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rust-bitcoin-unsafe-fast
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Merge pull request #126 from dongcarl/bip32-consistency 

Ready for Review: Improve consistency for bip32::ChildNumber
This commit is contained in:
Andrew Poelstra 2018-08-11 23:38:41 +00:00 committed by GitHub
parent ebe5133d1a c485a74c09
commit 147259d957
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 98 additions and 80 deletions
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176
src/util/bip32.rs
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@ -90,18 +90,62 @@ pub struct ExtendedPubKey {
/// A child number for a derived key
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
pub enum ChildNumber {
/// Non-hardened key, within [0, 2^31 - 1]
Normal(u32),
/// Hardened key index, within [2^31, 2^32 - 1]
Hardened(u32),
/// Non-hardened key
Normal {
/// Key index, within [0, 2^31 - 1]
index: u32
},
/// Hardened key
Hardened {
/// Key index, within [0, 2^31 - 1]
index: u32
},
}
impl ChildNumber {
/// Create a [`Normal`] from an index, panics if the index is not within
/// [0, 2^31 - 1].
///
/// [`Normal`]: #variant.Normal
pub fn from_normal_idx(index: u32) -> Self {
assert_eq!(index & (1 << 31), 0, "ChildNumber indices have to be within [0, 2^31 - 1], is: {}", index);
ChildNumber::Normal { index: index }
}
/// Create a [`Hardened`] from an index, panics if the index is not within
/// [0, 2^31 - 1].
///
/// [`Hardened`]: #variant.Hardened
pub fn from_hardened_idx(index: u32) -> Self {
assert_eq!(index & (1 << 31), 0, "ChildNumber indices have to be within [0, 2^31 - 1], is: {}", index);
ChildNumber::Hardened { index: index }
}
/// Returns `true` if the child number is a [`Normal`] value.
///
/// [`Normal`]: #variant.Normal
pub fn is_normal(&self) -> bool {
!self.is_hardened()
}
/// Returns `true` if the child number is a [`Hardened`] value.
///
/// [`Hardened`]: #variant.Hardened
pub fn is_hardened(&self) -> bool {
match *self {
ChildNumber::Hardened {..} => true,
ChildNumber::Normal {..} => false,
}
}
}
impl From<u32> for ChildNumber {
fn from(index: u32) -> Self {
if index & (1 << 31) != 0 {
ChildNumber::Hardened(index)
fn from(number: u32) -> Self {
if number & (1 << 31) != 0 {
ChildNumber::Hardened { index: number ^ (1 << 31) }
} else {
ChildNumber::Normal(index)
ChildNumber::Normal { index: number }
}
}
}
@ -109,8 +153,8 @@ impl From<u32> for ChildNumber {
impl From<ChildNumber> for u32 {
fn from(cnum: ChildNumber) -> Self {
match cnum {
ChildNumber::Normal(index) => index,
ChildNumber::Hardened(index) => index,
ChildNumber::Normal { index } => index,
ChildNumber::Hardened { index } => index | (1 << 31),
}
}
}
@ -118,31 +162,23 @@ impl From<ChildNumber> for u32 {
impl fmt::Display for ChildNumber {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
ChildNumber::Hardened(n) => write!(f, "{}h", n),
ChildNumber::Normal(n) => write!(f, "{}", n)
ChildNumber::Hardened { index } => write!(f, "{}'", index),
ChildNumber::Normal { index } => write!(f, "{}", index),
}
}
}
impl Serialize for ChildNumber {
fn serialize<S>(&self, s: &mut S) -> Result<(), S::Error>
where S: Serializer {
match *self {
ChildNumber::Hardened(n) => (n + (1 << 31)).serialize(s),
ChildNumber::Normal(n) => n.serialize(s)
}
fn serialize<S: Serializer>(&self, s: &mut S) -> Result<(), S::Error> {
u32::from(*self).serialize(s)
}
}
impl Deserialize for ChildNumber {
fn deserialize<D>(d: &mut D) -> Result<ChildNumber, D::Error>
where D: Deserializer {
let n: u32 = try!(Deserialize::deserialize(d));
if n < (1 << 31) {
Ok(ChildNumber::Normal(n))
} else {
Ok(ChildNumber::Hardened(n - (1 << 31)))
}
fn deserialize<D: Deserializer>(d: &mut D) -> Result<ChildNumber, D::Error> {
let n: u32 = Deserialize::deserialize(d)?;
Ok(ChildNumber::from(n))
}
}
@ -205,7 +241,7 @@ impl ExtendedPrivKey {
network: network,
depth: 0,
parent_fingerprint: Default::default(),
child_number: ChildNumber::Normal(0),
child_number: ChildNumber::from_normal_idx(0),
secret_key: try!(SecretKey::from_slice(secp, &result[..32]).map_err(Error::Ecdsa)),
chain_code: ChainCode::from(&result[32..])
})
@ -227,20 +263,18 @@ impl ExtendedPrivKey {
let mut hmac = Hmac::new(Sha512::new(), &self.chain_code[..]);
let mut be_n = [0; 4];
match i {
ChildNumber::Normal(n) => {
if n >= (1 << 31) { return Err(Error::InvalidChildNumber(i)) }
ChildNumber::Normal {..} => {
// Non-hardened key: compute public data and use that
hmac.input(&PublicKey::from_secret_key(secp, &self.secret_key).unwrap().serialize()[..]);
BigEndian::write_u32(&mut be_n, n);
}
ChildNumber::Hardened(n) => {
if n >= (1 << 31) { return Err(Error::InvalidChildNumber(i)) }
ChildNumber::Hardened {..} => {
// Hardened key: use only secret data to prevent public derivation
hmac.input(&[0u8]);
hmac.input(&self.secret_key[..]);
BigEndian::write_u32(&mut be_n, n + (1 << 31));
}
}
BigEndian::write_u32(&mut be_n, u32::from(i));
hmac.input(&be_n);
hmac.raw_result(&mut result);
let mut sk = try!(SecretKey::from_slice(secp, &result[..32]).map_err(Error::Ecdsa));
@ -296,14 +330,10 @@ impl ExtendedPubKey {
/// Compute the scalar tweak added to this key to get a child key
pub fn ckd_pub_tweak(&self, secp: &Secp256k1, i: ChildNumber) -> Result<(SecretKey, ChainCode), Error> {
match i {
ChildNumber::Hardened(n) => {
if n >= (1 << 31) {
Err(Error::InvalidChildNumber(i))
} else {
ChildNumber::Hardened {..} => {
Err(Error::CannotDeriveFromHardenedKey)
}
}
ChildNumber::Normal(n) => {
ChildNumber::Normal { index: n } => {
let mut hmac = Hmac::new(Sha512::new(), &self.chain_code[..]);
hmac.input(&self.public_key.serialize()[..]);
let mut be_n = [0; 4];
@ -367,14 +397,9 @@ impl ToString for ExtendedPrivKey {
}[..]);
ret[4] = self.depth as u8;
ret[5..9].copy_from_slice(&self.parent_fingerprint[..]);
match self.child_number {
ChildNumber::Hardened(n) => {
BigEndian::write_u32(&mut ret[9..13], n + (1 << 31));
}
ChildNumber::Normal(n) => {
BigEndian::write_u32(&mut ret[9..13], n);
}
}
BigEndian::write_u32(&mut ret[9..13], u32::from(self.child_number));
ret[13..45].copy_from_slice(&self.chain_code[..]);
ret[45] = 0;
ret[46..78].copy_from_slice(&self.secret_key[..]);
@ -393,9 +418,8 @@ impl FromStr for ExtendedPrivKey {
return Err(base58::Error::InvalidLength(data.len()));
}
let cn_int = Cursor::new(&data[9..13]).read_u32::<BigEndian>().unwrap();
let child_number = if cn_int < (1 << 31) { ChildNumber::Normal(cn_int) }
else { ChildNumber::Hardened(cn_int - (1 << 31)) };
let cn_int: u32 = Cursor::new(&data[9..13]).read_u32::<BigEndian>().unwrap();
let child_number: ChildNumber = ChildNumber::from(cn_int);
Ok(ExtendedPrivKey {
network: if &data[0..4] == [0x04u8, 0x88, 0xAD, 0xE4] {
@ -425,14 +449,9 @@ impl ToString for ExtendedPubKey {
}[..]);
ret[4] = self.depth as u8;
ret[5..9].copy_from_slice(&self.parent_fingerprint[..]);
match self.child_number {
ChildNumber::Hardened(n) => {
BigEndian::write_u32(&mut ret[9..13], n + (1 << 31));
}
ChildNumber::Normal(n) => {
BigEndian::write_u32(&mut ret[9..13], n);
}
}
BigEndian::write_u32(&mut ret[9..13], u32::from(self.child_number));
ret[13..45].copy_from_slice(&self.chain_code[..]);
ret[45..78].copy_from_slice(&self.public_key.serialize()[..]);
base58::check_encode_slice(&ret[..])
@ -450,9 +469,8 @@ impl FromStr for ExtendedPubKey {
return Err(base58::Error::InvalidLength(data.len()));
}
let cn_int = Cursor::new(&data[9..13]).read_u32::<BigEndian>().unwrap();
let child_number = if cn_int < (1 << 31) { ChildNumber::Normal(cn_int) }
else { ChildNumber::Hardened(cn_int - (1 << 31)) };
let cn_int: u32 = Cursor::new(&data[9..13]).read_u32::<BigEndian>().unwrap();
let child_number: ChildNumber = ChildNumber::from(cn_int);
Ok(ExtendedPubKey {
network: if &data[0..4] == [0x04u8, 0x88, 0xB2, 0x1E] {
@ -499,12 +517,12 @@ mod tests {
for &num in path.iter() {
sk = sk.ckd_priv(secp, num).unwrap();
match num {
Normal(_) => {
Normal {..} => {
let pk2 = pk.ckd_pub(secp, num).unwrap();
pk = ExtendedPubKey::from_private(secp, &sk);
assert_eq!(pk, pk2);
}
Hardened(_) => {
Hardened {..} => {
pk = ExtendedPubKey::from_private(secp, &sk);
}
}
@ -530,27 +548,27 @@ mod tests {
"xpub661MyMwAqRbcFtXgS5sYJABqqG9YLmC4Q1Rdap9gSE8NqtwybGhePY2gZ29ESFjqJoCu1Rupje8YtGqsefD265TMg7usUDFdp6W1EGMcet8");
// m/0h
test_path(&secp, Bitcoin, &seed, &[Hardened(0)],
test_path(&secp, Bitcoin, &seed, &[ChildNumber::from_hardened_idx(0)],
"xprv9uHRZZhk6KAJC1avXpDAp4MDc3sQKNxDiPvvkX8Br5ngLNv1TxvUxt4cV1rGL5hj6KCesnDYUhd7oWgT11eZG7XnxHrnYeSvkzY7d2bhkJ7",
"xpub68Gmy5EdvgibQVfPdqkBBCHxA5htiqg55crXYuXoQRKfDBFA1WEjWgP6LHhwBZeNK1VTsfTFUHCdrfp1bgwQ9xv5ski8PX9rL2dZXvgGDnw");
// m/0h/1
test_path(&secp, Bitcoin, &seed, &[Hardened(0), Normal(1)],
test_path(&secp, Bitcoin, &seed, &[ChildNumber::from_hardened_idx(0), ChildNumber::from_normal_idx(1)],
"xprv9wTYmMFdV23N2TdNG573QoEsfRrWKQgWeibmLntzniatZvR9BmLnvSxqu53Kw1UmYPxLgboyZQaXwTCg8MSY3H2EU4pWcQDnRnrVA1xe8fs",
"xpub6ASuArnXKPbfEwhqN6e3mwBcDTgzisQN1wXN9BJcM47sSikHjJf3UFHKkNAWbWMiGj7Wf5uMash7SyYq527Hqck2AxYysAA7xmALppuCkwQ");
// m/0h/1/2h
test_path(&secp, Bitcoin, &seed, &[Hardened(0), Normal(1), Hardened(2)],
test_path(&secp, Bitcoin, &seed, &[ChildNumber::from_hardened_idx(0), ChildNumber::from_normal_idx(1), ChildNumber::from_hardened_idx(2)],
"xprv9z4pot5VBttmtdRTWfWQmoH1taj2axGVzFqSb8C9xaxKymcFzXBDptWmT7FwuEzG3ryjH4ktypQSAewRiNMjANTtpgP4mLTj34bhnZX7UiM",
"xpub6D4BDPcP2GT577Vvch3R8wDkScZWzQzMMUm3PWbmWvVJrZwQY4VUNgqFJPMM3No2dFDFGTsxxpG5uJh7n7epu4trkrX7x7DogT5Uv6fcLW5");
// m/0h/1/2h/2
test_path(&secp, Bitcoin, &seed, &[Hardened(0), Normal(1), Hardened(2), Normal(2)],
test_path(&secp, Bitcoin, &seed, &[ChildNumber::from_hardened_idx(0), ChildNumber::from_normal_idx(1), ChildNumber::from_hardened_idx(2), ChildNumber::from_normal_idx(2)],
"xprvA2JDeKCSNNZky6uBCviVfJSKyQ1mDYahRjijr5idH2WwLsEd4Hsb2Tyh8RfQMuPh7f7RtyzTtdrbdqqsunu5Mm3wDvUAKRHSC34sJ7in334",
"xpub6FHa3pjLCk84BayeJxFW2SP4XRrFd1JYnxeLeU8EqN3vDfZmbqBqaGJAyiLjTAwm6ZLRQUMv1ZACTj37sR62cfN7fe5JnJ7dh8zL4fiyLHV");
// m/0h/1/2h/2/1000000000
test_path(&secp, Bitcoin, &seed, &[Hardened(0), Normal(1), Hardened(2), Normal(2), Normal(1000000000)],
test_path(&secp, Bitcoin, &seed, &[ChildNumber::from_hardened_idx(0), ChildNumber::from_normal_idx(1), ChildNumber::from_hardened_idx(2), ChildNumber::from_normal_idx(2), ChildNumber::from_normal_idx(1000000000)],
"xprvA41z7zogVVwxVSgdKUHDy1SKmdb533PjDz7J6N6mV6uS3ze1ai8FHa8kmHScGpWmj4WggLyQjgPie1rFSruoUihUZREPSL39UNdE3BBDu76",
"xpub6H1LXWLaKsWFhvm6RVpEL9P4KfRZSW7abD2ttkWP3SSQvnyA8FSVqNTEcYFgJS2UaFcxupHiYkro49S8yGasTvXEYBVPamhGW6cFJodrTHy");
}
@ -566,39 +584,39 @@ mod tests {
"xpub661MyMwAqRbcFW31YEwpkMuc5THy2PSt5bDMsktWQcFF8syAmRUapSCGu8ED9W6oDMSgv6Zz8idoc4a6mr8BDzTJY47LJhkJ8UB7WEGuduB");
// m/0
test_path(&secp, Bitcoin, &seed, &[Normal(0)],
test_path(&secp, Bitcoin, &seed, &[ChildNumber::from_normal_idx(0)],
"xprv9vHkqa6EV4sPZHYqZznhT2NPtPCjKuDKGY38FBWLvgaDx45zo9WQRUT3dKYnjwih2yJD9mkrocEZXo1ex8G81dwSM1fwqWpWkeS3v86pgKt",
"xpub69H7F5d8KSRgmmdJg2KhpAK8SR3DjMwAdkxj3ZuxV27CprR9LgpeyGmXUbC6wb7ERfvrnKZjXoUmmDznezpbZb7ap6r1D3tgFxHmwMkQTPH");
// m/0/2147483647h
test_path(&secp, Bitcoin, &seed, &[Normal(0), Hardened(2147483647)],
test_path(&secp, Bitcoin, &seed, &[ChildNumber::from_normal_idx(0), ChildNumber::from_hardened_idx(2147483647)],
"xprv9wSp6B7kry3Vj9m1zSnLvN3xH8RdsPP1Mh7fAaR7aRLcQMKTR2vidYEeEg2mUCTAwCd6vnxVrcjfy2kRgVsFawNzmjuHc2YmYRmagcEPdU9",
"xpub6ASAVgeehLbnwdqV6UKMHVzgqAG8Gr6riv3Fxxpj8ksbH9ebxaEyBLZ85ySDhKiLDBrQSARLq1uNRts8RuJiHjaDMBU4Zn9h8LZNnBC5y4a");
// m/0/2147483647h/1
test_path(&secp, Bitcoin, &seed, &[Normal(0), Hardened(2147483647), Normal(1)],
test_path(&secp, Bitcoin, &seed, &[ChildNumber::from_normal_idx(0), ChildNumber::from_hardened_idx(2147483647), ChildNumber::from_normal_idx(1)],
"xprv9zFnWC6h2cLgpmSA46vutJzBcfJ8yaJGg8cX1e5StJh45BBciYTRXSd25UEPVuesF9yog62tGAQtHjXajPPdbRCHuWS6T8XA2ECKADdw4Ef",
"xpub6DF8uhdarytz3FWdA8TvFSvvAh8dP3283MY7p2V4SeE2wyWmG5mg5EwVvmdMVCQcoNJxGoWaU9DCWh89LojfZ537wTfunKau47EL2dhHKon");
// m/0/2147483647h/1/2147483646h
test_path(&secp, Bitcoin, &seed, &[Normal(0), Hardened(2147483647), Normal(1), Hardened(2147483646)],
test_path(&secp, Bitcoin, &seed, &[ChildNumber::from_normal_idx(0), ChildNumber::from_hardened_idx(2147483647), ChildNumber::from_normal_idx(1), ChildNumber::from_hardened_idx(2147483646)],
"xprvA1RpRA33e1JQ7ifknakTFpgNXPmW2YvmhqLQYMmrj4xJXXWYpDPS3xz7iAxn8L39njGVyuoseXzU6rcxFLJ8HFsTjSyQbLYnMpCqE2VbFWc",
"xpub6ERApfZwUNrhLCkDtcHTcxd75RbzS1ed54G1LkBUHQVHQKqhMkhgbmJbZRkrgZw4koxb5JaHWkY4ALHY2grBGRjaDMzQLcgJvLJuZZvRcEL");
// m/0/2147483647h/1/2147483646h/2
test_path(&secp, Bitcoin, &seed, &[Normal(0), Hardened(2147483647), Normal(1), Hardened(2147483646), Normal(2)],
test_path(&secp, Bitcoin, &seed, &[ChildNumber::from_normal_idx(0), ChildNumber::from_hardened_idx(2147483647), ChildNumber::from_normal_idx(1), ChildNumber::from_hardened_idx(2147483646), ChildNumber::from_normal_idx(2)],
"xprvA2nrNbFZABcdryreWet9Ea4LvTJcGsqrMzxHx98MMrotbir7yrKCEXw7nadnHM8Dq38EGfSh6dqA9QWTyefMLEcBYJUuekgW4BYPJcr9E7j",
"xpub6FnCn6nSzZAw5Tw7cgR9bi15UV96gLZhjDstkXXxvCLsUXBGXPdSnLFbdpq8p9HmGsApME5hQTZ3emM2rnY5agb9rXpVGyy3bdW6EEgAtqt");
}
#[test]
pub fn encode_decode_childnumber() {
serde_round_trip!(Normal(0));
serde_round_trip!(Normal(1));
serde_round_trip!(Normal((1 << 31) - 1));
serde_round_trip!(Hardened(0));
serde_round_trip!(Hardened(1));
serde_round_trip!(Hardened((1 << 31) - 1));
serde_round_trip!(ChildNumber::from_normal_idx(0));
serde_round_trip!(ChildNumber::from_normal_idx(1));
serde_round_trip!(ChildNumber::from_normal_idx((1 << 31) - 1));
serde_round_trip!(ChildNumber::from_hardened_idx(0));
serde_round_trip!(ChildNumber::from_hardened_idx(1));
serde_round_trip!(ChildNumber::from_hardened_idx((1 << 31) - 1));
}
}