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)]
21pub enum EcParameters {
22    /// Elliptic curve named by a particular OID.
23    ///
24    /// > namedCurve identifies all the required values for a particular
25    /// > set of elliptic curve domain parameters to be represented by an
26    /// > object identifier.
27    NamedCurve(ObjectIdentifier),
28}
29
30impl<'a> DecodeValue<'a> for EcParameters {
31    fn decode_value<R: Reader<'a>>(decoder: &mut R, header: Header) -> der::Result<Self> {
32        ObjectIdentifier::decode_value(decoder, header).map(Self::NamedCurve)
33    }
34}
35
36impl EncodeValue for EcParameters {
37    fn value_len(&self) -> der::Result<Length> {
38        match self {
39            Self::NamedCurve(oid) => oid.value_len(),
40        }
41    }
42
43    fn encode_value(&self, writer: &mut impl Writer) -> der::Result<()> {
44        match self {
45            Self::NamedCurve(oid) => oid.encode_value(writer),
46        }
47    }
48}
49
50impl EcParameters {
51    /// Obtain the `namedCurve` OID.
52    pub fn named_curve(self) -> Option<ObjectIdentifier> {
53        match self {
54            Self::NamedCurve(oid) => Some(oid),
55        }
56    }
57}
58
59impl<'a> From<&'a EcParameters> for AnyRef<'a> {
60    fn from(params: &'a EcParameters) -> AnyRef<'a> {
61        match params {
62            EcParameters::NamedCurve(oid) => oid.into(),
63        }
64    }
65}
66
67impl From<ObjectIdentifier> for EcParameters {
68    fn from(oid: ObjectIdentifier) -> EcParameters {
69        EcParameters::NamedCurve(oid)
70    }
71}
72
73impl FixedTag for EcParameters {
74    const TAG: Tag = Tag::ObjectIdentifier;
75}
sec1/parameters.rs

sec1/
parameters.rs
