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// Copyright (c) 2019-2026 Provable Inc.
// This file is part of the snarkVM library.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at:
// http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
use super::*;
impl<A: Aleo> StatePath<A> {
/// Returns `true` if the state path is valid.
///
/// # Parameters
/// - `local_state_root` is the local transaction root for the current execution.
/// - `is_global` is a boolean indicating whether this is a global or local state root.
///
/// # Diagram
/// The `[[ ]]` notation is used to denote public inputs.
/// ```ignore
///
/// [[ global_state_root ]]
/// |
/// block_path
/// |
/// block_hash := Hash( previous_block_hash || header_root )
/// |
/// header_path
/// |
/// header_leaf
/// |
/// transactions_path [[ local_state_root ]]
/// | |
/// (true) ------ is_global ------ (false)
/// |
/// transaction_id
/// |
/// transaction_path
/// |
/// transaction_leaf
/// |
/// transition_id := Hash( transition_root || tcm )
/// |
/// transition_path
/// |
/// transition_leaf
/// ```
pub fn verify(&self, is_global: &Boolean<A>, local_state_root: &Field<A>) -> Boolean<A> {
// Ensure the transition path is valid.
let check_transition_path =
A::verify_merkle_path_bhp(&self.transition_path, &self.transition_root, &self.transition_leaf.to_bits_le())
& self.transition_leaf.variant().is_equal(&U8::constant(console::U8::new(3))); // Variant = 3 (Input::Record)
// Ensure the transaction leaf is valid.
let check_transaction_leaf =
A::hash_bhp512(&(&self.transition_root, &self.tcm).to_bits_le()).is_equal(self.transaction_leaf.id());
// Ensure the transaction path is valid.
let check_transaction_path = A::verify_merkle_path_bhp(
&self.transaction_path,
&self.transaction_id,
&self.transaction_leaf.to_bits_le(),
) & self.transaction_leaf.variant().is_equal(&U8::one()); // Variant = 1 (Transaction::Execution)
// Ensure the transactions path is valid.
let check_transactions_path = A::verify_merkle_path_bhp(
&self.transactions_path,
self.header_leaf.id(),
&self.transaction_id.to_bits_le(),
);
// Ensure the header path is valid.
let check_header_path =
A::verify_merkle_path_bhp(&self.header_path, &self.header_root, &self.header_leaf.to_bits_le())
& self.header_leaf.index().is_equal(&U8::one()); // Index = 1 (Header::transactions_root)
// Construct the block hash preimage.
let mut block_hash_preimage = self.previous_block_hash.to_bits_le();
self.header_root.write_bits_le(&mut block_hash_preimage);
// Ensure the block path is valid.
let check_block_hash = A::hash_bhp1024(&block_hash_preimage).is_equal(&self.block_hash);
// Ensure the global state root is correct.
let check_state_root =
A::verify_merkle_path_bhp(&self.block_path, &self.global_state_root, &self.block_hash.to_bits_le());
// Combine the transition and transaction path checks.
let check_transition_and_transaction_path =
check_transition_path & check_transaction_path & check_transaction_leaf;
// Check the state path.
let check_local = &check_transition_and_transaction_path & local_state_root.is_equal(&self.transaction_id);
let check_global = check_transition_and_transaction_path
& check_transactions_path
& check_header_path
& check_block_hash
& check_state_root;
// If the state path is for a global root, return 'check_global'. Else, return 'check_local'.
Boolean::ternary(is_global, &check_global, &check_local)
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::Circuit;
use snarkvm_utilities::rand::{TestRng, Uniform};
type CurrentNetwork = <Circuit as Environment>::Network;
const ITERATIONS: usize = 10;
fn check_verify_global(
mode: Mode,
is_global: bool,
num_constants: u64,
num_public: u64,
num_private: u64,
num_constraints: u64,
) -> Result<()> {
let rng = &mut TestRng::default();
for i in 0..ITERATIONS {
// Sample the console state path.
let console_state_path =
console::state_path::test_helpers::sample_global_state_path::<CurrentNetwork>(None, rng).unwrap();
// Sample the local state root.
let local_state_root = console::Field::rand(rng);
// Ensure the console state path is valid.
console_state_path.verify(true, local_state_root).unwrap();
Circuit::scope(format!("Verify global state path {mode} (is_global: {is_global})"), || {
// Inject the is_global boolean.
let circuit_is_global = Boolean::new(mode, is_global);
// Inject the local state root.
let circuit_local_state_root = Field::new(mode, local_state_root);
// Inject the state path.
let circuit_state_path = StatePath::<Circuit>::new(mode, console_state_path.clone());
// Ensure the state path is valid.
let is_valid = circuit_state_path.verify(&circuit_is_global, &circuit_local_state_root);
match is_global {
true => assert!(is_valid.eject_value()),
false => assert!(!is_valid.eject_value()),
}
assert!(Circuit::is_satisfied());
// TODO (howardwu): Resolve skipping the cost count checks for the burn-in round.
if i > 0 {
assert_scope!(num_constants, num_public, num_private, num_constraints);
}
});
Circuit::reset();
}
Ok(())
}
fn check_verify_local(
mode: Mode,
is_global: bool,
is_valid_local_root: bool,
num_constants: u64,
num_public: u64,
num_private: u64,
num_constraints: u64,
) -> Result<()> {
let rng = &mut TestRng::default();
for i in 0..ITERATIONS {
// Sample the console state path.
let console_state_path =
console::state_path::test_helpers::sample_local_state_path::<CurrentNetwork>(None, rng).unwrap();
// Sample the local state root.
let local_state_root = **console_state_path.transaction_id();
// Ensure the console state path is valid.
console_state_path.verify(false, local_state_root).unwrap();
Circuit::scope(
format!(
"Verify local state path {mode} (is_global: {is_global}, is_valid_local_root: {is_valid_local_root})"
),
|| {
// Inject the is_global boolean.
let circuit_is_global = Boolean::new(mode, is_global);
// Inject the local state root.
let circuit_local_state_root = if is_valid_local_root {
Field::new(mode, local_state_root)
} else {
Field::new(mode, console::Field::rand(rng))
};
// Inject the state path.
let circuit_state_path = StatePath::<Circuit>::new(mode, console_state_path.clone());
// Ensure the state path is valid.
let is_valid = circuit_state_path.verify(&circuit_is_global, &circuit_local_state_root);
match (is_global, is_valid_local_root) {
(false, true) => assert!(is_valid.eject_value()),
_ => assert!(!is_valid.eject_value()),
}
assert!(Circuit::is_satisfied());
// TODO (howardwu): Resolve skipping the cost count checks for the burn-in round.
if i > 0 {
assert_scope!(num_constants, num_public, num_private, num_constraints);
}
},
);
Circuit::reset();
}
Ok(())
}
#[test]
fn test_state_path_verify_global_constant() -> Result<()> {
check_verify_global(Mode::Constant, true, 112709, 1, 2, 2)?;
check_verify_global(Mode::Constant, false, 112709, 1, 2, 2)
}
#[test]
fn test_state_path_verify_global_public() -> Result<()> {
check_verify_global(Mode::Public, true, 29450, 453, 130867, 131522)?;
check_verify_global(Mode::Public, false, 29450, 453, 130867, 131522)
}
#[test]
fn test_state_path_verify_global_private() -> Result<()> {
check_verify_global(Mode::Private, true, 29450, 1, 131319, 131522)?;
check_verify_global(Mode::Private, false, 29450, 1, 131319, 131522)
}
#[test]
fn test_state_path_verify_local_constant() -> Result<()> {
check_verify_local(Mode::Constant, false, true, 112709, 1, 2, 2)?;
check_verify_local(Mode::Constant, false, false, 112709, 1, 2, 2)?;
check_verify_local(Mode::Constant, true, true, 112709, 1, 2, 2)?;
check_verify_local(Mode::Constant, true, false, 112709, 1, 2, 2)
}
#[test]
fn test_state_path_verify_local_public() -> Result<()> {
check_verify_local(Mode::Public, false, true, 29450, 453, 130867, 131522)?;
check_verify_local(Mode::Public, false, false, 29450, 453, 130867, 131522)?;
check_verify_local(Mode::Public, true, true, 29450, 453, 130867, 131522)?;
check_verify_local(Mode::Public, true, false, 29450, 453, 130867, 131522)
}
#[test]
fn test_state_path_verify_local_private() -> Result<()> {
check_verify_local(Mode::Private, false, true, 29450, 1, 131319, 131522)?;
check_verify_local(Mode::Private, false, false, 29450, 1, 131319, 131522)?;
check_verify_local(Mode::Private, true, true, 29450, 1, 131319, 131522)?;
check_verify_local(Mode::Private, true, false, 29450, 1, 131319, 131522)
}
}