sec1/
parameters.rs

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1use der::{
2    asn1::{AnyRef, ObjectIdentifier},
3    DecodeValue, EncodeValue, FixedTag, Header, Length, Reader, Tag, Writer,
4};
5
6/// Elliptic curve parameters as described in
7/// [RFC5480 Section 2.1.1](https://datatracker.ietf.org/doc/html/rfc5480#section-2.1.1):
8///
9/// ```text
10/// ECParameters ::= CHOICE {
11///   namedCurve         OBJECT IDENTIFIER
12///   -- implicitCurve   NULL
13///   -- specifiedCurve  SpecifiedECDomain
14/// }
15///   -- implicitCurve and specifiedCurve MUST NOT be used in PKIX.
16///   -- Details for SpecifiedECDomain can be found in [X9.62].
17///   -- Any future additions to this CHOICE should be coordinated
18///   -- with ANSI X9.
19/// ```
20#[derive(Copy, Clone, Debug, Eq, PartialEq)]
21#[cfg_attr(docsrs, doc(cfg(feature = "der")))]
22pub enum EcParameters {
23    /// Elliptic curve named by a particular OID.
24    ///
25    /// > namedCurve identifies all the required values for a particular
26    /// > set of elliptic curve domain parameters to be represented by an
27    /// > object identifier.
28    NamedCurve(ObjectIdentifier),
29}
30
31impl<'a> DecodeValue<'a> for EcParameters {
32    fn decode_value<R: Reader<'a>>(decoder: &mut R, header: Header) -> der::Result<Self> {
33        ObjectIdentifier::decode_value(decoder, header).map(Self::NamedCurve)
34    }
35}
36
37impl EncodeValue for EcParameters {
38    fn value_len(&self) -> der::Result<Length> {
39        match self {
40            Self::NamedCurve(oid) => oid.value_len(),
41        }
42    }
43
44    fn encode_value(&self, writer: &mut dyn Writer) -> der::Result<()> {
45        match self {
46            Self::NamedCurve(oid) => oid.encode_value(writer),
47        }
48    }
49}
50
51impl EcParameters {
52    /// Obtain the `namedCurve` OID.
53    pub fn named_curve(self) -> Option<ObjectIdentifier> {
54        match self {
55            Self::NamedCurve(oid) => Some(oid),
56        }
57    }
58}
59
60impl<'a> From<&'a EcParameters> for AnyRef<'a> {
61    fn from(params: &'a EcParameters) -> AnyRef<'a> {
62        match params {
63            EcParameters::NamedCurve(oid) => oid.into(),
64        }
65    }
66}
67
68impl From<ObjectIdentifier> for EcParameters {
69    fn from(oid: ObjectIdentifier) -> EcParameters {
70        EcParameters::NamedCurve(oid)
71    }
72}
73
74impl FixedTag for EcParameters {
75    const TAG: Tag = Tag::ObjectIdentifier;
76}
sec1/parameters.rs

sec1/
parameters.rs
