signblob.go

//
// Copyright 2021 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.

package cli

import (
	"fmt"
	"os"

	"github.com/pkg/errors"
	"github.com/sigstore/cosign/cmd/cosign/cli/generate"
	"github.com/sigstore/cosign/cmd/cosign/cli/options"
	"github.com/sigstore/cosign/cmd/cosign/cli/sign"
	"github.com/spf13/cobra"
	"github.com/spf13/viper"
)

func SignBlob() *cobra.Command {
	o := &options.SignBlobOptions{}
	viper.RegisterAlias("output", "output-signature")

	cmd := &cobra.Command{
		Use:   "sign-blob",
		Short: "Sign the supplied blob, outputting the base64-encoded signature to stdout.",
		Example: `  cosign sign-blob --key <key path>|<kms uri> <blob>

  # sign a blob with Google sign-in (experimental)
  COSIGN_EXPERIMENTAL=1 cosign --timeout 90s sign-blob <FILE>

  # sign a blob with a local key pair file
  cosign sign-blob --key cosign.key <FILE>

  # sign a blob with a key pair stored in Azure Key Vault
  cosign sign-blob --key azurekms://[VAULT_NAME][VAULT_URI]/[KEY] <FILE>

  # sign a blob with a key pair stored in AWS KMS
  cosign sign-blob --key awskms://[ENDPOINT]/[ID/ALIAS/ARN] <FILE>

  # sign a blob with a key pair stored in Google Cloud KMS
  cosign sign-blob --key gcpkms://projects/[PROJECT]/locations/global/keyRings/[KEYRING]/cryptoKeys/[KEY] <FILE>

  # sign a blob with a key pair stored in Hashicorp Vault
  cosign sign-blob --key hashivault://[KEY] <FILE>`,
		Args: cobra.MinimumNArgs(1),
		PreRunE: func(cmd *cobra.Command, args []string) error {
			// A key file is required unless we're in experimental mode!
			if !options.EnableExperimental() {
				if !options.OneOf(o.Key, o.SecurityKey.Use) {
					return &options.KeyParseError{}
				}
			}
			return nil
		},
		RunE: func(cmd *cobra.Command, args []string) error {
			oidcClientSecret, err := o.OIDC.ClientSecret()
			if err != nil {
				return err
			}
			ko := options.KeyOpts{
				KeyRef:                   o.Key,
				PassFunc:                 generate.GetPass,
				Sk:                       o.SecurityKey.Use,
				Slot:                     o.SecurityKey.Slot,
				FulcioURL:                o.Fulcio.URL,
				IDToken:                  o.Fulcio.IdentityToken,
				InsecureSkipFulcioVerify: o.Fulcio.InsecureSkipFulcioVerify,
				RekorURL:                 o.Rekor.URL,
				OIDCIssuer:               o.OIDC.Issuer,
				OIDCClientID:             o.OIDC.ClientID,
				OIDCClientSecret:         oidcClientSecret,
				OIDCRedirectURL:          o.OIDC.RedirectURL,
				OIDCDisableProviders:     o.OIDC.DisableAmbientProviders,
				BundlePath:               o.BundlePath,
			}
			for _, blob := range args {
				// TODO: remove when the output flag has been deprecated
				if o.Output != "" {
					fmt.Fprintln(os.Stderr, "WARNING: the '--output' flag is deprecated and will be removed in the future. Use '--output-signature'")
					o.OutputSignature = o.Output
				}
				if _, err := sign.SignBlobCmd(ro, ko, o.Registry, blob, o.Base64Output, o.OutputSignature, o.OutputCertificate); err != nil {
					return errors.Wrapf(err, "signing %s", blob)
				}
			}
			return nil
		},
	}

	o.AddFlags(cmd)
	return cmd
}