Struct domain::base::opt::cookie::Cookie

pub struct Cookie { /* private fields */ }

Option data for a DNS cookie.

A value of this type carries two parts: A mandatory ClientCookie and an optional ServerCookie. The client cookie is chosen by, yes, the client and added to a request when contacting a specific server for the first time. When responding, a server calculates a server cookie from the client cookie and adds both of them to the response. The client remembers both and includes them in subsequent requests. The server can now check that the the server cookie was indeed calculated by it and treat the repeat customer differently.

While you can create a new cookie using the new method, shortcuts are available for the standard workflow. A new initial cookie can be created via create_initial. As this will be a random client cookie, it needs the rand feature. The server can check whether a received cookie includes a server cookie created by it via the check_server_hash method. It needs the SipHash-2-4 algorithm and is thus available if the siphasher feature is enabled. The same feature also enables the create_response method which creates the server cookie to be included in a response.

Implementations

impl Cookie

pub fn new(client: ClientCookie, server: Option<ServerCookie>) -> Self

Creates a new cookie from client and optional server cookie.

pub fn client(&self) -> ClientCookie

Returns the client cookie.

pub fn server(&self) -> Option<&ServerCookie>

Returns a reference to the server cookie if present.

pub fn parse<Octs: AsRef<[u8]> + ?Sized>( parser: &mut Parser<'_, Octs> ) -> Result<Self, ParseError>

Parses the cookie from its wire format.

pub fn check_server_hash( &self, client_ip: IpAddr, secret: &[u8; 16], timestamp_ok: impl FnOnce(Serial) -> bool ) -> bool

Returns whether the standard server cookie’s hash is correct.

The client_ip is the source IP address of a request. The secret is the server cookie secret. The timestamp is checked via the timestamp_ok closure which is given the timestamp and should return whether it is acceptable.

Returns false if the cookie is not a server cookie, if it is but not a standard server cookie, or if it is but either the timestamp is not acceptable or the hash differs from what it should be.

Thus, if this method returns false, there is no valid server cookie and the server can proceed as if there was no server cookie as described in section 5.2.3 of RFC 7873.

pub fn create_initial() -> Self

Creates a random client cookie for including in an initial request.

pub fn create_response( &self, timestamp: Serial, client_ip: IpAddr, secret: &[u8; 16] ) -> Self

Creates a standard format cookie option for sending a response.

This method uses the client cookie and the additional values provided to produce a cookie option that should be included in a response.

Trait Implementations

impl Clone for Cookie

fn clone(&self) -> Cookie

Returns a copy of the value.

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

Performs copy-assignment from source.

impl ComposeOptData for Cookie

fn compose_len(&self) -> u16

fn compose_option<Target: OctetsBuilder + ?Sized>( &self, target: &mut Target ) -> Result<(), Target::AppendError>

impl Debug for Cookie

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

Formats the value using the given formatter.

impl Default for Cookie

fn default() -> Cookie

Returns the “default value” for a type.

impl Display for Cookie

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

Formats the value using the given formatter.

impl<Octs, Name> From<Cookie> for AllOptData<Octs, Name>

fn from(value: Cookie) -> Self

Converts to this type from the input type.

impl Hash for Cookie

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl OptData for Cookie

fn code(&self) -> OptionCode

Returns the option code associated with this option.

impl Ord for Cookie

fn cmp(&self, other: &Cookie) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized + PartialOrd,

Restrict a value to a certain interval.

impl<'a, Octs: AsRef<[u8]> + ?Sized> ParseOptData<'a, Octs> for Cookie

fn parse_option( code: OptionCode, parser: &mut Parser<'a, Octs> ) -> Result<Option<Self>, ParseError>

Parses the option code data.

impl PartialEq for Cookie

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl PartialOrd for Cookie

fn partial_cmp(&self, other: &Cookie) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

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

This method tests less than (for self and other) and is used by the < operator.

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

This method tests less than or equal to (for self and other) and is used by the <= operator.

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

This method tests greater than (for self and other) and is used by the > operator.

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

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Eq for Cookie

impl StructuralPartialEq for Cookie