2026-01-27 16:19:56 -05:00

259 lines
8.8 KiB
Rust

use secp256k1::Scalar;
use serde::{Deserialize, Serialize};
use crate::key_management::key_tree::traits::KeyNode;
#[derive(Debug, Serialize, Deserialize, Clone)]
pub struct ChildKeysPublic {
pub csk: nssa::PrivateKey,
pub cpk: nssa::PublicKey,
pub ccc: [u8; 32],
/// Can be [`None`] if root
pub cci: Option<u32>,
}
impl ChildKeysPublic {
fn compute_hash_value(&self, cci: u32) -> [u8; 64] {
let mut hash_input = vec![];
match ((2u32).pow(31)).cmp(&cci) {
// Non-harden
std::cmp::Ordering::Greater => {
hash_input.extend_from_slice(self.cpk.value());
hash_input.extend_from_slice(&cci.to_le_bytes());
hmac_sha512::HMAC::mac(hash_input, self.ccc)
}
// Harden
_ => {
hash_input.extend_from_slice(self.csk.value());
hash_input.extend_from_slice(&(cci).to_le_bytes());
hmac_sha512::HMAC::mac(hash_input, self.ccc)
}
}
}
}
impl KeyNode for ChildKeysPublic {
fn root(seed: [u8; 64]) -> Self {
let hash_value = hmac_sha512::HMAC::mac(seed, "LEE_master_pub");
let csk = nssa::PrivateKey::try_new(*hash_value.first_chunk::<32>().unwrap()).unwrap();
let ccc = *hash_value.last_chunk::<32>().unwrap();
let cpk = nssa::PublicKey::new_from_private_key(&csk);
Self {
csk,
cpk,
ccc,
cci: None,
}
}
fn nth_child(&self, cci: u32) -> Self {
let hash_value = self.compute_hash_value(cci);
let csk = secp256k1::SecretKey::from_byte_array(
*hash_value
.first_chunk::<32>()
.expect("hash_value is 64 bytes, must be safe to get first 32"),
)
.unwrap();
let csk = nssa::PrivateKey::try_new(
csk.add_tweak(&Scalar::from_le_bytes(*self.csk.value()).unwrap())
.expect("Expect a valid Scalar")
.secret_bytes(),
)
.unwrap();
if secp256k1::constants::CURVE_ORDER < *csk.value() {
panic!("Secret key cannot exceed curve order");
}
let ccc = *hash_value
.last_chunk::<32>()
.expect("hash_value is 64 bytes, must be safe to get last 32");
let cpk = nssa::PublicKey::new_from_private_key(&csk);
Self {
csk,
cpk,
ccc,
cci: Some(cci),
}
}
fn chain_code(&self) -> &[u8; 32] {
&self.ccc
}
fn child_index(&self) -> Option<u32> {
self.cci
}
fn account_id(&self) -> nssa::AccountId {
nssa::AccountId::from(&self.cpk)
}
}
impl<'a> From<&'a ChildKeysPublic> for &'a nssa::PrivateKey {
fn from(value: &'a ChildKeysPublic) -> Self {
&value.csk
}
}
#[cfg(test)]
mod tests {
use nssa::{PrivateKey, PublicKey};
use super::*;
#[test]
fn test_master_keys_generation() {
let seed = [
88, 189, 37, 237, 199, 125, 151, 226, 69, 153, 165, 113, 191, 69, 188, 221, 9, 34, 173,
134, 61, 109, 34, 103, 121, 39, 237, 14, 107, 194, 24, 194, 191, 14, 237, 185, 12, 87,
22, 227, 38, 71, 17, 144, 251, 118, 217, 115, 33, 222, 201, 61, 203, 246, 121, 214, 6,
187, 148, 92, 44, 253, 210, 37,
];
let keys = ChildKeysPublic::root(seed);
let expected_ccc = [
238, 94, 84, 154, 56, 224, 80, 218, 133, 249, 179, 222, 9, 24, 17, 252, 120, 127, 222,
13, 146, 126, 232, 239, 113, 9, 194, 219, 190, 48, 187, 155,
];
let expected_csk: PrivateKey = PrivateKey::try_new([
40, 35, 239, 19, 53, 178, 250, 55, 115, 12, 34, 3, 153, 153, 72, 170, 190, 36, 172, 36,
202, 148, 181, 228, 35, 222, 58, 84, 156, 24, 146, 86,
])
.unwrap();
let expected_cpk: PublicKey = PublicKey::try_new([
219, 141, 130, 105, 11, 203, 187, 124, 112, 75, 223, 22, 11, 164, 153, 127, 59, 247,
244, 166, 75, 66, 242, 224, 35, 156, 161, 75, 41, 51, 76, 245,
])
.unwrap();
assert!(expected_ccc == keys.ccc);
assert!(expected_csk == keys.csk);
assert!(expected_cpk == keys.cpk);
}
#[test]
fn test_harden_child_keys_generation() {
let seed = [
88, 189, 37, 237, 199, 125, 151, 226, 69, 153, 165, 113, 191, 69, 188, 221, 9, 34, 173,
134, 61, 109, 34, 103, 121, 39, 237, 14, 107, 194, 24, 194, 191, 14, 237, 185, 12, 87,
22, 227, 38, 71, 17, 144, 251, 118, 217, 115, 33, 222, 201, 61, 203, 246, 121, 214, 6,
187, 148, 92, 44, 253, 210, 37,
];
let root_keys = ChildKeysPublic::root(seed);
let cci = (2u32).pow(31) + 13;
let child_keys = ChildKeysPublic::nth_child(&root_keys, cci);
print!(
"{} {}",
child_keys.csk.value()[0],
child_keys.csk.value()[1]
);
let expected_ccc = [
126, 175, 244, 41, 41, 173, 134, 103, 139, 140, 195, 86, 194, 147, 116, 48, 71, 107,
253, 235, 114, 139, 60, 115, 226, 205, 215, 248, 240, 190, 196, 6,
];
let expected_csk: PrivateKey = PrivateKey::try_new([
128, 148, 53, 165, 222, 155, 163, 108, 186, 182, 124, 67, 90, 86, 59, 123, 95, 224,
171, 4, 51, 131, 254, 57, 241, 178, 82, 161, 204, 206, 79, 107,
])
.unwrap();
let expected_cpk: PublicKey = PublicKey::try_new([
149, 240, 55, 15, 178, 67, 245, 254, 44, 141, 95, 223, 238, 62, 85, 11, 248, 9, 11, 40,
69, 211, 116, 13, 189, 35, 8, 95, 233, 154, 129, 58,
])
.unwrap();
assert!(expected_ccc == child_keys.ccc);
assert!(expected_csk == child_keys.csk);
assert!(expected_cpk == child_keys.cpk);
}
#[test]
fn test_nonharden_child_keys_generation() {
let seed = [
88, 189, 37, 237, 199, 125, 151, 226, 69, 153, 165, 113, 191, 69, 188, 221, 9, 34, 173,
134, 61, 109, 34, 103, 121, 39, 237, 14, 107, 194, 24, 194, 191, 14, 237, 185, 12, 87,
22, 227, 38, 71, 17, 144, 251, 118, 217, 115, 33, 222, 201, 61, 203, 246, 121, 214, 6,
187, 148, 92, 44, 253, 210, 37,
];
let root_keys = ChildKeysPublic::root(seed);
let cci = 13;
let child_keys = ChildKeysPublic::nth_child(&root_keys, cci);
print!(
"{} {}",
child_keys.csk.value()[0],
child_keys.csk.value()[1]
);
let expected_ccc = [
50, 29, 113, 102, 49, 130, 64, 0, 247, 95, 135, 187, 118, 162, 65, 65, 194, 53, 189,
242, 66, 178, 168, 2, 51, 193, 155, 72, 209, 2, 207, 251,
];
let expected_csk: PrivateKey = PrivateKey::try_new([
162, 32, 211, 190, 180, 74, 151, 246, 189, 93, 8, 57, 182, 239, 125, 245, 192, 255, 24,
186, 251, 23, 194, 186, 252, 121, 190, 54, 147, 199, 1, 109,
])
.unwrap();
let expected_cpk: PublicKey = PublicKey::try_new([
183, 48, 207, 170, 221, 111, 118, 9, 40, 67, 123, 162, 159, 169, 34, 157, 23, 37, 232,
102, 231, 187, 199, 191, 205, 146, 159, 22, 79, 100, 10, 223,
])
.unwrap();
assert!(expected_ccc == child_keys.ccc);
assert!(expected_csk == child_keys.csk);
assert!(expected_cpk == child_keys.cpk);
}
#[test]
fn test_edge_case_child_keys_generation_2_power_31() {
let seed = [
88, 189, 37, 237, 199, 125, 151, 226, 69, 153, 165, 113, 191, 69, 188, 221, 9, 34, 173,
134, 61, 109, 34, 103, 121, 39, 237, 14, 107, 194, 24, 194, 191, 14, 237, 185, 12, 87,
22, 227, 38, 71, 17, 144, 251, 118, 217, 115, 33, 222, 201, 61, 203, 246, 121, 214, 6,
187, 148, 92, 44, 253, 210, 37,
];
let root_keys = ChildKeysPublic::root(seed);
let cci = (2u32).pow(31); //equivant to 0, thus non-harden.
let child_keys = ChildKeysPublic::nth_child(&root_keys, cci);
let expected_ccc = [
101, 15, 69, 152, 144, 22, 105, 89, 175, 21, 13, 50, 160, 167, 93, 80, 94, 99, 192,
252, 1, 126, 196, 217, 149, 164, 60, 75, 237, 90, 104, 83,
];
let expected_csk: PrivateKey = PrivateKey::try_new([
46, 196, 131, 199, 190, 180, 250, 222, 41, 188, 221, 156, 255, 239, 251, 207, 239, 202,
166, 216, 107, 236, 195, 48, 167, 69, 97, 13, 132, 117, 76, 89,
])
.unwrap();
let expected_cpk: PublicKey = PublicKey::try_new([
93, 151, 154, 238, 175, 198, 53, 146, 255, 43, 37, 52, 214, 165, 69, 161, 38, 20, 68,
166, 143, 80, 149, 216, 124, 203, 240, 114, 168, 111, 33, 83,
])
.unwrap();
assert!(expected_ccc == child_keys.ccc);
assert!(expected_csk == child_keys.csk);
assert!(expected_cpk == child_keys.cpk);
}
}