add client method to generate TLE struct

cmd/rekor-cli/app/format/wrap.go

@@ -19,6 +19,9 @@ import (
 	"encoding/json"
 	"fmt"
 
+	rekor_pb "github.com/sigstore/protobuf-specs/gen/pb-go/rekor/v1"
+
+	"github.com/sigstore/rekor/pkg/client"
 	"github.com/sigstore/rekor/pkg/log"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
@@ -46,6 +49,16 @@ func WrapCmd(f formatCmd) CobraCmd {
 			}
 		case "json":
 			fmt.Println(toJSON(obj))
+		case "tle":
+			if tle, ok := obj.(*rekor_pb.TransparencyLogEntry); ok {
+				json, err := client.MarshalTLEToJSON(tle)
+				if err != nil {
+					log.CliLogger.Fatalf("error converting to transparency log entry: %v", err)
+				}
+				fmt.Println(string(json))
+			} else {
+				log.CliLogger.Fatal("unable to print transparency log entry")
+			}
 		}
 	}
 }

cmd/rekor-cli/app/get.go

@@ -203,6 +203,10 @@ func compareEntryUUIDs(requestEntryUUID string, responseEntryUUID string) error
 }
 
 func parseEntry(uuid string, e models.LogEntryAnon) (interface{}, error) {
+	if viper.GetString("format") == "tle" {
+		return client.GenerateTransparencyLogEntry(e)
+	}
+
 	b, err := base64.StdEncoding.DecodeString(e.Body.(string))
 	if err != nil {
 		return nil, err

cmd/rekor-cli/app/pflags.go

@@ -111,7 +111,7 @@ func initializePFlagMap() {
 		},
 		formatFlag: func() pflag.Value {
 			// this validates the output format requested
-			return valueFactory(formatFlag, validateString("required,oneof=json default"), "")
+			return valueFactory(formatFlag, validateString("required,oneof=json default tle"), "")
 		},
 		timeoutFlag: func() pflag.Value {
 			// this validates the timeout is >= 0

go.mod

@@ -58,6 +58,7 @@ require (
 	github.com/hashicorp/go-cleanhttp v0.5.2
 	github.com/hashicorp/go-retryablehttp v0.7.2
 	github.com/redis/go-redis/v9 v9.0.4
+	github.com/sigstore/protobuf-specs v0.1.0
 	golang.org/x/exp v0.0.0-20230321023759-10a507213a29
 )
 

go.sum

@@ -1818,6 +1818,8 @@ github.com/shopspring/decimal v1.2.0/go.mod h1:DKyhrW/HYNuLGql+MJL6WCR6knT2jwCFR
 github.com/shurcooL/httpfs v0.0.0-20190707220628-8d4bc4ba7749/go.mod h1:ZY1cvUeJuFPAdZ/B6v7RHavJWZn2YPVFQ1OSXhCGOkg=
 github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
 github.com/shurcooL/vfsgen v0.0.0-20200824052919-0d455de96546/go.mod h1:TrYk7fJVaAttu97ZZKrO9UbRa8izdowaMIZcxYMbVaw=
+github.com/sigstore/protobuf-specs v0.1.0 h1:X0l/E2C2c79t/rI/lmSu8WAoKWsQtMqDzAMiDdEMGr8=
+github.com/sigstore/protobuf-specs v0.1.0/go.mod h1:5shUCxf82hGnjUEFVWiktcxwzdtn6EfeeJssxZ5Q5HE=
 github.com/sigstore/sigstore v1.6.4 h1:jH4AzR7qlEH/EWzm+opSpxCfuUcjHL+LJPuQE7h40WE=
 github.com/sigstore/sigstore v1.6.4/go.mod h1:pjR64lBxnjoSrAr+Ydye/FV73IfrgtoYlAI11a8xMfA=
 github.com/sirupsen/logrus v1.0.4-0.20170822132746-89742aefa4b2/go.mod h1:pMByvHTf9Beacp5x1UXfOR9xyW/9antXMhjMPG0dEzc=

pkg/client/rekor_client.go

@@ -15,7 +15,11 @@
 package client
 
 import (
+	"bytes"
 	"crypto/tls"
+	"encoding/base64"
+	"encoding/hex"
+	"fmt"
 	"net/http"
 	"net/url"
 
@@ -24,8 +28,13 @@ import (
 	"github.com/go-openapi/strfmt"
 	"github.com/hashicorp/go-cleanhttp"
 	retryablehttp "github.com/hashicorp/go-retryablehttp"
+	rekor_pb_common "github.com/sigstore/protobuf-specs/gen/pb-go/common/v1"
+	rekor_pb "github.com/sigstore/protobuf-specs/gen/pb-go/rekor/v1"
 	"github.com/sigstore/rekor/pkg/generated/client"
+	"github.com/sigstore/rekor/pkg/generated/models"
+	"github.com/sigstore/rekor/pkg/types"
 	"github.com/sigstore/rekor/pkg/util"
+	"google.golang.org/protobuf/encoding/protojson"
 )
 
 func GetRekorClient(rekorServerURL string, opts ...Option) (*client.Rekor, error) {
@@ -64,3 +73,70 @@ func GetRekorClient(rekorServerURL string, opts ...Option) (*client.Rekor, error
 	registry.Add("signedCheckpoint", &util.SignedNote{}, util.SignedCheckpointValidator)
 	return client.New(rt, registry), nil
 }
+
+// GenerateTransparencyLogEntry returns a sigstore/protobuf-specs compliant message containing a
+// TransparencyLogEntry as defined at https://github.com/sigstore/protobuf-specs/blob/main/protos/sigstore_rekor.proto
+func GenerateTransparencyLogEntry(anon models.LogEntryAnon) (*rekor_pb.TransparencyLogEntry, error) {
+	logIDHash, err := hex.DecodeString(*anon.LogID)
+	if err != nil {
+		return nil, fmt.Errorf("decoding logID string: %w", err)
+	}
+
+	rootHash, err := hex.DecodeString(*anon.Verification.InclusionProof.RootHash)
+	if err != nil {
+		return nil, fmt.Errorf("decoding inclusion proof root hash: %w", err)
+	}
+
+	inclusionProofHashes := make([][]byte, len(anon.Verification.InclusionProof.Hashes))
+	for i, hash := range anon.Verification.InclusionProof.Hashes {
+		hashBytes, err := hex.DecodeString(hash)
+		if err != nil {
+			return nil, fmt.Errorf("decoding inclusion proof hash: %w", err)
+		}
+		inclusionProofHashes[i] = hashBytes
+	}
+
+	b, err := base64.StdEncoding.DecodeString(anon.Body.(string))
+	if err != nil {
+		return nil, fmt.Errorf("base64 decoding body: %w", err)
+	}
+
+	pe, err := models.UnmarshalProposedEntry(bytes.NewReader(b), runtime.JSONConsumer())
+	if err != nil {
+		return nil, err
+	}
+	eimpl, err := types.UnmarshalEntry(pe)
+	if err != nil {
+		return nil, err
+	}
+
+	return &rekor_pb.TransparencyLogEntry{
+		LogIndex: *anon.LogIndex,
+		LogId: &rekor_pb_common.LogId{
+			KeyId: logIDHash,
+		},
+		KindVersion: &rekor_pb.KindVersion{
+			Kind:    pe.Kind(),
+			Version: eimpl.APIVersion(),
+		},
+		IntegratedTime: *anon.IntegratedTime,
+		InclusionPromise: &rekor_pb.InclusionPromise{
+			SignedEntryTimestamp: anon.Verification.SignedEntryTimestamp,
+		},
+		InclusionProof: &rekor_pb.InclusionProof{
+			LogIndex: *anon.LogIndex,
+			RootHash: rootHash,
+			TreeSize: *anon.Verification.InclusionProof.TreeSize,
+			Hashes:   inclusionProofHashes,
+			Checkpoint: &rekor_pb.Checkpoint{
+				Envelope: *anon.Verification.InclusionProof.Checkpoint,
+			},
+		},
+		CanonicalizedBody: b, // we don't call eimpl.Canonicalize in the case that the logic is different in this caller vs when it was persisted in the log
+	}, nil
+}
+
+// MarshalTLEToJSON marshals a TransparencyLogEntry message to JSON according to the protobuf JSON encoding rules
+func MarshalTLEToJSON(tle *rekor_pb.TransparencyLogEntry) ([]byte, error) {
+	return protojson.Marshal(tle)
+}