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