Change to use curve25519-voi's VRF (#633)

* draft: Use curve25519-voi's vrf function

`make build` passed.
The tendermint/tendermint master uses curve25519 at ed25519.go. Therefore, curve25519-voi should be used from the viewpoint of reducing implementation complexity and cost management. Also, curve25519-voi is based on ed25519-dalek and is more optimized than ref10 in cofactor processing.

* fix: Delete r2ishiguro and libsodium

* refactor: Mark unused parameters

* comment: fix the comment for `VRFVerify`

* fix: Leave the necessary jobs in coverage.yml and delete one unnecessary file

* fix: delete unnecessary line and describe length of proof for curve25519-voi

* typo

* fix: remove an unnecessary line

.github/workflows/build.yml

@@ -37,6 +37,3 @@ jobs:
       - name: Build Linux
         run: GOOS=linux GOARCH=${{ matrix.goarch }} CC=${{ matrix.gcc }} TARGET_HOST=${{ matrix.host }} make build
         if: "env.GIT_DIFF != ''"
-      - name: Build Linux with Libsodium
-        run: GOOS=linux GOARCH=${{ matrix.goarch }} CC=${{ matrix.gcc }} TARGET_HOST=${{ matrix.host }} LIBSODIUM=1 make build
-        if: "env.GIT_DIFF != ''"

.github/workflows/coverage.yml

@@ -38,25 +38,12 @@ jobs:
           name: "${{ github.sha }}-05"
           path: ./pkgs.txt.part.05
 
-  build-libsodium:
-    name: Build libsodium
-    runs-on: ubuntu-latest
-    needs: split-test-files
-    steps:
-      - uses: actions/checkout@v3
-      - run: make libsodium
-      - uses: actions/upload-artifact@v3
-        with:
-          name: libsodium
-          path: crypto/vrf/internal/vrf/sodium
-
   tests:
     runs-on: ubuntu-latest
-    needs: build-libsodium
+    needs: split-test-files
     strategy:
       fail-fast: false
       matrix:
-        vrf: ["r2ishiguro", "libsodium"]
         part: ["00", "01", "02", "03", "04", "05"]
     steps:
       - uses: actions/setup-go@v4
@@ -74,13 +61,9 @@ jobs:
         with:
           name: "${{ github.sha }}-${{ matrix.part }}"
         if: env.GIT_DIFF
-      - uses: actions/download-artifact@v3
-        with:
-          name: libsodium
-          path: crypto/vrf/internal/vrf/sodium
       - name: test & coverage report creation
         run: |
-          cat pkgs.txt.part.${{ matrix.part }} | xargs go test -mod=readonly -timeout 7m -race -coverprofile=${{ matrix.part }}profile.out -covermode=atomic -tags ${{ matrix.vrf }}
+          cat pkgs.txt.part.${{ matrix.part }} | xargs go test -mod=readonly -timeout 7m -race -coverprofile=${{ matrix.part }}profile.out -covermode=atomic
         if: env.GIT_DIFF
       - uses: actions/upload-artifact@v3
         with:

.github/workflows/e2e.yml

@@ -122,9 +122,6 @@ jobs:
           docker load -i ${{ needs.e2e-build.outputs.CACHE_FILE }}
         if: "env.GIT_DIFF != ''"
 
-      - name: Build libsodium
-        run: make libsodium
-
       - name: Build e2e runner
         working-directory: test/e2e
         run: make runner

Makefile

@@ -5,13 +5,6 @@ OUTPUT?=build/ostracon
 INCLUDE = -I=${GOPATH}/src/github.com/Finschia/ostracon -I=${GOPATH}/src -I=${GOPATH}/src/github.com/gogo/protobuf/protobuf
 BUILD_TAGS ?= ostracon
 VERSION := $(shell git describe --always)
-ifeq ($(LIBSODIUM), 1)
-  BUILD_TAGS += libsodium
-  LIBSODIUM_TARGET = libsodium
-else
-  BUILD_TAGS += r2ishiguro
-  LIBSODIUM_TARGET =
-endif
 LD_FLAGS = -X github.com/Finschia/ostracon/version.OCCoreSemVer=$(VERSION)
 BUILD_FLAGS = -mod=readonly -ldflags "$(LD_FLAGS)"
 HTTPS_GIT := https://github.com/Finschia/ostracon.git
@@ -64,11 +57,11 @@ include tests.mk
 ###                                Build Ostracon                           ###
 ###############################################################################
 
-build: $(LIBSODIUM_TARGET)
+build:
 	CGO_ENABLED=1 go build $(BUILD_FLAGS) -tags "$(BUILD_TAGS)" -o $(OUTPUT) ./cmd/ostracon/
 .PHONY: build
 
-install: $(LIBSODIUM_TARGET)
+install:
 	CGO_ENABLED=1 go install $(BUILD_FLAGS) -tags "$(BUILD_TAGS)" ./cmd/ostracon
 .PHONY: install
 
@@ -138,29 +131,6 @@ install_abci:
 ###                              Distribution                               ###
 ###############################################################################
 
-########################################
-### libsodium
-
-VRF_ROOT = $(SRCPATH)/crypto/vrf/internal/vrf
-LIBSODIUM_ROOT = $(VRF_ROOT)/libsodium
-LIBSODIUM_OS = $(VRF_ROOT)/sodium/$(TARGET_OS)_$(TARGET_ARCH)
-ifneq ($(TARGET_HOST), "")
-LIBSODIUM_HOST = "--host=$(TARGET_HOST)"
-endif
-
-libsodium:
-	@if [ ! -f $(LIBSODIUM_OS)/lib/libsodium.a ]; then \
-		rm -rf $(LIBSODIUM_ROOT) && \
-		mkdir $(LIBSODIUM_ROOT) && \
-		git submodule update --init --recursive && \
-		cd $(LIBSODIUM_ROOT) && \
-		./autogen.sh && \
-		./configure --disable-shared --prefix="$(LIBSODIUM_OS)" $(LIBSODIUM_HOST) && \
-		$(MAKE) && \
-		$(MAKE) install; \
-	fi
-.PHONY: libsodium
-
 ########################################
 ### Distribution
 
@@ -291,7 +261,7 @@ DOCKER_CMD = docker run --rm \
 DOCKER_IMG = golang:1.18-alpine
 BUILD_CMD = apk add --update --no-cache git make gcc libc-dev build-base curl jq bash file gmp-dev clang libtool autoconf automake \
 	&& cd $(DOCKER_HOME) \
-	&& LIBSODIUM=$(LIBSODIUM) make build-linux
+	&& make build-linux
 
 # Login docker-container for confirmation building linux binary
 build-shell:

README.md

@@ -21,18 +21,6 @@ git clone https://github.com/Finschia/ostracon.git
 git clone [email protected]:Finschia/ostracon.git
 ```
 
-### git clone with recursive if you want to use libsodium
-```shell
-git clone --recursive https://github.com/Finschia/ostracon.git
-# or
-git clone --recursive [email protected]:Finschia/ostracon.git
-```
-
-### git submodule if you forget to clone with submodule
-```shell
-git submodule update --init --recursive
-```
-
 ## Local Standalone
 **Build**
  ```sh

crypto/crypto.go

@@ -28,7 +28,7 @@ type PubKey interface {
 	Address() Address
 	Bytes() []byte
 	VerifySignature(msg []byte, sig []byte) bool
-	VRFVerify(proof Proof, seed []byte) (Output, error) // TODO 🏺 rename to VerifyVRFProof to match VerifySignature
+	VRFVerify(proof []byte, message []byte) (Output, error)
 	Equals(PubKey) bool
 	Type() string
 }

crypto/ed25519/ed25519.go

@@ -7,12 +7,11 @@ import (
 	"fmt"
 	"io"
 
-	"golang.org/x/crypto/ed25519"
-
 	"github.com/Finschia/ostracon/crypto"
 	"github.com/Finschia/ostracon/crypto/tmhash"
-	"github.com/Finschia/ostracon/crypto/vrf"
 	tmjson "github.com/Finschia/ostracon/libs/json"
+	"github.com/oasisprotocol/curve25519-voi/primitives/ed25519"
+	vrf "github.com/oasisprotocol/curve25519-voi/primitives/ed25519/extra/ecvrf"
 )
 
 //-------------------------------------
@@ -63,11 +62,8 @@ func (privKey PrivKey) Sign(msg []byte) ([]byte, error) {
 
 // VRFProve generates a VRF Proof for given message to generate a verifiable random.
 func (privKey PrivKey) VRFProve(message []byte) (crypto.Proof, error) {
-	proof, err := vrf.Prove(privKey[:], message)
-	if err != nil {
-		return nil, err
-	}
-	return crypto.Proof(proof[:]), nil
+	proof := vrf.Prove(ed25519.PrivateKey(privKey[:]), message)
+	return proof, nil
 }
 
 // PubKey gets the corresponding public key from the private key.
@@ -173,21 +169,17 @@ func (pubKey PubKey) Type() string {
 	return KeyType
 }
 
-// VRFVerify verifies that the given VRF Proof was generated from the message by the owner of this public key.
-func (pubKey PubKey) VRFVerify(proof crypto.Proof, message []byte) (crypto.Output, error) {
-	valid, err := vrf.Verify(pubKey[:], vrf.Proof(proof), message)
-	if err != nil {
-		return nil, fmt.Errorf("the specified proof is not a valid ed25519 proof: err: %s", err.Error())
-	}
-	if !valid {
-		return nil, fmt.Errorf("the specified Proof is not generated with this pair-key: %s",
+// VRFVerify guarantees that the public key is validated such that the "full uniqueness" and
+// "full collision" properties are satisfied.
+// The internal function of VRFVerify is implemented based on the IETF draft.
+// See sections 3.1 and 3.2 here https://datatracker.ietf.org/doc/draft-irtf-cfrg-vrf/.
+func (pubKey PubKey) VRFVerify(proof []byte, message []byte) (crypto.Output, error) {
+	isValid, hash := vrf.Verify(ed25519.PublicKey(pubKey), proof, message)
+	if !isValid {
+		return nil, fmt.Errorf("either Public Key or Proof is an invalid value.: err: %s",
 			hex.EncodeToString(proof))
 	}
-	output, err := vrf.ProofToHash(vrf.Proof(proof))
-	if err != nil {
-		return nil, err
-	}
-	return crypto.Output(output), nil
+	return hash, nil
 }
 
 func (pubKey PubKey) Equals(other crypto.PubKey) bool {

crypto/ed25519/ed25519_test.go

@@ -4,8 +4,6 @@ import (
 	"encoding/hex"
 	"testing"
 
-	coniks "github.com/coniks-sys/coniks-go/crypto/vrf"
-
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
@@ -36,7 +34,6 @@ func TestVRFProveAndVRFVerify(t *testing.T) {
 
 	privKey := ed25519.GenPrivKey()
 	pubKey := privKey.PubKey()
-
 	message, _ := hex.DecodeString("0000000000000000000000000000000000000000000000000000000000000000")
 	proof, err := privKey.VRFProve(message)
 	assert.Nil(t, err)
@@ -46,26 +43,20 @@ func TestVRFProveAndVRFVerify(t *testing.T) {
 	assert.Nil(t, err)
 	assert.NotNil(t, output)
 
-	// error
-	{
-		message, _ = hex.DecodeString("0000000000000000000000000000000000000000000000000000000000000001")
-		output, err = pubKey.VRFVerify(proof, message)
-		assert.NotNil(t, err)
-		assert.Nil(t, output)
-	}
-
-	// invalid
-	{
-		privateKey, _ := coniks.GenerateKey(nil)
-		copy(privKey[:], privateKey)
-		pubKey = privKey.PubKey()
-
-		proof, err = privKey.VRFProve(message)
-		assert.Nil(t, err)
-		assert.NotNil(t, proof)
-
-		output, err = pubKey.VRFVerify(proof, message)
-		assert.NotNil(t, err)
-		assert.Nil(t, output)
-	}
+	// *** If the combination of (pubkey, message, proof) is incorrect ***
+	// invalid message
+	inValidMessage, _ := hex.DecodeString("0000000000000000000000000000000000000000000000000000000000000001")
+	_, err1 := pubKey.VRFVerify(proof, inValidMessage)
+	assert.Error(t, err1)
+
+	// invalid pubkey
+	invalidPrivKey := ed25519.GenPrivKey()
+	invalidPubkey := invalidPrivKey.PubKey()
+	_, err2 := invalidPubkey.VRFVerify(proof, message)
+	assert.Error(t, err2)
+
+	// invalid proof
+	invalidProof, _ := invalidPrivKey.VRFProve(message)
+	_, err3 := pubKey.VRFVerify(invalidProof, message)
+	assert.Error(t, err3)
 }

crypto/secp256k1/secp256k1.go

@@ -187,7 +187,7 @@ func (pubKey PubKey) String() string {
 }
 
 // VRFVerify is not supported in Secp256k1.
-func (pubKey PubKey) VRFVerify(proof crypto.Proof, seed []byte) (crypto.Output, error) {
+func (pubKey PubKey) VRFVerify(_ []byte, _ []byte) (crypto.Output, error) {
 	return nil, fmt.Errorf("VRF verify is not supported by the secp256k1")
 }
 

crypto/sr25519/pubkey.go

@@ -59,7 +59,7 @@ func (pubKey PubKey) VerifySignature(msg []byte, sig []byte) bool {
 }
 
 // VRFVerify is not supported in Sr25519.
-func (pubKey PubKey) VRFVerify(proof crypto.Proof, seed []byte) (crypto.Output, error) {
+func (pubKey PubKey) VRFVerify(_ []byte, _ []byte) (crypto.Output, error) {
 	return nil, fmt.Errorf("VRF verify is not supported by the sr25519")
 }