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fix: ecpairing
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@enitrat
enitrat committed Nov 8, 2024
1 parent ed97e67 commit 36d8346
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Showing 4 changed files with 68 additions and 35 deletions.
2 changes: 1 addition & 1 deletion Scarb.lock
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Expand Up @@ -34,7 +34,7 @@ dependencies = [
[[package]]
name = "garaga"
version = "0.14.0"
source = "git+https://github.com/keep-starknet-strange/garaga.git?tag=v0.14.0#eb9be301d0cd61df8ffa546742e092b5e67e1505"
source = "git+https://github.com/keep-starknet-strange/garaga.git?branch=g2#7b1b9168347063d26b791c88a30440f9fc723c86"

[[package]]
name = "openzeppelin"
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2 changes: 1 addition & 1 deletion crates/evm/Scarb.toml
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Expand Up @@ -10,7 +10,7 @@ starknet.workspace = true
utils = { path = "../utils" }
contracts = { path = "../contracts" }
openzeppelin = { path = "../openzeppelin" }
garaga = { git = "https://github.com/keep-starknet-strange/garaga.git", tag = "v0.14.0" }
garaga = { git = "https://github.com/keep-starknet-strange/garaga.git", branch = "g2" }

[dev-dependencies]
snforge_std = { git = "https://github.com/foundry-rs/starknet-foundry.git", tag = "v0.33.0" }
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96 changes: 66 additions & 30 deletions crates/evm/src/precompiles/ec_operations/ec_pairing.cairo
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@@ -1,22 +1,24 @@
use core::num::traits::Zero;
use core::starknet::{EthAddress};
use crate::errors::EVMError;
use crate::precompiles::Precompile;
use crate::precompiles::ec_operations::{is_on_curve, BN254_PRIME};
use garaga::circuits::tower_circuits::run_BN254_E12T_MUL_circuit;
use garaga::definitions::G1G2Pair;
use garaga::ec_ops::{G1PointImpl};
use garaga::ec_ops_g2::{G2PointImpl};
use garaga::ec_ops_g2::{G2PointTrait, ec_mul as ec_mul_g2};

use garaga::single_pairing_tower::{
E12TOne, G1Point, G2Point, miller_loop_bn254_tower, final_exp_bn254_tower, u384
};
use utils::traits::bytes::FromBytes;
use utils::constants::{ONE_32_BYTES, ZERO_32_BYTES};
use utils::traits::bytes::FromBytes;

const BASE_COST: u64 = 45000;
const PAIRING_COST: u64 = 34000;
const U256_BYTES_LEN: usize = 32;
const GARAGA_BN254_CURVE_INDEX: u32 = 0;
const BN254_CURVE_ORDER: u256 =
21888242871839275222246405745257275088548364400416034343698204186575808495617;

pub impl EcPairing of Precompile {
fn address() -> EthAddress {
Expand All @@ -28,14 +30,9 @@ pub impl EcPairing of Precompile {

let gas = PAIRING_COST * n.into() + BASE_COST;

// "The input must always be a multiple of 6 32-byte values. 0 inputs is valid and returns
// 1"
// https://www.evm.codes/precompiled?fork=cancun#0x08

if rem != 0 || n == 1 {
if rem != 0 {
// rem != 0: input length must be a multiple of 196
// n == 1: single pairing is non-degerative by definition, can't be 1.
return Result::Err(EVMError::InvalidParameter('invalid ec_pairing input'));
return Result::Err(EVMError::InvalidParameter('invalid ec_pairing input length'));
}
if n == 0 {
return Result::Ok((BASE_COST, ONE_32_BYTES.span()));
Expand All @@ -52,21 +49,46 @@ pub impl EcPairing of Precompile {
let x0: u256 = input.slice(offset + 96, U256_BYTES_LEN).from_be_bytes().unwrap();
let y1: u256 = input.slice(offset + 128, U256_BYTES_LEN).from_be_bytes().unwrap();
let y0: u256 = input.slice(offset + 160, U256_BYTES_LEN).from_be_bytes().unwrap();
let x_384: u384 = x.into();
let y_384: u384 = y.into();
let p = G1Point { x: x_384, y: y_384 };
let q = G2Point { x0: x0.into(), x1: x1.into(), y0: y0.into(), y1: y1.into() };

if !is_on_curve(x_384, y_384)
|| !q.is_on_curve(GARAGA_BN254_CURVE_INDEX)
|| x >= BN254_PRIME
if x >= BN254_PRIME
|| y >= BN254_PRIME
|| x0 >= BN254_PRIME
|| x1 >= BN254_PRIME
|| y0 >= BN254_PRIME
|| y1 >= BN254_PRIME {
everything_ok = false;
break;
}

// If p and q are not the point at infinity, check that it's they're on the curve.
let x_384: u384 = x.into();
let y_384: u384 = y.into();
let p = G1Point { x: x_384, y: y_384 };
let p_infinity = p.is_zero();
if (!p_infinity) {
if (!is_on_curve(x_384, y_384)) {
everything_ok = false;
break;
}
}

let q = G2Point { x0: x0.into(), x1: x1.into(), y0: y0.into(), y1: y1.into() };
let q_infinity = q.is_zero();
if (!q_infinity) {
if (!q.is_on_curve(GARAGA_BN254_CURVE_INDEX)) {
everything_ok = false;
break;
}
}

// Subgroup check
// Cofactor for G1 group is 1, so we don't need to check for `p`
let q_mul_r = ec_mul_g2(q, BN254_CURVE_ORDER, GARAGA_BN254_CURVE_INDEX).unwrap();
if (!q_mul_r.is_zero()) {
everything_ok = false;
break;
}

pairs.append(G1G2Pair { p: p, q: q });
offset += 192;
};
Expand All @@ -86,21 +108,35 @@ pub impl EcPairing of Precompile {
}
}

// Assumes len is >= 2.
// Assumes len is >= 1.
// Assumes pairs are on curve.
// Returns true if Π e(Pi,Qi) = 1 where e is the optimal ate pairing on BN254
fn ec_pairing(pairs: Span<G1G2Pair>) -> bool {
let pair_0 = pairs.at(0);
let (mut m) = miller_loop_bn254_tower(*pair_0.p, *pair_0.q);

for i in 1_usize
..pairs
.len() {
let pair_i = pairs.at(i);
let (__m) = miller_loop_bn254_tower(*pair_i.p, *pair_i.q);
let (_m) = run_BN254_E12T_MUL_circuit(m, __m);
m = _m;
};
fn ec_pairing(mut pairs: Span<G1G2Pair>) -> bool {
let n_pairs = pairs.len();
let pair_0 = pairs.pop_front().unwrap();
let (mut m,) = match pair_0.p.is_zero() || pair_0.q.is_zero() {
true => {
if n_pairs == 1 {
return true;
}
(E12TOne::one(),)
},
false => { miller_loop_bn254_tower(*pair_0.p, *pair_0.q) }
};

// The original input had only one pair
if n_pairs == 1 {
return final_exp_bn254_tower(m).is_one();
};

for pair_i in pairs {
let (__m,) = match pair_i.p.is_zero() || pair_i.q.is_zero() {
true => { (E12TOne::one(),) },
false => { miller_loop_bn254_tower(*pair_i.p, *pair_i.q) }
};
let (_m) = run_BN254_E12T_MUL_circuit(m, __m);
m = _m;
};

let f = final_exp_bn254_tower(m);
return f.is_one();
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3 changes: 0 additions & 3 deletions crates/utils/src/constants.cairo
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Original file line number Diff line number Diff line change
Expand Up @@ -491,10 +491,7 @@ pub const POW_2_120: u128 = 0x1000000000000000000000000000000;
pub const POW_2_127: u128 = 0x80000000000000000000000000000000;

pub const MAX_ADDRESS: u256 = 0x7ffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff;


#[cairofmt::skip]
pub const ONE_32_BYTES: [ u8 ; 32] = [ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01 ];

#[cairofmt::skip]
pub const ZERO_32_BYTES: [ u8 ; 32] = [ 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 ];

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