refactor(privacy_preserving_circuit): extract output module

Refs: #454
This commit is contained in:
moudyellaz 2026-05-07 16:54:57 +02:00
parent ce3229f74f
commit bda50f1d2f
2 changed files with 301 additions and 279 deletions

View File

@ -4,11 +4,8 @@ use std::{
};
use nssa_core::{
Commitment, CommitmentSetDigest, DUMMY_COMMITMENT_HASH, EncryptionScheme, Identifier,
InputAccountIdentity, MembershipProof, Nullifier, NullifierPublicKey, NullifierSecretKey,
PrivacyPreservingCircuitInput, PrivacyPreservingCircuitOutput, SharedSecretKey,
account::{Account, AccountId, AccountWithMetadata, Nonce},
compute_digest_for_path,
InputAccountIdentity, NullifierPublicKey, PrivacyPreservingCircuitInput,
account::{Account, AccountId, AccountWithMetadata},
program::{
AccountPostState, BlockValidityWindow, ChainedCall, Claim, DEFAULT_PROGRAM_ID,
MAX_NUMBER_CHAINED_CALLS, PdaSeed, ProgramId, ProgramOutput, TimestampValidityWindow,
@ -17,7 +14,7 @@ use nssa_core::{
};
use risc0_zkvm::{guest::env, serde::to_vec};
const PRIVATE_PDA_FIXED_IDENTIFIER: Identifier = u128::MAX;
mod output;
/// State of the involved accounts before and after program execution.
struct ExecutionState {
@ -386,17 +383,26 @@ impl ExecutionState {
}
}
/// Get an iterator over pre and post states of each account involved in the execution.
pub fn into_states_iter(
/// Consume self and yield the validity windows alongside an iterator over pre and post
/// states of each account involved in the execution. Returning the windows here keeps the
/// fields module-private rather than forcing them visible to downstream consumers.
pub fn into_parts(
mut self,
) -> impl ExactSizeIterator<Item = (AccountWithMetadata, Account)> {
self.pre_states.into_iter().map(move |pre| {
) -> (
BlockValidityWindow,
TimestampValidityWindow,
impl ExactSizeIterator<Item = (AccountWithMetadata, Account)>,
) {
let block_validity_window = self.block_validity_window;
let timestamp_validity_window = self.timestamp_validity_window;
let states_iter = self.pre_states.into_iter().map(move |pre| {
let post = self
.post_states
.remove(&pre.account_id)
.expect("Account from pre states should exist in state diff");
(pre, post)
})
});
(block_validity_window, timestamp_validity_window, states_iter)
}
}
@ -476,273 +482,6 @@ fn resolve_authorization_and_record_bindings(
previous_is_authorized || matched_caller_seed.is_some()
}
fn compute_circuit_output(
execution_state: ExecutionState,
account_identities: &[InputAccountIdentity],
) -> PrivacyPreservingCircuitOutput {
let mut output = PrivacyPreservingCircuitOutput {
public_pre_states: Vec::new(),
public_post_states: Vec::new(),
ciphertexts: Vec::new(),
new_commitments: Vec::new(),
new_nullifiers: Vec::new(),
block_validity_window: execution_state.block_validity_window,
timestamp_validity_window: execution_state.timestamp_validity_window,
};
let states_iter = execution_state.into_states_iter();
assert_eq!(
account_identities.len(),
states_iter.len(),
"Invalid account_identities length"
);
let mut output_index = 0;
for (account_identity, (pre_state, post_state)) in account_identities.iter().zip(states_iter) {
match account_identity {
InputAccountIdentity::Public => {
output.public_pre_states.push(pre_state);
output.public_post_states.push(post_state);
}
InputAccountIdentity::PrivateAuthorizedInit {
ssk,
nsk,
identifier,
} => {
assert_ne!(
*identifier, PRIVATE_PDA_FIXED_IDENTIFIER,
"Identifier must be different from {PRIVATE_PDA_FIXED_IDENTIFIER}. This is reserved for private PDA."
);
let npk = NullifierPublicKey::from(nsk);
let account_id = AccountId::from((&npk, *identifier));
assert_eq!(account_id, pre_state.account_id, "AccountId mismatch");
assert!(
pre_state.is_authorized,
"Pre-state not authorized for authenticated private account"
);
assert_eq!(
pre_state.account,
Account::default(),
"Found new private account with non default values"
);
let new_nullifier = (
Nullifier::for_account_initialization(&account_id),
DUMMY_COMMITMENT_HASH,
);
let new_nonce = pre_state.account.nonce.private_account_nonce_increment(nsk);
emit_private_output(
&mut output,
&mut output_index,
post_state,
&account_id,
*identifier,
ssk,
new_nullifier,
new_nonce,
);
}
InputAccountIdentity::PrivateAuthorizedUpdate {
ssk,
nsk,
membership_proof,
identifier,
} => {
assert_ne!(
*identifier, PRIVATE_PDA_FIXED_IDENTIFIER,
"Identifier must be different from {PRIVATE_PDA_FIXED_IDENTIFIER}. This is reserved for private PDA."
);
let npk = NullifierPublicKey::from(nsk);
let account_id = AccountId::from((&npk, *identifier));
assert_eq!(account_id, pre_state.account_id, "AccountId mismatch");
assert!(
pre_state.is_authorized,
"Pre-state not authorized for authenticated private account"
);
let new_nullifier = compute_update_nullifier_and_set_digest(
membership_proof,
&pre_state.account,
&account_id,
nsk,
);
let new_nonce = pre_state.account.nonce.private_account_nonce_increment(nsk);
emit_private_output(
&mut output,
&mut output_index,
post_state,
&account_id,
*identifier,
ssk,
new_nullifier,
new_nonce,
);
}
InputAccountIdentity::PrivateUnauthorized {
npk,
ssk,
identifier,
} => {
assert_ne!(
*identifier, PRIVATE_PDA_FIXED_IDENTIFIER,
"Identifier must be different from {PRIVATE_PDA_FIXED_IDENTIFIER}. This is reserved for private PDA."
);
let account_id = AccountId::from((npk, *identifier));
assert_eq!(account_id, pre_state.account_id, "AccountId mismatch");
assert_eq!(
pre_state.account,
Account::default(),
"Found new private account with non default values",
);
assert!(
!pre_state.is_authorized,
"Found new private account marked as authorized."
);
let new_nullifier = (
Nullifier::for_account_initialization(&account_id),
DUMMY_COMMITMENT_HASH,
);
let new_nonce = Nonce::private_account_nonce_init(&account_id);
emit_private_output(
&mut output,
&mut output_index,
post_state,
&account_id,
*identifier,
ssk,
new_nullifier,
new_nonce,
);
}
InputAccountIdentity::PrivatePdaInit { npk: _, ssk } => {
// The npk-to-account_id binding is established upstream in
// `validate_and_sync_states` via `Claim::Pda(seed)` or a caller `pda_seeds`
// match. Here we only enforce the init pre-conditions. The supplied npk on
// the variant has been recorded into `private_pda_npk_by_position` and used
// for the binding check; we use `pre_state.account_id` directly for nullifier
// and commitment derivation.
assert!(
!pre_state.is_authorized,
"PrivatePdaInit requires unauthorized pre_state"
);
assert_eq!(
pre_state.account,
Account::default(),
"New private PDA must be default"
);
let new_nullifier = (
Nullifier::for_account_initialization(&pre_state.account_id),
DUMMY_COMMITMENT_HASH,
);
let new_nonce = Nonce::private_account_nonce_init(&pre_state.account_id);
let account_id = pre_state.account_id;
emit_private_output(
&mut output,
&mut output_index,
post_state,
&account_id,
PRIVATE_PDA_FIXED_IDENTIFIER,
ssk,
new_nullifier,
new_nonce,
);
}
InputAccountIdentity::PrivatePdaUpdate {
ssk,
nsk,
membership_proof,
} => {
// The npk binding is established upstream. Authorization must already be set;
// an unauthorized PrivatePdaUpdate would mean the prover supplied an nsk for an
// unbound PDA, which the upstream binding check would have rejected anyway,
// but we assert here to fail fast and document the precondition.
assert!(
pre_state.is_authorized,
"PrivatePdaUpdate requires authorized pre_state"
);
let new_nullifier = compute_update_nullifier_and_set_digest(
membership_proof,
&pre_state.account,
&pre_state.account_id,
nsk,
);
let new_nonce = pre_state.account.nonce.private_account_nonce_increment(nsk);
let account_id = pre_state.account_id;
emit_private_output(
&mut output,
&mut output_index,
post_state,
&account_id,
PRIVATE_PDA_FIXED_IDENTIFIER,
ssk,
new_nullifier,
new_nonce,
);
}
}
}
output
}
#[expect(
clippy::too_many_arguments,
reason = "All seven inputs are distinct concerns from the variant arms; bundling would be artificial"
)]
fn emit_private_output(
output: &mut PrivacyPreservingCircuitOutput,
output_index: &mut u32,
post_state: Account,
account_id: &AccountId,
identifier: Identifier,
shared_secret: &SharedSecretKey,
new_nullifier: (Nullifier, CommitmentSetDigest),
new_nonce: Nonce,
) {
output.new_nullifiers.push(new_nullifier);
let mut post_with_updated_nonce = post_state;
post_with_updated_nonce.nonce = new_nonce;
let commitment_post = Commitment::new(account_id, &post_with_updated_nonce);
let encrypted_account = EncryptionScheme::encrypt(
&post_with_updated_nonce,
identifier,
shared_secret,
&commitment_post,
*output_index,
);
output.new_commitments.push(commitment_post);
output.ciphertexts.push(encrypted_account);
*output_index = output_index
.checked_add(1)
.unwrap_or_else(|| panic!("Too many private accounts, output index overflow"));
}
fn compute_update_nullifier_and_set_digest(
membership_proof: &MembershipProof,
pre_account: &Account,
account_id: &AccountId,
nsk: &NullifierSecretKey,
) -> (Nullifier, CommitmentSetDigest) {
let commitment_pre = Commitment::new(account_id, pre_account);
let set_digest = compute_digest_for_path(&commitment_pre, membership_proof);
let nullifier = Nullifier::for_account_update(&commitment_pre, nsk);
(nullifier, set_digest)
}
fn main() {
let PrivacyPreservingCircuitInput {
program_outputs,
@ -753,7 +492,7 @@ fn main() {
let execution_state =
ExecutionState::derive_from_outputs(&account_identities, program_id, program_outputs);
let output = compute_circuit_output(execution_state, &account_identities);
let output = output::compute_circuit_output(execution_state, &account_identities);
env::commit(&output);
}

View File

@ -0,0 +1,283 @@
use nssa_core::{
Commitment, CommitmentSetDigest, DUMMY_COMMITMENT_HASH, EncryptionScheme, Identifier,
InputAccountIdentity, MembershipProof, Nullifier, NullifierPublicKey, NullifierSecretKey,
PrivacyPreservingCircuitOutput, SharedSecretKey,
account::{Account, AccountId, Nonce},
compute_digest_for_path,
};
use super::ExecutionState;
// SECURITY: the non-PDA private variants below assert that the prover-supplied `identifier` is
// not equal to this constant; the PDA variants pass it as the fixed identifier. This keeps the
// `(npk, identifier)` account-id space disjoint from private-PDA accounts. Single source of
// truth, do not redefine in another module.
const PRIVATE_PDA_FIXED_IDENTIFIER: Identifier = u128::MAX;
pub(super) fn compute_circuit_output(
execution_state: ExecutionState,
account_identities: &[InputAccountIdentity],
) -> PrivacyPreservingCircuitOutput {
let (block_validity_window, timestamp_validity_window, states_iter) =
execution_state.into_parts();
let mut output = PrivacyPreservingCircuitOutput {
public_pre_states: Vec::new(),
public_post_states: Vec::new(),
ciphertexts: Vec::new(),
new_commitments: Vec::new(),
new_nullifiers: Vec::new(),
block_validity_window,
timestamp_validity_window,
};
assert_eq!(
account_identities.len(),
states_iter.len(),
"Invalid account_identities length"
);
let mut output_index = 0;
for (account_identity, (pre_state, post_state)) in account_identities.iter().zip(states_iter) {
match account_identity {
InputAccountIdentity::Public => {
output.public_pre_states.push(pre_state);
output.public_post_states.push(post_state);
}
InputAccountIdentity::PrivateAuthorizedInit {
ssk,
nsk,
identifier,
} => {
assert_ne!(
*identifier, PRIVATE_PDA_FIXED_IDENTIFIER,
"Identifier must be different from {PRIVATE_PDA_FIXED_IDENTIFIER}. This is reserved for private PDA."
);
let npk = NullifierPublicKey::from(nsk);
let account_id = AccountId::from((&npk, *identifier));
assert_eq!(account_id, pre_state.account_id, "AccountId mismatch");
assert!(
pre_state.is_authorized,
"Pre-state not authorized for authenticated private account"
);
assert_eq!(
pre_state.account,
Account::default(),
"Found new private account with non default values"
);
let new_nullifier = (
Nullifier::for_account_initialization(&account_id),
DUMMY_COMMITMENT_HASH,
);
let new_nonce = pre_state.account.nonce.private_account_nonce_increment(nsk);
emit_private_output(
&mut output,
&mut output_index,
post_state,
&account_id,
*identifier,
ssk,
new_nullifier,
new_nonce,
);
}
InputAccountIdentity::PrivateAuthorizedUpdate {
ssk,
nsk,
membership_proof,
identifier,
} => {
assert_ne!(
*identifier, PRIVATE_PDA_FIXED_IDENTIFIER,
"Identifier must be different from {PRIVATE_PDA_FIXED_IDENTIFIER}. This is reserved for private PDA."
);
let npk = NullifierPublicKey::from(nsk);
let account_id = AccountId::from((&npk, *identifier));
assert_eq!(account_id, pre_state.account_id, "AccountId mismatch");
assert!(
pre_state.is_authorized,
"Pre-state not authorized for authenticated private account"
);
let new_nullifier = compute_update_nullifier_and_set_digest(
membership_proof,
&pre_state.account,
&account_id,
nsk,
);
let new_nonce = pre_state.account.nonce.private_account_nonce_increment(nsk);
emit_private_output(
&mut output,
&mut output_index,
post_state,
&account_id,
*identifier,
ssk,
new_nullifier,
new_nonce,
);
}
InputAccountIdentity::PrivateUnauthorized {
npk,
ssk,
identifier,
} => {
assert_ne!(
*identifier, PRIVATE_PDA_FIXED_IDENTIFIER,
"Identifier must be different from {PRIVATE_PDA_FIXED_IDENTIFIER}. This is reserved for private PDA."
);
let account_id = AccountId::from((npk, *identifier));
assert_eq!(account_id, pre_state.account_id, "AccountId mismatch");
assert_eq!(
pre_state.account,
Account::default(),
"Found new private account with non default values",
);
assert!(
!pre_state.is_authorized,
"Found new private account marked as authorized."
);
let new_nullifier = (
Nullifier::for_account_initialization(&account_id),
DUMMY_COMMITMENT_HASH,
);
let new_nonce = Nonce::private_account_nonce_init(&account_id);
emit_private_output(
&mut output,
&mut output_index,
post_state,
&account_id,
*identifier,
ssk,
new_nullifier,
new_nonce,
);
}
InputAccountIdentity::PrivatePdaInit { npk: _, ssk } => {
// The npk-to-account_id binding is established upstream in
// `validate_and_sync_states` via `Claim::Pda(seed)` or a caller `pda_seeds`
// match. Here we only enforce the init pre-conditions. The supplied npk on
// the variant has been recorded into `private_pda_npk_by_position` and used
// for the binding check; we use `pre_state.account_id` directly for nullifier
// and commitment derivation.
assert!(
!pre_state.is_authorized,
"PrivatePdaInit requires unauthorized pre_state"
);
assert_eq!(
pre_state.account,
Account::default(),
"New private PDA must be default"
);
let new_nullifier = (
Nullifier::for_account_initialization(&pre_state.account_id),
DUMMY_COMMITMENT_HASH,
);
let new_nonce = Nonce::private_account_nonce_init(&pre_state.account_id);
let account_id = pre_state.account_id;
emit_private_output(
&mut output,
&mut output_index,
post_state,
&account_id,
PRIVATE_PDA_FIXED_IDENTIFIER,
ssk,
new_nullifier,
new_nonce,
);
}
InputAccountIdentity::PrivatePdaUpdate {
ssk,
nsk,
membership_proof,
} => {
// The npk binding is established upstream. Authorization must already be set;
// an unauthorized PrivatePdaUpdate would mean the prover supplied an nsk for an
// unbound PDA, which the upstream binding check would have rejected anyway,
// but we assert here to fail fast and document the precondition.
assert!(
pre_state.is_authorized,
"PrivatePdaUpdate requires authorized pre_state"
);
let new_nullifier = compute_update_nullifier_and_set_digest(
membership_proof,
&pre_state.account,
&pre_state.account_id,
nsk,
);
let new_nonce = pre_state.account.nonce.private_account_nonce_increment(nsk);
let account_id = pre_state.account_id;
emit_private_output(
&mut output,
&mut output_index,
post_state,
&account_id,
PRIVATE_PDA_FIXED_IDENTIFIER,
ssk,
new_nullifier,
new_nonce,
);
}
}
}
output
}
#[expect(
clippy::too_many_arguments,
reason = "All seven inputs are distinct concerns from the variant arms; bundling would be artificial"
)]
fn emit_private_output(
output: &mut PrivacyPreservingCircuitOutput,
output_index: &mut u32,
post_state: Account,
account_id: &AccountId,
identifier: Identifier,
shared_secret: &SharedSecretKey,
new_nullifier: (Nullifier, CommitmentSetDigest),
new_nonce: Nonce,
) {
output.new_nullifiers.push(new_nullifier);
let mut post_with_updated_nonce = post_state;
post_with_updated_nonce.nonce = new_nonce;
let commitment_post = Commitment::new(account_id, &post_with_updated_nonce);
let encrypted_account = EncryptionScheme::encrypt(
&post_with_updated_nonce,
identifier,
shared_secret,
&commitment_post,
*output_index,
);
output.new_commitments.push(commitment_post);
output.ciphertexts.push(encrypted_account);
*output_index = output_index
.checked_add(1)
.unwrap_or_else(|| panic!("Too many private accounts, output index overflow"));
}
fn compute_update_nullifier_and_set_digest(
membership_proof: &MembershipProof,
pre_account: &Account,
account_id: &AccountId,
nsk: &NullifierSecretKey,
) -> (Nullifier, CommitmentSetDigest) {
let commitment_pre = Commitment::new(account_id, pre_account);
let set_digest = compute_digest_for_path(&commitment_pre, membership_proof);
let nullifier = Nullifier::for_account_update(&commitment_pre, nsk);
(nullifier, set_digest)
}