Struct rustls::client::ClientConfig

pub struct ClientConfig {
    pub alpn_protocols: Vec<Vec<u8>>,
    pub resumption: Resumption,
    pub max_fragment_size: Option<usize>,
    pub client_auth_cert_resolver: Arc<dyn ResolvesClientCert>,
    pub enable_sni: bool,
    pub key_log: Arc<dyn KeyLog>,
    pub enable_secret_extraction: bool,
    pub enable_early_data: bool,
    pub require_ems: bool,
    pub time_provider: Arc<dyn TimeProvider>,
    /* private fields */
}

Common configuration for (typically) all connections made by a program.

Making one of these is cheap, though one of the inputs may be expensive: gathering trust roots from the operating system to add to the RootCertStore passed to with_root_certificates() (the rustls-native-certs crate is often used for this) may take on the order of a few hundred milliseconds.

These must be created via the ClientConfig::builder() or ClientConfig::builder_with_provider() function.

Defaults

• ClientConfig::max_fragment_size: the default is None (meaning 16kB).
• ClientConfig::resumption: supports resumption with up to 256 server names, using session ids or tickets, with a max of eight tickets per server.
• ClientConfig::alpn_protocols: the default is empty – no ALPN protocol is negotiated.
• ClientConfig::key_log: key material is not logged.

Fields

alpn_protocols: Vec<Vec<u8>>

Which ALPN protocols we include in our client hello. If empty, no ALPN extension is sent.

resumption: Resumption

How and when the client can resume a previous session.

max_fragment_size: Option<usize>

The maximum size of plaintext input to be emitted in a single TLS record. A value of None is equivalent to the TLS maximum of 16 kB.

rustls enforces an arbitrary minimum of 32 bytes for this field. Out of range values are reported as errors from ClientConnection::new.

Setting this value to a little less than the TCP MSS may improve latency for stream-y workloads.

client_auth_cert_resolver: Arc<dyn ResolvesClientCert>

How to decide what client auth certificate/keys to use.

enable_sni: bool

Whether to send the Server Name Indication (SNI) extension during the client handshake.

The default is true.

key_log: Arc<dyn KeyLog>

How to output key material for debugging. The default does nothing.

enable_secret_extraction: bool

Allows traffic secrets to be extracted after the handshake, e.g. for kTLS setup.

enable_early_data: bool

Whether to send data on the first flight (“early data”) in TLS 1.3 handshakes.

The default is false.

require_ems: bool

If set to true, requires the server to support the extended master secret extraction method defined in RFC 7627.

The default is true if the fips crate feature is enabled, false otherwise.

It must be set to true to meet FIPS requirement mentioned in section D.Q Transition of the TLS 1.2 KDF to Support the Extended Master Secret from FIPS 140-3 IG.pdf.

time_provider: Arc<dyn TimeProvider>

Provides the current system time

Implementations

impl ClientConfig

pub fn builder() -> ConfigBuilder<Self, WantsVerifier>

Create a builder for a client configuration with the process-default CryptoProvider and safe protocol version defaults.

For more information, see the ConfigBuilder documentation.

pub fn builder_with_protocol_versions( versions: &[&'static SupportedProtocolVersion] ) -> ConfigBuilder<Self, WantsVerifier>

Create a builder for a client configuration with the process-default CryptoProvider and the provided protocol versions.

Panics if

• the supported versions are not compatible with the provider (eg. the combination of ciphersuites supported by the provider and supported versions lead to zero cipher suites being usable),
• if a CryptoProvider cannot be resolved using a combination of the crate features and process default.

For more information, see the ConfigBuilder documentation.

pub fn builder_with_provider( provider: Arc<CryptoProvider> ) -> ConfigBuilder<Self, WantsVersions>

Create a builder for a client configuration with a specific CryptoProvider.

This will use the provider’s configured ciphersuites. You must additionally choose which protocol versions to enable, using with_protocol_versions or with_safe_default_protocol_versions and handling the Result in case a protocol version is not supported by the provider’s ciphersuites.

For more information, see the ConfigBuilder documentation.

pub fn builder_with_details( provider: Arc<CryptoProvider>, time_provider: Arc<dyn TimeProvider> ) -> ConfigBuilder<Self, WantsVersions>

Create a builder for a client configuration with no default implementation details.

This API must be used by no_std users.

You must provide a specific TimeProvider.

You must provide a specific CryptoProvider.

This will use the provider’s configured ciphersuites. You must additionally choose which protocol versions to enable, using with_protocol_versions or with_safe_default_protocol_versions and handling the Result in case a protocol version is not supported by the provider’s ciphersuites.

For more information, see the ConfigBuilder documentation.

pub fn fips(&self) -> bool

Return true if connections made with this ClientConfig will operate in FIPS mode.

This is different from CryptoProvider::fips(): CryptoProvider::fips() is concerned only with cryptography, whereas this also covers TLS-level configuration that NIST recommends.

pub fn crypto_provider(&self) -> &Arc<CryptoProvider>

Return the crypto provider used to construct this client configuration.

pub fn dangerous(&mut self) -> DangerousClientConfig<'_>

Access configuration options whose use is dangerous and requires extra care.

Trait Implementations

impl Clone for ClientConfig

fn clone(&self) -> Self

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for ClientConfig

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl ConfigSide for ClientConfig