pub struct EcGroup(/* private fields */);Expand description
Describes the curve
A curve can be of the named curve type. These curves can be discovered
using openssl binary openssl ecparam -list_curves. Other operations
are available in the wiki. These named curves are available in the
Nid module.
Curves can also be generated using prime field parameters or a binary field.
Prime fields use the formula y^2 mod p = x^3 + ax + b mod p. Binary
fields use the formula y^2 + xy = x^3 + ax^2 + b. Named curves have
assured security. To prevent accidental vulnerabilities, they should
be preferred.
Implementations§
source§impl EcGroup
impl EcGroup
sourcepub fn from_curve_name(nid: Nid) -> Result<EcGroup, ErrorStack>
pub fn from_curve_name(nid: Nid) -> Result<EcGroup, ErrorStack>
Returns the group of a standard named curve.
§Examples
use openssl::nid::Nid;
use openssl::ec::{EcGroup, EcKey};
let nid = Nid::X9_62_PRIME256V1; // NIST P-256 curve
let group = EcGroup::from_curve_name(nid)?;
let key = EcKey::generate(&group)?;This corresponds to EC_GROUP_new_by_curve_name.
sourcepub fn from_components(
p: BigNum,
a: BigNum,
b: BigNum,
ctx: &mut BigNumContextRef,
) -> Result<EcGroup, ErrorStack>
pub fn from_components( p: BigNum, a: BigNum, b: BigNum, ctx: &mut BigNumContextRef, ) -> Result<EcGroup, ErrorStack>
Returns the group for given parameters
This corresponds to EC_GROUP_new_curve_GFp.
Methods from Deref<Target = EcGroupRef>§
sourcepub fn components_gfp(
&self,
p: &mut BigNumRef,
a: &mut BigNumRef,
b: &mut BigNumRef,
ctx: &mut BigNumContextRef,
) -> Result<(), ErrorStack>
pub fn components_gfp( &self, p: &mut BigNumRef, a: &mut BigNumRef, b: &mut BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>
Places the components of a curve over a prime field in the provided BigNums.
The components make up the formula y^2 mod p = x^3 + ax + b mod p.
This corresponds to EC_GROUP_get_curve_GFp.
sourcepub fn components_gf2m(
&self,
p: &mut BigNumRef,
a: &mut BigNumRef,
b: &mut BigNumRef,
ctx: &mut BigNumContextRef,
) -> Result<(), ErrorStack>
pub fn components_gf2m( &self, p: &mut BigNumRef, a: &mut BigNumRef, b: &mut BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>
Places the components of a curve over a binary field in the provided BigNums.
The components make up the formula y^2 + xy = x^3 + ax^2 + b.
In this form p relates to the irreducible polynomial. Each bit represents
a term in the polynomial. It will be set to 3 1s or 5 1s depending on
using a trinomial or pentanomial.
This corresponds to EC_GROUP_get_curve_GF2m.
sourcepub fn cofactor(
&self,
cofactor: &mut BigNumRef,
ctx: &mut BigNumContextRef,
) -> Result<(), ErrorStack>
pub fn cofactor( &self, cofactor: &mut BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>
Places the cofactor of the group in the provided BigNum.
This corresponds to EC_GROUP_get_cofactor.
sourcepub fn degree(&self) -> u32
pub fn degree(&self) -> u32
Returns the degree of the curve.
This corresponds to EC_GROUP_get_degree.
sourcepub fn order_bits(&self) -> u32
pub fn order_bits(&self) -> u32
Returns the number of bits in the group order.
This corresponds to EC_GROUP_order_bits.
sourcepub fn generator(&self) -> &EcPointRef
pub fn generator(&self) -> &EcPointRef
Returns the generator for the given curve as an EcPoint.
This corresponds to EC_GROUP_get0_generator.
sourcepub fn set_generator(
&mut self,
generator: EcPoint,
order: BigNum,
cofactor: BigNum,
) -> Result<(), ErrorStack>
pub fn set_generator( &mut self, generator: EcPoint, order: BigNum, cofactor: BigNum, ) -> Result<(), ErrorStack>
Sets the generator point for the given curve
This corresponds to EC_GROUP_set_generator.
sourcepub fn order(
&self,
order: &mut BigNumRef,
ctx: &mut BigNumContextRef,
) -> Result<(), ErrorStack>
pub fn order( &self, order: &mut BigNumRef, ctx: &mut BigNumContextRef, ) -> Result<(), ErrorStack>
Places the order of the curve in the provided BigNum.
This corresponds to EC_GROUP_get_order.
sourcepub fn set_asn1_flag(&mut self, flag: Asn1Flag)
pub fn set_asn1_flag(&mut self, flag: Asn1Flag)
Sets the flag determining if the group corresponds to a named curve or must be explicitly parameterized.
This defaults to EXPLICIT_CURVE in OpenSSL 1.0.1 and 1.0.2, but NAMED_CURVE in OpenSSL
1.1.0.
This corresponds to EC_GROUP_set_asn1_flag.
sourcepub fn asn1_flag(&self) -> Asn1Flag
pub fn asn1_flag(&self) -> Asn1Flag
Gets the flag determining if the group corresponds to a named curve.
This corresponds to EC_GROUP_get_asn1_flag.
sourcepub fn curve_name(&self) -> Option<Nid>
pub fn curve_name(&self) -> Option<Nid>
Returns the name of the curve, if a name is associated.
This corresponds to EC_GROUP_get_curve_name.