rust-lightning/lightning/src/util/crypto.rs
2022-05-05 18:04:42 +02:00

48 lines
1.5 KiB
Rust

use bitcoin::hashes::{Hash, HashEngine};
use bitcoin::hashes::hmac::{Hmac, HmacEngine};
use bitcoin::hashes::sha256::Hash as Sha256;
use bitcoin::secp256k1::{Message, Secp256k1, SecretKey, ecdsa::Signature, Signing};
macro_rules! hkdf_extract_expand {
($salt: expr, $ikm: expr) => {{
let mut hmac = HmacEngine::<Sha256>::new($salt);
hmac.input($ikm);
let prk = Hmac::from_engine(hmac).into_inner();
let mut hmac = HmacEngine::<Sha256>::new(&prk[..]);
hmac.input(&[1; 1]);
let t1 = Hmac::from_engine(hmac).into_inner();
let mut hmac = HmacEngine::<Sha256>::new(&prk[..]);
hmac.input(&t1);
hmac.input(&[2; 1]);
(t1, Hmac::from_engine(hmac).into_inner(), prk)
}};
($salt: expr, $ikm: expr, 2) => {{
let (k1, k2, _) = hkdf_extract_expand!($salt, $ikm);
(k1, k2)
}};
($salt: expr, $ikm: expr, 3) => {{
let (k1, k2, prk) = hkdf_extract_expand!($salt, $ikm);
let mut hmac = HmacEngine::<Sha256>::new(&prk[..]);
hmac.input(&k2);
hmac.input(&[3; 1]);
(k1, k2, Hmac::from_engine(hmac).into_inner())
}}
}
pub fn hkdf_extract_expand_twice(salt: &[u8], ikm: &[u8]) -> ([u8; 32], [u8; 32]) {
hkdf_extract_expand!(salt, ikm, 2)
}
pub fn hkdf_extract_expand_thrice(salt: &[u8], ikm: &[u8]) -> ([u8; 32], [u8; 32], [u8; 32]) {
hkdf_extract_expand!(salt, ikm, 3)
}
#[inline]
pub fn sign<C: Signing>(ctx: &Secp256k1<C>, msg: &Message, sk: &SecretKey) -> Signature {
#[cfg(feature = "grind_signatures")]
let sig = ctx.sign_ecdsa_low_r(msg, sk);
#[cfg(not(feature = "grind_signatures"))]
let sig = ctx.sign_ecdsa(msg, sk);
sig
}