trust.go

// Copyright 2015 The rkt 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.

//+build linux

// implements https://github.com/rkt/rkt/issues/367

package main

import (
	"net/url"

	"github.com/rkt/rkt/rkt/pubkey"

	"github.com/spf13/cobra"
)

var (
	cmdTrust = &cobra.Command{
		Use:   "trust [--prefix=PREFIX] [--insecure-allow-http] [--skip-fingerprint-review] [--root] [PUBKEY ...]",
		Short: "Trust a key for image verification",
		Long: `Adds keys to the local keystore for use in verifying signed images.

PUBKEY may be either a local file or URL.

PREFIX scopes the applicability of PUBKEY to image names sharing PREFIX.

Meta discovery of PUBKEY at PREFIX will be attempted if no PUBKEY is specified.

To trust a key for all images instead of for specific images, --root can be
specified. Path to a key file must be given (no discovery).`,
		Run: runWrapper(runTrust),
	}
	flagPrefix                string
	flagRoot                  bool
	flagAllowHTTP             bool
	flagSkipFingerprintReview bool
)

func init() {
	cmdRkt.AddCommand(cmdTrust)
	cmdTrust.Flags().StringVar(&flagPrefix, "prefix", "", "prefix to limit trust to")
	cmdTrust.Flags().BoolVar(&flagRoot, "root", false, "add root key from filesystem without a prefix")
	cmdTrust.Flags().BoolVar(&flagSkipFingerprintReview, "skip-fingerprint-review", false, "accept key without fingerprint confirmation")
	cmdTrust.Flags().BoolVar(&flagAllowHTTP, "insecure-allow-http", false, "allow HTTP use for key discovery and/or retrieval")
}

func runTrust(cmd *cobra.Command, args []string) (exit int) {
	if flagPrefix == "" && !flagRoot {
		if len(args) != 0 {
			stderr.Print(`aborting due to implicit unbounded trust (root domain)
Please provide a specific domain prefix to trust:
    rkt trust --prefix "example.com/foo" [PUBKEY]
    rkt trust --prefix "example.com/foo/*" [PUBKEY]
Otherwise, trust at the root domain (not recommended) must be explicitly requested:
    rkt trust --root PUBKEY`)
		} else {
			cmd.Usage()
		}
		return 254
	}

	if flagPrefix != "" && flagRoot {
		stderr.Print("--root and --prefix usage mutually exclusive")
		return 254
	}

	ks := getKeystore()
	if ks == nil {
		stderr.Print("could not get the keystore")
		return 254
	}

	// if the user included a scheme with the prefix, error on it
	u, err := url.Parse(flagPrefix)
	if err == nil && u.Scheme != "" {
		stderr.Printf("--prefix must not contain a URL scheme, omit %s://", u.Scheme)
		return 254
	}

	pkls := args
	m := &pubkey.Manager{
		InsecureAllowHTTP:    flagAllowHTTP,
		InsecureSkipTLSCheck: globalFlags.InsecureFlags.SkipTLSCheck(),
		TrustKeysFromHTTPS:   globalFlags.TrustKeysFromHTTPS,
		Ks:                   ks,
		Debug:                globalFlags.Debug,
	}
	if len(pkls) == 0 {
		pkls, err = m.GetPubKeyLocations(flagPrefix)
		if err != nil {
			stderr.PrintE("error determining key location", err)
			return 254
		}
	}

	acceptOpt := pubkey.AcceptAsk
	if flagSkipFingerprintReview {
		acceptOpt = pubkey.AcceptForce
	}

	if err := m.AddKeys(pkls, flagPrefix, acceptOpt); err != nil {
		stderr.PrintE("error adding keys", err)
		return 254
	}

	return 0
}