Implement signs having low-s.

Closes #159
This commit is contained in:
Gav Wood 2016-01-18 23:46:33 +01:00
parent 17969dcc1a
commit f946088e43

View File

@ -151,6 +151,12 @@ pub mod ec {
let mut signature: crypto::Signature = unsafe { ::std::mem::uninitialized() }; let mut signature: crypto::Signature = unsafe { ::std::mem::uninitialized() };
signature.clone_from_slice(&data); signature.clone_from_slice(&data);
signature[64] = rec_id.to_i32() as u8; signature[64] = rec_id.to_i32() as u8;
let (_, s, v) = signature.to_rsv();
let secp256k1n = U256::from_str("fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141").unwrap();
if !is_low_s(&s) {
signature = super::Signature::from_rsv(&H256::from_slice(&signature[0..32]), &H256::from(secp256k1n - s), v ^ 1);
}
Ok(signature) Ok(signature)
} }
/// Verify signature. /// Verify signature.
@ -174,7 +180,7 @@ pub mod ec {
/// Check if this is a "low" signature. /// Check if this is a "low" signature.
pub fn is_low(sig: &Signature) -> bool { pub fn is_low(sig: &Signature) -> bool {
H256::from_slice(&sig[32..64]) <= h256_from_hex("7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0") H256::from_slice(&sig[32..64]) <= h256_from_hex("7fffffffffffffffffffffffffffffff5d576e7357a4501ddfe92f46681b20a0")
} }
/// Check if this is a "low" signature. /// Check if this is a "low" signature.