openethereum/ethkey/src/secret.rs

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// Copyright 2015-2017 Parity Technologies (UK) Ltd.
// This file is part of Parity.
// Parity is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// Parity is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
// You should have received a copy of the GNU General Public License
// along with Parity. If not, see <http://www.gnu.org/licenses/>.
use std::fmt;
use std::ops::Deref;
use std::str::FromStr;
use secp256k1::key;
use bigint::hash::H256;
use {Error, SECP256K1};
#[derive(Clone, PartialEq, Eq)]
pub struct Secret {
inner: H256,
}
impl fmt::Debug for Secret {
fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
write!(fmt, "Secret: 0x{:x}{:x}..{:x}{:x}", self.inner[0], self.inner[1], self.inner[30], self.inner[31])
}
}
impl Secret {
pub fn from_slice(key: &[u8]) -> Self {
assert_eq!(32, key.len(), "Caller should provide 32-byte length slice");
let mut h = H256::default();
h.copy_from_slice(&key[0..32]);
Secret { inner: h }
}
/// Imports and validates the key.
pub fn from_unsafe_slice(key: &[u8]) -> Result<Self, Error> {
let secret = key::SecretKey::from_slice(&super::SECP256K1, key)?;
Ok(secret.into())
}
/// Checks validity of this key.
pub fn check_validity(&self) -> Result<(), Error> {
self.to_secp256k1_secret().map(|_| ())
}
/// Inplace add one secret key to another (scalar + scalar)
pub fn add(&mut self, other: &Secret) -> Result<(), Error> {
let mut key_secret = self.to_secp256k1_secret()?;
let other_secret = other.to_secp256k1_secret()?;
key_secret.add_assign(&SECP256K1, &other_secret)?;
*self = key_secret.into();
Ok(())
}
/// Inplace subtract one secret key from another (scalar - scalar)
pub fn sub(&mut self, other: &Secret) -> Result<(), Error> {
let mut key_secret = self.to_secp256k1_secret()?;
let mut other_secret = other.to_secp256k1_secret()?;
other_secret.mul_assign(&SECP256K1, &key::MINUS_ONE_KEY)?;
key_secret.add_assign(&SECP256K1, &other_secret)?;
*self = key_secret.into();
Ok(())
}
Fixing secretstore TODOs - part 1 (#5386) * ECDKG protocol prototype * added test for enc/dec math * get rid of decryption_session * added licenses * fix after merge * get rid of unused serde dependency * doc * decryption session [without commutative enc] * failed_dec_session * fixed tests * added commen * added more decryption session tests * helper to localize an issue * more computations to localize error * decryption_session::SessionParams * added tests for EC math to localize problem * secretstore network transport * encryption_session_works_over_network * network errors processing * connecting to KeyServer * licenses * get rid of debug println-s * fixed secretstore args * encryption results are stored in KS database * decryption protocol works over network * enc/dec Session traits * fixing warnings * fix after merge * on-chain ACL checker proto * fixed compilation * fixed compilation * finally fixed <odd>-of-N-scheme * temporary commented test * 1-of-N works in math * scheme 1-of-N works * updated AclStorage with real contract ABI * remove unnecessary unsafety * fixed grumbles * wakeup on access denied * encrypt secretstore messages * 'shadow' decryption * fix grumbles * lost files * secretstore cli-options * decryption seccion when ACL check failed on master * disallow regenerating key for existing document * removed obsolete TODO * fix after merge * switched to tokio_io * fix after merge * fix after merge * fix after merge * fix after merge * fix after merge * fixed test * fix after merge
2017-04-08 11:26:16 +02:00
/// Inplace decrease secret key (scalar - 1)
pub fn dec(&mut self) -> Result<(), Error> {
let mut key_secret = self.to_secp256k1_secret()?;
key_secret.add_assign(&SECP256K1, &key::MINUS_ONE_KEY)?;
*self = key_secret.into();
Ok(())
}
/// Inplace multiply one secret key to another (scalar * scalar)
pub fn mul(&mut self, other: &Secret) -> Result<(), Error> {
let mut key_secret = self.to_secp256k1_secret()?;
let other_secret = other.to_secp256k1_secret()?;
key_secret.mul_assign(&SECP256K1, &other_secret)?;
*self = key_secret.into();
Ok(())
}
/// Inplace negate secret key (-scalar)
pub fn neg(&mut self) -> Result<(), Error> {
let mut key_secret = self.to_secp256k1_secret()?;
key_secret.mul_assign(&SECP256K1, &key::MINUS_ONE_KEY)?;
*self = key_secret.into();
Ok(())
}
/// Inplace inverse secret key (1 / scalar)
pub fn inv(&mut self) -> Result<(), Error> {
let mut key_secret = self.to_secp256k1_secret()?;
key_secret.inv_assign(&SECP256K1)?;
*self = key_secret.into();
Ok(())
}
/// Compute power of secret key inplace (secret ^ pow).
/// This function is not intended to be used with large powers.
pub fn pow(&mut self, pow: usize) -> Result<(), Error> {
match pow {
0 => *self = key::ONE_KEY.into(),
1 => (),
_ => {
let c = self.clone();
for _ in 1..pow {
self.mul(&c)?;
}
},
}
Ok(())
}
/// Create `secp256k1::key::SecretKey` based on this secret
pub fn to_secp256k1_secret(&self) -> Result<key::SecretKey, Error> {
Ok(key::SecretKey::from_slice(&SECP256K1, &self[..])?)
}
}
impl FromStr for Secret {
type Err = Error;
fn from_str(s: &str) -> Result<Self, Self::Err> {
Ok(H256::from_str(s).map_err(|e| Error::Custom(format!("{:?}", e)))?.into())
}
}
impl From<H256> for Secret {
fn from(s: H256) -> Self {
Secret::from_slice(&s)
}
}
impl From<&'static str> for Secret {
fn from(s: &'static str) -> Self {
s.parse().expect(&format!("invalid string literal for {}: '{}'", stringify!(Self), s))
}
}
impl From<key::SecretKey> for Secret {
fn from(key: key::SecretKey) -> Self {
Self::from_slice(&key[0..32])
}
}
impl Deref for Secret {
type Target = H256;
fn deref(&self) -> &Self::Target {
&self.inner
}
}
#[cfg(test)]
mod tests {
use std::str::FromStr;
use super::super::{Random, Generator};
use super::Secret;
#[test]
fn multiplicating_secret_inversion_with_secret_gives_one() {
let secret = Random.generate().unwrap().secret().clone();
let mut inversion = secret.clone();
inversion.inv().unwrap();
inversion.mul(&secret).unwrap();
assert_eq!(inversion, Secret::from_str("0000000000000000000000000000000000000000000000000000000000000001").unwrap());
}
#[test]
fn secret_inversion_is_reversible_with_inversion() {
let secret = Random.generate().unwrap().secret().clone();
let mut inversion = secret.clone();
inversion.inv().unwrap();
inversion.inv().unwrap();
assert_eq!(inversion, secret);
}
#[test]
fn secret_pow() {
let secret = Random.generate().unwrap().secret().clone();
let mut pow0 = secret.clone();
pow0.pow(0).unwrap();
assert_eq!(pow0, Secret::from_str("0000000000000000000000000000000000000000000000000000000000000001").unwrap());
let mut pow1 = secret.clone();
pow1.pow(1).unwrap();
assert_eq!(pow1, secret);
let mut pow2 = secret.clone();
pow2.pow(2).unwrap();
let mut pow2_expected = secret.clone();
pow2_expected.mul(&secret).unwrap();
assert_eq!(pow2, pow2_expected);
let mut pow3 = secret.clone();
pow3.pow(3).unwrap();
let mut pow3_expected = secret.clone();
pow3_expected.mul(&secret).unwrap();
pow3_expected.mul(&secret).unwrap();
assert_eq!(pow3, pow3_expected);
}
}