qudag_crypto/kem/
mod.rs

1//! ML-KEM (Kyber) implementation for post-quantum key encapsulation
2
3// mod ml_kem;
4// pub use ml_kem::MlKem768Impl as MlKem768;
5
6use subtle::ConstantTimeEq;
7use thiserror::Error;
8use zeroize::{Zeroize, ZeroizeOnDrop};
9
10/// Errors that can occur during KEM operations
11#[derive(Debug, Error)]
12pub enum KEMError {
13    #[error("Key generation failed")]
14    KeyGenerationError,
15    #[error("Encapsulation failed")]
16    EncapsulationError,
17    #[error("Decapsulation failed")]
18    DecapsulationError,
19    #[error("Invalid length")]
20    InvalidLength,
21    #[error("Invalid key format")]
22    InvalidKey,
23    #[error("Internal error")]
24    InternalError,
25}
26
27/// ML-KEM public key.
28#[derive(Debug, Clone, Zeroize, ZeroizeOnDrop)]
29pub struct PublicKey(Vec<u8>);
30
31impl PublicKey {
32    pub fn from_bytes(bytes: &[u8]) -> Result<Self, KEMError> {
33        Ok(Self(bytes.to_vec()))
34    }
35
36    pub fn as_bytes(&self) -> &[u8] {
37        &self.0
38    }
39}
40
41impl AsRef<[u8]> for PublicKey {
42    fn as_ref(&self) -> &[u8] {
43        &self.0
44    }
45}
46
47impl PartialEq for PublicKey {
48    fn eq(&self, other: &Self) -> bool {
49        self.0.ct_eq(&other.0).into()
50    }
51}
52
53impl Eq for PublicKey {}
54
55/// ML-KEM secret key.
56#[derive(Debug, Clone, Zeroize, ZeroizeOnDrop)]
57pub struct SecretKey(Vec<u8>);
58
59impl SecretKey {
60    pub fn from_bytes(bytes: &[u8]) -> Result<Self, KEMError> {
61        Ok(Self(bytes.to_vec()))
62    }
63
64    pub fn as_bytes(&self) -> &[u8] {
65        &self.0
66    }
67}
68
69impl AsRef<[u8]> for SecretKey {
70    fn as_ref(&self) -> &[u8] {
71        &self.0
72    }
73}
74
75impl PartialEq for SecretKey {
76    fn eq(&self, other: &Self) -> bool {
77        self.0.ct_eq(&other.0).into()
78    }
79}
80
81impl Eq for SecretKey {}
82
83/// ML-KEM ciphertext.
84#[derive(Debug, Clone, Zeroize, ZeroizeOnDrop)]
85pub struct Ciphertext(Vec<u8>);
86
87impl Ciphertext {
88    pub fn from_bytes(bytes: &[u8]) -> Result<Self, KEMError> {
89        Ok(Self(bytes.to_vec()))
90    }
91
92    pub fn as_bytes(&self) -> &[u8] {
93        &self.0
94    }
95}
96
97impl AsRef<[u8]> for Ciphertext {
98    fn as_ref(&self) -> &[u8] {
99        &self.0
100    }
101}
102
103impl PartialEq for Ciphertext {
104    fn eq(&self, other: &Self) -> bool {
105        self.0.ct_eq(&other.0).into()
106    }
107}
108
109impl Eq for Ciphertext {}
110
111/// ML-KEM shared secret.
112#[derive(Debug, Clone, Zeroize, ZeroizeOnDrop)]
113pub struct SharedSecret(Vec<u8>);
114
115impl SharedSecret {
116    pub fn from_bytes(bytes: &[u8]) -> Result<Self, KEMError> {
117        Ok(Self(bytes.to_vec()))
118    }
119
120    pub fn as_bytes(&self) -> &[u8] {
121        &self.0
122    }
123}
124
125impl AsRef<[u8]> for SharedSecret {
126    fn as_ref(&self) -> &[u8] {
127        &self.0
128    }
129}
130
131impl PartialEq for SharedSecret {
132    fn eq(&self, other: &Self) -> bool {
133        self.0.ct_eq(&other.0).into()
134    }
135}
136
137impl Eq for SharedSecret {}
138
139/// ML-KEM key encapsulation trait.
140pub trait KeyEncapsulation {
141    /// Generate a new key pair.
142    fn keygen() -> Result<(PublicKey, SecretKey), KEMError>;
143
144    /// Encapsulate a shared secret using a public key.
145    fn encapsulate(public_key: &PublicKey) -> Result<(Ciphertext, SharedSecret), KEMError>;
146
147    /// Decapsulate a shared secret using a secret key and ciphertext.
148    fn decapsulate(
149        secret_key: &SecretKey,
150        ciphertext: &Ciphertext,
151    ) -> Result<SharedSecret, KEMError>;
152}
153
154/// ML-KEM key pair
155#[derive(Debug, ZeroizeOnDrop)]
156pub struct KeyPair {
157    pub public_key: Vec<u8>,
158    pub secret_key: Vec<u8>,
159}
160
161impl Default for KeyPair {
162    fn default() -> Self {
163        Self::new()
164    }
165}
166
167impl KeyPair {
168    /// Create a new key pair (placeholder implementation)
169    pub fn new() -> Self {
170        Self {
171            public_key: vec![0u8; 32], // Placeholder
172            secret_key: vec![0u8; 32], // Placeholder
173        }
174    }
175
176    /// Get public key reference
177    pub fn public_key(&self) -> &[u8] {
178        &self.public_key
179    }
180
181    /// Get secret key reference  
182    pub fn secret_key(&self) -> &[u8] {
183        &self.secret_key
184    }
185}
qudag_crypto/kem/mod.rs

qudag_crypto/kem/
mod.rs
