Files
neon/proxy/src/sasl.rs
Conrad Ludgate 96d89cde51 Proxy error reworking (#6453)
## Problem

Taking my ideas from https://github.com/neondatabase/neon/pull/6283 and
doing a bit less radical changes. smaller commits.

We currently don't report error classifications in proxy as the current
error handling made it hard to do so.

## Summary of changes

1. Add a `ReportableError` trait that all errors will implement. This
provides the error classification functionality.
2. Handle Client requests a strongly typed error
    * this error is a `ReportableError` and is logged appropriately
3. The handle client error only has a few possible error types, to
account for the fact that at this point errors should be returned to the
user.
2024-02-09 15:50:51 +00:00

86 lines
2.7 KiB
Rust

//! Simple Authentication and Security Layer.
//!
//! RFC: <https://datatracker.ietf.org/doc/html/rfc4422>.
//!
//! Reference implementation:
//! * <https://github.com/postgres/postgres/blob/94226d4506e66d6e7cbf4b391f1e7393c1962841/src/backend/libpq/auth-sasl.c>
//! * <https://github.com/postgres/postgres/blob/94226d4506e66d6e7cbf4b391f1e7393c1962841/src/interfaces/libpq/fe-auth.c>
mod channel_binding;
mod messages;
mod stream;
use crate::error::{ReportableError, UserFacingError};
use std::io;
use thiserror::Error;
pub use channel_binding::ChannelBinding;
pub use messages::FirstMessage;
pub use stream::{Outcome, SaslStream};
/// Fine-grained auth errors help in writing tests.
#[derive(Error, Debug)]
pub enum Error {
#[error("Channel binding failed: {0}")]
ChannelBindingFailed(&'static str),
#[error("Unsupported channel binding method: {0}")]
ChannelBindingBadMethod(Box<str>),
#[error("Bad client message: {0}")]
BadClientMessage(&'static str),
#[error("Internal error: missing digest")]
MissingBinding,
#[error(transparent)]
Io(#[from] io::Error),
}
impl UserFacingError for Error {
fn to_string_client(&self) -> String {
use Error::*;
match self {
ChannelBindingFailed(m) => m.to_string(),
ChannelBindingBadMethod(m) => format!("unsupported channel binding method {m}"),
_ => "authentication protocol violation".to_string(),
}
}
}
impl ReportableError for Error {
fn get_error_kind(&self) -> crate::error::ErrorKind {
match self {
Error::ChannelBindingFailed(_) => crate::error::ErrorKind::User,
Error::ChannelBindingBadMethod(_) => crate::error::ErrorKind::User,
Error::BadClientMessage(_) => crate::error::ErrorKind::User,
Error::MissingBinding => crate::error::ErrorKind::Service,
Error::Io(_) => crate::error::ErrorKind::ClientDisconnect,
}
}
}
/// A convenient result type for SASL exchange.
pub type Result<T> = std::result::Result<T, Error>;
/// A result of one SASL exchange.
#[must_use]
pub enum Step<T, R> {
/// We should continue exchanging messages.
Continue(T, String),
/// The client has been authenticated successfully.
Success(R, String),
/// Authentication failed (reason attached).
Failure(&'static str),
}
/// Every SASL mechanism (e.g. [SCRAM](crate::scram)) is expected to implement this trait.
pub trait Mechanism: Sized {
/// What's produced as a result of successful authentication.
type Output;
/// Produce a server challenge to be sent to the client.
/// This is how this method is called in PostgreSQL (`libpq/sasl.h`).
fn exchange(self, input: &str) -> Result<Step<Self, Self::Output>>;
}