QSsl Namespace

The QSsl namespace declares enums common to all SSL classes in Qt Network. More...

Header:	#include <QSsl>
qmake:	QT += network
Since:	Qt 4.3

• Obsolete members

Types

enum	AlternativeNameEntryType { EmailEntry, DnsEntry }
enum	EncodingFormat { Pem, Der }
enum	KeyAlgorithm { Rsa, Dsa, Ec, Opaque }
enum	KeyType { PrivateKey, PublicKey }
enum	SslOption { SslOptionDisableEmptyFragments, SslOptionDisableSessionTickets, SslOptionDisableCompression, SslOptionDisableServerNameIndication, ..., SslOptionDisableServerCipherPreference }
flags	SslOptions
enum	SslProtocol { SslV3, SslV2, TlsV1_0, TlsV1_0OrLater, ..., SecureProtocols }

Detailed Description

The QSsl namespace declares enums common to all SSL classes in Qt Network.

Type Documentation

enum QSsl::AlternativeNameEntryType

Describes the key types for alternative name entries in QSslCertificate.

Constant	Value	Description
QSsl::EmailEntry	0	An email entry; the entry contains an email address that the certificate is valid for.
QSsl::DnsEntry	1	A DNS host name entry; the entry contains a host name entry that the certificate is valid for. The entry may contain wildcards.

Note: In Qt 4, this enum was called AlternateNameEntryType. That name is deprecated in Qt 5.

See also QSslCertificate::subjectAlternativeNames().

enum QSsl::EncodingFormat

Describes supported encoding formats for certificates and keys.

Constant	Value	Description
QSsl::Pem	0	The PEM format.
QSsl::Der	1	The DER format.

enum QSsl::KeyAlgorithm

Describes the different key algorithms supported by QSslKey.

Constant	Value	Description
QSsl::Rsa	1	The RSA algorithm.
QSsl::Dsa	2	The DSA algorithm.
QSsl::Ec	3	The Elliptic Curve algorithm
QSsl::Opaque	0	A key that should be treated as a 'black box' by QSslKey.

The opaque key facility allows applications to add support for facilities such as PKCS#11 that Qt does not currently offer natively.

enum QSsl::KeyType

Describes the two types of keys QSslKey supports.

Constant	Value	Description
QSsl::PrivateKey	0	A private key.
QSsl::PublicKey	1	A public key.

enum QSsl::SslOptionflags QSsl::SslOptions

Describes the options that can be used to control the details of SSL behaviour. These options are generally used to turn features off to work around buggy servers.

Constant	Value	Description
QSsl::SslOptionDisableEmptyFragments	0x01	Disables the insertion of empty fragments into the data when using block ciphers. When enabled, this prevents some attacks (such as the BEAST attack), however it is incompatible with some servers.
QSsl::SslOptionDisableSessionTickets	0x02	Disables the SSL session ticket extension. This can cause slower connection setup, however some servers are not compatible with the extension.
QSsl::SslOptionDisableCompression	0x04	Disables the SSL compression extension. When enabled, this allows the data being passed over SSL to be compressed, however some servers are not compatible with this extension.
QSsl::SslOptionDisableServerNameIndication	0x08	Disables the SSL server name indication extension. When enabled, this tells the server the virtual host being accessed allowing it to respond with the correct certificate.
QSsl::SslOptionDisableLegacyRenegotiation	0x10	Disables the older insecure mechanism for renegotiating the connection parameters. When enabled, this option can allow connections for legacy servers, but it introduces the possibility that an attacker could inject plaintext into the SSL session.
QSsl::SslOptionDisableSessionSharing	0x20	Disables SSL session sharing via the session ID handshake attribute.
QSsl::SslOptionDisableSessionPersistence	0x40	Disables storing the SSL session in ASN.1 format as returned by QSslConfiguration::sessionTicket(). Enabling this feature adds memory overhead of approximately 1K per used session ticket.
QSsl::SslOptionDisableServerCipherPreference	0x80	Disables selecting the cipher chosen based on the servers preferences rather than the order ciphers were sent by the client. This option is only relevant to server sockets, and is only honored by the OpenSSL backend.

By default, SslOptionDisableEmptyFragments is turned on since this causes problems with a large number of servers. SslOptionDisableLegacyRenegotiation is also turned on, since it introduces a security risk. SslOptionDisableCompression is turned on to prevent the attack publicised by CRIME. SslOptionDisableSessionPersistence is turned on to optimize memory usage. The other options are turned off.

Note: Availability of above options depends on the version of the SSL backend in use.

The SslOptions type is a typedef for QFlags<SslOption>. It stores an OR combination of SslOption values.

enum QSsl::SslProtocol

Describes the protocol of the cipher.

Constant	Value	Description
QSsl::SslV3	0	SSLv3. When using the WinRT backend this option will also enable TLSv1.0
QSsl::SslV2	1	SSLv2. Note, SSLv2 support was removed in OpenSSL 1.1.
QSsl::TlsV1_0	2	TLSv1.0
QSsl::TlsV1_0OrLater	8	TLSv1.0 and later versions. This option is not available when using the WinRT backend due to platform limitations.
QSsl::TlsV1	TlsV1_0	Obsolete, means the same as TlsV1_0
QSsl::TlsV1_1	3	TLSv1.1. When using the WinRT backend this option will also enable TLSv1.0.
QSsl::TlsV1_1OrLater	9	TLSv1.1 and later versions. This option is not available when using the WinRT backend due to platform limitations.
QSsl::TlsV1_2	4	TLSv1.2. When using the WinRT backend this option will also enable TLSv1.0 and TLSv1.1.
QSsl::TlsV1_2OrLater	10	TLSv1.2 and later versions. This option is not available when using the WinRT backend due to platform limitations.
QSsl::DtlsV1_0	11	DTLSv1.0
QSsl::DtlsV1_0OrLater	12	DTLSv1.0 and later versions.
QSsl::DtlsV1_2	13	DTLSv1.2
QSsl::DtlsV1_2OrLater	14	DTLSv1.2 and later versions.
QSsl::TlsV1_3	15	TLSv1.3. (Since Qt 5.12)
QSsl::TlsV1_3OrLater	16	TLSv1.3 and later versions. (Since Qt 5.12)
QSsl::UnknownProtocol	-1	The cipher's protocol cannot be determined.
QSsl::AnyProtocol	5	The socket understands SSLv2, SSLv3, TLSv1.0 and all supported later versions of TLS. This value is used by QSslSocket only.
QSsl::TlsV1SslV3	6	On the client side, this will send a TLS 1.0 Client Hello, enabling TLSv1_0 and SSLv3 connections. On the server side, this will enable both SSLv3 and TLSv1_0 connections.
QSsl::SecureProtocols	7	The default option, using protocols known to be secure; currently behaves similar to TlsV1Ssl3 except denying SSLv3 connections that does not upgrade to TLS.

Note: most servers understand both SSL and TLS, but it is recommended to use TLS only for security reasons. However, SSL and TLS are not compatible with each other: if you get unexpected handshake failures, verify that you chose the correct setting for your protocol.