TlsConnection
Added in version 2.28.
Superclasses: IOStream
, Object
GTlsConnection
is the base TLS connection class type, which wraps
a IOStream
and provides TLS encryption on top of it. Its
subclasses, TlsClientConnection
and
TlsServerConnection
, implement client-side and server-side TLS,
respectively.
For DTLS (Datagram TLS) support, see DtlsConnection
.
Methods
- class TlsConnection
- emit_accept_certificate(peer_cert: TlsCertificate, errors: TlsCertificateFlags) bool
Used by
TlsConnection
implementations to emit theTlsConnection
::accept-certificate signal.Added in version 2.28.
- Parameters:
peer_cert – the peer’s
TlsCertificate
errors – the problems with
peer_cert
- get_certificate() TlsCertificate | None
Gets
conn
’s certificate, as set byset_certificate()
.Added in version 2.28.
- get_channel_binding_data(type: TlsChannelBindingType) tuple[bool, bytes]
Query the TLS backend for TLS channel binding data of
type
forconn
.This call retrieves TLS channel binding data as specified in RFC 5056, RFC 5929, and related RFCs. The binding data is returned in
data
. Thedata
is resized by the callee usingGByteArray
buffer management and will be freed when thedata
is destroyed byunref()
. Ifdata
isNone
, it will only check whether TLS backend is able to fetch the data (e.g. whethertype
is supported by the TLS backend). It does not guarantee that the data will be available though. That could happen if TLS connection does not supporttype
or the binding data is not available yet due to additional negotiation or input required.Added in version 2.66.
- Parameters:
type –
TlsChannelBindingType
type of data to fetch
- get_ciphersuite_name() str | None
Returns the name of the current TLS ciphersuite, or
None
if the connection has not handshaked or has been closed. Beware that the TLS backend may use any of multiple different naming conventions, because OpenSSL and GnuTLS have their own ciphersuite naming conventions that are different from each other and different from the standard, IANA- registered ciphersuite names. The ciphersuite name is intended to be displayed to the user for informative purposes only, and parsing it is not recommended.Added in version 2.70.
- get_database() TlsDatabase | None
Gets the certificate database that
conn
uses to verify peer certificates. Seeset_database()
.Added in version 2.30.
- get_interaction() TlsInteraction | None
Get the object that will be used to interact with the user. It will be used for things like prompting the user for passwords. If
None
is returned, then no user interaction will occur for this connection.Added in version 2.30.
- get_negotiated_protocol() str | None
Gets the name of the application-layer protocol negotiated during the handshake.
If the peer did not use the ALPN extension, or did not advertise a protocol that matched one of
conn
’s protocols, or the TLS backend does not support ALPN, then this will beNone
. Seeset_advertised_protocols()
.Added in version 2.60.
- get_peer_certificate() TlsCertificate | None
Gets
conn
’s peer’s certificate after the handshake has completed or failed. (It is not set during the emission ofTlsConnection
::accept-certificate.)Added in version 2.28.
- get_peer_certificate_errors() TlsCertificateFlags
Gets the errors associated with validating
conn
’s peer’s certificate, after the handshake has completed or failed. (It is not set during the emission ofTlsConnection
::accept-certificate.)See
TlsConnection
:peer-certificate-errors for more information.Added in version 2.28.
- get_protocol_version() TlsProtocolVersion
Returns the current TLS protocol version, which may be
UNKNOWN
if the connection has not handshaked, or has been closed, or if the TLS backend has implemented a protocol version that is not a recognizedTlsProtocolVersion
.Added in version 2.70.
- get_rehandshake_mode() TlsRehandshakeMode
Gets
conn
rehandshaking mode. Seeset_rehandshake_mode()
for details.Added in version 2.28.
Deprecated since version 2.60.: Changing the rehandshake mode is no longer required for compatibility. Also, rehandshaking has been removed from the TLS protocol in TLS 1.3.
- get_require_close_notify() bool
Tests whether or not
conn
expects a proper TLS close notification when the connection is closed. Seeset_require_close_notify()
for details.Added in version 2.28.
- get_use_system_certdb() bool
Gets whether
conn
uses the system certificate database to verify peer certificates. Seeset_use_system_certdb()
.Deprecated since version 2.30: Use
get_database()
instead
- handshake(cancellable: Cancellable | None = None) bool
Attempts a TLS handshake on
conn
.On the client side, it is never necessary to call this method; although the connection needs to perform a handshake after connecting (or after sending a “STARTTLS”-type command),
TlsConnection
will handle this for you automatically when you try to send or receive data on the connection. You can callhandshake()
manually if you want to know whether the initial handshake succeeded or failed (as opposed to just immediately trying to useconn
to read or write, in which case, if it fails, it may not be possible to tell if it failed before or after completing the handshake), but beware that servers may reject client authentication after the handshake has completed, so a successful handshake does not indicate the connection will be usable.Likewise, on the server side, although a handshake is necessary at the beginning of the communication, you do not need to call this function explicitly unless you want clearer error reporting.
Previously, calling
handshake()
after the initial handshake would trigger a rehandshake; however, this usage was deprecated in GLib 2.60 because rehandshaking was removed from the TLS protocol in TLS 1.3. Since GLib 2.64, calling this function after the initial handshake will no longer do anything.When using a
TlsConnection
created bySocketClient
, theSocketClient
performs the initial handshake, so calling this function manually is not recommended.TlsConnection
::accept_certificate may be emitted during the handshake.Added in version 2.28.
- Parameters:
cancellable – a
Cancellable
, orNone
- handshake_async(io_priority: int, cancellable: Cancellable | None = None, callback: Callable[[...], None] | None = None, *user_data: Any) None
Asynchronously performs a TLS handshake on
conn
. Seehandshake()
for more information.Added in version 2.28.
- Parameters:
io_priority – the [I/O priority][io-priority] of the request
cancellable – a
Cancellable
, orNone
callback – callback to call when the handshake is complete
user_data – the data to pass to the callback function
- handshake_finish(result: AsyncResult) bool
Finish an asynchronous TLS handshake operation. See
handshake()
for more information.Added in version 2.28.
- Parameters:
result – a
AsyncResult
.
- set_advertised_protocols(protocols: Sequence[str] | None = None) None
Sets the list of application-layer protocols to advertise that the caller is willing to speak on this connection. The Application-Layer Protocol Negotiation (ALPN) extension will be used to negotiate a compatible protocol with the peer; use
get_negotiated_protocol()
to find the negotiated protocol after the handshake. SpecifyingNone
for the the value ofprotocols
will disable ALPN negotiation.See IANA TLS ALPN Protocol IDs for a list of registered protocol IDs.
Added in version 2.60.
- Parameters:
protocols – a
None
-terminated array of ALPN protocol names (eg, “http/1.1”, “h2”), orNone
- set_certificate(certificate: TlsCertificate) None
This sets the certificate that
conn
will present to its peer during the TLS handshake. For aGTlsServerConnection
, it is mandatory to set this, and that will normally be done at construct time.For a
TlsClientConnection
, this is optional. If a handshake fails withCERTIFICATE_REQUIRED
, that means that the server requires a certificate, and if you try connecting again, you should call this method first. You can callget_accepted_cas()
on the failed connection to get a list of Certificate Authorities that the server will accept certificates from.(It is also possible that a server will allow the connection with or without a certificate; in that case, if you don’t provide a certificate, you can tell that the server requested one by the fact that
get_accepted_cas()
will return non-None
.)Added in version 2.28.
- Parameters:
certificate – the certificate to use for
conn
- set_database(database: TlsDatabase | None = None) None
Sets the certificate database that is used to verify peer certificates. This is set to the default database by default. See
get_default_database()
. If set toNone
, then peer certificate validation will always set theUNKNOWN_CA
error (meaningTlsConnection
::accept-certificate will always be emitted on client-side connections, unless that bit is not set inTlsClientConnection
:validation-flags).There are nonintuitive security implications when using a non-default database. See
TlsConnection
:database for details.Added in version 2.30.
- Parameters:
database – a
TlsDatabase
- set_interaction(interaction: TlsInteraction | None = None) None
Set the object that will be used to interact with the user. It will be used for things like prompting the user for passwords.
The
interaction
argument will normally be a derived subclass ofTlsInteraction
.None
can also be provided if no user interaction should occur for this connection.Added in version 2.30.
- Parameters:
interaction – an interaction object, or
None
- set_rehandshake_mode(mode: TlsRehandshakeMode) None
Since GLib 2.64, changing the rehandshake mode is no longer supported and will have no effect. With TLS 1.3, rehandshaking has been removed from the TLS protocol, replaced by separate post-handshake authentication and rekey operations.
Added in version 2.28.
Deprecated since version 2.60.: Changing the rehandshake mode is no longer required for compatibility. Also, rehandshaking has been removed from the TLS protocol in TLS 1.3.
- Parameters:
mode – the rehandshaking mode
- set_require_close_notify(require_close_notify: bool) None
Sets whether or not
conn
expects a proper TLS close notification before the connection is closed. If this isTrue
(the default), thenconn
will expect to receive a TLS close notification from its peer before the connection is closed, and will return aEOF
error if the connection is closed without proper notification (since this may indicate a network error, or man-in-the-middle attack).In some protocols, the application will know whether or not the connection was closed cleanly based on application-level data (because the application-level data includes a length field, or is somehow self-delimiting); in this case, the close notify is redundant and sometimes omitted. (TLS 1.1 explicitly allows this; in TLS 1.0 it is technically an error, but often done anyway.) You can use
set_require_close_notify()
to tellconn
to allow an “unannounced” connection close, in which case the close will show up as a 0-length read, as in a non-TLSSocketConnection
, and it is up to the application to check that the data has been fully received.Note that this only affects the behavior when the peer closes the connection; when the application calls
close()
itself onconn
, this will send a close notification regardless of the setting of this property. If you explicitly want to do an unclean close, you can closeconn
’sTlsConnection
:base-io-stream rather than closingconn
itself, but note that this may only be done when no other operations are pending onconn
or the base I/O stream.Added in version 2.28.
- Parameters:
require_close_notify – whether or not to require close notification
- set_use_system_certdb(use_system_certdb: bool) None
Sets whether
conn
uses the system certificate database to verify peer certificates. This isTrue
by default. If set toFalse
, then peer certificate validation will always set theUNKNOWN_CA
error (meaningTlsConnection
::accept-certificate will always be emitted on client-side connections, unless that bit is not set inTlsClientConnection
:validation-flags).Deprecated since version 2.30: Use
set_database()
instead- Parameters:
use_system_certdb – whether to use the system certificate database
Properties
- class TlsConnection
- props.advertised_protocols: Sequence[str]
The list of application-layer protocols that the connection advertises that it is willing to speak. See
set_advertised_protocols()
.Added in version 2.60.
- props.base_io_stream: IOStream
The
IOStream
that the connection wraps. The connection holds a reference to this stream, and may run operations on the stream from other threads throughout its lifetime. Consequently, after theIOStream
has been constructed, application code may only run its own operations on this stream when noIOStream
operations are running.Added in version 2.28.
- props.certificate: TlsCertificate
The connection’s certificate; see
set_certificate()
.Added in version 2.28.
- props.ciphersuite_name: str
The name of the TLS ciphersuite in use. See
get_ciphersuite_name()
.Added in version 2.70.
- props.database: TlsDatabase
The certificate database to use when verifying this TLS connection. If no certificate database is set, then the default database will be used. See
get_default_database()
.When using a non-default database,
TlsConnection
must fall back to using theTlsDatabase
to perform certificate verification usingverify_chain()
, which means certificate verification will not be able to make use of TLS session context. This may be less secure. For example, if you create your ownTlsDatabase
that just wraps the defaultTlsDatabase
, you might expect that you have not changed anything, but this is not true because you may have altered the behavior ofTlsConnection
by causing it to useverify_chain()
. See the documentation ofverify_chain()
for more details on specific security checks that may not be performed. Accordingly, setting a non-default database is discouraged except for specialty applications with unusual security requirements.Added in version 2.30.
- props.interaction: TlsInteraction
A
TlsInteraction
object to be used when the connection or certificate database need to interact with the user. This will be used to prompt the user for passwords where necessary.Added in version 2.30.
- props.negotiated_protocol: str
The application-layer protocol negotiated during the TLS handshake. See
get_negotiated_protocol()
.Added in version 2.60.
- props.peer_certificate: TlsCertificate
The connection’s peer’s certificate, after the TLS handshake has completed or failed. Note in particular that this is not yet set during the emission of
TlsConnection
::accept-certificate.(You can watch for a
Object
::notify signal on this property to detect when a handshake has occurred.)Added in version 2.28.
- props.peer_certificate_errors: TlsCertificateFlags
The errors noticed while verifying
TlsConnection
:peer-certificate. Normally this should be 0, but it may not be ifTlsClientConnection
:validation-flags is notVALIDATE_ALL
, or ifTlsConnection
::accept-certificate overrode the default behavior.GLib guarantees that if certificate verification fails, at least one error will be set, but it does not guarantee that all possible errors 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.Added in version 2.28.
- props.protocol_version: TlsProtocolVersion
The TLS protocol version in use. See
get_protocol_version()
.Added in version 2.70.
- props.rehandshake_mode: TlsRehandshakeMode
The rehandshaking mode. See
set_rehandshake_mode()
.Added in version 2.28.
Deprecated since version 2.60: The rehandshake mode is ignored.
- props.require_close_notify: bool
Whether or not proper TLS close notification is required. See
set_require_close_notify()
.Added in version 2.28.
- props.use_system_certdb: bool
Whether or not the system certificate database will be used to verify peer certificates. See
set_use_system_certdb()
.Deprecated since version 2.30: Use GTlsConnection:database instead
Signals
- class TlsConnection.signals
- accept_certificate(peer_cert: TlsCertificate, errors: TlsCertificateFlags) bool
Emitted during the TLS handshake after the peer certificate has been received. You can examine
peer_cert
’s certification path by callingget_issuer()
on it.For a client-side connection,
peer_cert
is the server’s certificate, and the signal will only be emitted if the certificate was not acceptable according toconn
’sTlsClientConnection
:validation_flags. If you would like the certificate to be accepted despiteerrors
, returnTrue
from the signal handler. Otherwise, if no handler accepts the certificate, the handshake will fail withBAD_CERTIFICATE
.GLib guarantees that if certificate verification fails, this signal will be emitted with at least one error will be set in
errors
, but it does not guarantee that all possible errors will be set. Accordingly, you may not safely decide to ignore any particular type of error. For example, it would be incorrect to ignoreEXPIRED
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.For a server-side connection,
peer_cert
is the certificate presented by the client, if this was requested via the server’sGTlsServerConnection
:authentication_mode. On the server side, the signal is always emitted when the client presents a certificate, and the certificate will only be accepted if a handler returnsTrue
.Note that if this signal is emitted as part of asynchronous I/O in the main thread, then you should not attempt to interact with the user before returning from the signal handler. If you want to let the user decide whether or not to accept the certificate, you would have to return
False
from the signal handler on the first attempt, and then after the connection attempt returns aBAD_CERTIFICATE
, you can interact with the user, and if the user decides to accept the certificate, remember that fact, create a new connection, and returnTrue
from the signal handler the next time.If you are doing I/O in another thread, you do not need to worry about this, and can simply block in the signal handler until the UI thread returns an answer.
Added in version 2.28.
- Parameters:
peer_cert – the peer’s
TlsCertificate
errors – the problems with
peer_cert
.
Virtual Methods
- class TlsConnection
- do_accept_certificate(peer_cert: TlsCertificate, errors: TlsCertificateFlags) bool
Check whether to accept a certificate.
- Parameters:
peer_cert
errors
- do_get_binding_data(type: TlsChannelBindingType, data: Sequence[int]) bool
Retrieve TLS channel binding data (Since: 2.66)
- Parameters:
type
data
- do_get_negotiated_protocol() str | None
Gets the name of the application-layer protocol negotiated during the handshake.
If the peer did not use the ALPN extension, or did not advertise a protocol that matched one of
conn
’s protocols, or the TLS backend does not support ALPN, then this will beNone
. Seeset_advertised_protocols()
.Added in version 2.60.
- do_handshake(cancellable: Cancellable | None = None) bool
Attempts a TLS handshake on
conn
.On the client side, it is never necessary to call this method; although the connection needs to perform a handshake after connecting (or after sending a “STARTTLS”-type command),
TlsConnection
will handle this for you automatically when you try to send or receive data on the connection. You can callhandshake()
manually if you want to know whether the initial handshake succeeded or failed (as opposed to just immediately trying to useconn
to read or write, in which case, if it fails, it may not be possible to tell if it failed before or after completing the handshake), but beware that servers may reject client authentication after the handshake has completed, so a successful handshake does not indicate the connection will be usable.Likewise, on the server side, although a handshake is necessary at the beginning of the communication, you do not need to call this function explicitly unless you want clearer error reporting.
Previously, calling
handshake()
after the initial handshake would trigger a rehandshake; however, this usage was deprecated in GLib 2.60 because rehandshaking was removed from the TLS protocol in TLS 1.3. Since GLib 2.64, calling this function after the initial handshake will no longer do anything.When using a
TlsConnection
created bySocketClient
, theSocketClient
performs the initial handshake, so calling this function manually is not recommended.TlsConnection
::accept_certificate may be emitted during the handshake.Added in version 2.28.
- Parameters:
cancellable – a
Cancellable
, orNone
- do_handshake_async(io_priority: int, cancellable: Cancellable | None = None, callback: Callable[[...], None] | None = None, *user_data: Any) None
Asynchronously performs a TLS handshake on
conn
. Seehandshake()
for more information.Added in version 2.28.
- Parameters:
io_priority – the [I/O priority][io-priority] of the request
cancellable – a
Cancellable
, orNone
callback – callback to call when the handshake is complete
user_data – the data to pass to the callback function
- do_handshake_finish(result: AsyncResult) bool
Finish an asynchronous TLS handshake operation. See
handshake()
for more information.Added in version 2.28.
- Parameters:
result – a
AsyncResult
.