add verify-tuf-root cmd

Signed-off-by: Meredith Lancaster <malancas@github.com>

pkg/cmd/attestation/attestation.go

@@ -3,6 +3,7 @@ package attestation
 import (
 	"github.com/cli/cli/v2/pkg/cmd/attestation/download"
 	"github.com/cli/cli/v2/pkg/cmd/attestation/inspect"
+	"github.com/cli/cli/v2/pkg/cmd/attestation/verifytufroot"
 	"github.com/cli/cli/v2/pkg/cmd/attestation/verify"
 	"github.com/cli/cli/v2/pkg/cmdutil"
 	
@@ -30,6 +31,7 @@ func NewCmdAttestation(f *cmdutil.Factory) *cobra.Command {
 	root.AddCommand(download.NewDownloadCmd(f))
 	root.AddCommand(inspect.NewInspectCmd(f))
 	root.AddCommand(verify.NewVerifyCmd(f))
+	root.AddCommand(verifytufroot.NewVerifyTUFRootCmd(f))
 
 	return root
 }

pkg/cmd/attestation/verifytufroot/verify-tuf-root.go

@@ -0,0 +1,73 @@
+package verifytufroot
+
+import (
+	"fmt"
+	"os"
+
+	"github.com/cli/cli/v2/pkg/cmdutil"
+	"github.com/cli/cli/v2/pkg/cmd/attestation/logger"
+	"github.com/cli/cli/v2/pkg/cmd/attestation/verification"
+	
+	"github.com/MakeNowJust/heredoc"
+	"github.com/sigstore/sigstore-go/pkg/tuf"
+	"github.com/spf13/cobra"
+)
+
+func NewVerifyTUFRootCmd(f *cmdutil.Factory) *cobra.Command {
+	var mirror string
+	var root string
+	var cmd = cobra.Command{
+		Use:   "verify-tuf-root --mirror <mirror-url> --root <root.json>",
+		Args:  cobra.ExactArgs(0),
+		Short: "Verify the TUF repository from a provided TUF root",
+		Long: heredoc.Docf(`
+			Verify a TUF repository from a local TUF root.
+
+			The command requires you provide the %[1]s--mirror%[1]s flag, which should be the URL 
+			of the TUF repository mirror.
+			
+			The command also requires you provide the %[1]s--root%[1]s flag, which should be the 
+			path to the TUF root file.
+		`, "`"),
+		Example: heredoc.Doc(`
+			# Verify the TUF repository from a provided TUF root
+			gh attestation tuf-root-verify --mirror https://tuf-repo.github.com --root /path/to/1.root.json
+		`),
+		Run: func(cmd *cobra.Command, args []string) {
+			logger := logger.NewDefaultLogger()
+			if err := verifyTUFRoot(mirror, root); err != nil {
+				fmt.Sprintln(logger.IO.Out, logger.ColorScheme.Redf("Failed to verify the TUF repository: %s", err))
+				os.Exit(1)
+			}
+			fmt.Sprintln(logger.IO.Out, logger.ColorScheme.Green("Successfully verified the TUF repository"))
+		},
+	}
+
+	cmd.Flags().StringVarP(&mirror, "mirror", "m", "", "URL to the TUF repository mirror")
+	cmd.MarkFlagRequired("mirror") //nolint:errcheck
+	cmd.Flags().StringVarP(&root, "root", "r", "", "Path to the TUF root file on disk")
+	cmd.MarkFlagRequired("root") //nolint:errcheck
+
+	return &cmd
+}
+
+func verifyTUFRoot(mirror, root string) error {
+	rb, err := os.ReadFile(root)
+	if err != nil {
+		return fmt.Errorf("failed to read root file %s: %w", root, err)
+	}
+	opts, err := verification.GitHubTUFOptions()
+	if err != nil {
+		return err
+	}
+	opts.Root = rb
+	opts.RepositoryBaseURL = mirror
+	// The purpose is the verify the TUF root and repository, make
+	// sure there is no caching enabled
+	opts.CacheValidity = 0
+	if _, err = tuf.New(opts); err != nil {
+		return fmt.Errorf("failed to create TUF client: %w", err)
+	}
+
+	return nil
+}