miden_tx/verifier/
mod.rs

1use miden_lib::transaction::TransactionKernel;
2use miden_objects::{transaction::ProvenTransaction, vm::ProgramInfo};
3use miden_verifier::verify;
4
5use super::TransactionVerifierError;
6
7// TRANSACTION VERIFIER
8// ================================================================================================
9
10/// The [TransactionVerifier] is used to verify  [ProvenTransaction]s.
11///
12/// The [TransactionVerifier] contains a [ProgramInfo] object which is associated with the
13/// transaction kernel program.  The `proof_security_level` specifies the minimum security
14/// level that the transaction proof must have in order to be considered valid.
15pub struct TransactionVerifier {
16    tx_program_info: ProgramInfo,
17    proof_security_level: u32,
18}
19
20impl TransactionVerifier {
21    /// Returns a new [TransactionVerifier] instantiated with the specified security level.
22    pub fn new(proof_security_level: u32) -> Self {
23        let tx_program_info = TransactionKernel::program_info();
24        Self { tx_program_info, proof_security_level }
25    }
26
27    /// Verifies the provided [ProvenTransaction] against the transaction kernel.
28    ///
29    /// # Errors
30    /// Returns an error if:
31    /// - Transaction verification fails.
32    /// - The security level of the verified proof is insufficient.
33    pub fn verify(&self, transaction: &ProvenTransaction) -> Result<(), TransactionVerifierError> {
34        // build stack inputs and outputs
35        let stack_inputs = TransactionKernel::build_input_stack(
36            transaction.account_id(),
37            transaction.account_update().initial_state_commitment(),
38            transaction.input_notes().commitment(),
39            transaction.ref_block_commitment(),
40            transaction.ref_block_num(),
41        );
42        let stack_outputs = TransactionKernel::build_output_stack(
43            transaction.account_update().final_state_commitment(),
44            transaction.output_notes().commitment(),
45            transaction.expiration_block_num(),
46        );
47
48        // verify transaction proof
49        let proof_security_level = verify(
50            self.tx_program_info.clone(),
51            stack_inputs,
52            stack_outputs,
53            transaction.proof().clone(),
54        )
55        .map_err(TransactionVerifierError::TransactionVerificationFailed)?;
56
57        // check security level
58        if proof_security_level < self.proof_security_level {
59            return Err(TransactionVerifierError::InsufficientProofSecurityLevel {
60                actual: proof_security_level,
61                expected_minimum: self.proof_security_level,
62            });
63        }
64
65        Ok(())
66    }
67}