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

            
49
mod bucket_array;
50
mod collision;
51
mod err;
52
mod solution;
53
mod solver;
54

            
55
// Export bucket_array::mem API only to the fuzzer.
56
// (This is not stable; you should not use it except for testing.)
57
#[cfg(feature = "bucket-array")]
58
pub use bucket_array::mem::{BucketArray, BucketArrayMemory, BucketArrayPair, Count, Uninit};
59

            
60
use hashx::{HashX, HashXBuilder};
61

            
62
pub use hashx::{Runtime, RuntimeOption};
63

            
64
pub use err::{Error, HashError};
65
pub use solution::{Solution, SolutionArray, SolutionByteArray, SolutionItem, SolutionItemArray};
66
pub use solver::SolverMemory;
67

            
68
/// One Equi-X instance, customized for a challenge string
69
///
70
/// This includes pre-computed state that depends on the
71
/// puzzle's challenge as well as any options set via [`EquiXBuilder`].
72
#[derive(Debug)]
73
pub struct EquiX {
74
    /// HashX instance generated for this puzzle's challenge string
75
    hash: HashX,
76
}
77

            
78
impl EquiX {
79
    /// Make a new [`EquiX`] instance with a challenge string and
80
    /// default options.
81
    ///
82
    /// It's normal for this to fail with a [`HashError::ProgramConstraints`]
83
    /// for a small fraction of challenge values. Those challenges must be
84
    /// skipped by solvers and rejected by verifiers.
85
1215
    pub fn new(challenge: &[u8]) -> Result<Self, Error> {
86
1215
        EquiXBuilder::new().build(challenge)
87
1215
    }
88

            
89
    /// Check which actual program runtime is in effect.
90
    ///
91
    /// By default we try to generate machine code at runtime to accelerate the
92
    /// hash function, but we fall back to an interpreter if this fails. The
93
    /// compiler can be disabled entirely using [`RuntimeOption::InterpretOnly`]
94
    /// and [`EquiXBuilder`].
95
    pub fn runtime(&self) -> Runtime {
96
        self.hash.runtime()
97
    }
98

            
99
    /// Check a [`Solution`] against this particular challenge.
100
    ///
101
    /// Having a [`Solution`] instance guarantees that the order of items
102
    /// has already been checked. This only needs to check hash tree sums.
103
    /// Returns either `Ok` or [`Error::HashSum`].
104
10314
    pub fn verify(&self, solution: &Solution) -> Result<(), Error> {
105
10314
        solution::check_all_tree_sums(&self.hash, solution)
106
10314
    }
107

            
108
    /// Search for solutions using this particular challenge.
109
    ///
110
    /// Returns a buffer with a variable number of solutions.
111
    /// Memory for the solver is allocated dynamically and not reused.
112
864
    pub fn solve(&self) -> SolutionArray {
113
864
        let mut mem = SolverMemory::new();
114
864
        self.solve_with_memory(&mut mem)
115
864
    }
116

            
117
    /// Search for solutions, using the provided [`SolverMemory`].
118
    ///
119
    /// Returns a buffer with a variable number of solutions.
120
    ///
121
    /// Allows reuse of solver memory. Preferred for callers which may perform
122
    /// several solve operations in rapid succession, such as in the common case
123
    /// of layering an effort adjustment protocol above Equi-X.
124
2025
    pub fn solve_with_memory(&self, mem: &mut SolverMemory) -> SolutionArray {
125
2025
        let mut result = Default::default();
126
2025
        solver::find_solutions(&self.hash, mem, &mut result);
127
2025
        result
128
2025
    }
129
}
130

            
131
/// Builder for creating [`EquiX`] instances with custom settings
132
#[derive(Debug, Clone, Eq, PartialEq)]
133
pub struct EquiXBuilder {
134
    /// Inner [`HashXBuilder`] for options related to our hash function
135
    hash: HashXBuilder,
136
}
137

            
138
impl EquiXBuilder {
139
    /// Create a new [`EquiXBuilder`] with default settings.
140
    ///
141
    /// Immediately calling [`Self::build()`] would be equivalent to using
142
    /// [`EquiX::new()`].
143
2619
    pub fn new() -> Self {
144
2619
        Self {
145
2619
            hash: HashXBuilder::new(),
146
2619
        }
147
2619
    }
148

            
149
    /// Select a new [`RuntimeOption`].
150
    pub fn runtime(&mut self, runtime: RuntimeOption) -> &mut Self {
151
        self.hash.runtime(runtime);
152
        self
153
    }
154

            
155
    /// Build an [`EquiX`] instance with a challenge string and the
156
    /// selected options.
157
    ///
158
    /// It's normal for this to fail with a [`HashError::ProgramConstraints`]
159
    /// for a small fraction of challenge values. Those challenges must be
160
    /// skipped by solvers and rejected by verifiers.
161
3024
    pub fn build(&self, challenge: &[u8]) -> Result<EquiX, Error> {
162
3024
        match self.hash.build(challenge) {
163
162
            Err(e) => Err(Error::Hash(e)),
164
2862
            Ok(hash) => Ok(EquiX { hash }),
165
        }
166
3024
    }
167

            
168
    /// Search for solutions to a particular challenge.
169
    ///
170
    /// Each solve invocation returns zero or more solutions.
171
    /// Memory for the solver is allocated dynamically and not reused.
172
    ///
173
    /// It's normal for this to fail with a [`HashError::ProgramConstraints`]
174
    /// for a small fraction of challenge values. Those challenges must be
175
    /// skipped by solvers and rejected by verifiers.
176
    pub fn solve(&self, challenge: &[u8]) -> Result<SolutionArray, Error> {
177
        Ok(self.build(challenge)?.solve())
178
    }
179

            
180
    /// Check a [`Solution`] against a particular challenge string.
181
    ///
182
    /// Having a [`Solution`] instance guarantees that the order of items
183
    /// has already been checked. This only needs to check hash tree sums.
184
    /// Returns either `Ok` or [`Error::HashSum`].
185
648
    pub fn verify(&self, challenge: &[u8], solution: &Solution) -> Result<(), Error> {
186
648
        self.build(challenge)?.verify(solution)
187
648
    }
188

            
189
    /// Check a [`SolutionItemArray`].
190
    ///
191
    /// Returns an error if the array is not a well formed [`Solution`] or it's
192
    /// not suitable for the given challenge.
193
    pub fn verify_array(&self, challenge: &[u8], array: &SolutionItemArray) -> Result<(), Error> {
194
        // Check Solution validity before we even construct the instance
195
        self.verify(challenge, &Solution::try_from_array(array)?)
196
    }
197

            
198
    /// Check a [`SolutionByteArray`].
199
    ///
200
    /// Returns an error if the array is not a well formed [`Solution`] or it's
201
    /// not suitable for the given challenge.
202
    pub fn verify_bytes(&self, challenge: &[u8], array: &SolutionByteArray) -> Result<(), Error> {
203
        self.verify(challenge, &Solution::try_from_bytes(array)?)
204
    }
205
}
206

            
207
impl Default for EquiXBuilder {
208
1404
    fn default() -> Self {
209
1404
        Self::new()
210
1404
    }
211
}
212

            
213
/// Search for solutions, using default [`EquiXBuilder`] options.
214
///
215
/// Each solve invocation returns zero or more solutions.
216
/// Memory for the solver is allocated dynamically and not reused.
217
///
218
/// It's normal for this to fail with a [`HashError::ProgramConstraints`] for
219
/// a small fraction of challenge values. Those challenges must be skipped
220
/// by solvers and rejected by verifiers.
221
pub fn solve(challenge: &[u8]) -> Result<SolutionArray, Error> {
222
    Ok(EquiX::new(challenge)?.solve())
223
}
224

            
225
/// Check a [`Solution`] against a particular challenge.
226
///
227
/// Having a [`Solution`] instance guarantees that the order of items
228
/// has already been checked. This only needs to check hash tree sums.
229
/// Returns either `Ok` or [`Error::HashSum`].
230
///
231
/// Uses default [`EquiXBuilder`] options.
232
81
pub fn verify(challenge: &[u8], solution: &Solution) -> Result<(), Error> {
233
81
    EquiX::new(challenge)?.verify(solution)
234
81
}
235

            
236
/// Check a [`SolutionItemArray`].
237
///
238
/// Returns an error if the array is not a well formed [`Solution`] or it's
239
/// not suitable for the given challenge.
240
///
241
/// Uses default [`EquiXBuilder`] options.
242
108
pub fn verify_array(challenge: &[u8], array: &SolutionItemArray) -> Result<(), Error> {
243
    // Check Solution validity before we even construct the instance
244
108
    verify(challenge, &Solution::try_from_array(array)?)
245
108
}
246

            
247
/// Check a [`SolutionByteArray`].
248
///
249
/// Returns an error if the array is not a well formed [`Solution`] or it's
250
/// not suitable for the given challenge.
251
///
252
/// Uses default [`EquiXBuilder`] options.
253
pub fn verify_bytes(challenge: &[u8], array: &SolutionByteArray) -> Result<(), Error> {
254
    // Check Solution validity before we even construct the instance
255
    verify(challenge, &Solution::try_from_bytes(array)?)
256
}