TlsClientConnection

Added in version 2.28.

class TlsClientConnection(*args, **kwargs)

GTlsClientConnection is the client-side subclass of TlsConnection, representing a client-side TLS connection.

Methods

class TlsClientConnection

get_accepted_cas() → list[Sequence[int]]

Gets the list of distinguished names of the Certificate Authorities that the server will accept certificates from. This will be set during the TLS handshake if the server requests a certificate. Otherwise, it will be None.

Each item in the list is a GByteArray which contains the complete subject DN of the certificate authority.

Added in version 2.28.

get_server_identity() → SocketConnectable | None

Gets conn’s expected server identity

Added in version 2.28.

get_use_ssl3() → bool

SSL 3.0 is no longer supported. See set_use_ssl3() for details.

Added in version 2.28.

Deprecated since version 2.56: SSL 3.0 is insecure.

get_validation_flags() → TlsCertificateFlags

Gets conn’s validation flags

This function does not work as originally designed and is impossible to use correctly. See TlsClientConnection:validation-flags for more information.

Added in version 2.28.

Deprecated since version 2.72: Do not attempt to ignore validation errors.

new(base_io_stream: IOStream, server_identity: SocketConnectable | None = None) → TlsClientConnection

Creates a new TlsClientConnection wrapping base_io_stream (which must have pollable input and output streams) which is assumed to communicate with the server identified by server_identity.

See the documentation for TlsConnection:base-io-stream for restrictions on when application code can run operations on the base_io_stream after this function has returned.

Added in version 2.28.

Parameters:

• base_io_stream – the IOStream to wrap

• server_identity – the expected identity of the server

set_server_identity(identity: SocketConnectable) → None

Sets conn’s expected server identity, which is used both to tell servers on virtual hosts which certificate to present, and also to let conn know what name to look for in the certificate when performing BAD_IDENTITY validation, if enabled.

Added in version 2.28.

Parameters:

identity – a SocketConnectable describing the expected server identity

set_use_ssl3(use_ssl3: bool) → None

Since GLib 2.42.1, SSL 3.0 is no longer supported.

From GLib 2.42.1 through GLib 2.62, this function could be used to force use of TLS 1.0, the lowest-supported TLS protocol version at the time. In the past, this was needed to connect to broken TLS servers that exhibited protocol version intolerance. Such servers are no longer common, and using TLS 1.0 is no longer considered acceptable.

Since GLib 2.64, this function does nothing.

Added in version 2.28.

Deprecated since version 2.56: SSL 3.0 is insecure.

Parameters:

use_ssl3 – a gboolean, ignored

set_validation_flags(flags: TlsCertificateFlags) → None

Sets conn’s validation flags, to override the default set of checks performed when validating a server certificate. By default, VALIDATE_ALL is used.

This function does not work as originally designed and is impossible to use correctly. See TlsClientConnection:validation-flags for more information.

Added in version 2.28.

Deprecated since version 2.72: Do not attempt to ignore validation errors.

Parameters:

flags – the TlsCertificateFlags to use

Properties

class TlsClientConnection

props.accepted_cas: list[None]

A list of the distinguished names of the Certificate Authorities that the server will accept client certificates signed by. If the server requests a client certificate during the handshake, then this property will be set after the handshake completes.

Each item in the list is a GByteArray which contains the complete subject DN of the certificate authority.

Added in version 2.28.

props.server_identity: SocketConnectable

A SocketConnectable describing the identity of the server that is expected on the other end of the connection.

If the BAD_IDENTITY flag is set in TlsClientConnection:validation-flags, this object will be used to determine the expected identify of the remote end of the connection; if TlsClientConnection:server-identity is not set, or does not match the identity presented by the server, then the BAD_IDENTITY validation will fail.

In addition to its use in verifying the server certificate, this is also used to give a hint to the server about what certificate we expect, which is useful for servers that serve virtual hosts.

Added in version 2.28.

props.use_ssl3: bool

SSL 3.0 is no longer supported. See set_use_ssl3() for details.

Added in version 2.28.

Deprecated since version 2.56: SSL 3.0 is insecure.

props.validation_flags: TlsCertificateFlags

What steps to perform when validating a certificate received from a server. Server certificates that fail to validate in any of the ways indicated here will be rejected unless the application overrides the default via TlsConnection::accept-certificate.

GLib guarantees that if certificate verification fails, at least one flag will be set, but it does not guarantee that all possible flags will be set. Accordingly, you may not safely decide to ignore any particular type of error. For example, it would be incorrect to mask EXPIRED if you want to allow expired certificates, because this could potentially be the only error flag set even if other problems exist with the certificate. Therefore, there is no safe way to use this property. This is not a horrible problem, though, because you should not be attempting to ignore validation errors anyway. If you really must ignore TLS certificate errors, connect to TlsConnection::accept-certificate.

Added in version 2.28.

Deprecated since version 2.72: Do not attempt to ignore validation errors.

Virtual Methods

class TlsClientConnection

do_copy_session_state(source: TlsClientConnection) → None

Possibly copies session state from one connection to another, for use in TLS session resumption. This is not normally needed, but may be used when the same session needs to be used between different endpoints, as is required by some protocols, such as FTP over TLS. source should have already completed a handshake and, since TLS 1.3, it should have been used to read data at least once. conn should not have completed a handshake.

It is not possible to know whether a call to this function will actually do anything. Because session resumption is normally used only for performance benefit, the TLS backend might not implement this function. Even if implemented, it may not actually succeed in allowing conn to resume source’s TLS session, because the server may not have sent a session resumption token to source, or it may refuse to accept the token from conn. There is no way to know whether a call to this function is actually successful.

Using this function is not required to benefit from session resumption. If the TLS backend supports session resumption, the session will be resumed automatically if it is possible to do so without weakening the privacy guarantees normally provided by TLS, without need to call this function. For example, with TLS 1.3, a session ticket will be automatically copied from any TlsClientConnection that has previously received session tickets from the server, provided a ticket is available that has not previously been used for session resumption, since session ticket reuse would be a privacy weakness. Using this function causes the ticket to be copied without regard for privacy considerations.

Added in version 2.46.

Parameters:

source – a TlsClientConnection