phase2-bn254/oldsrc/lib.rs
2017-11-20 23:01:15 -07:00

535 lines
14 KiB
Rust

extern crate pairing;
extern crate rand;
extern crate bit_vec;
extern crate futures;
extern crate futures_cpupool;
extern crate num_cpus;
extern crate crossbeam;
use pairing::{Engine, Field};
use std::ops::{Add, Sub};
use std::io;
pub mod multicore;
pub mod domain;
pub mod groth16;
pub mod multiexp;
#[derive(Debug)]
pub enum Error {
PolynomialDegreeTooLarge,
MalformedVerifyingKey,
AssignmentMissing,
UnexpectedIdentity,
UnconstrainedVariable(Variable),
IoError(io::Error)
}
impl From<io::Error> for Error {
fn from(e: io::Error) -> Error {
Error::IoError(e)
}
}
#[derive(Copy, Clone, Debug)]
pub struct Variable(Index);
#[derive(Clone, Copy, PartialEq, Eq, Hash, Debug)]
enum Index {
Input(usize),
Aux(usize)
}
pub struct LinearCombination<E: Engine>(Vec<(Index, E::Fr)>);
impl<E: Engine> Clone for LinearCombination<E> {
fn clone(&self) -> LinearCombination<E> {
LinearCombination(self.0.clone())
}
}
impl<E: Engine> LinearCombination<E> {
pub fn zero() -> LinearCombination<E> {
LinearCombination(vec![])
}
pub fn eval(
&self,
mut input_density: Option<&mut multiexp::DensityTracker>,
mut aux_density: Option<&mut multiexp::DensityTracker>,
input_assignment: &[E::Fr],
aux_assignment: &[E::Fr]
) -> E::Fr
{
let mut acc = E::Fr::zero();
for &(index, coeff) in self.0.iter() {
let mut tmp;
match index {
Index::Input(i) => {
tmp = input_assignment[i];
if let Some(ref mut v) = input_density {
v.inc(i);
}
},
Index::Aux(i) => {
tmp = aux_assignment[i];
if let Some(ref mut v) = aux_density {
v.inc(i);
}
}
}
if coeff == E::Fr::one() {
acc.add_assign(&tmp);
} else {
tmp.mul_assign(&coeff);
acc.add_assign(&tmp);
}
}
acc
}
}
impl<E: Engine> Add<Variable> for LinearCombination<E> {
type Output = LinearCombination<E>;
fn add(self, other: Variable) -> LinearCombination<E> {
self + (E::Fr::one(), other)
}
}
impl<E: Engine> Sub<Variable> for LinearCombination<E> {
type Output = LinearCombination<E>;
fn sub(self, other: Variable) -> LinearCombination<E> {
self - (E::Fr::one(), other)
}
}
impl<E: Engine> Add<(E::Fr, Variable)> for LinearCombination<E> {
type Output = LinearCombination<E>;
fn add(mut self, (coeff, var): (E::Fr, Variable)) -> LinearCombination<E> {
let mut must_insert = true;
for &mut (ref index, ref mut fr) in &mut self.0 {
if *index == var.0 {
fr.add_assign(&coeff);
must_insert = false;
break;
}
}
if must_insert {
self.0.push((var.0, coeff));
}
self
}
}
impl<E: Engine> Sub<(E::Fr, Variable)> for LinearCombination<E> {
type Output = LinearCombination<E>;
fn sub(self, (mut coeff, var): (E::Fr, Variable)) -> LinearCombination<E> {
coeff.negate();
self + (coeff, var)
}
}
impl<'a, E: Engine> Add<&'a LinearCombination<E>> for LinearCombination<E> {
type Output = LinearCombination<E>;
fn add(mut self, other: &'a LinearCombination<E>) -> LinearCombination<E> {
for &(k, v) in other.0.iter() {
self = self + (v, Variable(k));
}
self
}
}
impl<'a, E: Engine> Sub<&'a LinearCombination<E>> for LinearCombination<E> {
type Output = LinearCombination<E>;
fn sub(mut self, other: &'a LinearCombination<E>) -> LinearCombination<E> {
for &(k, v) in other.0.iter() {
self = self - (v, Variable(k));
}
self
}
}
pub trait Circuit<E: Engine> {
type InputMap: Input<E>;
/// Synthesize the circuit into a rank-1 quadratic constraint system
#[must_use]
fn synthesize<CS: ConstraintSystem<E>>(self, cs: &mut CS) -> Result<Self::InputMap, Error>;
}
pub trait Input<E: Engine> {
/// Synthesize the circuit, except with additional access to public input
/// variables
fn synthesize<CS: PublicConstraintSystem<E>>(self, cs: &mut CS) -> Result<(), Error>;
}
pub trait PublicConstraintSystem<E: Engine>: ConstraintSystem<E> {
/// Allocate a public input that the verifier knows. The provided function is used to
/// determine the assignment of the variable.
fn alloc_input<NR, N, F>(
&mut self,
name_fn: N,
f: F
) -> Result<Variable, Error>
where NR: Into<String>, N: FnOnce() -> NR, F: FnOnce() -> Result<E::Fr, Error>;
}
pub trait ConstraintSystem<E: Engine>: Sized {
type Root: ConstraintSystem<E>;
/// Return the "one" input variable
fn one() -> Variable {
Variable(Index::Input(0))
}
/// Allocate a private variable in the constraint system. The provided function is used to
/// determine the assignment of the variable.
fn alloc<NR, N, F>(
&mut self,
name_fn: N,
f: F
) -> Result<Variable, Error>
where NR: Into<String>, N: FnOnce() -> NR, F: FnOnce() -> Result<E::Fr, Error>;
/// Enforce that `A` * `B` = `C`.
fn enforce<NR: Into<String>, N: FnOnce() -> NR>(
&mut self,
name_fn: N,
a: LinearCombination<E>,
b: LinearCombination<E>,
c: LinearCombination<E>
);
fn push_namespace<NR, N>(&mut self, _: N)
where NR: Into<String>, N: FnOnce() -> NR
{
// Default is to do nothing.
}
fn pop_namespace(&mut self)
{
// Default is to do nothing.
}
/// Begin a namespace for the constraint system
fn namespace<'a, NR, N>(
&'a mut self,
name_fn: N
) -> Namespace<'a, E, Self::Root>
where NR: Into<String>, N: FnOnce() -> NR;
}
impl<'cs, E: Engine, CS: ConstraintSystem<E>> ConstraintSystem<E> for &'cs mut CS {
type Root = CS::Root;
/// Allocate a private variable in the constraint system. The provided function is used to
/// determine the assignment of the variable.
fn alloc<NR, N, F>(
&mut self,
name_fn: N,
f: F
) -> Result<Variable, Error>
where NR: Into<String>, N: FnOnce() -> NR, F: FnOnce() -> Result<E::Fr, Error>
{
(*self).alloc(name_fn, f)
}
/// Enforce that `A` * `B` = `C`.
fn enforce<NR: Into<String>, N: FnOnce() -> NR>(
&mut self,
name_fn: N,
a: LinearCombination<E>,
b: LinearCombination<E>,
c: LinearCombination<E>
)
{
(*self).enforce(name_fn, a, b, c)
}
fn push_namespace<NR, N>(&mut self, name_fn: N)
where NR: Into<String>, N: FnOnce() -> NR
{
(*self).push_namespace(name_fn)
}
fn pop_namespace(&mut self)
{
(*self).pop_namespace()
}
/// Begin a namespace for the constraint system
fn namespace<'a, NR, N>(
&'a mut self,
name_fn: N
) -> Namespace<'a, E, Self::Root>
where NR: Into<String>, N: FnOnce() -> NR
{
(*self).namespace(name_fn)
}
}
use std::marker::PhantomData;
pub struct Namespace<'a, E: Engine, CS: ConstraintSystem<E> + 'a>(&'a mut CS, PhantomData<E>);
impl<'cs, E: Engine, CS: ConstraintSystem<E>> ConstraintSystem<E> for Namespace<'cs, E, CS> {
type Root = CS;
fn alloc<NR, N, F>(
&mut self,
name_fn: N,
f: F
) -> Result<Variable, Error>
where NR: Into<String>, N: FnOnce() -> NR, F: FnOnce() -> Result<E::Fr, Error>
{
self.0.alloc(name_fn, f)
}
fn enforce<NR: Into<String>, N: FnOnce() -> NR>(
&mut self,
name_fn: N,
a: LinearCombination<E>,
b: LinearCombination<E>,
c: LinearCombination<E>
)
{
self.0.enforce(name_fn, a, b, c)
}
fn push_namespace<NR, N>(&mut self, name_fn: N)
where NR: Into<String>, N: FnOnce() -> NR
{
self.0.push_namespace(name_fn);
}
fn pop_namespace(&mut self)
{
self.0.pop_namespace();
}
/// Begin a namespace for the constraint system
fn namespace<'a, NR, N>(
&'a mut self,
name_fn: N
) -> Namespace<'a, E, Self::Root>
where NR: Into<String>, N: FnOnce() -> NR
{
self.0.push_namespace(name_fn);
Namespace(self.0, PhantomData)
}
}
impl<'a, E: Engine, CS: ConstraintSystem<E>> Drop for Namespace<'a, E, CS> {
fn drop(&mut self) {
self.0.pop_namespace()
}
}
use std::collections::HashMap;
#[derive(Debug)]
enum NamedObject {
Constraint(usize),
Input(usize),
Aux(usize),
Namespace
}
/// Constraint system for testing purposes.
pub struct TestConstraintSystem<E: Engine> {
named_objects: HashMap<String, NamedObject>,
current_namespace: Vec<String>,
constraints: Vec<(LinearCombination<E>, LinearCombination<E>, LinearCombination<E>, String)>,
inputs: Vec<E::Fr>,
aux: Vec<E::Fr>
}
impl<E: Engine> TestConstraintSystem<E> {
pub fn new() -> TestConstraintSystem<E> {
TestConstraintSystem {
named_objects: HashMap::new(),
current_namespace: vec![],
constraints: vec![],
inputs: vec![E::Fr::one()],
aux: vec![]
}
}
pub fn which_is_unsatisfied(&self) -> Option<&str> {
for &(ref a, ref b, ref c, ref path) in &self.constraints {
let mut a = a.eval(None, None, &self.inputs, &self.aux);
let b = b.eval(None, None, &self.inputs, &self.aux);
let c = c.eval(None, None, &self.inputs, &self.aux);
a.mul_assign(&b);
if a != c {
return Some(&*path)
}
}
None
}
pub fn is_satisfied(&self) -> bool
{
self.which_is_unsatisfied().is_none()
}
pub fn num_constraints(&self) -> usize
{
self.constraints.len()
}
pub fn assign(&mut self, path: &str, to: E::Fr)
{
match self.named_objects.get(path) {
Some(&NamedObject::Input(index)) => self.inputs[index] = to,
Some(&NamedObject::Aux(index)) => self.aux[index] = to,
Some(e) => panic!("tried to assign `{:?}` a value at path: {}", e, path),
_ => panic!("no variable exists at path: {}", path)
}
}
pub fn get(&mut self, path: &str) -> E::Fr
{
match self.named_objects.get(path) {
Some(&NamedObject::Input(index)) => self.inputs[index],
Some(&NamedObject::Aux(index)) => self.aux[index],
Some(e) => panic!("tried to get value of `{:?}` at path: {}", e, path),
_ => panic!("no variable exists at path: {}", path)
}
}
fn set_named_obj(&mut self, path: String, to: NamedObject) {
if self.named_objects.contains_key(&path) {
panic!("tried to create object at existing path: {}", path);
}
self.named_objects.insert(path, to);
}
}
fn compute_path(ns: &[String], this: String) -> String {
if this.chars().any(|a| a == '/') {
panic!("'/' is not allowed in names");
}
let mut name = String::new();
let mut needs_separation = false;
for ns in ns.iter().chain(Some(&this).into_iter())
{
if needs_separation {
name += "/";
}
name += ns;
needs_separation = true;
}
name
}
impl<E: Engine> PublicConstraintSystem<E> for TestConstraintSystem<E> {
fn alloc_input<NR, N, F>(
&mut self,
name_fn: N,
f: F
) -> Result<Variable, Error>
where NR: Into<String>, N: FnOnce() -> NR, F: FnOnce() -> Result<E::Fr, Error>
{
let this_path = compute_path(&self.current_namespace, name_fn().into());
let this_obj = NamedObject::Input(self.inputs.len());
self.set_named_obj(this_path, this_obj);
let var = Variable(Index::Input(self.inputs.len()));
self.inputs.push(f()?);
Ok(var)
}
}
impl<E: Engine> ConstraintSystem<E> for TestConstraintSystem<E> {
type Root = Self;
fn alloc<NR, N, F>(
&mut self,
name_fn: N,
f: F
) -> Result<Variable, Error>
where NR: Into<String>, N: FnOnce() -> NR, F: FnOnce() -> Result<E::Fr, Error>
{
let this_path = compute_path(&self.current_namespace, name_fn().into());
let this_obj = NamedObject::Aux(self.aux.len());
self.set_named_obj(this_path, this_obj);
let var = Variable(Index::Aux(self.aux.len()));
self.aux.push(f()?);
Ok(var)
}
fn enforce<NR: Into<String>, N: FnOnce() -> NR>(
&mut self,
name_fn: N,
a: LinearCombination<E>,
b: LinearCombination<E>,
c: LinearCombination<E>
)
{
let this_path = compute_path(&self.current_namespace, name_fn().into());
let this_obj = NamedObject::Constraint(self.constraints.len());
self.set_named_obj(this_path.clone(), this_obj);
self.constraints.push((a, b, c, this_path));
}
fn push_namespace<NR, N>(&mut self, name_fn: N)
where NR: Into<String>, N: FnOnce() -> NR
{
let name = name_fn().into();
let this_path = compute_path(&self.current_namespace, name.clone());
self.set_named_obj(this_path, NamedObject::Namespace);
self.current_namespace.push(name);
}
fn pop_namespace(&mut self)
{
self.current_namespace.pop();
}
/// Begin a namespace for the constraint system
fn namespace<'a, NR, N>(
&'a mut self,
name_fn: N
) -> Namespace<'a, E, Self::Root>
where NR: Into<String>, N: FnOnce() -> NR
{
self.push_namespace(name_fn);
Namespace(self, PhantomData)
}
}