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#![deny(clippy::unused_async)]
46//! <!-- @@ end lint list maintained by maint/add_warning @@ -->
47
48use std::time;
49use thiserror::Error;
50
51pub mod signed;
52pub mod timed;
53
54/// An error that can occur when checking whether a Timebound object is
55/// currently valid.
56#[derive(Debug, Clone, Error, PartialEq, Eq)]
57#[non_exhaustive]
58pub enum TimeValidityError {
59    /// The object is not yet valid
60    #[error("Object will not be valid for {}", humantime::format_duration(*.0))]
61    NotYetValid(time::Duration),
62    /// The object is expired
63    #[error("Object has been expired for {}", humantime::format_duration(*.0))]
64    Expired(time::Duration),
65    /// The object isn't timely, and we don't know why, or won't say.
66    #[error("Object is not currently valid")]
67    Unspecified,
68}
69
70/// A Timebound object is one that is only valid for a given range of time.
71///
72/// It's better to wrap things in a TimeBound than to give them an is_valid()
73/// valid method, so that you can make sure that nobody uses the object before
74/// checking it.
75pub trait Timebound<T>: Sized {
76    /// An error type that's returned when the object is _not_ timely.
77    type Error;
78
79    /// Check whether this object is valid at a given time.
80    ///
81    /// Return Ok if the object is valid, and an error if the object is not.
82    fn is_valid_at(&self, t: &time::SystemTime) -> Result<(), Self::Error>;
83
84    /// Return the underlying object without checking whether it's valid.
85    fn dangerously_assume_timely(self) -> T;
86
87    /// Unwrap this Timebound object if it is valid at a given time.
88    fn check_valid_at(self, t: &time::SystemTime) -> Result<T, Self::Error> {
89        self.is_valid_at(t)?;
90        Ok(self.dangerously_assume_timely())
91    }
92
93    /// Unwrap this Timebound object if it is valid now.
94    fn check_valid_now(self) -> Result<T, Self::Error> {
95        self.check_valid_at(&time::SystemTime::now())
96    }
97
98    /// Unwrap this object if it is valid at the provided time t.
99    /// If no time is provided, check the object at the current time.
100    fn check_valid_at_opt(self, t: Option<time::SystemTime>) -> Result<T, Self::Error> {
101        match t {
102            Some(when) => self.check_valid_at(&when),
103            None => self.check_valid_now(),
104        }
105    }
106}
107
108/// A cryptographically signed object that can be validated without
109/// additional public keys.
110///
111/// It's better to wrap things in a SelfSigned than to give them an is_valid()
112/// method, so that you can make sure that nobody uses the object before
113/// checking it.  It's better to wrap things in a SelfSigned than to check
114/// them immediately, since you might want to defer the signature checking
115/// operation to another thread.
116pub trait SelfSigned<T>: Sized {
117    /// An error type that's returned when the object is _not_ well-signed.
118    type Error;
119    /// Check the signature on this object
120    fn is_well_signed(&self) -> Result<(), Self::Error>;
121    /// Return the underlying object without checking its signature.
122    fn dangerously_assume_wellsigned(self) -> T;
123
124    /// Unwrap this object if the signature is valid
125    fn check_signature(self) -> Result<T, Self::Error> {
126        self.is_well_signed()?;
127        Ok(self.dangerously_assume_wellsigned())
128    }
129}
130
131/// A cryptographically signed object that needs an external public
132/// key to validate it.
133pub trait ExternallySigned<T>: Sized {
134    /// The type of the public key object.
135    ///
136    /// You can use a tuple or a vector here if the object is signed
137    /// with multiple keys.
138    type Key: ?Sized;
139
140    /// A type that describes what keys are missing for this object.
141    type KeyHint;
142
143    /// An error type that's returned when the object is _not_ well-signed.
144    type Error;
145
146    /// Check whether k is the right key for this object.  If not, return
147    /// an error describing what key would be right.
148    ///
149    /// This function is allowed to return 'true' for a bad key, but never
150    /// 'false' for a good key.
151    fn key_is_correct(&self, k: &Self::Key) -> Result<(), Self::KeyHint>;
152
153    /// Check the signature on this object
154    fn is_well_signed(&self, k: &Self::Key) -> Result<(), Self::Error>;
155
156    /// Unwrap this object without checking any signatures on it.
157    fn dangerously_assume_wellsigned(self) -> T;
158
159    /// Unwrap this object if it's correctly signed by a provided key.
160    fn check_signature(self, k: &Self::Key) -> Result<T, Self::Error> {
161        self.is_well_signed(k)?;
162        Ok(self.dangerously_assume_wellsigned())
163    }
164}
tor_checkable/lib.rs

tor_checkable/
lib.rs
