Struct ServerCookie

pub struct ServerCookie(/* private fields */);

A server cookie for DNS cookies.

In the original specification, the server cookie was of variable length between 8 and 32 octets. It was supposed to be generated via some sort of message authentication code from the client cookie and a server secret. Leaving the concrete mechanism to the implementer resulted in interoperability problems if servers from multiple vendors were placed behind the same public address. Thus, RFC 9018 defined a standard mechanism of the content and generation of the cookie.

This standard server cookie consists of a 1 octet version number (currently 1), 3 reserved octets that must be zero, a 4 octet timestamp as seconds since the Unix epoch, and 8 octets of hash value.

In version 1, the hash is calculated feeding the SipHash-2-4 that has been initialized with a server secret the concatenation of client cookie, version, reserved, timestamp, client IP address.

Implementations

impl ServerCookie

pub fn from_octets(slice: &[u8]) -> Self

Creates a new server cookie from the given octets.

Panics

The function panics if octets is shorter than 8 octets or longer than 32.

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

Parses a server cookie from its wire format.

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

Parses an optional server cookie from its wire format.

pub fn try_to_standard(&self) -> Option<StandardServerCookie>

Converts the cookie into a standard cookie if possible.

This is possible if the length of the cookie is 16 octets. Returns None otherwise.

pub fn compose_len(&self) -> u16

Returns the length of the wire format of the cookie.

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

Appends the wire format of the cookie to the target.

Trait Implementations

impl AsRef<[u8]> for ServerCookie

fn as_ref(&self) -> &[u8]

Converts this type into a shared reference of the (usually inferred) input type.

impl Clone for ServerCookie

fn clone(&self) -> ServerCookie

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ServerCookie

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

Formats the value using the given formatter.

impl Display for ServerCookie

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

Formats the value using the given formatter.

impl From<StandardServerCookie> for ServerCookie

fn from(src: StandardServerCookie) -> Self

Converts to this type from the input type.

impl Hash for ServerCookie

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 Ord for ServerCookie

fn cmp(&self, other: &ServerCookie) -> 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,

Restrict a value to a certain interval.

impl PartialEq for ServerCookie

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

Tests for self and other values to be equal, and is used by ==.

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

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

impl PartialOrd for ServerCookie

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

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

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

Tests less than (for self and other) and is used by the < operator.

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

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

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

Tests greater than (for self and other) and is used by the > operator.

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

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

impl Eq for ServerCookie

impl StructuralPartialEq for ServerCookie