keyfork-derive-util: make key parsing fallible again, since secp256k1 isn't guaranteed correct

This commit is contained in:
Ryan Heywood 2024-05-03 23:10:34 -04:00
parent 1a036a0b5f
commit d04989ef30
Signed by: ryan
GPG Key ID: 8E401478A3FBEF72
8 changed files with 82 additions and 63 deletions

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@ -15,7 +15,7 @@
//! * Derive Key
//!
//! ## Extended Private Keys
//!
//!
//! Keyfork doesn't need to be continuously called once a key has been derived. Once an Extended
//! Private Key (often shortened to "XPrv") has been created, further derivations can be performed.
//! The tests for this library ensure that all levels of Keyfork derivation beyond the required two
@ -108,6 +108,10 @@ pub enum Error {
/// An error encountered in Keyforkd.
#[error("Error in Keyforkd: {0}")]
Keyforkd(#[from] KeyforkdError),
/// An invalid key was returned.
#[error("Invalid key returned")]
InvalidKey,
}
#[allow(missing_docs)]
@ -234,11 +238,8 @@ impl Client {
}
let depth = path.len() as u8;
Ok(ExtendedPrivateKey::from_parts(
&d.data,
depth,
d.chain_code,
))
ExtendedPrivateKey::from_parts(&d.data, depth, d.chain_code)
.map_err(|_| Error::InvalidKey)
}
_ => Err(Error::InvalidResponse),
}

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@ -27,6 +27,10 @@ pub enum Error {
/// The given slice was of an inappropriate size to create a Private Key.
#[error("The given slice was of an inappropriate size to create a Private Key")]
InvalidSliceError(#[from] std::array::TryFromSliceError),
/// The given data was not a valid key for the chosen key type.
#[error("The given data was not a valid key for the chosen key type")]
InvalidKey,
}
type Result<T, E = Error> = std::result::Result<T, E>;
@ -127,7 +131,7 @@ mod serde_with {
let bytes: [u8; 32] = variable_len_bytes.try_into().expect(bug!(
"unable to parse serialized private key; no support for static len"
));
Ok(K::from_bytes(&bytes))
Ok(K::from_bytes(&bytes).expect(bug!("could not deserialize key with invalid scalar")))
}
}
@ -148,13 +152,9 @@ where
/// Generate a new [`ExtendedPrivateKey`] from a seed, ideally from a 12-word or 24-word
/// mnemonic, but may take 16-byte seeds.
///
/// # Panics
/// The method performs unchecked `try_into()` operations on a constant-sized slice.
///
/// # Errors
/// An error may be returned if:
/// * The given seed had an incorrect length.
/// * A `HmacSha512` can't be constructed.
/// The function may return an error if the derived master key could not be parsed as a key for
/// the given algorithm (such as exceeding values on the secp256k1 curve).
///
/// # Examples
/// ```rust
@ -167,11 +167,11 @@ where
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let xprv = ExtendedPrivateKey::<PrivateKey>::new(*seed);
/// ```
pub fn new(seed: impl as_private_key::AsPrivateKey) -> Self {
pub fn new(seed: impl as_private_key::AsPrivateKey) -> Result<Self> {
Self::new_internal(seed.as_private_key())
}
fn new_internal(seed: &[u8]) -> Self {
fn new_internal(seed: &[u8]) -> Result<Self> {
let hash = HmacSha512::new_from_slice(&K::key().bytes().collect::<Vec<_>>())
.expect(bug!("HmacSha512 InvalidLength should be infallible"))
.chain_update(seed)
@ -214,11 +214,16 @@ where
/// # b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB";
/// let xprv = ExtendedPrivateKey::<PrivateKey>::from_parts(key, 4, *chain_code);
/// ```
pub fn from_parts(key: &[u8; 32], depth: u8, chain_code: [u8; 32]) -> Self {
Self {
private_key: K::from_bytes(key),
depth,
chain_code,
pub fn from_parts(key: &[u8; 32], depth: u8, chain_code: [u8; 32]) -> Result<Self> {
match K::from_bytes(key) {
Ok(key) => {
Ok(Self {
private_key: key,
depth,
chain_code,
})
}
Err(_) => Err(Error::InvalidKey),
}
}
@ -232,12 +237,15 @@ where
/// # public_key::TestPublicKey as PublicKey,
/// # private_key::TestPrivateKey as PrivateKey,
/// # };
/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
/// let key: &[u8; 32] = //
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let chain_code: &[u8; 32] = //
/// # b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB";
/// let xprv = ExtendedPrivateKey::<PrivateKey>::from_parts(key, 4, *chain_code);
/// assert_eq!(xprv.private_key(), &PrivateKey::from_bytes(key));
/// let xprv = ExtendedPrivateKey::<PrivateKey>::from_parts(key, 4, *chain_code)?;
/// assert_eq!(xprv.private_key(), &PrivateKey::from_bytes(key)?);
/// # Ok(())
/// # }
/// ```
pub fn private_key(&self) -> &K {
&self.private_key
@ -262,7 +270,7 @@ where
/// # 102, 201, 210, 159, 219, 222, 42, 201, 44, 196, 27,
/// # 90, 221, 80, 85, 135, 79, 39, 253, 223, 35, 251
/// # ];
/// let xprv = ExtendedPrivateKey::<PrivateKey>::new(*seed);
/// let xprv = ExtendedPrivateKey::<PrivateKey>::new(*seed)?;
/// let xpub = xprv.extended_public_key();
/// assert_eq!(known_key, xpub.public_key().to_bytes());
/// # Ok(())
@ -286,7 +294,7 @@ where
/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
/// let seed: &[u8; 64] = //
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let xprv = ExtendedPrivateKey::<PrivateKey>::new(*seed);
/// let xprv = ExtendedPrivateKey::<PrivateKey>::new(*seed)?;
/// let pubkey = xprv.public_key();
/// # Ok(())
/// # }
@ -304,12 +312,15 @@ where
/// # public_key::TestPublicKey as PublicKey,
/// # private_key::TestPrivateKey as PrivateKey,
/// # };
/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
/// let key: &[u8; 32] = //
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let chain_code: &[u8; 32] = //
/// # b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB";
/// let xprv = ExtendedPrivateKey::<PrivateKey>::from_parts(key, 4, *chain_code);
/// let xprv = ExtendedPrivateKey::<PrivateKey>::from_parts(key, 4, *chain_code)?;
/// assert_eq!(xprv.depth(), 4);
/// # Ok(())
/// # }
/// ```
pub fn depth(&self) -> u8 {
self.depth
@ -324,12 +335,15 @@ where
/// # public_key::TestPublicKey as PublicKey,
/// # private_key::TestPrivateKey as PrivateKey,
/// # };
/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
/// let key: &[u8; 32] = //
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let chain_code: &[u8; 32] = //
/// # b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB";
/// let xprv = ExtendedPrivateKey::<PrivateKey>::from_parts(key, 4, *chain_code);
/// let xprv = ExtendedPrivateKey::<PrivateKey>::from_parts(key, 4, *chain_code)?;
/// assert_eq!(chain_code, &xprv.chain_code());
/// # Ok(())
/// # }
/// ```
pub fn chain_code(&self) -> [u8; 32] {
self.chain_code
@ -351,7 +365,7 @@ where
/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
/// let seed: &[u8; 64] = //
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let root_xprv = ExtendedPrivateKey::<PrivateKey>::new(*seed);
/// let root_xprv = ExtendedPrivateKey::<PrivateKey>::new(*seed)?;
/// let path = DerivationPath::default()
/// .chain_push(DerivationIndex::new(44, true)?)
/// .chain_push(DerivationIndex::new(0, true)?)
@ -397,7 +411,7 @@ where
/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
/// let seed: &[u8; 64] = //
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let root_xprv = ExtendedPrivateKey::<PrivateKey>::new(*seed);
/// let root_xprv = ExtendedPrivateKey::<PrivateKey>::new(*seed)?;
/// let bip44_wallet = DerivationPath::default()
/// .chain_push(DerivationIndex::new(44, true)?)
/// .chain_push(DerivationIndex::new(0, true)?)

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@ -2,8 +2,6 @@ use crate::PublicKey;
use thiserror::Error;
use keyfork_bug::bug;
pub(crate) type PrivateKeyBytes = [u8; 32];
/// Functions required to use an `ExtendedPrivateKey`.
@ -26,7 +24,7 @@ pub trait PrivateKey: Sized {
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let private_key = OurPrivateKey::from_bytes(key_data);
/// ```
fn from_bytes(b: &PrivateKeyBytes) -> Self;
fn from_bytes(b: &PrivateKeyBytes) -> Result<Self, Self::Err>;
/// Convert a &Self to bytes.
///
@ -38,7 +36,7 @@ pub trait PrivateKey: Sized {
/// # };
/// let key_data: &[u8; 32] = //
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let private_key = OurPrivateKey::from_bytes(key_data);
/// let private_key = OurPrivateKey::from_bytes(key_data).unwrap();
/// assert_eq!(key_data, &private_key.to_bytes());
/// ```
fn to_bytes(&self) -> PrivateKeyBytes;
@ -73,7 +71,7 @@ pub trait PrivateKey: Sized {
/// # };
/// let key_data: &[u8; 32] = //
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let private_key = OurPrivateKey::from_bytes(key_data);
/// let private_key = OurPrivateKey::from_bytes(key_data).unwrap();
/// let public_key = private_key.public_key();
/// ```
fn public_key(&self) -> Self::PublicKey;
@ -120,8 +118,8 @@ impl PrivateKey for k256::SecretKey {
"Bitcoin seed"
}
fn from_bytes(b: &PrivateKeyBytes) -> Self {
Self::from_slice(b).expect(bug!("Invalid private key bytes"))
fn from_bytes(b: &PrivateKeyBytes) -> Result<Self, Self::Err> {
Self::from_slice(b).map_err(|_| PrivateKeyError::InvalidScalar)
}
fn to_bytes(&self) -> PrivateKeyBytes {
@ -159,8 +157,8 @@ impl PrivateKey for ed25519_dalek::SigningKey {
"ed25519 seed"
}
fn from_bytes(b: &PrivateKeyBytes) -> Self {
Self::from_bytes(b)
fn from_bytes(b: &PrivateKeyBytes) -> Result<Self, Self::Err> {
Ok(Self::from_bytes(b))
}
fn to_bytes(&self) -> PrivateKeyBytes {
@ -204,8 +202,8 @@ impl PrivateKey for TestPrivateKey {
type PublicKey = TestPublicKey;
type Err = PrivateKeyError;
fn from_bytes(b: &PrivateKeyBytes) -> Self {
Self { key: *b }
fn from_bytes(b: &PrivateKeyBytes) -> Result<Self, Self::Err> {
Ok(Self { key: *b })
}
fn to_bytes(&self) -> PrivateKeyBytes {

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@ -30,7 +30,7 @@ pub trait PublicKey: Sized {
/// # };
/// let key_data: &[u8; 32] = //
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let private_key = OurPrivateKey::from_bytes(key_data);
/// let private_key = OurPrivateKey::from_bytes(key_data).unwrap();
/// let public_key_bytes = private_key.public_key().to_bytes();
/// ```
fn to_bytes(&self) -> PublicKeyBytes;
@ -56,7 +56,7 @@ pub trait PublicKey: Sized {
/// # };
/// let key_data: &[u8; 32] = //
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let private_key = OurPrivateKey::from_bytes(key_data);
/// let private_key = OurPrivateKey::from_bytes(key_data).unwrap();
/// let fingerprint = private_key.public_key().fingerprint();
/// ```
fn fingerprint(&self) -> [u8; 4] {

View File

@ -70,7 +70,7 @@ impl DerivationAlgorithm {
match self {
#[cfg(feature = "ed25519")]
Self::Ed25519 => {
let key = ExtendedPrivateKey::<ed25519_dalek::SigningKey>::new(seed);
let key = ExtendedPrivateKey::<ed25519_dalek::SigningKey>::new(seed)?;
let derived_key = key.derive_path(path)?;
Ok(DerivationResponse::with_algo_and_xprv(
self.clone(),
@ -79,7 +79,7 @@ impl DerivationAlgorithm {
}
#[cfg(feature = "secp256k1")]
Self::Secp256k1 => {
let key = ExtendedPrivateKey::<k256::SecretKey>::new(seed);
let key = ExtendedPrivateKey::<k256::SecretKey>::new(seed)?;
let derived_key = key.derive_path(path)?;
Ok(DerivationResponse::with_algo_and_xprv(
self.clone(),
@ -87,7 +87,7 @@ impl DerivationAlgorithm {
))
}
Self::TestAlgorithm => {
let key = ExtendedPrivateKey::<TestPrivateKey>::new(seed);
let key = ExtendedPrivateKey::<TestPrivateKey>::new(seed)?;
let derived_key = key.derive_path(path)?;
Ok(DerivationResponse::with_algo_and_xprv(
self.clone(),
@ -300,11 +300,9 @@ mod secp256k1 {
fn try_from(value: &DerivationResponse) -> Result<Self, Self::Error> {
match value.algorithm {
DerivationAlgorithm::Secp256k1 => Ok(Self::from_parts(
&value.data,
value.depth,
value.chain_code,
)),
DerivationAlgorithm::Secp256k1 => {
Self::from_parts(&value.data, value.depth, value.chain_code).map_err(Into::into)
}
_ => Err(Self::Error::Algorithm),
}
}
@ -335,11 +333,9 @@ mod ed25519 {
fn try_from(value: &DerivationResponse) -> Result<Self, Self::Error> {
match value.algorithm {
DerivationAlgorithm::Ed25519 => Ok(Self::from_parts(
&value.data,
value.depth,
value.chain_code,
)),
DerivationAlgorithm::Ed25519 => {
Self::from_parts(&value.data, value.depth, value.chain_code).map_err(Into::into)
}
_ => Err(Self::Error::Algorithm),
}
}

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@ -31,7 +31,7 @@ fn secp256k1() {
// Tests for ExtendedPrivateKey
let varlen_seed = VariableLengthSeed::new(seed);
let xkey = ExtendedPrivateKey::<SecretKey>::new(varlen_seed);
let xkey = ExtendedPrivateKey::<SecretKey>::new(varlen_seed).unwrap();
let derived_key = xkey.derive_path(&chain).unwrap();
assert_eq!(
derived_key.chain_code().as_slice(),
@ -77,7 +77,7 @@ fn ed25519() {
// Tests for ExtendedPrivateKey
let varlen_seed = VariableLengthSeed::new(seed);
let xkey = ExtendedPrivateKey::<SigningKey>::new(varlen_seed);
let xkey = ExtendedPrivateKey::<SigningKey>::new(varlen_seed).unwrap();
let derived_key = xkey.derive_path(&chain).unwrap();
assert_eq!(
derived_key.chain_code().as_slice(),
@ -110,7 +110,7 @@ fn panics_with_unhardened_derivation() {
use ed25519_dalek::SigningKey;
let seed = hex!("000102030405060708090a0b0c0d0e0f");
let xkey = ExtendedPrivateKey::<SigningKey>::new(seed);
let xkey = ExtendedPrivateKey::<SigningKey>::new(seed).unwrap();
xkey.derive_path(&DerivationPath::from_str("m/0").unwrap())
.unwrap();
}
@ -122,7 +122,7 @@ fn panics_at_depth() {
use ed25519_dalek::SigningKey;
let seed = hex!("000102030405060708090a0b0c0d0e0f");
let mut xkey = ExtendedPrivateKey::<SigningKey>::new(seed);
let mut xkey = ExtendedPrivateKey::<SigningKey>::new(seed).unwrap();
for i in 0..=u32::from(u8::MAX) {
xkey = xkey
.derive_child(&DerivationIndex::new(i, true).unwrap())

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@ -259,6 +259,7 @@ impl<P: PromptHandler> Format for OpenPGP<P> {
let userid = UserID::from("keyfork-sss");
let path = DerivationPath::from_str("m/7366512'/0'").expect(bug!("valid derivation path"));
let xprv = XPrv::new(seed)
.expect(bug!("could not create XPrv from key"))
.derive_path(&path)
.expect(bug!("valid derivation"));
keyfork_derive_openpgp::derive(

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@ -11,11 +11,12 @@ use keyfork_derive_openpgp::{
};
use keyfork_derive_util::{DerivationIndex, DerivationPath};
use keyfork_prompt::{
default_terminal,
validators::{SecurePinValidator, Validator},
Message, PromptHandler, DefaultTerminal, default_terminal
DefaultTerminal, Message, PromptHandler,
};
use keyfork_shard::{Format, openpgp::OpenPGP};
use keyfork_shard::{openpgp::OpenPGP, Format};
#[derive(thiserror::Error, Debug)]
#[error("Invalid PIN length: {0}")]
@ -44,7 +45,9 @@ fn derive_key(seed: [u8; 32], index: u8) -> Result<Cert> {
.chain_push(chain)
.chain_push(account)
.chain_push(subkey);
let xprv = XPrv::new(seed).derive_path(&path)?;
let xprv = XPrv::new(seed)
.expect("could not construct master key from seed")
.derive_path(&path)?;
let userid = UserID::from(format!("Keyfork Shard {index}"));
let cert = keyfork_derive_openpgp::derive(xprv, &subkeys, &userid)?;
Ok(cert)
@ -104,7 +107,7 @@ fn generate_shard_secret(
keys_per_shard: u8,
output_file: &Option<PathBuf>,
) -> Result<()> {
let seed = keyfork_entropy::generate_entropy_of_const_size::<{256 / 8}>()?;
let seed = keyfork_entropy::generate_entropy_of_const_size::<{ 256 / 8 }>()?;
let mut pm = default_terminal()?;
let mut certs = vec![];
let mut seen_cards: HashSet<String> = HashSet::new();
@ -171,7 +174,13 @@ fn generate_shard_secret(
let output = File::create(output_file)?;
opgp.shard_and_encrypt(threshold, certs.len() as u8, &seed, &certs[..], output)?;
} else {
opgp.shard_and_encrypt(threshold, certs.len() as u8, &seed, &certs[..], std::io::stdout())?;
opgp.shard_and_encrypt(
threshold,
certs.len() as u8,
&seed,
&certs[..],
std::io::stdout(),
)?;
}
Ok(())
}