Struct 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 time_provider: Arc<dyn TimeProvider>,
    pub cert_decompressors: Vec<&'static dyn CertDecompressor>,
    pub cert_compressors: Vec<&'static dyn CertCompressor>,
    pub cert_compression_cache: Arc<CompressionCache>,
    /* 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.

Note that using [ConfigBuilder<ClientConfig, WantsVersions>::with_ech()] will produce a common configuration specific to the provided [crate::client::EchConfig] that may not be appropriate for all connections made by the program. In this case the configuration should only be shared by connections intended for domains that offer the provided [crate::client::EchConfig] in their DNS zone.

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.
• ClientConfig::cert_decompressors: depends on the crate features, see [compress::default_cert_decompressors()].
• ClientConfig::cert_compressors: depends on the crate features, see [compress::default_cert_compressors()].
• ClientConfig::cert_compression_cache: caches the most recently used 4 compressions

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.

time_provider: Arc<dyn TimeProvider>

Provides the current system time

cert_decompressors: Vec<&'static dyn CertDecompressor>

How to decompress the server’s certificate chain.

If this is non-empty, the RFC8779 certificate compression extension is offered, and any compressed certificates are transparently decompressed during the handshake.

This only applies to TLS1.3 connections. It is ignored for TLS1.2 connections.

cert_compressors: Vec<&'static dyn CertCompressor>

How to compress the client’s certificate chain.

If a server supports this extension, and advertises support for one of the compression algorithms included here, the client certificate will be compressed according to RFC8779.

This only applies to TLS1.3 connections. It is ignored for TLS1.2 connections.

cert_compression_cache: Arc<CompressionCache>

Caching for compressed certificates.

This is optional: [compress::CompressionCache::Disabled] gives a cache that does no caching.

Implementations

impl ClientConfig

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

Create a builder for a client configuration with [the process-default CryptoProvider][CryptoProvider#using-the-per-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<ClientConfig, WantsVerifier>

Create a builder for a client configuration with [the process-default CryptoProvider][CryptoProvider#using-the-per-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<ClientConfig, 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<ClientConfig, 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, as well as ECH HPKE suites if applicable.

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) -> ClientConfig

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<(), Error>

Formats the value using the given formatter.

impl ConfigSide for ClientConfig