertificate::fromData(const QByteArray &data, QSsl::E
     return reader(data, -1);
 }
 
+/*!
+    \since 6.10
+
+    Reads the data from the file \a filePath and parses all certificates
+    that are encoded in the specified \a format and returns a list of
+    QSslCertificate objects.
+
+    If \a filePath isn't a regular file, this method will return an empty
+    list.
+
+    \sa fromData(), fromPath()
+*/
+QList<QSslCertificate> QSslCertificate::fromFile(const QString &filePath,
+                                                 QSsl::EncodingFormat format)
+{
+    QFile file(filePath);
+    QIODevice::OpenMode openMode = QIODevice::ReadOnly;
+    if (format == QSsl::Pem)
+        openMode |= QIODevice::Text;
+    if (file.open(openMode))
+        return QSslCertificate::fromData(file.readAll(), format);
+    return {};
+}
+
 #ifndef QT_NO_SSL
 /*!
     Verifies a certificate chain. The chain to be verified is passed in the

src/network/ssl/qsslcertificate.h

@@ -107,6 +107,8 @@ public:
         QIODevice *device, QSsl::EncodingFormat format = QSsl::Pem);
     static QList<QSslCertificate> fromData(
         const QByteArray &data, QSsl::EncodingFormat format = QSsl::Pem);
+    static QList<QSslCertificate> fromFile(
+        const QString &filePath, QSsl::EncodingFormat format = QSsl::Pem);
 
 #ifndef QT_NO_SSL
     static QList<QSslError> verify(const QList<QSslCertificate> &certificateChain, const QString &hostName = QString());

src/plugins/tls/openssl/qtlsbackend_openssl.cpp

@@ -410,7 +410,7 @@ QList<QSslCertificate> systemCaCertificates()
             }
         }
         for (const QString& file : std::as_const(certFiles))
-            systemCerts.append(QSslCertificate::fromPath(file, QSsl::Pem));
+            systemCerts.append(QSslCertificate::fromFile(file, QSsl::Pem));
     }
 #endif // platform
 #ifdef QSSLSOCKET_DEBUG

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

@@ -20,6 +20,8 @@
 #include <openssl/obj_mac.h>
 #endif
 
+using namespace Qt::StringLiterals;
+
 class tst_QSslCertificate : public QObject
 {
     Q_OBJECT
@@ -97,6 +99,9 @@ private slots:
     // helper for verbose test failure messages
     QString toString(const QList<QSslError>&);
 
+private:
+    void certInfo_helper(const char *methodName);
+
 // ### add tests for certificate bundles (multiple certificates concatenated into a single
 //     structure); both PEM and DER formatted
 #endif // QT_CONFIG(ssl)
@@ -494,12 +499,23 @@ 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);
+    }
+
+    {
+        const auto chain = QSslCertificate::fromFile(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()
@@ -701,9 +717,14 @@ void tst_QSslCertificate::fromPath_qregularexpression()
                                        pemencoding ? QSsl::Pem : QSsl::Der,
                                        QSslCertificate::PatternSyntax(syntax)).size(),
              numCerts);
+
+    if (QSslCertificate::PatternSyntax(syntax) == QSslCertificate::PatternSyntax::FixedString) {
+        const auto list = QSslCertificate::fromFile(path, pemencoding ? QSsl::Pem : QSsl::Der);
+        QCOMPARE(list.size(), numCerts);
+    }
 }
 
-void tst_QSslCertificate::certInfo()
+void tst_QSslCertificate::certInfo_helper(const char *methodName)
 {
 // MD5 Fingerprint=B6:CF:57:34:DA:A9:73:21:82:F7:CF:4D:3D:85:31:88
 // SHA1 Fingerprint=B6:D1:51:82:E0:29:CA:59:96:38:BD:B6:F9:40:05:91:6D:49:09:60
@@ -788,8 +809,14 @@ void tst_QSslCertificate::certInfo()
         "dc:c2:eb:b7:bb:50:18:05:ba:ad:af:08:49:fe:98:63"
         "55:ba:e7:fb:95:5d:91";
 
-    QSslCertificate cert =  QSslCertificate::fromPath(testDataDir + "certificates/cert.pem", QSsl::Pem,
+    QSslCertificate cert;
+    if (methodName == "fromPath"_L1) {
+        cert =  QSslCertificate::fromPath(testDataDir + "certificates/cert.pem", QSsl::Pem,
                                           QSslCertificate::PatternSyntax::FixedString).first();
+    } else if (methodName == "fromFile"_L1)  {
+        cert = QSslCertificate::fromFile(testDataDir + "certificates/cert.pem", QSsl::Pem).first();
+    }
+
     QVERIFY(!cert.isNull());
 
     QCOMPARE(cert.issuerInfo(QSslCertificate::Organization)[0], QString("CryptSoft Pty Ltd"));
@@ -845,8 +872,15 @@ void tst_QSslCertificate::certInfo()
     QCOMPARE(cert, QSslCertificate(QByteArray::fromHex(der), QSsl::Der));
 }
 
+void tst_QSslCertificate::certInfo()
+{
+    certInfo_helper("fromPath");
+    certInfo_helper("fromFile");
+}
+
 void tst_QSslCertificate::certInfoQByteArray()
 {
+    {
     QSslCertificate cert =  QSslCertificate::fromPath(testDataDir + "certificates/cert.pem", QSsl::Pem,
                                                       QSslCertificate::PatternSyntax::FixedString).first();
     QVERIFY(!cert.isNull());
@@ -855,6 +889,18 @@ void tst_QSslCertificate::certInfoQByteArray()
     // we fixed a bug we had with lazy initialization of the values.
     QCOMPARE(cert.issuerInfo("CN")[0], QString("Test CA (1024 bit)"));
     QCOMPARE(cert.subjectInfo("CN")[0], QString("name/with/slashes"));
+    }
+
+    {
+        QSslCertificate cert =
+            QSslCertificate::fromFile(testDataDir + "certificates/cert.pem", QSsl::Pem).first();
+        QVERIFY(!cert.isNull());
+
+        // in this test, check the bytearray variants before the enum variants to see if
+        // we fixed a bug we had with lazy initialization of the values.
+        QCOMPARE(cert.issuerInfo("CN")[0], QString("Test CA (1024 bit)"));
+        QCOMPARE(cert.subjectInfo("CN")[0], QString("name/with/slashes"));
+    }
 }
 
 void tst_QSslCertificate::task256066toPem()