Update trillian dependency (#281)

* Update trillian dependency to master

This removes calls to the trillian verifier and replaces them with calls to a new rekor verify package!
The `verify` package currently only verifies the signed log root.

Signed-off-by: Priya Wadhwa <priyawadhwa@google.com>

* Fix lint

Signed-off-by: Priya Wadhwa <priyawadhwa@google.com>

* Add verifier back in and update trillian images

Signed-off-by: Priya Wadhwa <priyawadhwa@google.com>

* Make verify private

Signed-off-by: Priya Wadhwa <priyawadhwa@google.com>

* Address code review comments

Signed-off-by: Priya Wadhwa <priyawadhwa@google.com>

* Roll back to trillian v1.3.13

Signed-off-by: Priya Wadhwa <priyawadhwa@google.com>

* Pin trillian to latest commit

Signed-off-by: Priya Wadhwa <priyawadhwa@google.com>

cmd/rekor-cli/app/log_info.go

@@ -17,9 +17,7 @@ package app
 
 import (
 	"bytes"
-	"crypto"
 	"crypto/x509"
-	"encoding/base64"
 	"encoding/hex"
 	"encoding/pem"
 	"errors"
@@ -27,9 +25,6 @@ import (
 	"strings"
 	"time"
 
-	"github.com/google/trillian"
-	tclient "github.com/google/trillian/client"
-	tcrypto "github.com/google/trillian/crypto"
 	"github.com/google/trillian/merkle/logverifier"
 	rfc6962 "github.com/google/trillian/merkle/rfc6962/hasher"
 	"github.com/spf13/cobra"
@@ -39,6 +34,7 @@ import (
 	"github.com/sigstore/rekor/cmd/rekor-cli/app/state"
 	"github.com/sigstore/rekor/pkg/generated/client/tlog"
 	"github.com/sigstore/rekor/pkg/log"
+	"github.com/sigstore/rekor/pkg/verify"
 )
 
 type logInfoCmdOutput struct {
@@ -76,24 +72,14 @@ var logInfoCmd = &cobra.Command{
 
 		logInfo := result.GetPayload()
 
-		keyHint, err := base64.StdEncoding.DecodeString(logInfo.SignedTreeHead.KeyHint.String())
-		if err != nil {
-			return nil, err
+		logRoot := *logInfo.SignedTreeHead.LogRoot
+		if logRoot == nil {
+			return nil, errors.New("logroot should not be nil")
 		}
-		logRoot, err := base64.StdEncoding.DecodeString(logInfo.SignedTreeHead.LogRoot.String())
-		if err != nil {
-			return nil, err
+		signature := *logInfo.SignedTreeHead.Signature
+		if signature == nil {
+			return nil, errors.New("signature should not be nil")
 		}
-		signature, err := base64.StdEncoding.DecodeString(logInfo.SignedTreeHead.Signature.String())
-		if err != nil {
-			return nil, err
-		}
-		sth := trillian.SignedLogRoot{
-			KeyHint:          keyHint,
-			LogRoot:          logRoot,
-			LogRootSignature: signature,
-		}
-
 		publicKey := viper.GetString("rekor_server_public_key")
 		if publicKey == "" {
 			// fetch key from server
@@ -114,8 +100,7 @@ var logInfoCmd = &cobra.Command{
 			return nil, err
 		}
 
-		verifier := tclient.NewLogVerifier(rfc6962.DefaultHasher, pub, crypto.SHA256)
-		lr, err := tcrypto.VerifySignedLogRoot(verifier.PubKey, verifier.SigHash, &sth)
+		lr, err := verify.SignedLogRoot(pub, logRoot, signature)
 		if err != nil {
 			return nil, err
 		}

cmd/rekor-server/app/watch.go

@@ -19,10 +19,8 @@ import (
 	"context"
 	"crypto"
 	"crypto/x509"
-	"encoding/base64"
 	"encoding/json"
 	"encoding/pem"
-	"errors"
 	"flag"
 	"fmt"
 	"os"
@@ -31,17 +29,17 @@ import (
 	_ "gocloud.dev/blob/fileblob" // fileblob
 	_ "gocloud.dev/blob/gcsblob"
 
-	"github.com/google/trillian"
-	tclient "github.com/google/trillian/client"
-	"github.com/google/trillian/merkle/rfc6962/hasher"
 	"github.com/google/trillian/types"
+	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 	"gocloud.dev/blob"
 
 	"github.com/sigstore/rekor/cmd/rekor-cli/app"
 	"github.com/sigstore/rekor/pkg/generated/client"
+	"github.com/sigstore/rekor/pkg/generated/models"
 	"github.com/sigstore/rekor/pkg/log"
+	"github.com/sigstore/rekor/pkg/verify"
 )
 
 const rekorSthBucketEnv = "REKOR_STH_BUCKET"
@@ -90,7 +88,6 @@ var watchCmd = &cobra.Command{
 			return err
 		}
 
-		verifier := tclient.NewLogVerifier(hasher.DefaultHasher, pub, crypto.SHA256)
 		ctx := context.Background()
 		bucketURL := os.Getenv(rekorSthBucketEnv)
 		if bucketURL == "" {
@@ -107,7 +104,7 @@ var watchCmd = &cobra.Command{
 		for {
 			<-tick.C
 			log.Logger.Info("performing check")
-			lr, err := doCheck(c, verifier)
+			lr, err := doCheck(c, pub)
 			if err != nil {
 				log.Logger.Warnf("error verifiying tree: %s", err)
 				continue
@@ -134,36 +131,28 @@ func init() {
 	rootCmd.AddCommand(watchCmd)
 }
 
-func doCheck(c *client.Rekor, v *tclient.LogVerifier) (*SignedAndUnsignedLogRoot, error) {
+func doCheck(c *client.Rekor, pub crypto.PublicKey) (*SignedAndUnsignedLogRoot, error) {
 	li, err := c.Tlog.GetLogInfo(nil)
 	if err != nil {
-		return nil, err
+		return nil, errors.Wrap(err, "getting log info")
 	}
-	keyHint, err := base64.StdEncoding.DecodeString(li.Payload.SignedTreeHead.KeyHint.String())
-	if err != nil {
-		return nil, err
+	logRoot := *li.Payload.SignedTreeHead.LogRoot
+	if logRoot == nil {
+		return nil, errors.New("logroot should not be nil")
 	}
-	logRoot, err := base64.StdEncoding.DecodeString(li.Payload.SignedTreeHead.LogRoot.String())
-	if err != nil {
-		return nil, err
+	signature := *li.Payload.SignedTreeHead.Signature
+	if signature == nil {
+		return nil, errors.New("signature should not be nil")
 	}
-	signature, err := base64.StdEncoding.DecodeString(li.Payload.SignedTreeHead.Signature.String())
+
+	verifiedLogRoot, err := verify.SignedLogRoot(pub, logRoot, signature)
 	if err != nil {
-		return nil, err
-	}
-	sth := trillian.SignedLogRoot{
-		KeyHint:          keyHint,
-		LogRoot:          logRoot,
-		LogRootSignature: signature,
+		return nil, errors.Wrap(err, "signing log root")
 	}
 
-	lr := &types.LogRootV1{}
-	if err := lr.UnmarshalBinary(sth.LogRoot); err != nil {
-		return nil, err
-	}
 	return &SignedAndUnsignedLogRoot{
-		SignedLogRoot:   &sth,
-		VerifiedLogRoot: lr,
+		SignedLogRoot:   li.GetPayload().SignedTreeHead,
+		VerifiedLogRoot: verifiedLogRoot,
 	}, nil
 }
 
@@ -187,6 +176,6 @@ func uploadToBlobStorage(ctx context.Context, bucket *blob.Bucket, lr *SignedAnd
 
 // For JSON marshalling
 type SignedAndUnsignedLogRoot struct {
-	SignedLogRoot   *trillian.SignedLogRoot
+	SignedLogRoot   *models.LogInfoSignedTreeHead
 	VerifiedLogRoot *types.LogRootV1
 }

docker-compose.yml

@@ -16,7 +16,7 @@
 version: '3.4'
 services:
   mysql:
-    image: gcr.io/trillian-opensource-ci/db_server:v1.3.13
+    image: gcr.io/trillian-opensource-ci/db_server:5e12fb368c8fd19e10aeb5a5cf785107f8069c08
     environment:
       - MYSQL_ROOT_PASSWORD=zaphod
       - MYSQL_DATABASE=test
@@ -45,7 +45,7 @@ services:
       retries: 3
       start_period: 5s
   trillian-log-server:
-    image: gcr.io/trillian-opensource-ci/log_server:v1.3.13
+    image: gcr.io/trillian-opensource-ci/log_server:5e12fb368c8fd19e10aeb5a5cf785107f8069c08
     command: [
       "--storage_system=mysql",
       "--mysql_uri=test:zaphod@tcp(mysql:3306)/test",
@@ -60,7 +60,7 @@ services:
     depends_on:
       - mysql
   trillian-log-signer:
-    image: gcr.io/trillian-opensource-ci/log_signer:v1.3.13
+    image: gcr.io/trillian-opensource-ci/log_signer:5e12fb368c8fd19e10aeb5a5cf785107f8069c08
     command: [
       "--storage_system=mysql",
       "--mysql_uri=test:zaphod@tcp(mysql:3306)/test",

go.mod

@@ -16,7 +16,7 @@ require (
 	github.com/go-openapi/swag v0.19.15
 	github.com/go-openapi/validate v0.20.2
 	github.com/google/rpmpack v0.0.0-20210107155803-d6befbf05148
-	github.com/google/trillian v1.3.13
+	github.com/google/trillian v1.3.14-0.20210413093047-5e12fb368c8f
 	github.com/howeyc/gopass v0.0.0-20190910152052-7cb4b85ec19c // indirect
 	github.com/jedisct1/go-minisign v0.0.0-20210106175330-e54e81d562c7
 	github.com/mediocregopher/radix/v4 v4.0.0-beta.1

pkg/api/tlog.go

@@ -46,7 +46,6 @@ func GetLogInfoHandler(params tlog.GetLogInfoParams) middleware.Responder {
 
 	hashString := hex.EncodeToString(root.RootHash)
 	treeSize := int64(root.TreeSize)
-	keyHint := strfmt.Base64(result.SignedLogRoot.GetKeyHint())
 	logRoot := strfmt.Base64(result.SignedLogRoot.GetLogRoot())
 
 	// sign the log root ourselves to get the log root signature
@@ -58,7 +57,6 @@ func GetLogInfoHandler(params tlog.GetLogInfoParams) middleware.Responder {
 	signature := strfmt.Base64(sig)
 
 	sth := models.LogInfoSignedTreeHead{
-		KeyHint:   &keyHint,
 		LogRoot:   &logRoot,
 		Signature: &signature,
 	}

pkg/api/trillian_client.go

@@ -21,7 +21,8 @@ import (
 	"fmt"
 	"time"
 
-	_ "github.com/google/trillian/merkle/rfc6962" // register hasher
+	"github.com/google/trillian/merkle/logverifier"
+	"github.com/google/trillian/merkle/rfc6962/hasher"
 
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
@@ -216,7 +217,8 @@ func (t *TrillianClient) getLeafAndProofByIndex(index int64) *Response {
 		})
 
 	if resp != nil && resp.Proof != nil {
-		if err := t.verifier.VerifyInclusionAtIndex(&root, resp.Leaf.LeafValue, index, resp.Proof.Hashes); err != nil {
+		logVerifier := logverifier.New(hasher.DefaultHasher)
+		if err := logVerifier.VerifyInclusionProof(index, int64(root.TreeSize), resp.Proof.Hashes, root.RootHash, resp.GetLeaf().MerkleLeafHash); err != nil {
 			return &Response{
 				status: status.Code(err),
 				err:    err,
@@ -322,7 +324,6 @@ func createAndInitTree(ctx context.Context, adminClient trillian.TrillianAdminCl
 	t, err := adminClient.CreateTree(ctx, &trillian.CreateTreeRequest{
 		Tree: &trillian.Tree{
 			TreeType:           trillian.TreeType_LOG,
-			HashStrategy:       trillian.HashStrategy_RFC6962_SHA256,
 			HashAlgorithm:      sigpb.DigitallySigned_SHA256,
 			SignatureAlgorithm: sigpb.DigitallySigned_ECDSA,
 			TreeState:          trillian.TreeState_ACTIVE,

pkg/verify/log_root.go

+//
+// Copyright 2021 The Sigstore Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package verify
+
+import (
+	"crypto"
+	"crypto/ecdsa"
+	"fmt"
+
+	"github.com/google/trillian/types"
+	"github.com/pkg/errors"
+)
+
+// this verification copied from https://github.com/google/trillian/blob/v1.3.13/crypto/verifier.go
+// which has since been deleted
+
+// SignedLogRoot verifies the signed log root and returns its contents
+func SignedLogRoot(pub crypto.PublicKey, logRoot, logRootSignature []byte) (*types.LogRootV1, error) {
+	hash := crypto.SHA256
+	if err := verify(pub, hash, logRoot, logRootSignature); err != nil {
+		return nil, err
+	}
+
+	var lr types.LogRootV1
+	if err := lr.UnmarshalBinary(logRoot); err != nil {
+		return nil, err
+	}
+	return &lr, nil
+}
+
+// verify cryptographically verifies the output of Signer.
+func verify(pub crypto.PublicKey, hasher crypto.Hash, data, sig []byte) error {
+	if sig == nil {
+		return errors.New("signature is nil")
+	}
+
+	h := hasher.New()
+	if _, err := h.Write(data); err != nil {
+		return errors.Wrap(err, "write")
+	}
+	digest := h.Sum(nil)
+
+	switch pub := pub.(type) {
+	case *ecdsa.PublicKey:
+		if !ecdsa.VerifyASN1(pub, digest, sig) {
+			return errors.New("verification failed")
+		}
+	default:
+		return fmt.Errorf("unknown public key type: %T", pub)
+	}
+	return nil
+}

pkg/verify/log_root_test.go

+//
+// Copyright 2021 The Sigstore Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package verify
+
+import (
+	"context"
+	"crypto"
+	"testing"
+
+	"github.com/sigstore/rekor/pkg/signer"
+)
+
+func TestVerify(t *testing.T) {
+	signer, err := signer.NewMemory()
+	if err != nil {
+		t.Fatalf("getting signer: %v", signer)
+	}
+
+	// sign and verify
+	ctx := context.Background()
+	msg := []byte("foo")
+	signature, _, err := signer.Sign(ctx, msg)
+	if err != nil {
+		t.Fatalf("signing: %v", err)
+	}
+
+	// get public key
+	pubKey, err := signer.PublicKey(ctx)
+	if err != nil {
+		t.Fatalf("getting public key: %v", err)
+	}
+
+	// verify should work with correct signature
+	if err := verify(pubKey, crypto.SHA256, msg, signature); err != nil {
+		t.Fatalf("error verifying: %v", err)
+	}
+
+	// and fail with an incorrect signature
+	if err := verify(pubKey, crypto.SHA256, msg, []byte("nope")); err == nil {
+		t.Fatalf("expected failure with incorrect signature")
+	}
+}