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update VDAF references and rebase
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Rebasing means a couple methods need an agg param argument, since
`Vdaf::prepare_shares_to_prepare_message` needs agg param.
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@tgeoghegan
tgeoghegan committed Sep 13, 2023
1 parent 7112081 commit a2076f9
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Showing 2 changed files with 35 additions and 32 deletions.
62 changes: 32 additions & 30 deletions src/topology/ping_pong.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -4,11 +4,7 @@
//! two aggregators, designated "Leader" and "Helper". This topology is required for implementing
//! the [Distributed Aggregation Protocol][DAP].
//!
//! Note that while this implementation is compatible with VDAF-06, it actually implements the
//! ping-pong wrappers specified in VDAF-07 (forthcoming) since those line up better with the VDAF
//! implementation in this crate.
//!
//! [VDAF]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vdaf-06#section-5.8
//! [VDAF]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vdaf-07#section-5.8
//! [DAP]: https://datatracker.ietf.org/doc/html/draft-ietf-ppm-dap
use crate::{
Expand All @@ -24,9 +20,9 @@ pub enum PingPongError {
#[error("vdaf.prepare_init: {0}")]
VdafPrepareInit(VdafError),

/// Error running prepare_preprocess
#[error("vdaf.prepare_preprocess {0}")]
VdafPreparePreprocess(VdafError),
/// Error running prepare_shares_to_prepare_message
#[error("vdaf.prepare_shares_to_prepare_message {0}")]
VdafPrepareSharesToPrepareMessage(VdafError),

/// Error running prepare_step
#[error("vdaf.prepare_step {0}")]
Expand Down Expand Up @@ -67,7 +63,7 @@ pub enum PingPongError {
/// variants are opaque byte buffers. This is because the ping-pong routines take responsibility for
/// decoding preparation shares and messages, which usually requires having the preparation state.
///
/// [VDAF]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vdaf-06#section-5.8
/// [VDAF]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vdaf-07#section-5.8
#[derive(Clone, PartialEq, Eq)]
pub enum PingPongMessage {
/// Corresponds to MessageType.initialize.
Expand Down Expand Up @@ -186,7 +182,7 @@ impl Decode for PingPongMessage {
/// preprocessed prepare message. Their encoding is much smaller than the `(State, Message)` tuple,
/// which can always be recomputed with [`Self::evaluate`].
///
/// [VDAF]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vdaf-06#section-5.8
/// [VDAF]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vdaf-07#section-5.8
#[derive(Clone, Debug, Eq)]
pub struct PingPongTransition<
const VERIFY_KEY_SIZE: usize,
Expand Down Expand Up @@ -218,7 +214,7 @@ impl<
> {
let prep_msg = self.current_prepare_message.get_encoded();

vdaf.prepare_step(
vdaf.prepare_next(
self.previous_prepare_state.clone(),
self.current_prepare_message.clone(),
)
Expand Down Expand Up @@ -297,7 +293,7 @@ where
/// code, and the `Rejected` state is represented as `std::result::Result::Err`, so this enum does
/// not include those variants.
///
/// [VDAF]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vdaf-06#section-5.8
/// [VDAF]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vdaf-07#section-5.8
#[derive(Clone, Debug, PartialEq, Eq)]
pub enum PingPongState<
const VERIFY_KEY_SIZE: usize,
Expand Down Expand Up @@ -335,7 +331,7 @@ pub enum PingPongContinuedValue<

/// Extension trait on [`crate::vdaf::Aggregator`] which adds the [VDAF Ping-Pong Topology][VDAF].
///
/// [VDAF]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vdaf-06#section-5.8
/// [VDAF]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vdaf-07#section-5.8
pub trait PingPongTopology<const VERIFY_KEY_SIZE: usize, const NONCE_SIZE: usize>:
Aggregator<VERIFY_KEY_SIZE, NONCE_SIZE>
{
Expand All @@ -355,7 +351,7 @@ pub trait PingPongTopology<const VERIFY_KEY_SIZE: usize, const NONCE_SIZE: usize
/// leader along with the next [`PingPongMessage`] received from the helper as input to
/// [`Self::leader_continued`] to advance to the next round.
///
/// [VDAF]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vdaf-06#section-5.8
/// [VDAF]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vdaf-07#section-5.8
fn leader_initialized(
&self,
verify_key: &[u8; VERIFY_KEY_SIZE],
Expand Down Expand Up @@ -426,11 +422,12 @@ pub trait PingPongTopology<const VERIFY_KEY_SIZE: usize, const NONCE_SIZE: usize
/// aggregation parameter. This may change in the future if/when [#670][issue] is addressed.
///
///
/// [VDAF]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vdaf-06#section-5.8
/// [VDAF]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vdaf-07#section-5.8
/// [issue]: https://github.com/divviup/libprio-rs/issues/670
fn leader_continued(
&self,
leader_state: Self::State,
agg_param: &Self::AggregationParam,
inbound: &PingPongMessage,
) -> Result<Self::ContinuedValue, PingPongError>;

Expand Down Expand Up @@ -468,11 +465,12 @@ pub trait PingPongTopology<const VERIFY_KEY_SIZE: usize, const NONCE_SIZE: usize
/// aggregation parameter. This may change in the future if/when [#670][issue] is addressed.
///
///
/// [VDAF]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vdaf-06#section-5.8
/// [VDAF]: https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-vdaf-07#section-5.8
/// [issue]: https://github.com/divviup/libprio-rs/issues/670
fn helper_continued(
&self,
helper_state: Self::State,
agg_param: &Self::AggregationParam,
inbound: &PingPongMessage,
) -> Result<Self::ContinuedValue, PingPongError>;
}
Expand All @@ -484,7 +482,8 @@ trait PingPongTopologyPrivate<const VERIFY_KEY_SIZE: usize, const NONCE_SIZE: us
fn continued(
&self,
is_leader: bool,
helper_state: Self::State,
host_state: Self::State,
agg_param: &Self::AggregationParam,
inbound: &PingPongMessage,
) -> Result<Self::ContinuedValue, PingPongError>;
}
Expand Down Expand Up @@ -556,8 +555,8 @@ where
};

let current_prepare_message = self
.prepare_preprocess([inbound_prep_share, prep_share])
.map_err(PingPongError::VdafPreparePreprocess)?;
.prepare_shares_to_prepare_message(agg_param, [inbound_prep_share, prep_share])
.map_err(PingPongError::VdafPrepareSharesToPrepareMessage)?;

Ok(PingPongTransition {
previous_prepare_state: prep_state,
Expand All @@ -568,17 +567,19 @@ where
fn leader_continued(
&self,
leader_state: Self::State,
agg_param: &Self::AggregationParam,
inbound: &PingPongMessage,
) -> Result<Self::ContinuedValue, PingPongError> {
self.continued(true, leader_state, inbound)
self.continued(true, leader_state, agg_param, inbound)
}

fn helper_continued(
&self,
helper_state: Self::State,
agg_param: &Self::AggregationParam,
inbound: &PingPongMessage,
) -> Result<Self::ContinuedValue, PingPongError> {
self.continued(false, helper_state, inbound)
self.continued(false, helper_state, agg_param, inbound)
}
}

Expand All @@ -591,6 +592,7 @@ where
&self,
is_leader: bool,
host_state: Self::State,
agg_param: &Self::AggregationParam,
inbound: &PingPongMessage,
) -> Result<Self::ContinuedValue, PingPongError> {
let host_prep_state = if let PingPongState::Continued(state) = host_state {
Expand Down Expand Up @@ -619,7 +621,7 @@ where
let prep_msg = Self::PrepareMessage::get_decoded_with_param(&host_prep_state, prep_msg)
.map_err(PingPongError::CodecPrepMessage)?;
let host_prep_transition = self
.prepare_step(host_prep_state, prep_msg)
.prepare_next(host_prep_state, prep_msg)
.map_err(PingPongError::VdafPrepareStep)?;

match (host_prep_transition, next_peer_prep_share) {
Expand All @@ -637,8 +639,8 @@ where
prep_shares.reverse();
}
let current_prepare_message = self
.prepare_preprocess(prep_shares)
.map_err(PingPongError::VdafPreparePreprocess)?;
.prepare_shares_to_prepare_message(agg_param, prep_shares)
.map_err(PingPongError::VdafPrepareSharesToPrepareMessage)?;

Ok(PingPongContinuedValue::WithMessage {
transition: PingPongTransition {
Expand Down Expand Up @@ -715,7 +717,7 @@ mod tests {
assert_matches!(helper_state, PingPongState::Finished(_));

let leader_state = leader
.leader_continued(leader_state, &helper_message)
.leader_continued(leader_state, &aggregation_param, &helper_message)
.unwrap();
// 1 round VDAF: leader should finish when it gets helper message and emit no message.
assert_matches!(
Expand Down Expand Up @@ -765,7 +767,7 @@ mod tests {
assert_matches!(helper_state, PingPongState::Continued(_));

let leader_state = leader
.leader_continued(leader_state, &helper_message)
.leader_continued(leader_state, &aggregation_param, &helper_message)
.unwrap();
// 2 round VDAF, round 1: leader should finish and emit a finish message.
let leader_message = assert_matches!(
Expand All @@ -777,7 +779,7 @@ mod tests {
);

let helper_state = helper
.helper_continued(helper_state, &leader_message)
.helper_continued(helper_state, &aggregation_param, &leader_message)
.unwrap();
// 2 round vdaf, round 1: helper should finish and emit no message.
assert_matches!(
Expand Down Expand Up @@ -827,7 +829,7 @@ mod tests {
assert_matches!(helper_state, PingPongState::Continued(_));

let leader_state = leader
.leader_continued(leader_state, &helper_message)
.leader_continued(leader_state, &aggregation_param, &helper_message)
.unwrap();
// 3 round VDAF, round 1: leader should continue and emit a continue message.
let (leader_state, leader_message) = assert_matches!(
Expand All @@ -839,7 +841,7 @@ mod tests {
);

let helper_state = helper
.helper_continued(helper_state, &leader_message)
.helper_continued(helper_state, &aggregation_param, &leader_message)
.unwrap();
// 3 round vdaf, round 2: helper should finish and emit a finish message.
let helper_message = assert_matches!(
Expand All @@ -851,7 +853,7 @@ mod tests {
);

let leader_state = leader
.leader_continued(leader_state, &helper_message)
.leader_continued(leader_state, &aggregation_param, &helper_message)
.unwrap();
// 3 round VDAF, round 2: leader should finish and emit no message.
assert_matches!(
Expand Down
5 changes: 3 additions & 2 deletions src/vdaf/dummy.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -137,14 +137,15 @@ impl vdaf::Aggregator<0, 16> for Vdaf {
))
}

fn prepare_preprocess<M: IntoIterator<Item = Self::PrepareMessage>>(
fn prepare_shares_to_prepare_message<M: IntoIterator<Item = Self::PrepareShare>>(
&self,
_: &Self::AggregationParam,
_: M,
) -> Result<Self::PrepareMessage, VdafError> {
Ok(())
}

fn prepare_step(
fn prepare_next(
&self,
state: Self::PrepareState,
_: Self::PrepareMessage,
Expand Down

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