keyforkd{,-client}: lots of documentationings

This commit is contained in:
Ryan Heywood 2024-08-01 08:59:01 -04:00
parent bac762f5be
commit 536e6da5ad
Signed by: ryan
GPG Key ID: 8E401478A3FBEF72
3 changed files with 170 additions and 42 deletions

View File

@ -1,8 +1,10 @@
//! # The Keyforkd Client
//!
//! Keyfork allows securing the master key and highest-level derivation keys by having derivation
//! requests performed against a server, "Keyforkd" or the "Keyfork Server". The server is operated
//! on a UNIX socket with messages sent using the Keyfork Frame format.
//! requests performed against a server, "Keyforkd" or the "Keyfork Server". This allows
//! enforcement of policies, such as requiring at least two leves of a derivation path (for
//! instance, `m/0'` would not be allowed, but `m/0'/0'` would). The server is operated on a UNIX
//! socket with messages sent using the Keyfork Frame format.
//!
//! Programs using the Keyfork Client should ensure they are built against a compatible version of
//! the Keyfork Server. For versions prior to `1.0.0`, all versions within a "minor" version (i.e.,
@ -10,18 +12,23 @@
//! after `1.0.0`, all versions within a "major" version (i.e., `1.0.0`) will be compatible, but
//! `1.x.y` will not be compatible with `2.0.0`.
//!
//! Presently, the Keyfork server only supports the following requests:
//! The Keyfork Client documentation makes extensive use of the `keyforkd::test_util` module.
//! This provides testing infrastructure to set up a temporary Keyfork Daemon. In
//! your code, you should assume the daemon has already been initialized, whether by another
//! process, on another terminal, or some other instance. At no point should a program deriving an
//! "endpoint" key have control over a mnemonic or a seed.
//!
//! * Derive Key
//! ## Server Requests
//!
//! ## Extended Private Keys
//! Keyfork is designed as a client-request/server-response model. The client sends a request, such
//! as a derivation request, and the server sends its response. Presently, the Keyfork server
//! supports the following requests:
//!
//! 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
//! will be derived similarly between the server and the client.
//! ### Request: Derive Key
//!
//! The client creates a derivation path of at least two indices and requests a derived XPrv
//! (Extended Private Key) from the server.
//!
//! # Examples
//! ```rust
//! use std::str::FromStr;
//!
@ -31,17 +38,121 @@
//! // use k256::SecretKey as PrivateKey;
//! // use ed25519_dalek::SigningKey as PrivateKey;
//!
//! # let seed = b"funky accordion noises";
//! # keyforkd::test_util::run_test(seed, |socket_path| {
//! # std::env::set_var("KEYFORKD_SOCKET_PATH", socket_path);
//! let derivation_path = DerivationPath::from_str("m/44'/0'").unwrap();
//! let mut client = Client::discover_socket().unwrap();
//! let xprv = client.request_xprv::<PrivateKey>(&derivation_path).unwrap();
//! # keyforkd::test_util::Infallible::Ok(())
//! # }).unwrap();
//! #[derive(Debug, thiserror::Error)]
//! enum Error {
//! #[error(transparent)]
//! Path(#[from] keyfork_derive_util::PathError),
//!
//! #[error(transparent)]
//! Keyforkd(#[from] keyforkd_client::Error),
//! }
//!
//! fn main() -> Result<(), Error> {
//! # let seed = b"funky accordion noises";
//! # keyforkd::test_util::run_test(seed, |socket_path| {
//! let derivation_path = DerivationPath::from_str("m/44'/0'")?;
//! let mut client = Client::discover_socket()?;
//! let xprv = client.request_xprv::<PrivateKey>(&derivation_path)?;
//! # Ok::<_, Error>(())
//! # })?;
//! Ok(())
//! }
//! ```
//!
//! In tests, the Keyforkd test_util module and TestPrivateKeys can be used.
//! ---
//!
//! Request objects are typically handled by the Keyfork Client library (such as with
//! [`Client::request_xprv`]). While unadvised, clients can also attempt to handle their own
//! requests, using [`Client::request`].
//!
//! ## 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
//! will be derived similarly between the server and the client.
//!
//! ```rust
//! use std::str::FromStr;
//!
//! use keyforkd_client::Client;
//! use keyfork_derive_util::{DerivationIndex, DerivationPath};
//! # use keyfork_derive_util::private_key::TestPrivateKey as PrivateKey;
//! // use k256::SecretKey as PrivateKey;
//! // use ed25519_dalek::SigningKey as PrivateKey;
//! # fn check_wallet<T>(_: T) {}
//!
//! #[derive(Debug, thiserror::Error)]
//! enum Error {
//! #[error(transparent)]
//! Index(#[from] keyfork_derive_util::IndexError),
//!
//! #[error(transparent)]
//! Path(#[from] keyfork_derive_util::PathError),
//!
//! #[error(transparent)]
//! PrivateKey(#[from] keyfork_derive_util::PrivateKeyError),
//!
//! #[error(transparent)]
//! Keyforkd(#[from] keyforkd_client::Error),
//! }
//!
//! fn main() -> Result<(), Error> {
//! # let seed = b"funky accordion noises";
//! # keyforkd::test_util::run_test(seed, |socket_path| {
//! let derivation_path = DerivationPath::from_str("m/44'/0'/0'/0")?;
//! let mut client = Client::discover_socket()?;
//! let xprv = client.request_xprv::<PrivateKey>(&derivation_path)?;
//! // scan first 20 wallets
//! for index in 0..20 {
//! // use non-hardened derivation
//! let new_xprv = xprv.derive_child(&DerivationIndex::new(index, false)?);
//! check_wallet(new_xprv)
//! }
//! # Ok::<_, Error>(())
//! # })?;
//! Ok(())
//! }
//! ```
//!
//! ## Testing Infrastructure
//!
//! In tests, the `keyforkd::test_util` module and TestPrivateKeys can be used. These provide
//! useful utilities for writing tests that interact with the Keyfork Server without needing to
//! manually create the server for the purpose of the test. The `run_test` method can be used to
//! run a test, which can handle both returning errors and correctly translating panics (though,
//! the panics definitely won't look tidy).
//!
//! ```rust
//! use std::str::FromStr;
//!
//! use keyforkd_client::Client;
//! use keyfork_derive_util::DerivationPath;
//! use keyfork_derive_util::private_key::TestPrivateKey as PrivateKey;
//!
//! #[derive(Debug, thiserror::Error)]
//! enum Error {
//! #[error(transparent)]
//! Path(#[from] keyfork_derive_util::PathError),
//!
//! #[error(transparent)]
//! Keyforkd(#[from] keyforkd_client::Error),
//! }
//!
//! fn main() -> Result<(), Error> {
//! let seed = b"funky accordion noises";
//! keyforkd::test_util::run_test(seed, |socket_path| {
//! let derivation_path = DerivationPath::from_str("m/44'/0'")?;
//! let mut client = Client::discover_socket()?;
//! let xprv = client.request_xprv::<PrivateKey>(&derivation_path)?;
//! Ok::<_, Error>(())
//! })?;
//! Ok(())
//! }
//! ```
//!
//! If you would rather write tests to panic rather than error, or would rather not deal with error
//! types, the Panicable type should be used, which will handle the Error type for the closure.
//!
//! ```rust
//! use std::str::FromStr;
@ -52,11 +163,10 @@
//!
//! let seed = b"funky accordion noises";
//! keyforkd::test_util::run_test(seed, |socket_path| {
//! std::env::set_var("KEYFORKD_SOCKET_PATH", socket_path);
//! let derivation_path = DerivationPath::from_str("m/44'/0'").unwrap();
//! let mut client = Client::discover_socket().unwrap();
//! let xprv = client.request_xprv::<PrivateKey>(&derivation_path).unwrap();
//! keyforkd::test_util::Infallible::Ok(())
//! keyforkd::test_util::Panicable::Ok(())
//! }).unwrap();
//! ```
@ -165,10 +275,9 @@ impl Client {
///
/// # let seed = b"funky accordion noises";
/// # keyforkd::test_util::run_test(seed, |socket_path| {
/// # std::env::set_var("KEYFORKD_SOCKET_PATH", socket_path);
/// let mut socket = get_socket().unwrap();
/// let mut socket = get_socket()?;
/// let mut client = Client::new(socket);
/// # keyforkd::test_util::Infallible::Ok(())
/// # Ok::<_, keyforkd_client::Error>(())
/// # }).unwrap();
/// ```
pub fn new(socket: UnixStream) -> Self {
@ -187,9 +296,8 @@ impl Client {
///
/// # let seed = b"funky accordion noises";
/// # keyforkd::test_util::run_test(seed, |socket_path| {
/// # std::env::set_var("KEYFORKD_SOCKET_PATH", socket_path);
/// let mut client = Client::discover_socket().unwrap();
/// # keyforkd::test_util::Infallible::Ok(())
/// let mut client = Client::discover_socket()?;
/// # Ok::<_, keyforkd_client::Error>(())
/// # }).unwrap();
/// ```
pub fn discover_socket() -> Result<Self> {
@ -217,11 +325,10 @@ impl Client {
///
/// # let seed = b"funky accordion noises";
/// # keyforkd::test_util::run_test(seed, |socket_path| {
/// # std::env::set_var("KEYFORKD_SOCKET_PATH", socket_path);
/// let derivation_path = DerivationPath::from_str("m/44'/0'").unwrap();
/// let mut client = Client::discover_socket().unwrap();
/// let xprv = client.request_xprv::<PrivateKey>(&derivation_path).unwrap();
/// # keyforkd::test_util::Infallible::Ok(())
/// # keyforkd::test_util::Panicable::Ok(())
/// # }).unwrap();
/// ```
pub fn request_xprv<K>(&mut self, path: &DerivationPath) -> Result<ExtendedPrivateKey<K>>
@ -244,15 +351,20 @@ impl Client {
_ => Err(Error::InvalidResponse),
}
}
}
impl Client {
/// Serialize and send a [`Request`] to the server, awaiting a [`Result<Response>`].
///
/// This function does not properly assert the association between a request type and a
/// response type, and does not perform any serialization of native objects into Request or
/// Response types, and should only be used when absolutely necessary.
///
/// # Errors
/// An error may be returned if:
/// * Reading or writing from or to the socket encountered an error.
/// * Bincode could not serialize the request or deserialize the response.
/// * An error occurred in Keyforkd.
#[doc(hidden)]
pub fn request(&mut self, req: &Request) -> Result<Response> {
try_encode_to(&bincode::serialize(&req)?, &mut self.socket)?;
let resp = try_decode_from(&mut self.socket)?;

View File

@ -1,7 +1,7 @@
use crate::Client;
use keyfork_derive_util::{request::*, DerivationPath};
use keyfork_slip10_test_data::test_data;
use keyforkd::test_util::{run_test, Infallible};
use keyforkd::test_util::{run_test, Panicable};
use std::{os::unix::net::UnixStream, str::FromStr};
#[test]
@ -109,7 +109,7 @@ fn ed25519_test_suite() {
DerivationResponse::try_from(client.request(&req.into()).unwrap()).unwrap();
assert_eq!(&response.data, test.private_key.as_slice());
}
Infallible::Ok(())
Panicable::Ok(())
})
.unwrap();
}

View File

@ -12,20 +12,21 @@ use keyfork_bug::bug;
#[derive(Debug, thiserror::Error)]
#[error("This error can never be instantiated")]
#[doc(hidden)]
pub struct InfallibleError {
protected: (),
}
pub enum UninstantiableError {}
/// An infallible result. This type can be used to represent a function that should never error.
/// A panicable result. This type can be used when a closure chooses to panic instead of
/// returning an error. This doesn't necessarily mean a closure _has_ to panic, and its absence
/// doesn't imply a closure _can't_ panic, but this is a useful utility function for writing tests,
/// to avoid the necessity of making custom error types.
///
/// ```rust
/// use keyforkd::test_util::Infallible;
/// use keyforkd::test_util::Panicable;
/// let closure = || {
/// Infallible::Ok(())
/// Panicable::Ok(())
/// };
/// assert!(closure().is_ok());
/// ```
pub type Infallible<T> = std::result::Result<T, InfallibleError>;
pub type Panicable<T> = std::result::Result<T, UninstantiableError>;
/// Run a test making use of a Keyforkd server. The test may use a seed (the first argument) from a
/// test suite, or (as shown in the example below) a simple seed may be used solely to ensure
@ -39,6 +40,8 @@ pub type Infallible<T> = std::result::Result<T, InfallibleError>;
/// runtime.
///
/// # Examples
/// The test utility provides a socket that can be connected to for deriving keys.
///
/// ```rust
/// use std::os::unix::net::UnixStream;
/// let seed = b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
@ -46,6 +49,18 @@ pub type Infallible<T> = std::result::Result<T, InfallibleError>;
/// UnixStream::connect(&path).map(|_| ())
/// }).unwrap();
/// ```
///
/// The `keyforkd-client` crate uses the `KEYFORKD_SOCKET_PATH` variable to determine the default
/// socket path. The test will export the environment variable so it may be used by default.
///
/// ```rust
/// use std::os::unix::net::UnixStream;
/// let seed = b"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA";
/// keyforkd::test_util::run_test(seed.as_slice(), |path| {
/// assert_eq!(std::env::var_os("KEYFORKD_SOCKET_PATH").unwrap(), path.as_os_str());
/// UnixStream::connect(&path).map(|_| ())
/// }).unwrap();
/// ```
#[allow(clippy::missing_errors_doc)]
pub fn run_test<F, E>(seed: &[u8], closure: F) -> Result<(), E>
where
@ -82,6 +97,7 @@ where
rx.recv()
.await
.expect(bug!("can't receive server start signal from channel"));
std::env::set_var("KEYFORKD_SOCKET_PATH", &socket_path);
let test_handle = tokio::task::spawn_blocking(move || closure(&socket_path));
let result = test_handle.await;
@ -89,8 +105,8 @@ where
result
});
if let Err(e) = result {
if e.is_panic() {
std::panic::resume_unwind(e.into_panic());
if let Ok(reason) = e.try_into_panic() {
std::panic::resume_unwind(reason);
}
}
Ok(())
@ -103,6 +119,6 @@ mod tests {
#[test]
fn test_run_test() {
let seed = b"beefbeef";
run_test(seed, |_path| Infallible::Ok(())).expect("infallible");
run_test(seed, |_path| Panicable::Ok(())).expect("infallible");
}
}