mls_rs_crypto_traits/
ec.rs

1// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
2// Copyright by contributors to this project.
3// SPDX-License-Identifier: (Apache-2.0 OR MIT)
4
5use mls_rs_core::crypto::CipherSuite;
6
7use crate::SamplingMethod;
8
9/// Elliptic curve types
10#[derive(Clone, Copy, Debug, Eq, PartialEq)]
11#[repr(u8)]
12#[non_exhaustive]
13pub enum Curve {
14    /// NIST Curve-P256
15    P256,
16    /// NIST Curve-P384
17    P384,
18    /// NIST Curve-P521
19    P521,
20    /// Elliptic-curve Diffie-Hellman key exchange Curve25519
21    X25519,
22    /// Edwards-curve Digital Signature Algorithm Curve25519
23    Ed25519,
24    /// Elliptic-curve Diffie-Hellman key exchange Curve448
25    X448,
26    /// Edwards-curve Digital Signature Algorithm Curve448
27    Ed448,
28}
29
30impl Curve {
31    /// Returns the amount of bytes of a secret key using this curve
32    #[inline(always)]
33    pub fn secret_key_size(&self) -> usize {
34        match self {
35            Curve::P256 => 32,
36            Curve::P384 => 48,
37            Curve::P521 => 66,
38            Curve::X25519 => 32,
39            Curve::Ed25519 => 64,
40            Curve::X448 => 56,
41            Curve::Ed448 => 114,
42        }
43    }
44
45    #[inline(always)]
46    pub fn public_key_size(&self) -> usize {
47        match self {
48            Curve::P256 | Curve::P384 | Curve::P521 => 2 * self.secret_key_size() + 1,
49            Curve::X25519 | Curve::Ed25519 | Curve::X448 | Curve::Ed448 => self.secret_key_size(),
50        }
51    }
52
53    pub fn from_ciphersuite(cipher_suite: CipherSuite, for_sig: bool) -> Option<Self> {
54        match cipher_suite {
55            CipherSuite::P256_AES128 => Some(Curve::P256),
56            CipherSuite::P384_AES256 => Some(Curve::P384),
57            CipherSuite::P521_AES256 => Some(Curve::P521),
58            CipherSuite::CURVE25519_AES128 | CipherSuite::CURVE25519_CHACHA if for_sig => {
59                Some(Curve::Ed25519)
60            }
61            CipherSuite::CURVE25519_AES128 | CipherSuite::CURVE25519_CHACHA => Some(Curve::X25519),
62            CipherSuite::CURVE448_AES256 | CipherSuite::CURVE448_CHACHA if for_sig => {
63                Some(Curve::Ed448)
64            }
65            CipherSuite::CURVE448_AES256 | CipherSuite::CURVE448_CHACHA => Some(Curve::X448),
66            _ => None,
67        }
68    }
69
70    #[inline(always)]
71    pub fn hpke_sampling_method(&self) -> SamplingMethod {
72        match self {
73            Curve::P256 | Curve::P384 => SamplingMethod::HpkeWithBitmask(0xFF),
74            Curve::P521 => SamplingMethod::HpkeWithBitmask(0x01),
75            _ => SamplingMethod::HpkeWithoutBitmask,
76        }
77    }
78}
mls_rs_crypto_traits/ec.rs

mls_rs_crypto_traits/
ec.rs
