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snarkvm_synthesizer_process/trace/inclusion/
assignment.rs

1// Copyright (c) 2019-2025 Provable Inc.
2// This file is part of the snarkVM library.
3
4// Licensed under the Apache License, Version 2.0 (the "License");
5// you may not use this file except in compliance with the License.
6// You may obtain a copy of the License at:
7
8// http://www.apache.org/licenses/LICENSE-2.0
9
10// Unless required by applicable law or agreed to in writing, software
11// distributed under the License is distributed on an "AS IS" BASIS,
12// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13// See the License for the specific language governing permissions and
14// limitations under the License.
15
16use super::*;
17
18#[derive(Clone, Debug)]
19pub struct InclusionAssignment<N: Network> {
20    pub(crate) state_path: StatePath<N>,
21    commitment: Field<N>,
22    gamma: Group<N>,
23    serial_number: Field<N>,
24    is_record_block_height_reached: bool,
25    upgrade_block_height: u32,
26    local_state_root: N::TransactionID,
27    is_global: bool,
28}
29
30impl<N: Network> InclusionAssignment<N> {
31    /// Initializes a new inclusion assignment.
32    pub fn new(
33        state_path: StatePath<N>,
34        commitment: Field<N>,
35        gamma: Group<N>,
36        serial_number: Field<N>,
37        is_record_block_height_reached: bool,
38        upgrade_block_height: u32,
39        local_state_root: N::TransactionID,
40        is_global: bool,
41    ) -> Self {
42        Self {
43            state_path,
44            commitment,
45            gamma,
46            serial_number,
47            is_record_block_height_reached,
48            upgrade_block_height,
49            local_state_root,
50            is_global,
51        }
52    }
53
54    /// The circuit for state path verification.
55    ///
56    /// # Diagram
57    /// The `[[ ]]` notation is used to denote public inputs.
58    /// ```ignore
59    ///             [[ global_state_root ]] || [[ local_state_root ]] [[ is_record_block_height_reached ]]
60    ///                        |                          |                            |
61    ///                        -------- is_global --------                             |
62    ///                                     |                                          |
63    ///                                state_path ------- record_block_height ------ compare ------ [[ upgrade_block_height ]]
64    ///                                    |                                           |
65    ///                                    |                                           |
66    ///                                    |                        is_global ------ check
67    ///                                    |
68    /// [[ serial_number ]] := Commit( commitment || Hash( COFACTOR * gamma ) )
69    /// ```
70    pub fn to_circuit_assignment<A: circuit::Aleo<Network = N>>(&self) -> Result<circuit::Assignment<N::Field>> {
71        use circuit::Inject;
72
73        // Ensure the circuit environment is clean.
74        assert_eq!(A::count(), (0, 1, 0, 0, (0, 0, 0)));
75        A::reset();
76
77        // Inject the state path as `Mode::Private` (with a global state root as `Mode::Public`).
78        let state_path = circuit::StatePath::<A>::new(circuit::Mode::Private, self.state_path.clone());
79        // Inject the commitment as `Mode::Private`.
80        let commitment = circuit::Field::<A>::new(circuit::Mode::Private, self.commitment);
81        // Inject the gamma as `Mode::Private`.
82        let gamma = circuit::Group::<A>::new(circuit::Mode::Private, self.gamma);
83
84        // Inject the local state root as `Mode::Public`.
85        let local_state_root = circuit::Field::<A>::new(circuit::Mode::Public, *self.local_state_root);
86        // Inject the 'is_global' flag as `Mode::Private`.
87        let is_global = circuit::Boolean::<A>::new(circuit::Mode::Private, self.is_global);
88
89        // Inject the serial number as `Mode::Public`.
90        let serial_number = circuit::Field::<A>::new(circuit::Mode::Public, self.serial_number);
91
92        // Inject the `is_record_block_height_reached` flag as `Mode::Public`.
93        let is_record_block_height_reached =
94            circuit::Boolean::<A>::new(circuit::Mode::Public, self.is_record_block_height_reached);
95        // Inject the `upgrade_block_height` as `Mode::Public`.
96        // This is cast into a u32 to prevent requiring 32 field elements as input.
97        let upgrade_block_height_field = circuit::Field::<A>::new(
98            circuit::Mode::Public,
99            console::types::Field::<N>::from_u32(self.upgrade_block_height),
100        );
101        let upgrade_block_height = circuit::U32::from_field(upgrade_block_height_field);
102
103        // Compute the candidate serial number.
104        let candidate_serial_number =
105            circuit::Record::<A, circuit::Plaintext<A>>::serial_number_from_gamma(&gamma, commitment.clone());
106        // Enforce that the candidate serial number is equal to the serial number.
107        A::assert_eq(candidate_serial_number, serial_number);
108
109        // Enforce the starting leaf is the claimed commitment.
110        A::assert_eq(state_path.transition_leaf().id(), commitment);
111        // Enforce the state path from leaf to root is correct.
112        A::assert(state_path.verify(&is_global, &local_state_root));
113
114        // Fetch the record block height from the state path.
115        let record_block_height = U32::<A>::from_bits_le(&state_path.block_path().leaf_index().to_bits_le());
116        // Determine if the record block height is at or past the upgrade height.
117        let is_record_block_height_past_upgrade_block_height =
118            record_block_height.is_greater_than_or_equal(&upgrade_block_height);
119        // Determine if the record block height is correctly evaluated.
120        let is_block_height_check_valid =
121            is_record_block_height_reached.is_equal(&is_record_block_height_past_upgrade_block_height);
122        // Check that the height is valid if the record is from a global state path.
123        A::assert(is_global.not().bitor(is_block_height_check_valid));
124
125        Stack::log_circuit::<A>(format_args!("State Path for {}", self.serial_number));
126
127        // Eject the assignment and reset the circuit environment.
128        Ok(A::eject_assignment_and_reset())
129    }
130}