tor_checkable/
lib.rs

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

tor_checkable/
lib.rs
