feat: blob inspect command

cmd/notation/blob/cmd.go

@@ -29,6 +29,7 @@ func Cmd() *cobra.Command {
 		signCommand(nil),
 		verifyCommand(nil),
 		policy.Cmd(),
+		inspectCommand(),
 	)
 	return command
 }

cmd/notation/blob/inspect.go

@@ -0,0 +1,90 @@
+// Copyright The Notary Project 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 blob
+
+import (
+	"errors"
+	"fmt"
+	"os"
+
+	"github.com/notaryproject/notation-core-go/signature"
+	"github.com/notaryproject/notation/cmd/notation/internal/display"
+	"github.com/notaryproject/notation/cmd/notation/internal/option"
+	"github.com/spf13/cobra"
+)
+
+type inspectOpts struct {
+	option.Common
+	option.Format
+	sigPath string
+}
+
+func inspectCommand() *cobra.Command {
+	opts := &inspectOpts{}
+	command := &cobra.Command{
+		Use:   "inspect [flags] <signature_path>",
+		Short: "Inspect a signature associated with a blob",
+		Long: `Inspect a signature associated with a blob.
+
+Example - Inspect a signature:
+  notation blob inspect blob.cose.sig
+
+Example - Inspect a signature and output as JSON:
+  notation blob inspect -o json blob.cose.sig
+`,
+		Args: func(cmd *cobra.Command, args []string) error {
+			if len(args) == 0 {
+				return errors.New("missing signature path: use `notation blob inspect --help` to see what parameters are required")
+			}
+			opts.sigPath = args[0]
+			return nil
+		},
+		PreRun: func(cmd *cobra.Command, args []string) {
+			opts.Common.Parse(cmd)
+		},
+		RunE: func(cmd *cobra.Command, args []string) error {
+			return runInspect(opts)
+		},
+	}
+
+	opts.Format.ApplyFlags(command.Flags(), option.FormatTypeText, option.FormatTypeJSON)
+	return command
+}
+
+func runInspect(opts *inspectOpts) error {
+	// initialize display handler
+	displayHandler, err := display.NewBlobInspectHandler(opts.Printer, opts.Format)
+	if err != nil {
+		return err
+	}
+
+	// parse signature file
+	signatureMediaType, err := parseSignatureMediaType(opts.sigPath)
+	if err != nil {
+		return err
+	}
+	envelopeBytes, err := os.ReadFile(opts.sigPath)
+	if err != nil {
+		return fmt.Errorf("failed to read signature file: %w", err)
+	}
+	envelope, err := signature.ParseEnvelope(signatureMediaType, envelopeBytes)
+	if err != nil {
+		return fmt.Errorf("failed to parse signature: %w", err)
+	}
+	if err := displayHandler.OnEnvelopeParsed(opts.sigPath, signatureMediaType, envelope); err != nil {
+		return err
+	}
+
+	return displayHandler.Render()
+}

cmd/notation/inspect.go

@@ -96,7 +96,7 @@ func runInspect(command *cobra.Command, opts *inspectOpts) error {
 	// set log level
 	ctx := opts.LoggingFlagOpts.InitializeLogger(command.Context())
 
-	displayHandler, err := display.NewInpsectHandler(opts.Printer, opts.Format)
+	displayHandler, err := display.NewInspectHandler(opts.Printer, opts.Format)
 	if err != nil {
 		return err
 	}
@@ -124,14 +124,14 @@ func runInspect(command *cobra.Command, opts *inspectOpts) error {
 			return nil
 		}
 
-		sigEnvelope, err := signature.ParseEnvelope(sigDesc.MediaType, sigBlob)
+		envelope, err := signature.ParseEnvelope(sigDesc.MediaType, sigBlob)
 		if err != nil {
 			logSkippedSignature(sigManifestDesc, err)
 			skippedSignatures = true
 			return nil
 		}
 
-		if err := displayHandler.InspectSignature(sigManifestDesc, sigEnvelope); err != nil {
+		if err := displayHandler.InspectSignature(sigManifestDesc, sigDesc, envelope); err != nil {
 			logSkippedSignature(sigManifestDesc, err)
 			skippedSignatures = true
 			return nil

cmd/notation/internal/display/handler.go

@@ -30,9 +30,9 @@ import (
 	"github.com/notaryproject/notation/cmd/notation/internal/option"
 )
 
-// NewInpsectHandler creates a new metadata InspectHandler based on the output
+// NewInspectHandler creates a new metadata InspectHandler based on the output
 // format.
-func NewInpsectHandler(printer *output.Printer, format option.Format) (metadata.InspectHandler, error) {
+func NewInspectHandler(printer *output.Printer, format option.Format) (metadata.InspectHandler, error) {
 	switch option.FormatType(format.CurrentType) {
 	case option.FormatTypeJSON:
 		return json.NewInspectHandler(printer), nil
@@ -42,6 +42,18 @@ func NewInpsectHandler(printer *output.Printer, format option.Format) (metadata.
 	return nil, fmt.Errorf("unrecognized output format %s", format.CurrentType)
 }
 
+// NewBlobInspectHandler creates a new metadata BlobInspectHandler based on the
+// output format.
+func NewBlobInspectHandler(printer *output.Printer, format option.Format) (metadata.BlobInspectHandler, error) {
+	switch option.FormatType(format.CurrentType) {
+	case option.FormatTypeJSON:
+		return json.NewBlobInspectHandler(printer), nil
+	case option.FormatTypeText:
+		return tree.NewBlobInspectHandler(printer), nil
+	}
+	return nil, fmt.Errorf("unrecognized output format %s", format.CurrentType)
+}
+
 // NewVerifyHandler creates a new metadata VerifyHandler for printing
 // verification result and warnings.
 func NewVerifyHandler(printer *output.Printer) metadata.VerifyHandler {

cmd/notation/internal/display/metadata/interface.go

@@ -36,7 +36,16 @@ type InspectHandler interface {
 	OnReferenceResolved(reference, mediaType string)
 
 	// InspectSignature inspects a signature to get it ready to be rendered.
-	InspectSignature(manifestDesc ocispec.Descriptor, envelope signature.Envelope) error
+	InspectSignature(manifestDesc, signatureDesc ocispec.Descriptor, envelope signature.Envelope) error
+}
+
+// BlobInspectHandler is a handler for rendering metadata information of a blob
+// signature.
+type BlobInspectHandler interface {
+	Renderer
+
+	// OnEnvelopeParsed sets the parsed envelope for the handler.
+	OnEnvelopeParsed(signaturePath, signatureMediaType string, envelope signature.Envelope) error
 }
 
 // VerifyHandler is a handler for rendering metadata information of

cmd/notation/internal/display/metadata/json/blob_inspect.go

@@ -0,0 +1,51 @@
+// Copyright The Notary Project 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 json
+
+import (
+	coresignature "github.com/notaryproject/notation-core-go/signature"
+	"github.com/notaryproject/notation/cmd/notation/internal/display/output"
+)
+
+// BlobInspectHandler is a handler for inspecting metadata information and
+// rendering it in JSON format. It implements the metadata.BlobInspectHandler
+// interface.
+type BlobInspectHandler struct {
+	printer   *output.Printer
+	signature *signature
+}
+
+// NewBlobInspectHandler creates a BlobInspectHandler to inspect signature and
+// print in JSON format.
+func NewBlobInspectHandler(printer *output.Printer) *BlobInspectHandler {
+	return &BlobInspectHandler{
+		printer: printer,
+	}
+}
+
+// OnEnvelopeParsed sets the parsed envelope for the handler.
+func (h *BlobInspectHandler) OnEnvelopeParsed(nodeName, signatureMediaType string, envelope coresignature.Envelope) error {
+	// blob signature does not have a digest
+	sig, err := newSignature("", signatureMediaType, envelope)
+	if err != nil {
+		return err
+	}
+	h.signature = sig
+	return nil
+}
+
+// Render prints out the metadata information in JSON format.
+func (h *BlobInspectHandler) Render() error {
+	return output.PrintPrettyJSON(h.printer, h.signature)
+}