@polygon-hermez/vm
Version:
An Ethereum VM implementation
49 lines • 1.92 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
const ethereumjs_util_1 = require("ethereumjs-util");
const evm_1 = require("../evm");
const exceptions_1 = require("../../exceptions");
const assert = require('assert');
const { BLS12_381_ToFp2Point, BLS12_381_FromG2Point } = require('./util/bls12_381');
async function default_1(opts) {
assert(opts.data);
const mcl = opts._VM._mcl;
const inputData = opts.data;
// note: the gas used is constant; even if the input is incorrect.
const gasUsed = new ethereumjs_util_1.BN(opts._common.paramByEIP('gasPrices', 'Bls12381MapG2Gas', 2537));
if (opts.gasLimit.lt(gasUsed)) {
return (0, evm_1.OOGResult)(opts.gasLimit);
}
if (inputData.length != 128) {
return (0, evm_1.VmErrorResult)(new exceptions_1.VmError(exceptions_1.ERROR.BLS_12_381_INVALID_INPUT_LENGTH), opts.gasLimit);
}
// check if some parts of input are zero bytes.
const zeroBytes16 = Buffer.alloc(16, 0);
const zeroByteCheck = [
[0, 16],
[64, 80],
];
for (const index in zeroByteCheck) {
const slicedBuffer = opts.data.slice(zeroByteCheck[index][0], zeroByteCheck[index][1]);
if (!slicedBuffer.equals(zeroBytes16)) {
return (0, evm_1.VmErrorResult)(new exceptions_1.VmError(exceptions_1.ERROR.BLS_12_381_POINT_NOT_ON_CURVE), opts.gasLimit);
}
}
// convert input to mcl Fp2 point
let Fp2Point;
try {
Fp2Point = BLS12_381_ToFp2Point(opts.data.slice(0, 64), opts.data.slice(64, 128), mcl);
}
catch (e) {
return (0, evm_1.VmErrorResult)(e, opts.gasLimit);
}
// map it to G2
const result = Fp2Point.mapToG2();
const returnValue = BLS12_381_FromG2Point(result);
return {
gasUsed,
returnValue: returnValue,
};
}
exports.default = default_1;
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