Struct ClientHelloShape 

pub struct ClientHelloShape { /* private fields */ }

Available on crate feature boring only.

The cross-cutting choices that shape one connection’s ClientHello.

Lists (ciphers, groups, key shares, versions, signature algorithms and the extension order) are set with their own setters, as they appear on the wire: a GREASE codepoint in a list marks a GREASE slot at that position, and a set list has no other GREASE values. The extension order orders: the extensions it lists come first, then the other extensions this connection enables, natively. Which extensions are sent follows from the connection’s settings. This shape decides what those GREASE slots become, which native lists get GREASE, what happens to values the connection cannot negotiate, the padding, and the bodies of GREASE and preserved extensions. Everything left unset keeps BoringSSL’s behaviour. All of it is combined when the ClientHello is written, so the order in which settings are applied does not matter.

With a real ECH configuration, GREASE slots and preserved extensions of the extension order do not apply (the encrypted ClientHello references the outer extensions natively); the order of known extensions still does.

Implementations

impl ClientHelloShape

pub fn new() -> ClientHelloShape

pub fn set_grease_lists(&mut self, lists: GreaseLists) -> &mut ClientHelloShape

Native lists that get a GREASE value, replacing the context’s GREASE settings for this connection. Unset, the context’s settings apply.

pub fn with_grease_lists(self, lists: GreaseLists) -> ClientHelloShape

pub fn set_grease_values( &mut self, values: GreaseValues, ) -> &mut ClientHelloShape

pub fn with_grease_values(self, values: GreaseValues) -> ClientHelloShape

pub fn set_unknown_values( &mut self, values: UnknownValues, ) -> &mut ClientHelloShape

pub fn with_unknown_values(self, values: UnknownValues) -> ClientHelloShape

pub fn set_padding(&mut self, padding: Padding) -> &mut ClientHelloShape

pub fn with_padding(self, padding: Padding) -> ClientHelloShape

pub fn set_legacy_extensions(&mut self, enabled: bool) -> &mut ClientHelloShape

Sends initial EMS and renegotiation_info with a TLS 1.3 minimum to match browser hellos.

pub fn with_legacy_extensions(self, enabled: bool) -> ClientHelloShape

pub fn set_ec_point_formats(&mut self, enabled: bool) -> &mut ClientHelloShape

Sends ec_point_formats, listing only uncompressed points ([0]), with a TLS 1.3 minimum, as clients that also speak TLS 1.2 do. Below a TLS 1.3 minimum it is always sent. A TLS 1.3 server never echoes it, so negotiation is unchanged. Once sent, the extension order orders it like any other extension.

pub fn with_ec_point_formats(self, enabled: bool) -> ClientHelloShape

pub fn set_omit_psk_key_exchange_modes( &mut self, omit: bool, ) -> &mut ClientHelloShape

Omits psk_key_exchange_modes from a ClientHello offering TLS 1.3, as clients that never resume do.

A pre_shared_key requires psk_key_exchange_modes (RFC 8446, section 4.2.9), so such a connection does not resume: it offers no session, TLS 1.2 ones included, and so no early data, whatever session was set or cached. A configured PSK credential fails the handshake with NO_SUPPORTED_PSK_MODE. Tickets a server sends anyway still reach the new-session callback; a later connection that sends the extension may resume them.

pub fn with_omit_psk_key_exchange_modes(self, omit: bool) -> ClientHelloShape

pub fn set_ech_grease( &mut self, shape: Option<EchGreaseShape>, ) -> &mut ClientHelloShape

Overrides ECH GREASE algorithms and payload length. None restores BoringSSL’s randomized, hardware-dependent defaults. This does not enable GREASE; see EchGreaseShape for enablement, real ECH and retry behavior. This setting is independent of GreaseValues.

pub fn with_ech_grease(self, shape: Option<EchGreaseShape>) -> ClientHelloShape

pub fn set_extension_body( &mut self, id: ExtensionType, body: impl Into<Vec<u8>>, ) -> &mut ClientHelloShape

The body sent for extension id of the extension order: a GREASE codepoint or a preserved extension BoringSSL does not build. GREASE extensions default to an empty first and one-byte later body; preserved extensions default to an empty body. A later body for id replaces it.

pub fn with_extension_body( self, id: ExtensionType, body: impl Into<Vec<u8>>, ) -> ClientHelloShape

Trait Implementations

impl Clone for ClientHelloShape

fn clone(&self) -> ClientHelloShape

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ClientHelloShape

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

Formats the value using the given formatter.

impl Default for ClientHelloShape

fn default() -> ClientHelloShape

Returns the “default value” for a type.

impl Eq for ClientHelloShape

impl PartialEq for ClientHelloShape

fn eq(&self, other: &ClientHelloShape) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for ClientHelloShape