librustzcash/tinysnark/src/lib.rs

#![feature(box_syntax, repr_simd)]
#![allow(improper_ctypes)]
//#![cfg_attr(test, feature(test))]
extern crate libc;

mod arith;
mod r1cs;

pub use self::arith::*;
pub use self::r1cs::*;

use std::sync::{Once, ONCE_INIT};

static START: Once = ONCE_INIT;
static mut INITIALIZED: bool = false;

extern "C" {
    fn tinysnark_init_public_params();
    pub fn tinysnark_test();
}

pub fn init() {
    START.call_once(|| {
        unsafe { tinysnark_init_public_params(); }
        unsafe { INITIALIZED = true; }
    });
}

pub fn is_initialized() -> bool {
    unsafe { INITIALIZED }
}

#[cfg(test)]
mod tests {
    //extern crate test;
    use super::{init, FieldT, Proof, Keypair, LinearTerm, ConstraintSystem};
    //use self::test::Bencher;

    #[test]
    fn test_zk() {
        fn test_cs_and_prove<N: Into<FieldT> + Copy>(cs: &ConstraintSystem, primary: &[N], aux: &[N]) -> bool
        {
            let primary: Vec<FieldT> = primary.iter().map(|n| (*n).into()).collect();
            let aux: Vec<FieldT> = aux.iter().map(|n| (*n).into()).collect();

            if !cs.test(&primary, &aux) {
                return false;
            }

            let kp = Keypair::new(cs);
            let proof = Proof::new(&kp, &primary, &aux);
            // If we construct a proof, it should be impossible
            // that it doesn't verify.
            assert!(proof.verify(&kp, &primary));

            return true;
        }

        init();
        {
            let mut cs = ConstraintSystem::new(1, 2);
            // zkpok { (a, b) c = a * b }
            cs.add_constraint(
                &[LinearTerm{coeff: FieldT::one(), index: 2}],
                &[LinearTerm{coeff: FieldT::one(), index: 3}],
                &[LinearTerm{coeff: FieldT::one(), index: 1}]
            );

            assert!(test_cs_and_prove(&cs, &[1], &[1, 1]));
            assert!(test_cs_and_prove(&cs, &[0], &[0, 1]));
            assert!(test_cs_and_prove(&cs, &[10], &[5, 2]));
            assert!(!test_cs_and_prove(&cs, &[10], &[6, 2]));
        }
        {
            let mut cs = ConstraintSystem::new(0, 1);
            // simple boolean constraint
            // (1-x) * x = 0
            cs.add_constraint(
                &[LinearTerm{coeff: FieldT::one(), index: 0},
                  LinearTerm{coeff: -FieldT::one(), index: 1}],
                &[LinearTerm{coeff: FieldT::one(), index: 1}],
                &[LinearTerm{coeff: FieldT::zero(), index: 0}]
            );

            assert!(test_cs_and_prove(&cs, &[], &[0]));
            assert!(test_cs_and_prove(&cs, &[], &[1]));
            assert!(!test_cs_and_prove(&cs, &[], &[2]));
        }
        {
            let mut cs = ConstraintSystem::new(2, 1);
            // boolean + xor
            cs.add_constraint(
                &[LinearTerm{coeff: FieldT::one(), index: 0},
                  LinearTerm{coeff: -FieldT::one(), index: 3}],
                &[LinearTerm{coeff: FieldT::one(), index: 3}],
                &[LinearTerm{coeff: FieldT::zero(), index: 0}]
            );
            cs.add_constraint(
                &[LinearTerm{coeff: FieldT::from(2), index: 2}],
                &[LinearTerm{coeff: FieldT::one(), index: 3}],
                &[LinearTerm{coeff: FieldT::one(), index: 2},
                  LinearTerm{coeff: FieldT::one(), index: 3},
                  LinearTerm{coeff: -FieldT::one(), index: 1}]
            );

            assert!(test_cs_and_prove(&cs, &[0, 0], &[0]));
            assert!(test_cs_and_prove(&cs, &[1, 1], &[0]));
            assert!(test_cs_and_prove(&cs, &[1, 0], &[1]));
            assert!(test_cs_and_prove(&cs, &[0, 1], &[1]));
            assert!(!test_cs_and_prove(&cs, &[0, 1], &[100]));
        }
    }

    #[test]
    fn test_one() {
        init();
        let one = FieldT::one();
        let negone = -one;
        let newone = -negone;

        assert!(one == newone);
        assert!(one != negone);
        assert!(newone != negone);

        assert_eq!(one, 1.into());
        assert_eq!(negone, (-1).into());

        assert!(one.debug_equal([251, 255, 255, 79, 28, 52, 150, 172, 41, 205, 96, 159, 149, 118, 252, 54, 46, 70, 121, 120, 111, 163, 110, 102, 47, 223, 7, 154, 193, 119, 10, 14]));
        assert!(negone.debug_equal([6, 0, 0, 160, 119, 193, 75, 151, 103, 163, 88, 218, 178, 113, 55, 241, 46, 18, 8, 9, 71, 162, 225, 81, 250, 192, 41, 71, 177, 214, 89, 34]));
    }

    #[test]
    fn test_math() {
        init();

        assert_eq!(FieldT::one() + 10.into(), 11.into());
        assert_eq!(FieldT::from(2) + 2.into(), FieldT::from(2) * 2.into());
        assert_eq!(FieldT::from(2), FieldT::from(-1) + FieldT::one() * 3.into());

        assert_eq!(FieldT::one(), FieldT::from(100) * FieldT::from(100).inverse());
    }

    #[test]
    fn test_conversions() {
        init();

        for i in 0..10000 {
            let num: FieldT = i.into();
            let back: u64 = num.into();

            assert_eq!(i, back as i64);
        }

        assert_eq!(u64::from(FieldT::from(-1)), 4891460686036598784);
    }
}