Enum Curve

#[non_exhaustive]
pub enum Curve {
    NistP256,
    NistP384,
    NistP521,
    BrainpoolP256,
    BrainpoolP384,
    BrainpoolP512,
    Ed25519,
    Cv25519,
    Unknown(Box<[u8]>),
}

Elliptic curves used in OpenPGP.

PublicKeyAlgorithm does not differentiate between elliptic curves. Instead, the curve is specified using an OID prepended to the key material. We provide this type to be able to match on the curves.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

NistP256

NIST curve P-256.

NistP384

NIST curve P-384.

NistP521

NIST curve P-521.

BrainpoolP256

brainpoolP256r1.

BrainpoolP384

brainpoolP384r1.

BrainpoolP512

brainpoolP512r1.

Ed25519

D.J. Bernstein’s “Twisted” Edwards curve Ed25519.

Cv25519

Elliptic curve Diffie-Hellman using D.J. Bernstein’s Curve25519.

Unknown(Box<[u8]>)

Unknown curve.

Implementations

impl Curve

pub fn bits(&self) -> Result<usize>

Returns the length of public keys over this curve in bits.

For the Kobliz curves this is the size of the underlying finite field. For X25519 it is 256.

This value is also equal to the length of a coordinate in bits.

Note: This information is useless and should not be used to gauge the security of a particular curve. This function exists only because some legacy PGP application like HKP need it.

Examples

use sequoia_openpgp as openpgp;
use openpgp::types::Curve;

assert_eq!(Curve::NistP256.bits()?, 256);
assert_eq!(Curve::NistP384.bits()?, 384);
assert_eq!(Curve::Ed25519.bits()?, 256);
assert!(Curve::Unknown(Box::new([0x2B, 0x11])).bits().is_err());

pub fn field_size(&self) -> Result<usize>

Returns the curve’s field size in bytes.

Examples

use sequoia_openpgp as openpgp;
use openpgp::types::Curve;

assert_eq!(Curve::NistP256.field_size()?, 32);
assert_eq!(Curve::NistP384.field_size()?, 48);
assert_eq!(Curve::NistP521.field_size()?, 66);
assert_eq!(Curve::Ed25519.field_size()?, 32);
assert!(Curve::Unknown(Box::new([0x2B, 0x11])).field_size().is_err());

impl Curve

pub fn from_oid(oid: &[u8]) -> Curve

Parses the given OID.

Examples

use sequoia_openpgp as openpgp;
use openpgp::types::Curve;

assert_eq!(Curve::from_oid(&[0x2B, 0x81, 0x04, 0x00, 0x22]), Curve::NistP384);
assert_eq!(Curve::from_oid(&[0x2B, 0x11]), Curve::Unknown(Box::new([0x2B, 0x11])));

pub fn oid(&self) -> &[u8]

Returns this curve’s OID.

Examples

use sequoia_openpgp as openpgp;
use openpgp::types::Curve;

assert_eq!(Curve::NistP384.oid(), &[0x2B, 0x81, 0x04, 0x00, 0x22]);
assert_eq!(Curve::Unknown(Box::new([0x2B, 0x11])).oid(), &[0x2B, 0x11]);

pub fn is_supported(&self) -> bool

Returns whether this algorithm is supported.

Examples

use sequoia_openpgp as openpgp;
use openpgp::types::Curve;

assert!(Curve::Ed25519.is_supported());
assert!(!Curve::Unknown(Box::new([0x2B, 0x11])).is_supported());

pub fn variants() -> impl Iterator<Item = Self>

Returns an iterator over all valid variants.

Trait Implementations

impl Clone for Curve

fn clone(&self) -> Curve

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Curve

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

Formats the value using the given formatter.

impl Display for Curve

Formats the elliptic curve name.

There are two ways the elliptic curve name can be formatted. By default the short name is used. The alternate format uses the full curve name.

Examples

use sequoia_openpgp as openpgp;
use openpgp::types::Curve;

// default, short format
assert_eq!("NIST P-256", format!("{}", Curve::NistP256));

// alternate, long format
assert_eq!("NIST curve P-256", format!("{:#}", Curve::NistP256));

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

Formats the value using the given formatter.

impl Hash for Curve

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 Curve

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

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

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

const 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 Curve

fn partial_cmp(&self, other: &Curve) -> 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 Curve

impl StructuralPartialEq for Curve