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28 Commits

Author SHA1 Message Date
Anton Livaja 9cdd3b5aca
feat: require key to be at least 128 bits 2024-04-29 14:39:23 -04:00
Ryan Heywood e0687434ef
keyfork-shard: display error message on duplicate key fingerprints found 2024-04-24 13:29:32 -04:00
Ryan Heywood 23db50956f
keyfork-shard: improve wording for counting shardholders 2024-04-24 13:13:48 -04:00
Ryan Heywood 94617722a0
keyfork-shard: ignore duplicate certificate entries 2024-04-22 17:06:13 -04:00
Ryan Heywood 001fc0bccc
remove trailing hitespace :( 2024-04-19 00:30:38 -04:00
Ryan Heywood 6a265ad203
keyfork-mnemonic-util: add MnemonicBase::from_nonstandard_bytes 2024-04-18 23:53:59 -04:00
Ryan Heywood 5d2309e301
keyfork-prompt: add SecurePinValidator for making new, secure, PINs 2024-04-18 23:01:03 -04:00
Ryan Heywood c0b19e2457
keyfork-shard: assert shared secrets are contributory 2024-04-17 15:36:42 -04:00
Ryan Heywood cdf401515f
keyfork wizard: use correct derivation path for re-deriving shard decryption keys 2024-04-17 15:25:22 -04:00
Ryan Heywood f0e5ae9a8b
keyfork-derive-openpgp: document KEYFORK_OPENPGP_EXPIRE 2024-04-17 15:25:20 -04:00
Ryan Heywood 289cec36ef
keyfork wizard: upcast i and index to avoid wrapping add 2024-04-17 15:25:19 -04:00
Ryan Heywood 0fe5301352
keyfork-shard: add in bug messages 2024-04-17 15:25:18 -04:00
Ryan Heywood 9f089e723a
keyfork-derive-openpgp: use .first() in place of .get(0) 2024-04-17 15:25:15 -04:00
Ryan Heywood 1de466cad0
keyfork-derive-util: allow zeroable input for non-master-key derivation 2024-04-17 15:25:02 -04:00
Ryan Heywood 57354fc714
Cargo.lock: bump insta, remove unmaintained yaml-rust 2024-04-14 21:27:57 -04:00
Ryan Heywood 61871a77f0
keyfork-derive-util: make private and public test keys more visible 2024-04-14 21:26:44 -04:00
Ryan Heywood 08a66e2365
keyfork-shard: base64 encode content instead of base16 2024-04-14 21:19:57 -04:00
Ryan Heywood 6fa434e89c
keyfork-shard: shorten length and pad inside encrypted block 2024-04-14 21:19:56 -04:00
Ryan Heywood 68f07f6f02
bump mio and iana-time-zone 2024-04-14 21:19:54 -04:00
Ryan Heywood 9394500f2f
keyfork-shard: generate nonce using hkdf 2024-04-14 21:19:52 -04:00
Ryan Heywood 2bca0a1580
keyfork-derive-util: make Test{Public,Private}Key public, rename Internal algorithm 2024-04-12 16:23:24 -04:00
Ryan Heywood 5438f4e111
keyfork-entropy: downgrade entropy size limit to warning 2024-04-12 16:14:41 -04:00
Ryan Heywood 71b6e4ed0c
Merge branch 'ryan/use-instant-time-qrcode' 2024-04-10 15:35:50 -04:00
Ryan Heywood 4f4e3cfc65
Merge branch 'ryan/harden-derivation-on-highest-level-keys' 2024-04-10 15:35:40 -04:00
Ryan Heywood 194d475d59
keyfork-shard: validate signatures using shard-specific validation requirements 2024-04-10 15:17:30 -04:00
Ryan Heywood 40551a5c26
keyforkd: require hardened derivation on two highest indexes 2024-04-09 20:14:59 -04:00
Ryan Heywood fa125e7cbe
keyfork-qrcode: prefer Instant over SystemTime for infallible time comparison 2024-04-09 19:54:11 -04:00
Ryan Heywood f96ad11422
docs: add basic documentation on shard remote-decrypt protocol 2024-04-08 14:44:26 -04:00
31 changed files with 516 additions and 227 deletions

41
Cargo.lock generated
View File

@ -341,6 +341,12 @@ version = "0.21.7"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "9d297deb1925b89f2ccc13d7635fa0714f12c87adce1c75356b39ca9b7178567" checksum = "9d297deb1925b89f2ccc13d7635fa0714f12c87adce1c75356b39ca9b7178567"
[[package]]
name = "base64"
version = "0.22.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "9475866fec1451be56a3c2400fd081ff546538961565ccb5b7142cbd22bc7a51"
[[package]] [[package]]
name = "base64ct" name = "base64ct"
version = "1.6.0" version = "1.6.0"
@ -1497,9 +1503,9 @@ dependencies = [
[[package]] [[package]]
name = "iana-time-zone" name = "iana-time-zone"
version = "0.1.59" version = "0.1.60"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "b6a67363e2aa4443928ce15e57ebae94fd8949958fd1223c4cfc0cd473ad7539" checksum = "e7ffbb5a1b541ea2561f8c41c087286cc091e21e556a4f09a8f6cbf17b69b141"
dependencies = [ dependencies = [
"android_system_properties", "android_system_properties",
"core-foundation-sys", "core-foundation-sys",
@ -1572,15 +1578,14 @@ dependencies = [
[[package]] [[package]]
name = "insta" name = "insta"
version = "1.34.0" version = "1.38.0"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "5d64600be34b2fcfc267740a243fa7744441bb4947a619ac4e5bb6507f35fbfc" checksum = "3eab73f58e59ca6526037208f0e98851159ec1633cf17b6cd2e1f2c3fd5d53cc"
dependencies = [ dependencies = [
"console", "console",
"lazy_static", "lazy_static",
"linked-hash-map", "linked-hash-map",
"similar", "similar",
"yaml-rust",
] ]
[[package]] [[package]]
@ -1758,7 +1763,7 @@ dependencies = [
[[package]] [[package]]
name = "keyfork-derive-util" name = "keyfork-derive-util"
version = "0.1.0" version = "0.1.1"
dependencies = [ dependencies = [
"digest", "digest",
"ed25519-dalek", "ed25519-dalek",
@ -1776,7 +1781,7 @@ dependencies = [
[[package]] [[package]]
name = "keyfork-entropy" name = "keyfork-entropy"
version = "0.1.0" version = "0.1.1"
dependencies = [ dependencies = [
"keyfork-bug", "keyfork-bug",
"smex", "smex",
@ -1818,7 +1823,7 @@ dependencies = [
[[package]] [[package]]
name = "keyfork-qrcode" name = "keyfork-qrcode"
version = "0.1.0" version = "0.1.1"
dependencies = [ dependencies = [
"image", "image",
"keyfork-bug", "keyfork-bug",
@ -1830,10 +1835,11 @@ dependencies = [
[[package]] [[package]]
name = "keyfork-shard" name = "keyfork-shard"
version = "0.1.0" version = "0.2.0"
dependencies = [ dependencies = [
"aes-gcm", "aes-gcm",
"anyhow", "anyhow",
"base64 0.22.0",
"card-backend", "card-backend",
"card-backend-pcsc", "card-backend-pcsc",
"hkdf", "hkdf",
@ -1879,7 +1885,7 @@ dependencies = [
[[package]] [[package]]
name = "keyforkd" name = "keyforkd"
version = "0.1.0" version = "0.1.1"
dependencies = [ dependencies = [
"bincode", "bincode",
"hex-literal", "hex-literal",
@ -2103,9 +2109,9 @@ dependencies = [
[[package]] [[package]]
name = "mio" name = "mio"
version = "0.8.10" version = "0.8.11"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "8f3d0b296e374a4e6f3c7b0a1f5a51d748a0d34c85e7dc48fc3fa9a87657fe09" checksum = "a4a650543ca06a924e8b371db273b2756685faae30f8487da1b56505a8f78b0c"
dependencies = [ dependencies = [
"libc", "libc",
"log", "log",
@ -2886,7 +2892,7 @@ dependencies = [
"aes", "aes",
"aes-gcm", "aes-gcm",
"anyhow", "anyhow",
"base64", "base64 0.21.7",
"block-padding", "block-padding",
"blowfish", "blowfish",
"buffered-reader", "buffered-reader",
@ -3811,15 +3817,6 @@ version = "0.8.8"
source = "registry+https://github.com/rust-lang/crates.io-index" source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "53be06678ed9e83edb1745eb72efc0bbcd7b5c3c35711a860906aed827a13d61" checksum = "53be06678ed9e83edb1745eb72efc0bbcd7b5c3c35711a860906aed827a13d61"
[[package]]
name = "yaml-rust"
version = "0.4.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "56c1936c4cc7a1c9ab21a1ebb602eb942ba868cbd44a99cb7cdc5892335e1c85"
dependencies = [
"linked-hash-map",
]
[[package]] [[package]]
name = "zerocopy" name = "zerocopy"
version = "0.7.32" version = "0.7.32"

View File

@ -234,7 +234,7 @@ impl Client {
} }
let depth = path.len() as u8; let depth = path.len() as u8;
Ok(ExtendedPrivateKey::new_from_parts( Ok(ExtendedPrivateKey::from_parts(
&d.data, &d.data,
depth, depth,
d.chain_code, d.chain_code,

View File

@ -25,6 +25,9 @@ fn secp256k1_test_suite() {
if chain_len < 2 { if chain_len < 2 {
continue; continue;
} }
if chain.iter().take(2).any(|index| !index.is_hardened()) {
continue;
}
// Consistency check: ensure the server and the client can each derive the same // Consistency check: ensure the server and the client can each derive the same
// key using an XPrv, for all but the last XPrv, which is verified after this // key using an XPrv, for all but the last XPrv, which is verified after this
for i in 2..chain_len { for i in 2..chain_len {

View File

@ -43,6 +43,10 @@ pub enum DerivationError {
#[error("Invalid derivation length: Expected at least 2, actual: {0}")] #[error("Invalid derivation length: Expected at least 2, actual: {0}")]
InvalidDerivationLength(usize), InvalidDerivationLength(usize),
/// The derivation request did not use hardened derivation on the 2 highest indexes.
#[error("Invalid derivation paths: expected index #{0} (1) to be hardened")]
InvalidDerivationPath(usize, u32),
/// An error occurred while deriving data. /// An error occurred while deriving data.
#[error("Derivation error: {0}")] #[error("Derivation error: {0}")]
Derivation(String), Derivation(String),

View File

@ -1,6 +1,6 @@
[package] [package]
name = "keyforkd" name = "keyforkd"
version = "0.1.0" version = "0.1.1"
edition = "2021" edition = "2021"
license = "AGPL-3.0-only" license = "AGPL-3.0-only"

View File

@ -69,6 +69,18 @@ impl Service<Request> for Keyforkd {
return Err(DerivationError::InvalidDerivationLength(len).into()); return Err(DerivationError::InvalidDerivationLength(len).into());
} }
if let Some((i, unhardened_index)) = req
.path()
.iter()
.take(2)
.enumerate()
.find(|(_, index)| {
!index.is_hardened()
})
{
return Err(DerivationError::InvalidDerivationPath(i, unhardened_index.inner()).into())
}
#[cfg(feature = "tracing")] #[cfg(feature = "tracing")]
if let Some(target) = guess_target(req.path()) { if let Some(target) = guess_target(req.path()) {
info!("Deriving path: {target}"); info!("Deriving path: {target}");
@ -110,6 +122,9 @@ mod tests {
if chain.len() < 2 { if chain.len() < 2 {
continue; continue;
} }
if chain.iter().take(2).any(|index| !index.is_hardened()) {
continue;
}
let req = DerivationRequest::new(DerivationAlgorithm::Secp256k1, &chain); let req = DerivationRequest::new(DerivationAlgorithm::Secp256k1, &chain);
let response: DerivationResponse = keyforkd let response: DerivationResponse = keyforkd
.ready() .ready()

View File

@ -61,7 +61,7 @@ where
)); ));
let socket_dir = tempfile::tempdir().expect(bug!("can't create tempdir")); let socket_dir = tempfile::tempdir().expect(bug!("can't create tempdir"));
let socket_path = socket_dir.path().join("keyforkd.sock"); let socket_path = socket_dir.path().join("keyforkd.sock");
rt.block_on(async move { let result = rt.block_on(async move {
let (tx, mut rx) = tokio::sync::mpsc::channel(1); let (tx, mut rx) = tokio::sync::mpsc::channel(1);
let server_handle = tokio::spawn({ let server_handle = tokio::spawn({
let socket_path = socket_path.clone(); let socket_path = socket_path.clone();
@ -87,8 +87,13 @@ where
let result = test_handle.await; let result = test_handle.await;
server_handle.abort(); server_handle.abort();
result result
}) });
.expect(bug!("runtime could not join all threads")) if let Err(e) = result {
if e.is_panic() {
std::panic::resume_unwind(e.into_panic());
}
}
Ok(())
} }
#[cfg(test)] #[cfg(test)]

View File

@ -59,13 +59,17 @@ pub enum Error {
#[allow(missing_docs)] #[allow(missing_docs)]
pub type Result<T, E = Error> = std::result::Result<T, E>; pub type Result<T, E = Error> = std::result::Result<T, E>;
/// Create an OpenPGP Cert with derived keys from the given derivation response, keys, and User /// Create an OpenPGP Cert with private key data, with derived keys from the given derivation
/// ID. /// response, keys, and User ID.
///
/// Certificates are created with a default expiration of one day, but may be configured to expire
/// later using the `KEYFORK_OPENPGP_EXPIRE` environment variable using values such as "15d" (15
/// days), "1m" (one month), or "2y" (two years).
/// ///
/// # Errors /// # Errors
/// The function may error for any condition mentioned in [`Error`]. /// The function may error for any condition mentioned in [`Error`].
pub fn derive(xprv: XPrv, keys: &[KeyFlags], userid: &UserID) -> Result<Cert> { pub fn derive(xprv: XPrv, keys: &[KeyFlags], userid: &UserID) -> Result<Cert> {
let primary_key_flags = match keys.get(0) { let primary_key_flags = match keys.first() {
Some(kf) if kf.for_certification() => kf, Some(kf) if kf.for_certification() => kf,
_ => return Err(Error::NotCert), _ => return Err(Error::NotCert),
}; };
@ -109,7 +113,7 @@ pub fn derive(xprv: XPrv, keys: &[KeyFlags], userid: &UserID) -> Result<Cert> {
let cert = cert.insert_packets(vec![Packet::from(userid.clone()), binding.into()])?; let cert = cert.insert_packets(vec![Packet::from(userid.clone()), binding.into()])?;
let policy = sequoia_openpgp::policy::StandardPolicy::new(); let policy = sequoia_openpgp::policy::StandardPolicy::new();
// Set certificate expiration to one day // Set certificate expiration to configured expiration or (default) one day
let mut keypair = primary_key.clone().into_keypair()?; let mut keypair = primary_key.clone().into_keypair()?;
let signatures = let signatures =
cert.set_expiration_time(&policy, None, &mut keypair, Some(expiration_date))?; cert.set_expiration_time(&policy, None, &mut keypair, Some(expiration_date))?;

View File

@ -1,6 +1,6 @@
[package] [package]
name = "keyfork-derive-util" name = "keyfork-derive-util"
version = "0.1.0" version = "0.1.1"
edition = "2021" edition = "2021"
license = "MIT" license = "MIT"

View File

@ -124,9 +124,9 @@ mod serde_with {
K: PrivateKey + Clone, K: PrivateKey + Clone,
{ {
let variable_len_bytes = <&[u8]>::deserialize(deserializer)?; let variable_len_bytes = <&[u8]>::deserialize(deserializer)?;
let bytes: [u8; 32] = variable_len_bytes let bytes: [u8; 32] = variable_len_bytes.try_into().expect(bug!(
.try_into() "unable to parse serialized private key; no support for static len"
.expect(bug!("unable to parse serialized private key; no support for static len")); ));
Ok(K::from_bytes(&bytes)) Ok(K::from_bytes(&bytes))
} }
} }
@ -179,13 +179,20 @@ where
.into_bytes(); .into_bytes();
let (private_key, chain_code) = hash.split_at(KEY_SIZE / 8); let (private_key, chain_code) = hash.split_at(KEY_SIZE / 8);
Self::new_from_parts( assert!(
!private_key.iter().all(|byte| *byte == 0),
bug!("hmac function returned all-zero master key")
);
Self::from_parts(
private_key private_key
.try_into() .try_into()
.expect(bug!("KEY_SIZE / 8 did not give a 32 byte slice")), .expect(bug!("KEY_SIZE / 8 did not give a 32 byte slice")),
0, 0,
// Checked: chain_code is always the same length, hash is static size // Checked: chain_code is always the same length, hash is static size
chain_code.try_into().expect(bug!("Invalid chain code length")), chain_code
.try_into()
.expect(bug!("Invalid chain code length")),
) )
} }
@ -205,9 +212,9 @@ where
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"; /// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let chain_code: &[u8; 32] = // /// let chain_code: &[u8; 32] = //
/// # b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB"; /// # b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB";
/// let xprv = ExtendedPrivateKey::<PrivateKey>::new_from_parts(key, 4, *chain_code); /// let xprv = ExtendedPrivateKey::<PrivateKey>::from_parts(key, 4, *chain_code);
/// ``` /// ```
pub fn new_from_parts(key: &[u8; 32], depth: u8, chain_code: [u8; 32]) -> Self { pub fn from_parts(key: &[u8; 32], depth: u8, chain_code: [u8; 32]) -> Self {
Self { Self {
private_key: K::from_bytes(key), private_key: K::from_bytes(key),
depth, depth,
@ -229,7 +236,7 @@ where
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"; /// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let chain_code: &[u8; 32] = // /// let chain_code: &[u8; 32] = //
/// # b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB"; /// # b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB";
/// let xprv = ExtendedPrivateKey::<PrivateKey>::new_from_parts(key, 4, *chain_code); /// let xprv = ExtendedPrivateKey::<PrivateKey>::from_parts(key, 4, *chain_code);
/// assert_eq!(xprv.private_key(), &PrivateKey::from_bytes(key)); /// assert_eq!(xprv.private_key(), &PrivateKey::from_bytes(key));
/// ``` /// ```
pub fn private_key(&self) -> &K { pub fn private_key(&self) -> &K {
@ -262,7 +269,7 @@ where
/// # } /// # }
/// ``` /// ```
pub fn extended_public_key(&self) -> ExtendedPublicKey<K::PublicKey> { pub fn extended_public_key(&self) -> ExtendedPublicKey<K::PublicKey> {
ExtendedPublicKey::new_from_parts(self.public_key(), self.depth, self.chain_code) ExtendedPublicKey::from_parts(self.public_key(), self.depth, self.chain_code)
} }
/// Return a public key for the current [`PrivateKey`]. /// Return a public key for the current [`PrivateKey`].
@ -301,7 +308,7 @@ where
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"; /// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let chain_code: &[u8; 32] = // /// let chain_code: &[u8; 32] = //
/// # b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB"; /// # b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB";
/// let xprv = ExtendedPrivateKey::<PrivateKey>::new_from_parts(key, 4, *chain_code); /// let xprv = ExtendedPrivateKey::<PrivateKey>::from_parts(key, 4, *chain_code);
/// assert_eq!(xprv.depth(), 4); /// assert_eq!(xprv.depth(), 4);
/// ``` /// ```
pub fn depth(&self) -> u8 { pub fn depth(&self) -> u8 {
@ -321,7 +328,7 @@ where
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"; /// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let chain_code: &[u8; 32] = // /// let chain_code: &[u8; 32] = //
/// # b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB"; /// # b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB";
/// let xprv = ExtendedPrivateKey::<PrivateKey>::new_from_parts(key, 4, *chain_code); /// let xprv = ExtendedPrivateKey::<PrivateKey>::from_parts(key, 4, *chain_code);
/// assert_eq!(chain_code, &xprv.chain_code()); /// assert_eq!(chain_code, &xprv.chain_code());
/// ``` /// ```
pub fn chain_code(&self) -> [u8; 32] { pub fn chain_code(&self) -> [u8; 32] {

View File

@ -11,8 +11,8 @@ const KEY_SIZE: usize = 256;
/// Errors associated with creating or deriving Extended Public Keys. /// Errors associated with creating or deriving Extended Public Keys.
#[derive(Error, Clone, Debug)] #[derive(Error, Clone, Debug)]
pub enum Error { pub enum Error {
/// BIP-0032 does not support deriving public keys from hardened private keys. /// BIP-0032 does not support hardened public key derivation from parent public keys.
#[error("Public keys may not be derived when hardened")] #[error("Hardened child public keys may not be derived from parent public keys")]
HardenedIndex, HardenedIndex,
/// The maximum depth for key derivation has been reached. The supported maximum depth is 255. /// The maximum depth for key derivation has been reached. The supported maximum depth is 255.
@ -60,11 +60,11 @@ where
/// let chain_code: &[u8; 32] = // /// let chain_code: &[u8; 32] = //
/// # b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB"; /// # b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB";
/// let pubkey = PublicKey::from_bytes(key); /// let pubkey = PublicKey::from_bytes(key);
/// let xpub = ExtendedPublicKey::<PublicKey>::new_from_parts(pubkey, 0, *chain_code); /// let xpub = ExtendedPublicKey::<PublicKey>::from_parts(pubkey, 0, *chain_code);
/// # Ok(()) /// # Ok(())
/// # } /// # }
/// ``` /// ```
pub fn new_from_parts(public_key: K, depth: u8, chain_code: ChainCode) -> Self { pub fn from_parts(public_key: K, depth: u8, chain_code: ChainCode) -> Self {
Self { Self {
public_key, public_key,
depth, depth,
@ -86,7 +86,7 @@ where
/// # let chain_code: &[u8; 32] = b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB"; /// # let chain_code: &[u8; 32] = b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB";
/// # let pubkey = PublicKey::from_bytes(key); /// # let pubkey = PublicKey::from_bytes(key);
/// let xpub = // /// let xpub = //
/// # ExtendedPublicKey::<PublicKey>::new_from_parts(pubkey, 0, *chain_code); /// # ExtendedPublicKey::<PublicKey>::from_parts(pubkey, 0, *chain_code);
/// let pubkey = xpub.public_key(); /// let pubkey = xpub.public_key();
/// # Ok(()) /// # Ok(())
/// # } /// # }
@ -121,7 +121,7 @@ where
/// # let chain_code: &[u8; 32] = b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB"; /// # let chain_code: &[u8; 32] = b"BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB";
/// # let pubkey = PublicKey::from_bytes(key); /// # let pubkey = PublicKey::from_bytes(key);
/// let xpub = // /// let xpub = //
/// # ExtendedPublicKey::<PublicKey>::new_from_parts(pubkey, 0, *chain_code); /// # ExtendedPublicKey::<PublicKey>::from_parts(pubkey, 0, *chain_code);
/// let index = DerivationIndex::new(0, false)?; /// let index = DerivationIndex::new(0, false)?;
/// let child = xpub.derive_child(&index)?; /// let child = xpub.derive_child(&index)?;
/// # Ok(()) /// # Ok(())

View File

@ -85,7 +85,7 @@ pub trait PrivateKey: Sized {
/// # Errors /// # Errors
/// ///
/// An error may be returned if: /// An error may be returned if:
/// * A nonzero `other` is provided. /// * An all-zero `other` is provided.
/// * An error specific to the given algorithm was encountered. /// * An error specific to the given algorithm was encountered.
fn derive_child(&self, other: &PrivateKeyBytes) -> Result<Self, Self::Err>; fn derive_child(&self, other: &PrivateKeyBytes) -> Result<Self, Self::Err>;
@ -102,6 +102,10 @@ pub enum PrivateKeyError {
/// For the given algorithm, the private key must be nonzero. /// For the given algorithm, the private key must be nonzero.
#[error("The provided private key must be nonzero, but is not")] #[error("The provided private key must be nonzero, but is not")]
NonZero, NonZero,
/// A scalar could not be constructed for the given algorithm.
#[error("A scalar could not be constructed for the given algorithm")]
InvalidScalar,
} }
#[cfg(feature = "secp256k1")] #[cfg(feature = "secp256k1")]
@ -130,20 +134,19 @@ impl PrivateKey for k256::SecretKey {
} }
fn derive_child(&self, other: &PrivateKeyBytes) -> Result<Self, Self::Err> { fn derive_child(&self, other: &PrivateKeyBytes) -> Result<Self, Self::Err> {
if other.iter().all(|n| n == &0) { use k256::elliptic_curve::ScalarPrimitive;
return Err(PrivateKeyError::NonZero); use k256::{Scalar, Secp256k1};
}
let other = *other; // Construct a scalar from bytes
// Checked: See above nonzero check let scalar = ScalarPrimitive::<Secp256k1>::from_bytes(other.into());
let scalar = Option::<NonZeroScalar>::from(NonZeroScalar::from_repr(other.into())) let scalar = Option::<ScalarPrimitive<Secp256k1>>::from(scalar);
.expect(bug!("Should have been able to get a NonZeroScalar")); let scalar = scalar.ok_or(PrivateKeyError::InvalidScalar)?;
let scalar = Scalar::from(scalar);
let derived_scalar = self.to_nonzero_scalar().as_ref() + scalar.as_ref(); let derived_scalar = self.to_nonzero_scalar().as_ref() + scalar.as_ref();
Ok( let nonzero_scalar = Option::<NonZeroScalar>::from(NonZeroScalar::new(derived_scalar))
Option::<NonZeroScalar>::from(NonZeroScalar::new(derived_scalar)) .ok_or(PrivateKeyError::NonZero)?;
.map(Into::into) Ok(Self::from(nonzero_scalar))
.expect(bug!("Should be able to make Key")),
)
} }
} }
@ -180,7 +183,8 @@ impl PrivateKey for ed25519_dalek::SigningKey {
use crate::public_key::TestPublicKey; use crate::public_key::TestPublicKey;
#[doc(hidden)] /// A private key that can be used for testing purposes. Does not utilize any significant
/// cryptographic operations.
#[derive(Clone, Debug, PartialEq, Eq)] #[derive(Clone, Debug, PartialEq, Eq)]
pub struct TestPrivateKey { pub struct TestPrivateKey {
key: [u8; 32], key: [u8; 32],
@ -201,9 +205,7 @@ impl PrivateKey for TestPrivateKey {
type Err = PrivateKeyError; type Err = PrivateKeyError;
fn from_bytes(b: &PrivateKeyBytes) -> Self { fn from_bytes(b: &PrivateKeyBytes) -> Self {
Self { Self { key: *b }
key: *b
}
} }
fn to_bytes(&self) -> PrivateKeyBytes { fn to_bytes(&self) -> PrivateKeyBytes {

View File

@ -42,7 +42,7 @@ pub trait PublicKey: Sized {
/// # Errors /// # Errors
/// ///
/// An error may be returned if: /// An error may be returned if:
/// * A nonzero `other` is provided. /// * An all-zero `other` is provided.
/// * An error specific to the given algorithm was encountered. /// * An error specific to the given algorithm was encountered.
fn derive_child(&self, other: PrivateKeyBytes) -> Result<Self, Self::Err>; fn derive_child(&self, other: PrivateKeyBytes) -> Result<Self, Self::Err>;
@ -77,6 +77,10 @@ pub enum PublicKeyError {
#[error("The provided public key must be nonzero, but is not")] #[error("The provided public key must be nonzero, but is not")]
NonZero, NonZero,
/// A scalar could not be constructed for the given algorithm.
#[error("A scalar could not be constructed for the given algorithm")]
InvalidScalar,
/// Public key derivation is unsupported for this algorithm. /// Public key derivation is unsupported for this algorithm.
#[error("Public key derivation is unsupported for this algorithm")] #[error("Public key derivation is unsupported for this algorithm")]
DerivationUnsupported, DerivationUnsupported,
@ -85,7 +89,7 @@ pub enum PublicKeyError {
#[cfg(feature = "secp256k1")] #[cfg(feature = "secp256k1")]
use k256::{ use k256::{
elliptic_curve::{group::prime::PrimeCurveAffine, sec1::ToEncodedPoint}, elliptic_curve::{group::prime::PrimeCurveAffine, sec1::ToEncodedPoint},
AffinePoint, NonZeroScalar, AffinePoint,
}; };
#[cfg(feature = "secp256k1")] #[cfg(feature = "secp256k1")]
@ -105,14 +109,16 @@ impl PublicKey for k256::PublicKey {
} }
fn derive_child(&self, other: PrivateKeyBytes) -> Result<Self, Self::Err> { fn derive_child(&self, other: PrivateKeyBytes) -> Result<Self, Self::Err> {
if other.iter().all(|n| n == &0) { use k256::elliptic_curve::ScalarPrimitive;
return Err(PublicKeyError::NonZero); use k256::{Secp256k1, Scalar};
}
// Checked: See above
let scalar = Option::<NonZeroScalar>::from(NonZeroScalar::from_repr(other.into()))
.expect(bug!("Should have been able to get a NonZeroScalar"));
let point = self.to_projective() + (AffinePoint::generator() * *scalar); // Construct a scalar from bytes
let scalar = ScalarPrimitive::<Secp256k1>::from_bytes(&other.into());
let scalar = Option::<ScalarPrimitive<Secp256k1>>::from(scalar);
let scalar = scalar.ok_or(PublicKeyError::InvalidScalar)?;
let scalar = Scalar::from(scalar);
let point = self.to_projective() + (AffinePoint::generator() * scalar);
Ok(Self::from_affine(point.into()) Ok(Self::from_affine(point.into())
.expect(bug!("Could not from_affine after scalar arithmetic"))) .expect(bug!("Could not from_affine after scalar arithmetic")))
} }
@ -142,14 +148,15 @@ impl PublicKey for VerifyingKey {
} }
} }
#[doc(hidden)] /// A public key that can be used for testing purposes. Does not utilize any significant
/// cryptographic operations.
#[derive(Clone)] #[derive(Clone)]
pub struct TestPublicKey { pub struct TestPublicKey {
pub(crate) key: [u8; 33], pub(crate) key: [u8; 33],
} }
impl TestPublicKey { impl TestPublicKey {
#[doc(hidden)] /// Create a new TestPublicKey from the given bytes.
#[allow(dead_code)] #[allow(dead_code)]
pub fn from_bytes(b: &[u8]) -> Self { pub fn from_bytes(b: &[u8]) -> Self {
Self { Self {

View File

@ -57,7 +57,7 @@ pub enum DerivationAlgorithm {
#[allow(missing_docs)] #[allow(missing_docs)]
Secp256k1, Secp256k1,
#[doc(hidden)] #[doc(hidden)]
Internal, TestAlgorithm,
} }
impl DerivationAlgorithm { impl DerivationAlgorithm {
@ -86,7 +86,7 @@ impl DerivationAlgorithm {
&derived_key, &derived_key,
)) ))
} }
Self::Internal => { Self::TestAlgorithm => {
let key = ExtendedPrivateKey::<TestPrivateKey>::new(seed); let key = ExtendedPrivateKey::<TestPrivateKey>::new(seed);
let derived_key = key.derive_path(path)?; let derived_key = key.derive_path(path)?;
Ok(DerivationResponse::with_algo_and_xprv( Ok(DerivationResponse::with_algo_and_xprv(
@ -120,7 +120,7 @@ pub trait AsAlgorithm: PrivateKey {
impl AsAlgorithm for TestPrivateKey { impl AsAlgorithm for TestPrivateKey {
fn as_algorithm() -> DerivationAlgorithm { fn as_algorithm() -> DerivationAlgorithm {
DerivationAlgorithm::Internal DerivationAlgorithm::TestAlgorithm
} }
} }
@ -144,7 +144,7 @@ impl DerivationRequest {
/// # }; /// # };
/// # fn main() -> Result<(), Box<dyn std::error::Error>> { /// # fn main() -> Result<(), Box<dyn std::error::Error>> {
/// let algo: DerivationAlgorithm = // /// let algo: DerivationAlgorithm = //
/// # DerivationAlgorithm::Internal; /// # DerivationAlgorithm::TestAlgorithm;
/// let path: DerivationPath = // /// let path: DerivationPath = //
/// # DerivationPath::default(); /// # DerivationPath::default();
/// let request = DerivationRequest::new(algo, &path); /// let request = DerivationRequest::new(algo, &path);
@ -169,7 +169,7 @@ impl DerivationRequest {
/// # }; /// # };
/// # fn main() -> Result<(), Box<dyn std::error::Error>> { /// # fn main() -> Result<(), Box<dyn std::error::Error>> {
/// let algo: DerivationAlgorithm = // /// let algo: DerivationAlgorithm = //
/// # DerivationAlgorithm::Internal; /// # DerivationAlgorithm::TestAlgorithm;
/// let path: DerivationPath = // /// let path: DerivationPath = //
/// # DerivationPath::default(); /// # DerivationPath::default();
/// let request = DerivationRequest::new(algo, &path); /// let request = DerivationRequest::new(algo, &path);
@ -199,7 +199,7 @@ impl DerivationRequest {
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA", /// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
/// # )?; /// # )?;
/// let algo: DerivationAlgorithm = // /// let algo: DerivationAlgorithm = //
/// # DerivationAlgorithm::Internal; /// # DerivationAlgorithm::TestAlgorithm;
/// let path: DerivationPath = // /// let path: DerivationPath = //
/// # DerivationPath::default(); /// # DerivationPath::default();
/// let request = DerivationRequest::new(algo, &path); /// let request = DerivationRequest::new(algo, &path);
@ -228,7 +228,7 @@ impl DerivationRequest {
/// let seed: &[u8; 64] = // /// let seed: &[u8; 64] = //
/// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"; /// # b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let algo: DerivationAlgorithm = // /// let algo: DerivationAlgorithm = //
/// # DerivationAlgorithm::Internal; /// # DerivationAlgorithm::TestAlgorithm;
/// let path: DerivationPath = // /// let path: DerivationPath = //
/// # DerivationPath::default(); /// # DerivationPath::default();
/// let request = DerivationRequest::new(algo, &path); /// let request = DerivationRequest::new(algo, &path);
@ -300,7 +300,7 @@ mod secp256k1 {
fn try_from(value: &DerivationResponse) -> Result<Self, Self::Error> { fn try_from(value: &DerivationResponse) -> Result<Self, Self::Error> {
match value.algorithm { match value.algorithm {
DerivationAlgorithm::Secp256k1 => Ok(Self::new_from_parts( DerivationAlgorithm::Secp256k1 => Ok(Self::from_parts(
&value.data, &value.data,
value.depth, value.depth,
value.chain_code, value.chain_code,
@ -335,7 +335,7 @@ mod ed25519 {
fn try_from(value: &DerivationResponse) -> Result<Self, Self::Error> { fn try_from(value: &DerivationResponse) -> Result<Self, Self::Error> {
match value.algorithm { match value.algorithm {
DerivationAlgorithm::Ed25519 => Ok(Self::new_from_parts( DerivationAlgorithm::Ed25519 => Ok(Self::from_parts(
&value.data, &value.data,
value.depth, value.depth,
value.chain_code, value.chain_code,

View File

@ -1,6 +1,6 @@
[package] [package]
name = "keyfork-shard" name = "keyfork-shard"
version = "0.1.0" version = "0.2.0"
edition = "2021" edition = "2021"
license = "AGPL-3.0-only" license = "AGPL-3.0-only"
@ -37,3 +37,4 @@ card-backend-pcsc = { version = "0.5.0", optional = true }
openpgp-card-sequoia = { version = "0.2.0", optional = true, default-features = false } openpgp-card-sequoia = { version = "0.2.0", optional = true, default-features = false }
openpgp-card = { version = "0.4.0", optional = true } openpgp-card = { version = "0.4.0", optional = true }
sequoia-openpgp = { version = "1.17.0", optional = true, default-features = false } sequoia-openpgp = { version = "1.17.0", optional = true, default-features = false }
base64 = "0.22.0"

View File

@ -7,22 +7,28 @@ use std::{
}; };
use aes_gcm::{ use aes_gcm::{
aead::{consts::U12, Aead, AeadCore, OsRng}, aead::{consts::U12, Aead},
Aes256Gcm, KeyInit, Nonce, Aes256Gcm, KeyInit, Nonce,
}; };
use base64::prelude::{Engine, BASE64_STANDARD};
use hkdf::Hkdf; use hkdf::Hkdf;
use keyfork_bug::{bug, POISONED_MUTEX}; use keyfork_bug::{bug, POISONED_MUTEX};
use keyfork_mnemonic_util::{English, Mnemonic}; use keyfork_mnemonic_util::{English, Mnemonic};
use keyfork_prompt::{ use keyfork_prompt::{
validators::{mnemonic::MnemonicSetValidator, Validator}, validators::{
mnemonic::{MnemonicSetValidator, MnemonicValidator, WordLength},
Validator,
},
Message as PromptMessage, PromptHandler, Terminal, Message as PromptMessage, PromptHandler, Terminal,
}; };
use sha2::Sha256; use sha2::Sha256;
use sharks::{Share, Sharks}; use sharks::{Share, Sharks};
use x25519_dalek::{EphemeralSecret, PublicKey}; use x25519_dalek::{EphemeralSecret, PublicKey};
// 256 bit share encrypted is 49 bytes, couple more bytes before we reach max size // 32-byte share, 1-byte index, 1-byte threshold, 1-byte version == 36 bytes
const ENC_LEN: u8 = 4 * 16; // Encrypted, is 52 bytes
const PLAINTEXT_LENGTH: u8 = 36;
const ENCRYPTED_LENGTH: u8 = PLAINTEXT_LENGTH + 16;
#[cfg(feature = "openpgp")] #[cfg(feature = "openpgp")]
pub mod openpgp; pub mod openpgp;
@ -194,7 +200,6 @@ pub trait Format {
let encrypted_messages = self.parse_shard_file(reader)?; let encrypted_messages = self.parse_shard_file(reader)?;
// establish AES-256-GCM key via ECDH // establish AES-256-GCM key via ECDH
let mut nonce_data: Option<[u8; 12]> = None;
let mut pubkey_data: Option<[u8; 32]> = None; let mut pubkey_data: Option<[u8; 32]> = None;
// receive remote data via scanning QR code from camera // receive remote data via scanning QR code from camera
@ -204,12 +209,13 @@ pub trait Format {
.lock() .lock()
.expect(bug!(POISONED_MUTEX)) .expect(bug!(POISONED_MUTEX))
.prompt_message(PromptMessage::Text(QRCODE_PROMPT.to_string()))?; .prompt_message(PromptMessage::Text(QRCODE_PROMPT.to_string()))?;
if let Ok(Some(hex)) = if let Ok(Some(qrcode_content)) =
keyfork_qrcode::scan_camera(std::time::Duration::from_secs(30), 0) keyfork_qrcode::scan_camera(std::time::Duration::from_secs(30), 0)
{ {
let decoded_data = smex::decode(&hex)?; let decoded_data = BASE64_STANDARD
nonce_data = Some(decoded_data[..12].try_into().map_err(|_| InvalidData)?); .decode(qrcode_content)
pubkey_data = Some(decoded_data[12..].try_into().map_err(|_| InvalidData)?) .expect(bug!("qrcode should contain base64 encoded data"));
pubkey_data = Some(decoded_data.try_into().map_err(|_| InvalidData)?)
} else { } else {
prompt prompt
.lock() .lock()
@ -219,43 +225,43 @@ pub trait Format {
} }
// if QR code scanning failed or was unavailable, read from a set of mnemonics // if QR code scanning failed or was unavailable, read from a set of mnemonics
let (nonce, their_pubkey) = match (nonce_data, pubkey_data) { let their_pubkey = match pubkey_data {
(Some(nonce), Some(pubkey)) => (nonce, pubkey), Some(pubkey) => pubkey,
_ => { None => {
let validator = MnemonicSetValidator { let validator = MnemonicValidator {
word_lengths: [9, 24], word_length: Some(WordLength::Count(24)),
}; };
let [nonce_mnemonic, pubkey_mnemonic] = prompt prompt
.lock() .lock()
.expect(bug!(POISONED_MUTEX)) .expect(bug!(POISONED_MUTEX))
.prompt_validated_wordlist::<English, _>( .prompt_validated_wordlist::<English, _>(
QRCODE_COULDNT_READ, QRCODE_COULDNT_READ,
3, 3,
validator.to_fn(), validator.to_fn(),
)?; )?
let nonce = nonce_mnemonic
.as_bytes() .as_bytes()
.try_into() .try_into()
.map_err(|_| InvalidData)?; .map_err(|_| InvalidData)?
let pubkey = pubkey_mnemonic
.as_bytes()
.try_into()
.map_err(|_| InvalidData)?;
(nonce, pubkey)
} }
}; };
// create our shared key // create our shared key
let our_key = EphemeralSecret::random(); let our_key = EphemeralSecret::random();
let our_pubkey_mnemonic = Mnemonic::from_bytes(PublicKey::from(&our_key).as_bytes())?; let our_pubkey_mnemonic = Mnemonic::from_bytes(PublicKey::from(&our_key).as_bytes())?;
let shared_secret = our_key let shared_secret = our_key.diffie_hellman(&PublicKey::from(their_pubkey));
.diffie_hellman(&PublicKey::from(their_pubkey)) assert!(
.to_bytes(); shared_secret.was_contributory(),
let hkdf = Hkdf::<Sha256>::new(None, &shared_secret); bug!("shared secret might be insecure")
let mut hkdf_output = [0u8; 256 / 8]; );
hkdf.expand(&[], &mut hkdf_output)?; let hkdf = Hkdf::<Sha256>::new(None, shared_secret.as_bytes());
let shared_key = Aes256Gcm::new_from_slice(&hkdf_output)?;
let mut shared_key_data = [0u8; 256 / 8];
hkdf.expand(b"key", &mut shared_key_data)?;
let shared_key = Aes256Gcm::new_from_slice(&shared_key_data)?;
let mut nonce_data = [0u8; 12];
hkdf.expand(b"nonce", &mut nonce_data)?;
let nonce = Nonce::<U12>::from_slice(&nonce_data);
// decrypt a single shard and create the payload // decrypt a single shard and create the payload
let (share, threshold) = let (share, threshold) =
@ -264,49 +270,47 @@ pub trait Format {
payload.insert(0, HUNK_VERSION); payload.insert(0, HUNK_VERSION);
payload.insert(1, threshold); payload.insert(1, threshold);
assert!( assert!(
payload.len() <= ENC_LEN as usize, payload.len() < PLAINTEXT_LENGTH as usize,
"invalid share length (too long, max {ENC_LEN} bytes)" "invalid share length (too long, max {PLAINTEXT_LENGTH} bytes)"
); );
// encrypt data // convert plaintext to static-size payload
let nonce = Nonce::<U12>::from_slice(&nonce);
let payload_bytes = shared_key.encrypt(nonce, payload.as_slice())?;
// convert data to a static-size payload
// NOTE: Padding length is less than u8::MAX because ENC_LEN < u8::MAX
#[allow(clippy::assertions_on_constants)] #[allow(clippy::assertions_on_constants)]
{ {
assert!(ENC_LEN < u8::MAX, "padding byte can be u8"); assert!(PLAINTEXT_LENGTH < u8::MAX, "length byte can be u8");
} }
// NOTE: Previous versions of Keyfork Shard would modify the padding bytes to avoid
// duplicate mnemonic words. This version does not include that, and instead uses a
// repeated length byte.
#[allow(clippy::cast_possible_truncation)] #[allow(clippy::cast_possible_truncation)]
let mut out_bytes = [payload_bytes.len() as u8; ENC_LEN as usize]; let mut plaintext_bytes = [u8::try_from(payload.len()).expect(bug!(
assert!( "previously asserted length must be < {PLAINTEXT_LENGTH}",
payload_bytes.len() < out_bytes.len(), PLAINTEXT_LENGTH = PLAINTEXT_LENGTH
"encrypted payload larger than acceptable limit" )); PLAINTEXT_LENGTH as usize];
plaintext_bytes[..payload.len()].clone_from_slice(&payload);
// encrypt data
let encrypted_bytes = shared_key.encrypt(nonce, plaintext_bytes.as_slice())?;
assert_eq!(
encrypted_bytes.len(),
ENCRYPTED_LENGTH as usize,
bug!("encrypted bytes size != expected len"),
); );
out_bytes[..payload_bytes.len()].clone_from_slice(&payload_bytes); let mut mnemonic_bytes = [0u8; ENCRYPTED_LENGTH as usize];
mnemonic_bytes.copy_from_slice(&encrypted_bytes);
// NOTE: This previously used a single repeated value as the padding byte, but resulted in let payload_mnemonic = Mnemonic::from_nonstandard_bytes(mnemonic_bytes);
// difficulty when entering in prompts manually, as one's place could be lost due to
// repeated keywords. This is resolved below by having sequentially increasing numbers up to
// but not including the last byte.
#[allow(clippy::cast_possible_truncation)]
for (i, byte) in (out_bytes[payload_bytes.len()..(ENC_LEN as usize - 1)])
.iter_mut()
.enumerate()
{
*byte = (i % u8::MAX as usize) as u8;
}
// safety: size of out_bytes is constant and always % 4 == 0
let payload_mnemonic = unsafe { Mnemonic::from_raw_bytes(&out_bytes) };
#[cfg(feature = "qrcode")] #[cfg(feature = "qrcode")]
{ {
use keyfork_qrcode::{qrencode, ErrorCorrection}; use keyfork_qrcode::{qrencode, ErrorCorrection};
let mut qrcode_data = our_pubkey_mnemonic.to_bytes(); let mut qrcode_data = our_pubkey_mnemonic.to_bytes();
qrcode_data.extend(payload_mnemonic.as_bytes()); qrcode_data.extend(payload_mnemonic.as_bytes());
if let Ok(qrcode) = qrencode(&smex::encode(&qrcode_data), ErrorCorrection::Highest) { if let Ok(qrcode) = qrencode(
&BASE64_STANDARD.encode(qrcode_data),
ErrorCorrection::Highest,
) {
prompt prompt
.lock() .lock()
.expect(bug!(POISONED_MUTEX)) .expect(bug!(POISONED_MUTEX))
@ -401,7 +405,7 @@ pub struct InvalidData;
/// 1 byte: Version /// 1 byte: Version
/// 1 byte: Threshold /// 1 byte: Threshold
/// Data: &[u8] /// Data: &[u8]
pub(crate) const HUNK_VERSION: u8 = 1; pub(crate) const HUNK_VERSION: u8 = 2;
pub(crate) const HUNK_OFFSET: usize = 2; pub(crate) const HUNK_OFFSET: usize = 2;
const QRCODE_PROMPT: &str = "Press enter, then present QR code to camera."; const QRCODE_PROMPT: &str = "Press enter, then present QR code to camera.";
@ -432,22 +436,22 @@ pub fn remote_decrypt(w: &mut impl Write) -> Result<(), Box<dyn std::error::Erro
while iter_count.is_none() || iter_count.is_some_and(|i| i > 0) { while iter_count.is_none() || iter_count.is_some_and(|i| i > 0) {
iter += 1; iter += 1;
let nonce = Aes256Gcm::generate_nonce(&mut OsRng);
let nonce_mnemonic = unsafe { Mnemonic::from_raw_bytes(nonce.as_slice()) };
let our_key = EphemeralSecret::random(); let our_key = EphemeralSecret::random();
let key_mnemonic = Mnemonic::from_bytes(PublicKey::from(&our_key).as_bytes())?; let key_mnemonic = Mnemonic::from_bytes(PublicKey::from(&our_key).as_bytes())?;
#[cfg(feature = "qrcode")] #[cfg(feature = "qrcode")]
{ {
use keyfork_qrcode::{qrencode, ErrorCorrection}; use keyfork_qrcode::{qrencode, ErrorCorrection};
let mut qrcode_data = nonce_mnemonic.to_bytes(); let qrcode_data = key_mnemonic.to_bytes();
qrcode_data.extend(key_mnemonic.as_bytes()); if let Ok(qrcode) = qrencode(
if let Ok(qrcode) = qrencode(&smex::encode(&qrcode_data), ErrorCorrection::Highest) { &BASE64_STANDARD.encode(qrcode_data),
ErrorCorrection::Highest,
) {
pm.prompt_message(PromptMessage::Text(format!( pm.prompt_message(PromptMessage::Text(format!(
concat!( concat!(
"A QR code will be displayed after this prompt. ", "QR code #{iter} will be displayed after this prompt. ",
"Send the QR code to only shardholder {iter}. ", "Send the QR code to the next shardholder. ",
"Nobody else should scan this QR code." "Only the next shardholder should scan the QR code."
), ),
iter = iter iter = iter
)))?; )))?;
@ -457,11 +461,9 @@ pub fn remote_decrypt(w: &mut impl Write) -> Result<(), Box<dyn std::error::Erro
pm.prompt_message(PromptMessage::Text(format!( pm.prompt_message(PromptMessage::Text(format!(
concat!( concat!(
"Upon request, these words should be sent to shardholder {iter}: ", "Upon request, these words should be sent to the shardholder: ",
"{nonce_mnemonic} {key_mnemonic}" "{key_mnemonic}"
), ),
iter = iter,
nonce_mnemonic = nonce_mnemonic,
key_mnemonic = key_mnemonic, key_mnemonic = key_mnemonic,
)))?; )))?;
@ -471,10 +473,17 @@ pub fn remote_decrypt(w: &mut impl Write) -> Result<(), Box<dyn std::error::Erro
#[cfg(feature = "qrcode")] #[cfg(feature = "qrcode")]
{ {
pm.prompt_message(PromptMessage::Text(QRCODE_PROMPT.to_string()))?; pm.prompt_message(PromptMessage::Text(QRCODE_PROMPT.to_string()))?;
if let Ok(Some(hex)) = if let Ok(Some(qrcode_content)) =
keyfork_qrcode::scan_camera(std::time::Duration::from_secs(QRCODE_TIMEOUT), 0) keyfork_qrcode::scan_camera(std::time::Duration::from_secs(QRCODE_TIMEOUT), 0)
{ {
let decoded_data = smex::decode(&hex)?; let decoded_data = BASE64_STANDARD
.decode(qrcode_content)
.expect(bug!("qrcode should contain base64 encoded data"));
assert_eq!(
decoded_data.len(),
ENCRYPTED_LENGTH as usize,
bug!("invalid payload data")
);
let _ = pubkey_data.insert(decoded_data[..32].try_into().map_err(|_| InvalidData)?); let _ = pubkey_data.insert(decoded_data[..32].try_into().map_err(|_| InvalidData)?);
let _ = payload_data.insert(decoded_data[32..].to_vec()); let _ = payload_data.insert(decoded_data[32..].to_vec());
} else { } else {
@ -486,7 +495,7 @@ pub fn remote_decrypt(w: &mut impl Write) -> Result<(), Box<dyn std::error::Erro
(Some(pubkey), Some(payload)) => (pubkey, payload), (Some(pubkey), Some(payload)) => (pubkey, payload),
_ => { _ => {
let validator = MnemonicSetValidator { let validator = MnemonicSetValidator {
word_lengths: [24, 48], word_lengths: [24, 39],
}; };
let [pubkey_mnemonic, payload_mnemonic] = pm let [pubkey_mnemonic, payload_mnemonic] = pm
@ -504,14 +513,28 @@ pub fn remote_decrypt(w: &mut impl Write) -> Result<(), Box<dyn std::error::Erro
} }
}; };
let shared_secret = our_key.diffie_hellman(&PublicKey::from(pubkey)).to_bytes(); assert_eq!(
let hkdf = Hkdf::<Sha256>::new(None, &shared_secret); payload.len(),
let mut hkdf_output = [0u8; 256 / 8]; ENCRYPTED_LENGTH as usize,
hkdf.expand(&[], &mut hkdf_output)?; bug!("invalid payload data")
let shared_key = Aes256Gcm::new_from_slice(&hkdf_output)?; );
let payload = let shared_secret = our_key.diffie_hellman(&PublicKey::from(pubkey));
shared_key.decrypt(&nonce, &payload[..payload[payload.len() - 1] as usize])?; assert!(
shared_secret.was_contributory(),
bug!("shared secret might be insecure")
);
let hkdf = Hkdf::<Sha256>::new(None, shared_secret.as_bytes());
let mut shared_key_data = [0u8; 256 / 8];
hkdf.expand(b"key", &mut shared_key_data)?;
let shared_key = Aes256Gcm::new_from_slice(&shared_key_data)?;
let mut nonce_data = [0u8; 12];
hkdf.expand(b"nonce", &mut nonce_data)?;
let nonce = Nonce::<U12>::from_slice(&nonce_data);
let payload = shared_key.decrypt(nonce, payload.as_slice())?;
assert_eq!(HUNK_VERSION, payload[0], "Incompatible hunk version"); assert_eq!(HUNK_VERSION, payload[0], "Incompatible hunk version");
match &mut iter_count { match &mut iter_count {
@ -526,7 +549,8 @@ pub fn remote_decrypt(w: &mut impl Write) -> Result<(), Box<dyn std::error::Erro
} }
} }
shares.push(payload[HUNK_OFFSET..].to_vec()); let payload_len = payload.last().expect(bug!("payload should not be empty"));
shares.push(payload[HUNK_OFFSET..usize::from(*payload_len)].to_vec());
} }
let shares = shares let shares = shares

View File

@ -194,33 +194,52 @@ impl<P: PromptHandler> OpenPGP<P> {
} }
impl<P: PromptHandler> OpenPGP<P> { impl<P: PromptHandler> OpenPGP<P> {
/// Read all OpenPGP certificates in a path and return a [`Vec`] of them. Certificates are read /// Read all OpenPGP certificates in a path and return a [`Vec`] of them.
/// from a file, or from files one level deep in a directory. ///
/// Certificates are read from a file, or from files one level deep in a directory.
/// Certificates with duplicated fingerprints will be discarded.
/// ///
/// # Errors /// # Errors
/// The function may return an error if it is unable to read the directory or if Sequoia is unable /// The function may return an error if it is unable to read the directory or if Sequoia is
/// to load certificates from the file. /// unable to load certificates from the file.
pub fn discover_certs(path: impl AsRef<Path>) -> Result<Vec<Cert>> { pub fn discover_certs(path: impl AsRef<Path>) -> Result<Vec<Cert>> {
let path = path.as_ref(); let path = path.as_ref();
let mut pubkeys = std::collections::HashSet::new();
let mut certs = HashMap::new();
if path.is_file() { if path.is_file() {
let mut vec = vec![]; for maybe_cert in CertParser::from_file(path).map_err(Error::Sequoia)? {
for cert in CertParser::from_file(path).map_err(Error::Sequoia)? { let cert = maybe_cert.map_err(Error::Sequoia)?;
vec.push(cert.map_err(Error::Sequoia)?); let certfp = cert.fingerprint();
for key in cert.keys() {
let fp = key.fingerprint();
if pubkeys.contains(&fp) {
eprintln!("Received duplicate key: {fp} in public key: {certfp}");
}
pubkeys.insert(fp);
}
certs.insert(certfp, cert);
} }
Ok(vec)
} else { } else {
let mut vec = vec![];
for entry in path for entry in path
.read_dir() .read_dir()
.map_err(Error::Io)? .map_err(Error::Io)?
.filter_map(Result::ok) .filter_map(Result::ok)
.filter(|p| p.path().is_file()) .filter(|p| p.path().is_file())
{ {
vec.push(Cert::from_file(entry.path()).map_err(Error::Sequoia)?); let cert = Cert::from_file(entry.path()).map_err(Error::Sequoia)?;
let certfp = cert.fingerprint();
for key in cert.keys() {
let fp = key.fingerprint();
if pubkeys.contains(&fp) {
eprintln!("Received duplicate key: {fp} in public key: {certfp}");
} }
Ok(vec) pubkeys.insert(fp);
} }
certs.insert(certfp, cert);
}
}
Ok(certs.into_values().collect())
} }
} }

View File

@ -84,13 +84,23 @@ impl<P: PromptHandler> VerificationHelper for &mut Keyring<P> {
aead_algo, aead_algo,
} => {} } => {}
MessageLayer::SignatureGroup { results } => { MessageLayer::SignatureGroup { results } => {
for result in results { match &results[..] {
if let Err(e) = result { [Ok(_)] => {
return Ok(());
}
_ => {
// FIXME: anyhow leak: VerificationError impl std::error::Error // FIXME: anyhow leak: VerificationError impl std::error::Error
// return Err(e.context("Invalid signature")); // return Err(e.context("Invalid signature"));
return Err(anyhow::anyhow!("Error validating signature; either multiple signatures were passed or the single signature was not valid"));
}
}
/*
for result in results {
if let Err(e) = result {
return Err(anyhow::anyhow!("Invalid signature: {e}")); return Err(anyhow::anyhow!("Invalid signature: {e}"));
} }
} }
*/
} }
} }
} }

View File

@ -193,12 +193,23 @@ impl<P: PromptHandler> VerificationHelper for &mut SmartcardManager<P> {
aead_algo, aead_algo,
} => {} } => {}
MessageLayer::SignatureGroup { results } => { MessageLayer::SignatureGroup { results } => {
match &results[..] {
[Ok(_)] => {
return Ok(());
}
_ => {
// FIXME: anyhow leak: VerificationError impl std::error::Error
// return Err(e.context("Invalid signature"));
return Err(anyhow::anyhow!("Error validating signature; either multiple signatures were passed or the single signature was not valid"));
}
}
/*
for result in results { for result in results {
if let Err(e) = result { if let Err(e) = result {
// FIXME: anyhow leak return Err(anyhow::anyhow!("Invalid signature: {e}"));
return Err(anyhow::anyhow!("Verification error: {}", e.to_string()));
} }
} }
*/
} }
} }
} }
@ -264,8 +275,8 @@ impl<P: PromptHandler> DecryptionHelper for &mut SmartcardManager<P> {
} else { } else {
format!("Unlock card {card_id} ({cardholder_name})\n{rpea}: {attempts}\n\nPIN: ") format!("Unlock card {card_id} ({cardholder_name})\n{rpea}: {attempts}\n\nPIN: ")
}; };
let temp_pin = let temp_pin = self
self.pm .pm
.lock() .lock()
.expect(bug!(POISONED_MUTEX)) .expect(bug!(POISONED_MUTEX))
.prompt_validated_passphrase(&message, 3, &pin_validator)?; .prompt_validated_passphrase(&message, 3, &pin_validator)?;

View File

@ -32,7 +32,7 @@ keyfork-entropy = { version = "0.1.0", path = "../util/keyfork-entropy", registr
keyfork-mnemonic-util = { version = "0.2.0", path = "../util/keyfork-mnemonic-util", registry = "distrust" } keyfork-mnemonic-util = { version = "0.2.0", path = "../util/keyfork-mnemonic-util", registry = "distrust" }
keyfork-prompt = { version = "0.1.0", path = "../util/keyfork-prompt", registry = "distrust" } keyfork-prompt = { version = "0.1.0", path = "../util/keyfork-prompt", registry = "distrust" }
keyfork-qrcode = { version = "0.1.0", path = "../qrcode/keyfork-qrcode", default-features = false, registry = "distrust" } keyfork-qrcode = { version = "0.1.0", path = "../qrcode/keyfork-qrcode", default-features = false, registry = "distrust" }
keyfork-shard = { version = "0.1.0", path = "../keyfork-shard", default-features = false, features = ["openpgp", "openpgp-card", "qrcode"], registry = "distrust" } keyfork-shard = { version = "0.2.0", path = "../keyfork-shard", default-features = false, features = ["openpgp", "openpgp-card", "qrcode"], registry = "distrust" }
smex = { version = "0.1.0", path = "../util/smex", registry = "distrust" } smex = { version = "0.1.0", path = "../util/smex", registry = "distrust" }
clap = { version = "4.4.2", features = ["derive", "env", "wrap_help"] } clap = { version = "4.4.2", features = ["derive", "env", "wrap_help"] }

View File

@ -20,8 +20,12 @@ pub enum DeriveSubcommands {
/// Derive an OpenPGP Transferable Secret Key (private key). The key is encoded using OpenPGP /// Derive an OpenPGP Transferable Secret Key (private key). The key is encoded using OpenPGP
/// ASCII Armor, a format usable by most programs using OpenPGP. /// ASCII Armor, a format usable by most programs using OpenPGP.
/// ///
/// The key is generated with a 24-hour expiration time. The operation to set the expiration /// Certificates are created with a default expiration of one day, but may be configured to
/// time to a higher value is left to the user to ensure the key is usable by the user. /// expire later using the `KEYFORK_OPENPGP_EXPIRE` environment variable using values such as
/// "15d" (15 days), "1m" (one month), or "2y" (two years).
///
/// It is recommended to use the default expiration of one day and to change the expiration
/// using an external utility, to ensure the Certify key is usable.
#[command(name = "openpgp")] #[command(name = "openpgp")]
OpenPGP { OpenPGP {
/// Default User ID for the certificate, using the OpenPGP User ID format. /// Default User ID for the certificate, using the OpenPGP User ID format.

View File

@ -11,7 +11,7 @@ use keyfork_derive_openpgp::{
}; };
use keyfork_derive_util::{DerivationIndex, DerivationPath}; use keyfork_derive_util::{DerivationIndex, DerivationPath};
use keyfork_prompt::{ use keyfork_prompt::{
validators::{PinValidator, Validator}, validators::{SecurePinValidator, Validator},
Message, PromptHandler, DefaultTerminal, default_terminal Message, PromptHandler, DefaultTerminal, default_terminal
}; };
@ -38,7 +38,7 @@ fn derive_key(seed: [u8; 32], index: u8) -> Result<Cert> {
let chain = DerivationIndex::new(u32::from_be_bytes(pgp_u32), true)?; let chain = DerivationIndex::new(u32::from_be_bytes(pgp_u32), true)?;
let mut shrd_u32 = [0u8; 4]; let mut shrd_u32 = [0u8; 4];
shrd_u32[..].copy_from_slice(&"shrd".bytes().collect::<Vec<u8>>()); shrd_u32[..].copy_from_slice(&"shrd".bytes().collect::<Vec<u8>>());
let account = DerivationIndex::new(u32::from_be_bytes(pgp_u32), true)?; let account = DerivationIndex::new(u32::from_be_bytes(shrd_u32), true)?;
let subkey = DerivationIndex::new(u32::from(index), true)?; let subkey = DerivationIndex::new(u32::from(index), true)?;
let path = DerivationPath::default() let path = DerivationPath::default()
.chain_push(chain) .chain_push(chain)
@ -116,12 +116,12 @@ fn generate_shard_secret(
); );
} }
let user_pin_validator = PinValidator { let user_pin_validator = SecurePinValidator {
min_length: Some(6), min_length: Some(6),
..Default::default() ..Default::default()
} }
.to_fn(); .to_fn();
let admin_pin_validator = PinValidator { let admin_pin_validator = SecurePinValidator {
min_length: Some(8), min_length: Some(8),
..Default::default() ..Default::default()
} }
@ -132,8 +132,8 @@ fn generate_shard_secret(
for i in 0..keys_per_shard { for i in 0..keys_per_shard {
pm.prompt_message(Message::Text(format!( pm.prompt_message(Message::Text(format!(
"Please remove all keys and insert key #{} for user #{}", "Please remove all keys and insert key #{} for user #{}",
i + 1, (i as u16) + 1,
index + 1, (index as u16) + 1,
)))?; )))?;
let card_backend = loop { let card_backend = loop {
if let Some(c) = PcscBackend::cards(None)?.next().transpose()? { if let Some(c) = PcscBackend::cards(None)?.next().transpose()? {

View File

@ -1,6 +1,6 @@
[package] [package]
name = "keyfork-qrcode" name = "keyfork-qrcode"
version = "0.1.0" version = "0.1.1"
repository = "https://git.distrust.co/public/keyfork" repository = "https://git.distrust.co/public/keyfork"
edition = "2021" edition = "2021"
license = "MIT" license = "MIT"

View File

@ -5,7 +5,7 @@ use keyfork_bug as bug;
use image::io::Reader as ImageReader; use image::io::Reader as ImageReader;
use std::{ use std::{
io::{Cursor, Write}, io::{Cursor, Write},
time::{Duration, SystemTime}, time::{Duration, Instant},
process::{Command, Stdio}, process::{Command, Stdio},
}; };
use v4l::{ use v4l::{
@ -110,11 +110,10 @@ pub fn scan_camera(timeout: Duration, index: usize) -> Result<Option<String>, QR
fmt.fourcc = FourCC::new(b"MPG1"); fmt.fourcc = FourCC::new(b"MPG1");
device.set_format(&fmt)?; device.set_format(&fmt)?;
let mut stream = Stream::with_buffers(&device, Type::VideoCapture, 4)?; let mut stream = Stream::with_buffers(&device, Type::VideoCapture, 4)?;
let start = SystemTime::now(); let start = Instant::now();
while SystemTime::now() while Instant::now()
.duration_since(start) .duration_since(start)
.unwrap_or(Duration::from_secs(0))
< timeout < timeout
{ {
let (buffer, _) = stream.next()?; let (buffer, _) = stream.next()?;
@ -141,12 +140,11 @@ pub fn scan_camera(timeout: Duration, index: usize) -> Result<Option<String>, QR
fmt.fourcc = FourCC::new(b"MPG1"); fmt.fourcc = FourCC::new(b"MPG1");
device.set_format(&fmt)?; device.set_format(&fmt)?;
let mut stream = Stream::with_buffers(&device, Type::VideoCapture, 4)?; let mut stream = Stream::with_buffers(&device, Type::VideoCapture, 4)?;
let start = SystemTime::now(); let start = Instant::now();
let mut scanner = keyfork_zbar::image_scanner::ImageScanner::new(); let mut scanner = keyfork_zbar::image_scanner::ImageScanner::new();
while SystemTime::now() while Instant::now()
.duration_since(start) .duration_since(start)
.unwrap_or(Duration::from_secs(0))
< timeout < timeout
{ {
let (buffer, _) = stream.next()?; let (buffer, _) = stream.next()?;

View File

@ -1,6 +1,6 @@
[package] [package]
name = "keyfork-entropy" name = "keyfork-entropy"
version = "0.1.0" version = "0.1.1"
edition = "2021" edition = "2021"
license = "MIT" license = "MIT"

View File

@ -11,9 +11,15 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
"Bit size must be divisible by 8, got: {bit_size}" "Bit size must be divisible by 8, got: {bit_size}"
); );
assert!( assert!(
bit_size <= 256, bit_size >= 128,
"Maximum supported bit size is 256, got: {bit_size}" "Minimum supported bit size is 128, got {bit_size}"
); );
match bit_size {
128 | 256 | 512 => {}
_ => {
eprintln!("reading entropy of uncommon size: {bit_size}");
}
}
let entropy = keyfork_entropy::generate_entropy_of_size(bit_size / 8)?; let entropy = keyfork_entropy::generate_entropy_of_size(bit_size / 8)?;
println!("{}", smex::encode(entropy)); println!("{}", smex::encode(entropy));

View File

@ -8,7 +8,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
input.read_line(&mut line)?; input.read_line(&mut line)?;
let decoded = smex::decode(line.trim())?; let decoded = smex::decode(line.trim())?;
let mnemonic = unsafe { Mnemonic::from_raw_bytes(&decoded) }; let mnemonic = Mnemonic::from_raw_bytes(&decoded) ;
println!("{mnemonic}"); println!("{mnemonic}");

View File

@ -125,6 +125,13 @@ impl Wordlist for English {
} }
} }
struct AssertValidMnemonicSize<const N: usize>;
impl<const N: usize> AssertValidMnemonicSize<N> {
const OK_CHUNKS: () = assert!(N % 4 == 0, "bytes must be a length divisible by 4");
const OK_SIZE: () = assert!(N <= 1024, "bytes must be less-or-equal 1024");
}
/// A BIP-0039 mnemonic with reference to a [`Wordlist`]. /// A BIP-0039 mnemonic with reference to a [`Wordlist`].
#[derive(Debug, Clone, PartialEq, Eq)] #[derive(Debug, Clone, PartialEq, Eq)]
pub struct MnemonicBase<W: Wordlist> { pub struct MnemonicBase<W: Wordlist> {
@ -276,7 +283,36 @@ where
return Err(MnemonicGenerationError::InvalidByteLength(bit_count)); return Err(MnemonicGenerationError::InvalidByteLength(bit_count));
} }
Ok(unsafe { Self::from_raw_bytes(bytes) }) Ok( Self::from_raw_bytes(bytes) )
}
/// Generate a [`Mnemonic`] from the provided data and [`Wordlist`]. The data may be of a size
/// of a factor of 4, up to 1024 bytes.
///
/// ```rust
/// use keyfork_mnemonic_util::Mnemonic;
/// let data = b"hello world!";
/// let mnemonic = Mnemonic::from_nonstandard_bytes(*data);
/// ```
///
/// If an invalid size is requested, the code will fail to compile:
///
/// ```rust,compile_fail
/// use keyfork_mnemonic_util::Mnemonic;
/// let mnemonic = Mnemonic::from_nonstandard_bytes([0u8; 53]);
/// ```
///
/// ```rust,compile_fail
/// use keyfork_mnemonic_util::Mnemonic;
/// let mnemonic = Mnemonic::from_nonstandard_bytes([0u8; 1024 + 4]);
/// ```
pub fn from_nonstandard_bytes<const N: usize>(bytes: [u8; N]) -> MnemonicBase<W> {
#[allow(clippy::let_unit_value)]
{
let () = AssertValidMnemonicSize::<N>::OK_CHUNKS;
let () = AssertValidMnemonicSize::<N>::OK_SIZE;
}
Self::from_raw_bytes(&bytes)
} }
/// Generate a [`Mnemonic`] from the provided data and [`Wordlist`]. The data is expected to be /// Generate a [`Mnemonic`] from the provided data and [`Wordlist`]. The data is expected to be
@ -292,11 +328,12 @@ where
/// Create a Mnemonic using an arbitrary length of given data. The length does not need to /// Create a Mnemonic using an arbitrary length of given data. The length does not need to
/// conform to BIP-0039 standards, but should be a multiple of 32 bits or 4 bytes. /// conform to BIP-0039 standards, but should be a multiple of 32 bits or 4 bytes.
/// ///
/// # Safety /// # Panics
///
/// This function can potentially produce mnemonics that are not BIP-0039 compliant or can't /// This function can potentially produce mnemonics that are not BIP-0039 compliant or can't
/// properly be encoded as a mnemonic. It is assumed the caller asserts the byte count is `% 4 /// properly be encoded as a mnemonic. It is assumed the caller asserts the byte count is `% 4
/// == 0`. If the assumption is incorrect, code may panic. /// == 0`. If the assumption is incorrect, code may panic. The
/// [`MnemonicBase::from_nonstandard_bytes`] function may be used to generate entropy if the
/// length of the data is known at compile-time.
/// ///
/// # Examples /// # Examples
/// ```rust /// ```rust
@ -315,11 +352,10 @@ where
/// // NOTE: Data is of invalid length, 31 /// // NOTE: Data is of invalid length, 31
/// let data = b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"; /// let data = b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// let mnemonic = unsafe { Mnemonic::from_raw_bytes(data.as_slice()) }; /// let mnemonic = unsafe { Mnemonic::from_raw_bytes(data.as_slice()) };
/// let mnemonic_text = mnemonic.to_string();
/// // NOTE: panic happens here
/// let new_mnemonic = Mnemonic::from_str(&mnemonic_text).unwrap();
/// ``` /// ```
pub unsafe fn from_raw_bytes(bytes: &[u8]) -> MnemonicBase<W> { pub fn from_raw_bytes(bytes: &[u8]) -> MnemonicBase<W> {
assert!(bytes.len() % 4 == 0);
assert!(bytes.len() <= 1024);
MnemonicBase { MnemonicBase {
data: bytes.to_vec(), data: bytes.to_vec(),
marker: PhantomData, marker: PhantomData,
@ -520,12 +556,30 @@ mod tests {
} }
#[test] #[test]
fn can_do_up_to_1024_bits() { fn can_do_up_to_8192_bits() {
let entropy = &mut [0u8; 128]; let mut entropy = [0u8; 1024];
let mut random = std::fs::File::open("/dev/urandom").unwrap(); let mut random = std::fs::File::open("/dev/urandom").unwrap();
random.read_exact(&mut entropy[..]).unwrap(); random.read_exact(&mut entropy[..]).unwrap();
let mnemonic = unsafe { Mnemonic::from_raw_bytes(&entropy[..]) }; let mnemonic = Mnemonic::from_nonstandard_bytes(entropy);
let words = mnemonic.words(); let words = mnemonic.words();
assert!(words.len() == 96); assert_eq!(words.len(), 768);
}
#[test]
#[should_panic]
fn fails_over_8192_bits() {
let entropy = &mut [0u8; 1024 + 4];
let mut random = std::fs::File::open("/dev/urandom").unwrap();
random.read_exact(&mut entropy[..]).unwrap();
let _mnemonic = Mnemonic::from_raw_bytes(&entropy[..]);
}
#[test]
#[should_panic]
fn fails_over_invalid_size() {
let entropy = &mut [0u8; 255];
let mut random = std::fs::File::open("/dev/urandom").unwrap();
random.read_exact(&mut entropy[..]).unwrap();
let _mnemonic = Mnemonic::from_raw_bytes(&entropy[..]);
} }
} }

View File

@ -29,6 +29,84 @@ pub enum PinError {
/// The PIN contained invalid characters. /// The PIN contained invalid characters.
#[error("PIN contained invalid characters (found {0} at position {1})")] #[error("PIN contained invalid characters (found {0} at position {1})")]
InvalidCharacters(char, usize), InvalidCharacters(char, usize),
/// The provided PIN had either too many repeated characters or too many sequential characters.
#[error("PIN contained too many repeated or sequential characters")]
InsecurePIN,
}
/// Validate that a PIN is of a certain length, matches a range of characters, and does not use
/// incrementing or decrementing sequences of characters.
///
/// The validator determines a score for a passphrase and, if the score is high enough, returns an
/// error.
///
/// Score is calculated based on:
/// * how many sequential characters are in the passphrase (ascending or descending)
/// * how many repeated characters are in the passphrase
#[derive(Default, Clone)]
pub struct SecurePinValidator {
/// The minimum length of provided PINs.
pub min_length: Option<usize>,
/// The maximum length of provided PINs.
pub max_length: Option<usize>,
/// The characters allowed by the PIN parser.
pub range: Option<RangeInclusive<char>>,
/// Whether repeated characters count against the PIN.
pub ignore_repeated_characters: bool,
/// Whether sequential characters count against the PIN.
pub ignore_sequential_characters: bool,
}
impl Validator for SecurePinValidator {
type Output = String;
type Error = PinError;
fn to_fn(&self) -> Box<dyn Fn(String) -> Result<String, Box<dyn std::error::Error>>> {
let min_len = self.min_length.unwrap_or(usize::MIN);
let max_len = self.max_length.unwrap_or(usize::MAX);
let range = self.range.clone().unwrap_or('0'..='9');
let ignore_repeated_characters = self.ignore_repeated_characters;
let ignore_sequential_characters = self.ignore_sequential_characters;
Box::new(move |mut s: String| {
s.truncate(s.trim_end().len());
let len = s.len();
if len < min_len {
return Err(Box::new(PinError::TooShort(len, min_len)));
}
if len > max_len {
return Err(Box::new(PinError::TooLong(len, max_len)));
}
let mut last_char = 0;
let mut score = 0;
for (index, ch) in s.chars().enumerate() {
if !range.contains(&ch) {
return Err(Box::new(PinError::InvalidCharacters(ch, index)));
}
if [-1, 1].contains(&(ch as i32 - last_char))
&& !ignore_sequential_characters
{
score += 1;
}
last_char = ch as i32;
}
let mut chars = s.chars().collect::<Vec<_>>();
chars.sort();
chars.dedup();
if !ignore_repeated_characters {
// SAFETY: the amount of characters can't have _increased_ since deduping
score += s.chars().count() - chars.len();
}
if score * 2 > s.chars().count() {
return Err(Box::new(PinError::InsecurePIN))
}
Ok(s)
})
}
} }
/// Validate that a PIN is of a certain length and matches a range of characters. /// Validate that a PIN is of a certain length and matches a range of characters.
@ -79,8 +157,8 @@ pub mod mnemonic {
use super::Validator; use super::Validator;
use keyfork_mnemonic_util::{Mnemonic, MnemonicFromStrError};
use keyfork_bug::bug; use keyfork_bug::bug;
use keyfork_mnemonic_util::{Mnemonic, MnemonicFromStrError};
/// A mnemonic could not be validated from the given input. /// A mnemonic could not be validated from the given input.
#[derive(thiserror::Error, Debug)] #[derive(thiserror::Error, Debug)]

View File

@ -33,3 +33,4 @@
- [Provisioners](./dev-guide/provisioners.md) - [Provisioners](./dev-guide/provisioners.md)
- [Auditing Dependencies](./dev-guide/auditing.md) - [Auditing Dependencies](./dev-guide/auditing.md)
- [Entropy Guide](./dev-guide/entropy.md) - [Entropy Guide](./dev-guide/entropy.md)
- [The Shard Protocol](./dev-guide/shard-protocol.md)

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# The Shard Protocol
Keyfork Shard uses a single-handshake protocol to transfer encrypted shards.
The initial payload is generated by the program combining the shards, while the
response is generated by the program transport-encrypting the shards.
## Combiner Payload
The combiner payload consists of a 12-byte nonce and a 32-byte x25519 public
key. The payload is then either encoded to hex and displayed as a QR code, and
encoded as a mnemonic and printed on-screen.
```
[12-byte nonce | 32-byte public key]
```
The transporter receives the 12-byte nonce and 32-byte x25519 key and generates
their own x25519 key. Using HKDF-Sha256 with no salt on the resulting key
generates the AES-256-GCM key used to encrypt the now-decrypted shard, along
with the received nonce.
## Transporter Payload
The transporter payload consists of a 32-byte x25519 public key and a
64-byte-padded encrypted "hunk". The hunk contains a version byte, a threshold
byte, and the encrypted shard. The last byte of the 64-byte sequence is the
total length of the encrypted hunk.
```
Handshake:
[32-byte public key | 63-byte-padded encrypted hunk | 1-byte hunk length ]
Hunk:
[1-byte version | 1-byte threshold | variable-length shard ]
```
The combiner receives the 32-byte x25519 key and the 64-byte hunk, and uses the
same key derivation scheme as above to generate the decryption key. The
threshold byte is used to determine how many shares (in total) are needed.