Added support for sha384/sha512 hash algorithms in hashedrekords (#1959)

* Added support for sha384/sha512 hash algorithms in hashedrekords

Includes changes provided by @bobcallaway

Signed-off-by: Riccardo Schirone <riccardo.schirone@trailofbits.com>

* Added e2e test for hashedrekord type

Make sure Rekor accepts SHA256 digest but not SHA1

Signed-off-by: Riccardo Schirone <riccardo.schirone@trailofbits.com>

* hashedrekord: add a SHA1 backstop test for CreateFromArtifactProperties

Signed-off-by: William Woodruff <william@trailofbits.com>

---------

Signed-off-by: Riccardo Schirone <riccardo.schirone@trailofbits.com>
Signed-off-by: William Woodruff <william@trailofbits.com>
Co-authored-by: William Woodruff <william@trailofbits.com>

pkg/types/hashedrekord/v0.0.1/e2e_test.go

@@ -0,0 +1,94 @@
+//
+// Copyright 2024 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.
+
+//go:build e2e
+
+package hashedrekord
+
+import (
+	"bytes"
+	"context"
+	"crypto"
+	"crypto/ecdsa"
+	"crypto/elliptic"
+	"crypto/rand"
+	"os"
+	"testing"
+	"time"
+
+	"github.com/sigstore/rekor/pkg/client"
+	"github.com/sigstore/rekor/pkg/generated/client/entries"
+	"github.com/sigstore/rekor/pkg/types"
+	"github.com/sigstore/sigstore/pkg/cryptoutils"
+	"github.com/sigstore/sigstore/pkg/signature"
+)
+
+func rekorServer() string {
+	if s := os.Getenv("REKOR_SERVER"); s != "" {
+		return s
+	}
+	return "http://localhost:3000"
+}
+
+// TestSHA256HashedRekordEntry tests sending a valid HashedRekord proposed entry.
+func TestSHA256HashedRekordEntry(t *testing.T) {
+	privKey, err := ecdsa.GenerateKey(elliptic.P256(), rand.Reader)
+	if err != nil {
+		t.Fatalf("error generating key: %v", err)
+	}
+	pubBytes, err := cryptoutils.MarshalPublicKeyToPEM(privKey.Public())
+	if err != nil {
+		t.Fatalf("error marshaling public key: %v", err)
+	}
+
+	data := []byte("data")
+	signer, err := signature.LoadSigner(privKey, crypto.SHA256)
+	if err != nil {
+		t.Fatalf("error loading verifier: %v", err)
+	}
+	signature, err := signer.SignMessage(bytes.NewReader(data))
+	if err != nil {
+		t.Fatalf("error signing message: %v", err)
+	}
+
+	ap := types.ArtifactProperties{
+		ArtifactBytes:  []byte("data"),
+		ArtifactHash:   "sha256:3a6eb0790f39ac87c94f3856b2dd2c5d110e6811602261a9a923d3bb23adc8b7",
+		PublicKeyBytes: [][]byte{pubBytes},
+		PKIFormat:      "x509",
+		SignatureBytes: signature,
+	}
+
+	ei := NewEntry()
+
+	entry, err := ei.CreateFromArtifactProperties(context.Background(), ap)
+	if err != nil {
+		t.Fatalf("error creating entry: %v", err)
+	}
+
+	rc, err := client.GetRekorClient(rekorServer())
+	if err != nil {
+		t.Errorf("error getting client: %v", err)
+	}
+
+	params := &entries.CreateLogEntryParams{}
+	params.SetProposedEntry(entry)
+	params.SetContext(context.Background())
+	params.SetTimeout(5 * time.Second)
+
+	if _, err = rc.Entries.CreateLogEntry(params); err != nil {
+		t.Fatalf("expected no errors when submitting hashedrekord entry with sha256 to rekor %s", err)
+	}
+}

pkg/types/hashedrekord/v0.0.1/entry.go

@@ -18,6 +18,7 @@ package hashedrekord
 import (
 	"bytes"
 	"context"
+	"crypto"
 	"crypto/ed25519"
 	"crypto/sha256"
 	"encoding/hex"
@@ -38,6 +39,7 @@ import (
 	"github.com/sigstore/rekor/pkg/pki/x509"
 	"github.com/sigstore/rekor/pkg/types"
 	hashedrekord "github.com/sigstore/rekor/pkg/types/hashedrekord"
+	"github.com/sigstore/rekor/pkg/util"
 	"github.com/sigstore/sigstore/pkg/signature/options"
 )
 
@@ -178,17 +180,38 @@ func (v *V001Entry) validate() (pki.Signature, pki.PublicKey, error) {
 		return nil, nil, types.ValidationError(errors.New("invalid value for hash"))
 	}
 
+	var alg crypto.Hash
+	switch swag.StringValue(hash.Algorithm) {
+	case models.HashedrekordV001SchemaDataHashAlgorithmSha384:
+		alg = crypto.SHA384
+	case models.HashedrekordV001SchemaDataHashAlgorithmSha512:
+		alg = crypto.SHA512
+	default:
+		alg = crypto.SHA256
+	}
+
 	decoded, err := hex.DecodeString(*hash.Value)
 	if err != nil {
 		return nil, nil, err
 	}
-	if err := sigObj.Verify(nil, keyObj, options.WithDigest(decoded)); err != nil {
+	if err := sigObj.Verify(nil, keyObj, options.WithDigest(decoded), options.WithCryptoSignerOpts(alg)); err != nil {
 		return nil, nil, types.ValidationError(fmt.Errorf("verifying signature: %w", err))
 	}
 
 	return sigObj, keyObj, nil
 }
 
+func getDataHashAlgorithm(hashAlgorithm crypto.Hash) string {
+	switch hashAlgorithm {
+	case crypto.SHA384:
+		return models.HashedrekordV001SchemaDataHashAlgorithmSha384
+	case crypto.SHA512:
+		return models.HashedrekordV001SchemaDataHashAlgorithmSha512
+	default:
+		return models.HashedrekordV001SchemaDataHashAlgorithmSha256
+	}
+}
+
 func (v V001Entry) CreateFromArtifactProperties(_ context.Context, props types.ArtifactProperties) (models.ProposedEntry, error) {
 	returnVal := models.Hashedrekord{}
 	re := V001Entry{}
@@ -230,10 +253,11 @@ func (v V001Entry) CreateFromArtifactProperties(_ context.Context, props types.A
 		return nil, errors.New("only one public key must be provided")
 	}
 
+	hashAlgorithm, hashValue := util.UnprefixSHA(props.ArtifactHash)
 	re.HashedRekordObj.Signature.PublicKey.Content = strfmt.Base64(publicKeyBytes[0])
 	re.HashedRekordObj.Data.Hash = &models.HashedrekordV001SchemaDataHash{
-		Algorithm: swag.String(models.HashedrekordV001SchemaDataHashAlgorithmSha256),
-		Value:     swag.String(props.ArtifactHash),
+		Algorithm: swag.String(getDataHashAlgorithm(hashAlgorithm)),
+		Value:     swag.String(hashValue),
 	}
 
 	if _, _, err := re.validate(); err != nil {