111 lines
3.5 KiB
Go
111 lines
3.5 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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// Package kzg4844 implements the KZG crypto for EIP-4844.
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package kzg4844
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import (
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"embed"
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"errors"
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"sync/atomic"
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)
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//go:embed trusted_setup.json
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var content embed.FS
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// Blob represents a 4844 data blob.
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type Blob [131072]byte
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// Commitment is a serialized commitment to a polynomial.
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type Commitment [48]byte
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// Proof is a serialized commitment to the quotient polynomial.
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type Proof [48]byte
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// Point is a BLS field element.
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type Point [32]byte
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// Claim is a claimed evaluation value in a specific point.
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type Claim [32]byte
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// useCKZG controls whether the cryptography should use the Go or C backend.
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var useCKZG atomic.Bool
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// UseCKZG can be called to switch the default Go implementation of KZG to the C
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// library if fo some reason the user wishes to do so (e.g. consensus bug in one
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// or the other).
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func UseCKZG(use bool) error {
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if use && !ckzgAvailable {
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return errors.New("CKZG unavailable on your platform")
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}
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useCKZG.Store(use)
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// Initializing the library can take 2-4 seconds - and can potentially crash
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// on CKZG and non-ADX CPUs - so might as well so it now and don't wait until
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// a crypto operation is actually needed live.
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if use {
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ckzgIniter.Do(ckzgInit)
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} else {
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gokzgIniter.Do(gokzgInit)
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}
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return nil
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}
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// BlobToCommitment creates a small commitment out of a data blob.
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func BlobToCommitment(blob Blob) (Commitment, error) {
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if useCKZG.Load() {
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return ckzgBlobToCommitment(blob)
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}
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return gokzgBlobToCommitment(blob)
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}
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// ComputeProof computes the KZG proof at the given point for the polynomial
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// represented by the blob.
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func ComputeProof(blob Blob, point Point) (Proof, Claim, error) {
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if useCKZG.Load() {
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return ckzgComputeProof(blob, point)
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}
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return gokzgComputeProof(blob, point)
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}
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// VerifyProof 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 VerifyProof(commitment Commitment, point Point, claim Claim, proof Proof) error {
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if useCKZG.Load() {
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return ckzgVerifyProof(commitment, point, claim, proof)
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}
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return gokzgVerifyProof(commitment, point, claim, proof)
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}
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// ComputeBlobProof 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 ComputeBlobProof(blob Blob, commitment Commitment) (Proof, error) {
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if useCKZG.Load() {
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return ckzgComputeBlobProof(blob, commitment)
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}
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return gokzgComputeBlobProof(blob, commitment)
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}
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// VerifyBlobProof verifies that the blob data corresponds to the provided commitment.
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func VerifyBlobProof(blob Blob, commitment Commitment, proof Proof) error {
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if useCKZG.Load() {
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return ckzgVerifyBlobProof(blob, commitment, proof)
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}
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return gokzgVerifyBlobProof(blob, commitment, proof)
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}
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