Include checkpoint (STH) in entry upload and retrieve responses

cmd/rekor-cli/app/get.go

@@ -118,6 +118,13 @@ var getCmd = &cobra.Command{
 					return nil, fmt.Errorf("unable to verify entry was added to log: %w", err)
 				}
 
+				// verify checkpoint
+				if entry.Verification.InclusionProof.Checkpoint != nil {
+					if err := verify.VerifyCheckpointSignature(&e, verifier); err != nil {
+						return nil, err
+					}
+				}
+
 				return parseEntry(ix, entry)
 			}
 		}

cmd/rekor-cli/app/upload.go

@@ -141,6 +141,17 @@ var uploadCmd = &cobra.Command{
 		if err := verify.VerifySignedEntryTimestamp(ctx, &logEntry, verifier); err != nil {
 			return nil, fmt.Errorf("unable to verify entry was added to log: %w", err)
 		}
+		// TODO: Remove conditional once inclusion proof/checkpoint is always returned by server.
+		if logEntry.Verification.InclusionProof != nil {
+			// verify inclusion proof
+			if err := verify.VerifyInclusion(ctx, &logEntry); err != nil {
+				return nil, fmt.Errorf("error verifying inclusion proof: %w", err)
+			}
+			// verify checkpoint
+			if err := verify.VerifyCheckpointSignature(&logEntry, verifier); err != nil {
+				return nil, err
+			}
+		}
 
 		return &uploadCmdOutput{
 			Location: string(resp.Location),

cmd/rekor-cli/app/verify.go

@@ -37,18 +37,24 @@ import (
 )
 
 type verifyCmdOutput struct {
-	RootHash  string
-	EntryUUID string
-	Index     int64
-	Size      int64
-	Hashes    []string
+	RootHash   string
+	EntryUUID  string
+	Index      int64
+	Size       int64
+	Hashes     []string
+	Checkpoint string
 }
 
 func (v *verifyCmdOutput) String() string {
 	s := fmt.Sprintf("Current Root Hash: %v\n", v.RootHash)
 	s += fmt.Sprintf("Entry Hash: %v\n", v.EntryUUID)
 	s += fmt.Sprintf("Entry Index: %v\n", v.Index)
-	s += fmt.Sprintf("Current Tree Size: %v\n\n", v.Size)
+	s += fmt.Sprintf("Current Tree Size: %v\n", v.Size)
+	if len(v.Checkpoint) > 0 {
+		s += fmt.Sprintf("Checkpoint:\n%v\n\n", v.Checkpoint)
+	} else {
+		s += "\n"
+	}
 
 	s += "Inclusion Proof:\n"
 	hasher := rfc6962.DefaultHasher
@@ -147,6 +153,9 @@ var verifyCmd = &cobra.Command{
 				Size:      *v.Verification.InclusionProof.TreeSize,
 				Hashes:    v.Verification.InclusionProof.Hashes,
 			}
+			if v.Verification.InclusionProof.Checkpoint != nil {
+				o.Checkpoint = *v.Verification.InclusionProof.Checkpoint
+			}
 			entry = v
 		}
 
@@ -167,6 +176,7 @@ var verifyCmd = &cobra.Command{
 			return nil, err
 		}
 
+		// verify inclusion proof, checkpoint, and SET
 		if err := verify.VerifyLogEntry(ctx, &entry, verifier); err != nil {
 			return nil, fmt.Errorf("validating entry: %w", err)
 		}

openapi.yaml

@@ -631,11 +631,16 @@ definitions:
           type: string
           description: SHA256 hash value expressed in hexadecimal format
           pattern: '^[0-9a-fA-F]{64}$'
+      checkpoint:
+        type: string
+        format: signedCheckpoint
+        description: The checkpoint (signed tree head) that the inclusion proof is based on
     required:
       - logIndex
       - rootHash
       - treeSize
       - hashes
+      - checkpoint
 
   Error:
     type: object

pkg/api/entries.go

@@ -42,6 +42,7 @@ import (
 	"github.com/sigstore/rekor/pkg/log"
 	"github.com/sigstore/rekor/pkg/sharding"
 	"github.com/sigstore/rekor/pkg/types"
+	"github.com/sigstore/rekor/pkg/util"
 	"github.com/sigstore/sigstore/pkg/signature"
 	"github.com/sigstore/sigstore/pkg/signature/options"
 )
@@ -92,11 +93,17 @@ func logEntryFromLeaf(ctx context.Context, signer signature.Signer, tc TrillianC
 		return nil, fmt.Errorf("signing entry error: %w", err)
 	}
 
+	scBytes, err := util.CreateAndSignCheckpoint(ctx, viper.GetString("rekor_server.hostname"), tc.logID, root, api.signer)
+	if err != nil {
+		return nil, err
+	}
+
 	inclusionProof := models.InclusionProof{
-		TreeSize: swag.Int64(int64(root.TreeSize)),
-		RootHash: swag.String(hex.EncodeToString(root.RootHash)),
-		LogIndex: swag.Int64(proof.GetLeafIndex()),
-		Hashes:   hashes,
+		TreeSize:   swag.Int64(int64(root.TreeSize)),
+		RootHash:   swag.String(hex.EncodeToString(root.RootHash)),
+		LogIndex:   swag.Int64(proof.GetLeafIndex()),
+		Hashes:     hashes,
+		Checkpoint: stringPointer(string(scBytes)),
 	}
 
 	uuid := hex.EncodeToString(leaf.MerkleLeafHash)
@@ -261,7 +268,30 @@ func createLogEntry(params entries.CreateLogEntryParams) (models.LogEntry, middl
 		return nil, handleRekorAPIError(params, http.StatusInternalServerError, fmt.Errorf("signing entry error: %v", err), signingError)
 	}
 
+	root := &ttypes.LogRootV1{}
+	if err := root.UnmarshalBinary(resp.getLeafAndProofResult.SignedLogRoot.LogRoot); err != nil {
+		return nil, handleRekorAPIError(params, http.StatusInternalServerError, fmt.Errorf("error unmarshalling log root: %v", err), sthGenerateError)
+	}
+	hashes := []string{}
+	for _, hash := range resp.getLeafAndProofResult.Proof.Hashes {
+		hashes = append(hashes, hex.EncodeToString(hash))
+	}
+
+	scBytes, err := util.CreateAndSignCheckpoint(ctx, viper.GetString("rekor_server.hostname"), tc.logID, root, api.signer)
+	if err != nil {
+		return nil, handleRekorAPIError(params, http.StatusInternalServerError, err, sthGenerateError)
+	}
+
+	inclusionProof := models.InclusionProof{
+		TreeSize:   swag.Int64(int64(root.TreeSize)),
+		RootHash:   swag.String(hex.EncodeToString(root.RootHash)),
+		LogIndex:   swag.Int64(queuedLeaf.LeafIndex),
+		Hashes:     hashes,
+		Checkpoint: stringPointer(string(scBytes)),
+	}
+
 	logEntryAnon.Verification = &models.LogEntryAnonVerification{
+		InclusionProof:       &inclusionProof,
 		SignedEntryTimestamp: strfmt.Base64(signature),
 	}
 

pkg/api/tlog.go

@@ -21,7 +21,6 @@ import (
 	"fmt"
 	"net/http"
 	"strconv"
-	"time"
 
 	"github.com/go-openapi/runtime/middleware"
 	"github.com/go-openapi/swag"
@@ -33,7 +32,6 @@ import (
 	"github.com/sigstore/rekor/pkg/generated/restapi/operations/tlog"
 	"github.com/sigstore/rekor/pkg/log"
 	"github.com/sigstore/rekor/pkg/util"
-	"github.com/sigstore/sigstore/pkg/signature/options"
 )
 
 // GetLogInfoHandler returns the current size of the tree and the STH
@@ -68,32 +66,16 @@ func GetLogInfoHandler(params tlog.GetLogInfoParams) middleware.Responder {
 	hashString := hex.EncodeToString(root.RootHash)
 	treeSize := int64(root.TreeSize)
 
-	sth, err := util.CreateSignedCheckpoint(util.Checkpoint{
-		Origin: fmt.Sprintf("%s - %d", viper.GetString("rekor_server.hostname"), tc.ranges.ActiveTreeID()),
-		Size:   root.TreeSize,
-		Hash:   root.RootHash,
-	})
+	scBytes, err := util.CreateAndSignCheckpoint(params.HTTPRequest.Context(),
+		viper.GetString("rekor_server.hostname"), tc.ranges.ActiveTreeID(), root, api.signer)
 	if err != nil {
-		return handleRekorAPIError(params, http.StatusInternalServerError, fmt.Errorf("marshalling error: %w", err), sthGenerateError)
+		return handleRekorAPIError(params, http.StatusInternalServerError, err, sthGenerateError)
 	}
-	sth.SetTimestamp(uint64(time.Now().UnixNano()))
-
-	// sign the log root ourselves to get the log root signature
-	_, err = sth.Sign(viper.GetString("rekor_server.hostname"), api.signer, options.WithContext(params.HTTPRequest.Context()))
-	if err != nil {
-		return handleRekorAPIError(params, http.StatusInternalServerError, fmt.Errorf("signing error: %w", err), signingError)
-	}
-
-	scBytes, err := sth.SignedNote.MarshalText()
-	if err != nil {
-		return handleRekorAPIError(params, http.StatusInternalServerError, fmt.Errorf("marshalling error: %w", err), sthGenerateError)
-	}
-	scString := string(scBytes)
 
 	logInfo := models.LogInfo{
 		RootHash:       &hashString,
 		TreeSize:       &treeSize,
-		SignedTreeHead: &scString,
+		SignedTreeHead: stringPointer(string(scBytes)),
 		TreeID:         stringPointer(fmt.Sprintf("%d", tc.logID)),
 		InactiveShards: inactiveShards,
 	}
@@ -169,25 +151,11 @@ func inactiveShardLogInfo(ctx context.Context, tid int64) (*models.InactiveShard
 	hashString := hex.EncodeToString(root.RootHash)
 	treeSize := int64(root.TreeSize)
 
-	sth, err := util.CreateSignedCheckpoint(util.Checkpoint{
-		Origin: fmt.Sprintf("%s - %d", viper.GetString("rekor_server.hostname"), tid),
-		Size:   root.TreeSize,
-		Hash:   root.RootHash,
-	})
+	scBytes, err := util.CreateAndSignCheckpoint(ctx, viper.GetString("rekor_server.hostname"), tid, root, api.signer)
 	if err != nil {
 		return nil, err
 	}
-	sth.SetTimestamp(uint64(time.Now().UnixNano()))
 
-	// sign the log root ourselves to get the log root signature
-	if _, err := sth.Sign(viper.GetString("rekor_server.hostname"), api.signer, options.WithContext(ctx)); err != nil {
-		return nil, err
-	}
-
-	scBytes, err := sth.SignedNote.MarshalText()
-	if err != nil {
-		return nil, err
-	}
 	m := models.InactiveShardLogInfo{
 		RootHash:       &hashString,
 		TreeSize:       &treeSize,

pkg/api/trillian_client.go

@@ -185,6 +185,8 @@ func (t *TrillianClient) addLeaf(byteValue []byte) *Response {
 		status:       status.Code(err),
 		err:          err,
 		getAddResult: resp,
+		// include getLeafAndProofResult for inclusion proof
+		getLeafAndProofResult: leafResp.getLeafAndProofResult,
 	}
 }
 

pkg/util/checkpoint.go

@@ -17,11 +17,17 @@ package util
 
 import (
 	"bytes"
+	"context"
 	"encoding/base64"
 	"errors"
 	"fmt"
 	"strconv"
 	"strings"
+	"time"
+
+	"github.com/google/trillian/types"
+	"github.com/sigstore/sigstore/pkg/signature"
+	"github.com/sigstore/sigstore/pkg/signature/options"
 )
 
 // heavily borrowed from https://github.com/google/trillian-examples/blob/master/formats/log/checkpoint.go
@@ -160,3 +166,24 @@ func (r *SignedCheckpoint) GetTimestamp() uint64 {
 	}
 	return ts
 }
+
+// CreateAndSignCheckpoint creates a signed checkpoint as a commitment to the current root hash
+func CreateAndSignCheckpoint(ctx context.Context, hostname string, treeID int64, root *types.LogRootV1, signer signature.Signer) ([]byte, error) {
+	sth, err := CreateSignedCheckpoint(Checkpoint{
+		Origin: fmt.Sprintf("%s - %d", hostname, treeID),
+		Size:   root.TreeSize,
+		Hash:   root.RootHash,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("error creating checkpoint: %v", err)
+	}
+	sth.SetTimestamp(uint64(time.Now().UnixNano()))
+	if _, err := sth.Sign(hostname, signer, options.WithContext(ctx)); err != nil {
+		return nil, fmt.Errorf("error signing checkpoint: %v", err)
+	}
+	scBytes, err := sth.SignedNote.MarshalText()
+	if err != nil {
+		return nil, fmt.Errorf("error marshalling checkpoint: %v", err)
+	}
+	return scBytes, nil
+}