mithril_stm/bls_multi_signature/
signing_key.rs

1use blst::min_sig::SecretKey as BlstSk;
2use rand_core::{CryptoRng, RngCore};
3
4use crate::bls_multi_signature::signature::BlsSignature;
5use crate::error::{blst_err_to_mithril, MultiSignatureError};
6
7/// MultiSig secret key, which is a wrapper over the BlstSk type from the blst
8/// library.
9#[derive(Debug, Clone)]
10pub struct BlsSigningKey(pub BlstSk);
11
12impl BlsSigningKey {
13    /// Generate a secret key
14    pub fn generate(rng: &mut (impl RngCore + CryptoRng)) -> Self {
15        let mut ikm = [0u8; 32];
16        rng.fill_bytes(&mut ikm);
17        BlsSigningKey(
18            BlstSk::key_gen(&ikm, &[])
19                .expect("Error occurs when the length of ikm < 32. This will not happen here."),
20        )
21    }
22
23    /// Sign a message with the given secret key
24    pub fn sign(&self, msg: &[u8]) -> BlsSignature {
25        BlsSignature(self.0.sign(msg, &[], &[]))
26    }
27
28    /// Convert the secret key into byte string.
29    pub fn to_bytes(&self) -> [u8; 32] {
30        self.0.to_bytes()
31    }
32
33    /// Convert a string of bytes into a `SigningKey`.
34    ///
35    /// # Error
36    /// Fails if the byte string represents a scalar larger than the group order.
37    pub fn from_bytes(bytes: &[u8]) -> Result<Self, MultiSignatureError> {
38        let bytes = bytes
39            .get(..32)
40            .ok_or(MultiSignatureError::SerializationError)?;
41        match BlstSk::from_bytes(bytes) {
42            Ok(sk) => Ok(Self(sk)),
43            Err(e) => Err(blst_err_to_mithril(e, None, None)
44                .expect_err("If deserialization is not successful, blst returns and error different to SUCCESS."))
45        }
46    }
47
48    pub(crate) fn to_blst_sk(&self) -> BlstSk {
49        self.0.clone()
50    }
51}
mithril_stm/bls_multi_signature/signing_key.rs

mithril_stm/bls_multi_signature/
signing_key.rs
