Struct rustls::ClientConnection
source · pub struct ClientConnection { /* private fields */ }Expand description
This represents a single TLS client connection.
Implementations§
source§impl ClientConnection
impl ClientConnection
sourcepub fn new(config: Arc<ClientConfig>, name: ServerName) -> Result<Self, Error>
pub fn new(config: Arc<ClientConfig>, name: ServerName) -> Result<Self, Error>
Make a new ClientConnection. config controls how
we behave in the TLS protocol, name is the
name of the server we want to talk to.
sourcepub fn early_data(&mut self) -> Option<WriteEarlyData<'_>>
pub fn early_data(&mut self) -> Option<WriteEarlyData<'_>>
Returns an io::Write implementer you can write bytes to
to send TLS1.3 early data (a.k.a. “0-RTT data”) to the server.
This returns None in many circumstances when the capability to send early data is not available, including but not limited to:
- The server hasn’t been talked to previously.
- The server does not support resumption.
- The server does not support early data.
- The resumption data for the server has expired.
The server specifies a maximum amount of early data. You can learn this limit through the returned object, and writes through it will process only this many bytes.
The server can choose not to accept any sent early data –
in this case the data is lost but the connection continues. You
can tell this happened using is_early_data_accepted.
sourcepub fn is_early_data_accepted(&self) -> bool
pub fn is_early_data_accepted(&self) -> bool
Returns True if the server signalled it will process early data.
If you sent early data and this returns false at the end of the handshake then the server will not process the data. This is not an error, but you may wish to resend the data.
Methods from Deref<Target = ConnectionCommon<ClientConnectionData>>§
sourcepub fn complete_io<T>(&mut self, io: &mut T) -> Result<(usize, usize), Error>where
Self: Sized,
T: Read + Write,
pub fn complete_io<T>(&mut self, io: &mut T) -> Result<(usize, usize), Error>where Self: Sized, T: Read + Write,
This function uses io to complete any outstanding IO for
this connection.
This is a convenience function which solely uses other parts of the public API.
What this means depends on the connection state:
- If the connection
is_handshaking, then IO is performed until the handshake is complete. - Otherwise, if
wants_writeis true,write_tlsis invoked until it is all written. - Otherwise, if
wants_readis true,read_tlsis invoked once.
The return value is the number of bytes read from and written
to io, respectively.
This function will block if io blocks.
Errors from TLS record handling (i.e., from process_new_packets)
are wrapped in an io::ErrorKind::InvalidData-kind error.
sourcepub fn process_new_packets(&mut self) -> Result<IoState, Error>
pub fn process_new_packets(&mut self) -> Result<IoState, Error>
Processes any new packets read by a previous call to
Connection::read_tls.
Errors from this function relate to TLS protocol errors, and
are fatal to the connection. Future calls after an error will do
no new work and will return the same error. After an error is
received from process_new_packets, you should not call read_tls
any more (it will fill up buffers to no purpose). However, you
may call the other methods on the connection, including write,
send_close_notify, and write_tls. Most likely you will want to
call write_tls to send any alerts queued by the error and then
close the underlying connection.
Success from this function comes with some sundry state data about the connection.
sourcepub fn read_tls(&mut self, rd: &mut dyn Read) -> Result<usize, Error>
pub fn read_tls(&mut self, rd: &mut dyn Read) -> Result<usize, Error>
Read TLS content from rd into the internal buffer.
Due to the internal buffering, rd can supply TLS messages in arbitrary-sized chunks (like
a socket or pipe might).
You should call process_new_packets() each time a call to this function succeeds in order
to empty the incoming TLS data buffer.
This function returns Ok(0) when the underlying rd does so. This typically happens when
a socket is cleanly closed, or a file is at EOF. Errors may result from the IO done through
rd; additionally, errors of ErrorKind::Other are emitted to signal backpressure:
- In order to empty the incoming TLS data buffer, you should call
process_new_packets()each time a call to this function succeeds. - In order to empty the incoming plaintext data buffer, you should empty it through
the
reader()after the call toprocess_new_packets().
sourcepub fn export_keying_material(
&self,
output: &mut [u8],
label: &[u8],
context: Option<&[u8]>
) -> Result<(), Error>
pub fn export_keying_material( &self, output: &mut [u8], label: &[u8], context: Option<&[u8]> ) -> Result<(), Error>
Derives key material from the agreed connection secrets.
This function fills in output with output.len() bytes of key
material derived from the master session secret using label
and context for diversification.
See RFC5705 for more details on what this does and is for.
For TLS1.3 connections, this function does not use the “early” exporter at any point.
This function fails if called prior to the handshake completing;
check with CommonState::is_handshaking first.
Methods from Deref<Target = CommonState>§
sourcepub fn wants_write(&self) -> bool
pub fn wants_write(&self) -> bool
Returns true if the caller should call CommonState::write_tls as soon
as possible.
sourcepub fn is_handshaking(&self) -> bool
pub fn is_handshaking(&self) -> bool
Returns true if the connection is currently performing the TLS handshake.
During this time plaintext written to the connection is buffered in memory. After
Connection::process_new_packets has been called, this might start to return false
while the final handshake packets still need to be extracted from the connection’s buffers.
sourcepub fn peer_certificates(&self) -> Option<&[Certificate]>
pub fn peer_certificates(&self) -> Option<&[Certificate]>
Retrieves the certificate chain used by the peer to authenticate.
The order of the certificate chain is as it appears in the TLS protocol: the first certificate relates to the peer, the second certifies the first, the third certifies the second, and so on.
This is made available for both full and resumed handshakes.
For clients, this is the certificate chain of the server.
For servers, this is the certificate chain of the client, if client authentication was completed.
The return value is None until this value is available.
sourcepub fn alpn_protocol(&self) -> Option<&[u8]>
pub fn alpn_protocol(&self) -> Option<&[u8]>
Retrieves the protocol agreed with the peer via ALPN.
A return value of None after handshake completion
means no protocol was agreed (because no protocols
were offered or accepted by the peer).
sourcepub fn negotiated_cipher_suite(&self) -> Option<SupportedCipherSuite>
pub fn negotiated_cipher_suite(&self) -> Option<SupportedCipherSuite>
Retrieves the ciphersuite agreed with the peer.
This returns None until the ciphersuite is agreed.
sourcepub fn protocol_version(&self) -> Option<ProtocolVersion>
pub fn protocol_version(&self) -> Option<ProtocolVersion>
Retrieves the protocol version agreed with the peer.
This returns None until the version is agreed.
sourcepub fn write_tls(&mut self, wr: &mut dyn Write) -> Result<usize, Error>
pub fn write_tls(&mut self, wr: &mut dyn Write) -> Result<usize, Error>
Writes TLS messages to wr.
On success, this function returns Ok(n) where n is a number of bytes written to wr
(after encoding and encryption).
After this function returns, the connection buffer may not yet be fully flushed. The
CommonState::wants_write function can be used to check if the output buffer is empty.
sourcepub fn set_buffer_limit(&mut self, limit: Option<usize>)
pub fn set_buffer_limit(&mut self, limit: Option<usize>)
Sets a limit on the internal buffers used to buffer
unsent plaintext (prior to completing the TLS handshake)
and unsent TLS records. This limit acts only on application
data written through Connection::writer.
By default the limit is 64KB. The limit can be set at any time, even if the current buffer use is higher.
None means no limit applies, and will mean that written
data is buffered without bound – it is up to the application
to appropriately schedule its plaintext and TLS writes to bound
memory usage.
For illustration: Some(1) means a limit of one byte applies:
Connection::writer will accept only one byte, encrypt it and
add a TLS header. Once this is sent via CommonState::write_tls,
another byte may be sent.
Internal write-direction buffering
rustls has two buffers whose size are bounded by this setting:
Buffering of unsent plaintext data prior to handshake completion
Calls to Connection::writer before or during the handshake
are buffered (up to the limit specified here). Once the
handshake completes this data is encrypted and the resulting
TLS records are added to the outgoing buffer.
Buffering of outgoing TLS records
This buffer is used to store TLS records that rustls needs to send to the peer. It is used in these two circumstances:
- by
Connection::process_new_packetswhen a handshake or alert TLS record needs to be sent. - by
Connection::writerpost-handshake: the plaintext is encrypted and the resulting TLS record is buffered.
This buffer is emptied by CommonState::write_tls.
sourcepub fn send_close_notify(&mut self)
pub fn send_close_notify(&mut self)
Queues a close_notify warning alert to be sent in the next
CommonState::write_tls call. This informs the peer that the
connection is being closed.
sourcepub fn wants_read(&self) -> bool
pub fn wants_read(&self) -> bool
Returns true if the caller should call Connection::read_tls as soon
as possible.
If there is pending plaintext data to read with Connection::reader,
this returns false. If your application respects this mechanism,
only one full TLS message will be buffered by rustls.