tor_checkable/
lib.rs

1#![cfg_attr(docsrs, feature(doc_cfg))]
2#![doc = include_str!("../README.md")]
3// @@ begin lint list maintained by maint/add_warning @@
4#![allow(renamed_and_removed_lints)] // @@REMOVE_WHEN(ci_arti_stable)
5#![allow(unknown_lints)] // @@REMOVE_WHEN(ci_arti_nightly)
6#![warn(missing_docs)]
7#![warn(noop_method_call)]
8#![warn(unreachable_pub)]
9#![warn(clippy::all)]
10#![deny(clippy::await_holding_lock)]
11#![deny(clippy::cargo_common_metadata)]
12#![deny(clippy::cast_lossless)]
13#![deny(clippy::checked_conversions)]
14#![warn(clippy::cognitive_complexity)]
15#![deny(clippy::debug_assert_with_mut_call)]
16#![deny(clippy::exhaustive_enums)]
17#![deny(clippy::exhaustive_structs)]
18#![deny(clippy::expl_impl_clone_on_copy)]
19#![deny(clippy::fallible_impl_from)]
20#![deny(clippy::implicit_clone)]
21#![deny(clippy::large_stack_arrays)]
22#![warn(clippy::manual_ok_or)]
23#![deny(clippy::missing_docs_in_private_items)]
24#![warn(clippy::needless_borrow)]
25#![warn(clippy::needless_pass_by_value)]
26#![warn(clippy::option_option)]
27#![deny(clippy::print_stderr)]
28#![deny(clippy::print_stdout)]
29#![warn(clippy::rc_buffer)]
30#![deny(clippy::ref_option_ref)]
31#![warn(clippy::semicolon_if_nothing_returned)]
32#![warn(clippy::trait_duplication_in_bounds)]
33#![deny(clippy::unchecked_time_subtraction)]
34#![deny(clippy::unnecessary_wraps)]
35#![warn(clippy::unseparated_literal_suffix)]
36#![deny(clippy::unwrap_used)]
37#![deny(clippy::mod_module_files)]
38#![allow(clippy::let_unit_value)] // This can reasonably be done for explicitness
39#![allow(clippy::uninlined_format_args)]
40#![allow(clippy::significant_drop_in_scrutinee)] // arti/-/merge_requests/588/#note_2812945
41#![allow(clippy::result_large_err)] // temporary workaround for arti#587
42#![allow(clippy::needless_raw_string_hashes)] // complained-about code is fine, often best
43#![allow(clippy::needless_lifetimes)] // See arti#1765
44#![allow(mismatched_lifetime_syntaxes)] // temporary workaround for arti#2060
45#![allow(clippy::collapsible_if)] // See arti#2342
46#![deny(clippy::unused_async)]
47//! <!-- @@ end lint list maintained by maint/add_warning @@ -->
48
49use std::time;
50use thiserror::Error;
51use web_time_compat::{SystemTime, SystemTimeExt};
52
53pub mod signed;
54pub mod timed;
55
56/// An error that can occur when checking whether a Timebound object is
57/// currently valid.
58#[derive(Debug, Clone, Error, PartialEq, Eq)]
59#[non_exhaustive]
60pub enum TimeValidityError {
61    /// The object is not yet valid
62    #[error("Object will not be valid for {}", humantime::format_duration(*.0))]
63    NotYetValid(time::Duration),
64    /// The object is expired
65    #[error("Object has been expired for {}", humantime::format_duration(*.0))]
66    Expired(time::Duration),
67    /// The object isn't timely, and we don't know why, or won't say.
68    #[error("Object is not currently valid")]
69    Unspecified,
70}
71
72/// A Timebound object is one that is only valid for a given range of time.
73///
74/// It's better to wrap things in a TimeBound than to give them an is_valid()
75/// valid method, so that you can make sure that nobody uses the object before
76/// checking it.
77pub trait Timebound<T>: Sized {
78    /// An error type that's returned when the object is _not_ timely.
79    type Error;
80
81    /// Check whether this object is valid at a given time.
82    ///
83    /// Return Ok if the object is valid, and an error if the object is not.
84    fn is_valid_at(&self, t: &time::SystemTime) -> Result<(), Self::Error>;
85
86    /// Return the underlying object without checking whether it's valid.
87    fn dangerously_assume_timely(self) -> T;
88
89    /// Unwrap this Timebound object if it is valid at a given time.
90    fn check_valid_at(self, t: &time::SystemTime) -> Result<T, Self::Error> {
91        self.is_valid_at(t)?;
92        Ok(self.dangerously_assume_timely())
93    }
94
95    /// Unwrap this Timebound object if it is valid now.
96    fn check_valid_now(self) -> Result<T, Self::Error> {
97        self.check_valid_at(&SystemTime::get())
98    }
99
100    /// Unwrap this object if it is valid at the provided time t.
101    /// If no time is provided, check the object at the current time.
102    fn check_valid_at_opt(self, t: Option<time::SystemTime>) -> Result<T, Self::Error> {
103        match t {
104            Some(when) => self.check_valid_at(&when),
105            None => self.check_valid_now(),
106        }
107    }
108}
109
110/// A cryptographically signed object that can be validated without
111/// additional public keys.
112///
113/// It's better to wrap things in a SelfSigned than to give them an is_valid()
114/// method, so that you can make sure that nobody uses the object before
115/// checking it.  It's better to wrap things in a SelfSigned than to check
116/// them immediately, since you might want to defer the signature checking
117/// operation to another thread.
118pub trait SelfSigned<T>: Sized {
119    /// An error type that's returned when the object is _not_ well-signed.
120    type Error;
121    /// Check the signature on this object
122    fn is_well_signed(&self) -> Result<(), Self::Error>;
123    /// Return the underlying object without checking its signature.
124    fn dangerously_assume_wellsigned(self) -> T;
125
126    /// Unwrap this object if the signature is valid
127    fn check_signature(self) -> Result<T, Self::Error> {
128        self.is_well_signed()?;
129        Ok(self.dangerously_assume_wellsigned())
130    }
131}
132
133/// A cryptographically signed object that needs an external public
134/// key to validate it.
135pub trait ExternallySigned<T>: Sized {
136    /// The type of the public key object.
137    ///
138    /// You can use a tuple or a vector here if the object is signed
139    /// with multiple keys.
140    type Key: ?Sized;
141
142    /// A type that describes what keys are missing for this object.
143    type KeyHint;
144
145    /// An error type that's returned when the object is _not_ well-signed.
146    type Error;
147
148    /// Check whether k is the right key for this object.  If not, return
149    /// an error describing what key would be right.
150    ///
151    /// This function is allowed to return 'true' for a bad key, but never
152    /// 'false' for a good key.
153    fn key_is_correct(&self, k: &Self::Key) -> Result<(), Self::KeyHint>;
154
155    /// Check the signature on this object
156    fn is_well_signed(&self, k: &Self::Key) -> Result<(), Self::Error>;
157
158    /// Unwrap this object without checking any signatures on it.
159    fn dangerously_assume_wellsigned(self) -> T;
160
161    /// Unwrap this object if it's correctly signed by a provided key.
162    fn check_signature(self, k: &Self::Key) -> Result<T, Self::Error> {
163        self.is_well_signed(k)?;
164        Ok(self.dangerously_assume_wellsigned())
165    }
166}
tor_checkable/lib.rs

tor_checkable/
lib.rs
