bc_components/encrypted_key/
scrypt_params.rs

1use anyhow::Result;
2use bc_crypto::scrypt_opt;
3use dcbor::prelude::*;
4
5use super::{KeyDerivation, KeyDerivationMethod, SALT_LEN};
6use crate::{EncryptedMessage, Nonce, Salt, SymmetricKey};
7
8/// Struct representing Scrypt parameters.
9///
10/// CDDL:
11/// ```cddl
12/// ScryptParams = [2, Salt, log_n: uint, r: uint, p: uint]
13/// ```
14#[derive(Debug, Clone, PartialEq, Eq)]
15pub struct ScryptParams {
16    salt: Salt,
17    log_n: u8,
18    r: u32,
19    p: u32,
20}
21
22impl ScryptParams {
23    pub fn new() -> Self {
24        Self::new_opt(Salt::new_with_len(SALT_LEN).unwrap(), 15, 8, 1)
25    }
26
27    pub fn new_opt(salt: Salt, log_n: u8, r: u32, p: u32) -> Self {
28        Self { salt, log_n, r, p }
29    }
30
31    pub fn salt(&self) -> &Salt { &self.salt }
32
33    pub fn log_n(&self) -> u8 { self.log_n }
34
35    pub fn r(&self) -> u32 { self.r }
36
37    pub fn p(&self) -> u32 { self.p }
38}
39
40impl KeyDerivation for ScryptParams {
41    const INDEX: usize = KeyDerivationMethod::Scrypt as usize;
42    fn lock(
43        &mut self,
44        content_key: &SymmetricKey,
45        secret: impl AsRef<[u8]>,
46    ) -> Result<EncryptedMessage> {
47        let derived_key: SymmetricKey =
48            scrypt_opt(secret, &self.salt, 32, self.log_n, self.r, self.p)
49                .try_into()
50                .unwrap();
51        let encoded_method: Vec<u8> = self.to_cbor_data();
52        Ok(derived_key.encrypt(
53            content_key,
54            Some(encoded_method),
55            Option::<Nonce>::None,
56        ))
57    }
58
59    fn unlock(
60        &self,
61        encrypted_message: &EncryptedMessage,
62        secret: impl AsRef<[u8]>,
63    ) -> Result<SymmetricKey> {
64        let derived_key: SymmetricKey =
65            scrypt_opt(secret, &self.salt, 32, self.log_n, self.r, self.p)
66                .try_into()?;
67        derived_key.decrypt(encrypted_message)?.try_into()
68    }
69}
70
71impl std::fmt::Display for ScryptParams {
72    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
73        write!(f, "Scrypt")
74    }
75}
76
77impl Into<CBOR> for ScryptParams {
78    fn into(self) -> CBOR {
79        vec![
80            CBOR::from(Self::INDEX),
81            self.salt.into(),
82            self.log_n.into(),
83            self.r.into(),
84            self.p.into(),
85        ]
86        .into()
87    }
88}
89
90impl TryFrom<CBOR> for ScryptParams {
91    type Error = dcbor::Error;
92
93    fn try_from(cbor: CBOR) -> dcbor::Result<Self> {
94        let a = cbor.try_into_array()?;
95        a.len()
96            .eq(&5)
97            .then_some(())
98            .ok_or_else(|| dcbor::Error::msg("Invalid ScryptParams"))?;
99        let mut iter = a.into_iter();
100        let _index: usize = iter
101            .next()
102            .ok_or_else(|| dcbor::Error::msg("Missing index"))?
103            .try_into()?;
104        let salt: Salt = iter
105            .next()
106            .ok_or_else(|| dcbor::Error::msg("Missing salt"))?
107            .try_into()?;
108        let log_n: u8 = iter
109            .next()
110            .ok_or_else(|| dcbor::Error::msg("Missing log_n"))?
111            .try_into()?;
112        let r: u32 = iter
113            .next()
114            .ok_or_else(|| dcbor::Error::msg("Missing r"))?
115            .try_into()?;
116        let p: u32 = iter
117            .next()
118            .ok_or_else(|| dcbor::Error::msg("Missing p"))?
119            .try_into()?;
120        Ok(Self { salt, log_n, r, p })
121    }
122}
bc_components/encrypted_key/scrypt_params.rs

bc_components/encrypted_key/
scrypt_params.rs
