plugeth/crypto/kzg4844/kzg4844_ckzg_cgo.go

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// Copyright 2023 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
//go:build ckzg && !nacl && !js && cgo && !gofuzz
package kzg4844
import (
"encoding/json"
"errors"
"sync"
gokzg4844 "github.com/crate-crypto/go-kzg-4844"
ckzg4844 "github.com/ethereum/c-kzg-4844/bindings/go"
"github.com/ethereum/go-ethereum/common/hexutil"
)
// ckzgAvailable signals whether the library was compiled into Geth.
const ckzgAvailable = true
// ckzgIniter ensures that we initialize the KZG library once before using it.
var ckzgIniter sync.Once
// ckzgInit initializes the KZG library with the provided trusted setup.
func ckzgInit() {
config, err := content.ReadFile("trusted_setup.json")
if err != nil {
panic(err)
}
params := new(gokzg4844.JSONTrustedSetup)
if err = json.Unmarshal(config, params); err != nil {
panic(err)
}
if err = gokzg4844.CheckTrustedSetupIsWellFormed(params); err != nil {
panic(err)
}
g1s := make([]byte, len(params.SetupG1Lagrange)*(len(params.SetupG1Lagrange[0])-2)/2)
for i, g1 := range params.SetupG1Lagrange {
copy(g1s[i*(len(g1)-2)/2:], hexutil.MustDecode(g1))
}
g2s := make([]byte, len(params.SetupG2)*(len(params.SetupG2[0])-2)/2)
for i, g2 := range params.SetupG2 {
copy(g2s[i*(len(g2)-2)/2:], hexutil.MustDecode(g2))
}
if err = ckzg4844.LoadTrustedSetup(g1s, g2s); err != nil {
panic(err)
}
}
// ckzgBlobToCommitment creates a small commitment out of a data blob.
func ckzgBlobToCommitment(blob Blob) (Commitment, error) {
ckzgIniter.Do(ckzgInit)
commitment, err := ckzg4844.BlobToKZGCommitment((ckzg4844.Blob)(blob))
if err != nil {
return Commitment{}, err
}
return (Commitment)(commitment), nil
}
// ckzgComputeProof computes the KZG proof at the given point for the polynomial
// represented by the blob.
func ckzgComputeProof(blob Blob, point Point) (Proof, Claim, error) {
ckzgIniter.Do(ckzgInit)
proof, claim, err := ckzg4844.ComputeKZGProof((ckzg4844.Blob)(blob), (ckzg4844.Bytes32)(point))
if err != nil {
return Proof{}, Claim{}, err
}
return (Proof)(proof), (Claim)(claim), nil
}
// ckzgVerifyProof verifies the KZG proof that the polynomial represented by the blob
// evaluated at the given point is the claimed value.
func ckzgVerifyProof(commitment Commitment, point Point, claim Claim, proof Proof) error {
ckzgIniter.Do(ckzgInit)
valid, err := ckzg4844.VerifyKZGProof((ckzg4844.Bytes48)(commitment), (ckzg4844.Bytes32)(point), (ckzg4844.Bytes32)(claim), (ckzg4844.Bytes48)(proof))
if err != nil {
return err
}
if !valid {
return errors.New("invalid proof")
}
return nil
}
// ckzgComputeBlobProof returns the KZG proof that is used to verify the blob against
// the commitment.
//
// This method does not verify that the commitment is correct with respect to blob.
func ckzgComputeBlobProof(blob Blob, commitment Commitment) (Proof, error) {
ckzgIniter.Do(ckzgInit)
proof, err := ckzg4844.ComputeBlobKZGProof((ckzg4844.Blob)(blob), (ckzg4844.Bytes48)(commitment))
if err != nil {
return Proof{}, err
}
return (Proof)(proof), nil
}
// ckzgVerifyBlobProof verifies that the blob data corresponds to the provided commitment.
func ckzgVerifyBlobProof(blob Blob, commitment Commitment, proof Proof) error {
ckzgIniter.Do(ckzgInit)
valid, err := ckzg4844.VerifyBlobKZGProof((ckzg4844.Blob)(blob), (ckzg4844.Bytes48)(commitment), (ckzg4844.Bytes48)(proof))
if err != nil {
return err
}
if !valid {
return errors.New("invalid proof")
}
return nil
}