perkeep/cmd/camput/init.go

/*
Copyright 2011 Google Inc.

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 main

import (
	"encoding/json"
	"errors"
	"flag"
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"os/exec"
	"path"

	"camlistore.org/pkg/blobref"
	"camlistore.org/pkg/client"
	"camlistore.org/pkg/cmdmain"
	"camlistore.org/pkg/jsonsign"
	"camlistore.org/pkg/osutil"
)

type initCmd struct {
	gpgkey string
}

func init() {
	cmdmain.RegisterCommand("init", func(flags *flag.FlagSet) cmdmain.CommandRunner {
		cmd := new(initCmd)
		flags.StringVar(&cmd.gpgkey, "gpgkey", "", "GPG key to use for signing (overrides $GPGKEY environment)")
		return cmd
	})
}

func (c *initCmd) Describe() string {
	return "Initialize the camput configuration file."
}

func (c *initCmd) Usage() {
	fmt.Fprintf(cmdmain.Stderr, "Usage: camput init [opts]")
}

func (c *initCmd) Examples() []string {
	return []string{
		"",
		"--gpgkey=XXXXX",
	}
}

func (c *initCmd) keyId() (string, error) {
	if k := c.gpgkey; k != "" {
		return k, nil
	}
	if k := os.Getenv("GPGKEY"); k != "" {
		return k, nil
	}

	// TODO: move camlistored.go's keyIdFromRing into
	// pkg/jsonsign/keys.go and use that (which looks for an
	// identify file with exactly one identity)

	// TODO: run and parse gpg --list-secret-keys and see if there's just one and suggest that?  Or show
	// a list of them?
	return "", errors.New("Initialization requires your public GPG key.  Set --gpgkey=<pubid> or set $GPGKEY in your environment.  Run gpg --list-secret-keys to find their key IDs.")
}

func (c *initCmd) getPublicKeyArmoredFromFile(secretRingFileName, keyId string) (b []byte, err error) {
	entity, err := jsonsign.EntityFromSecring(keyId, secretRingFileName)
	if err == nil {
		pubArmor, err := jsonsign.ArmoredPublicKey(entity)
		if err == nil {
			return []byte(pubArmor), nil
		}
	}
	b, err = exec.Command("gpg", "--export", "--armor", keyId).Output()
	if err != nil {
		return nil, fmt.Errorf("Error running gpg to export public key %q: %v", keyId, err)
	}
	if len(b) == 0 {
		return nil, fmt.Errorf("gpg export of public key %q was empty.", keyId)
	}
	return b, nil
}

func (c *initCmd) getPublicKeyArmored(keyId string) (b []byte, err error) {
	files := []string{osutil.IdentitySecretRing(), jsonsign.DefaultSecRingPath()}
	for _, file := range files {
		b, err = c.getPublicKeyArmoredFromFile(file, keyId)
		if err == nil {
			return b, nil
		}
	}
	return nil, fmt.Errorf("failed to export armored public key ID %q from locations: %q", keyId, files)
}

func (c *initCmd) RunCommand(args []string) error {
	if len(args) > 0 {
		return cmdmain.ErrUsage
	}

	blobDir := path.Join(osutil.CamliConfigDir(), "keyblobs")
	os.Mkdir(osutil.CamliConfigDir(), 0700)
	os.Mkdir(blobDir, 0700)

	keyId, err := c.keyId()
	if err != nil {
		return err
	}

	if os.Getenv("GPG_AGENT_INFO") == "" {
		log.Printf("No GPG_AGENT_INFO found in environment; you should setup gnupg-agent.  camput might be annoying otherwise, if your private key is encrypted.")
	}

	pubArmor, err := c.getPublicKeyArmored(keyId)
	if err != nil {
		return err
	}

	bref := blobref.SHA1FromString(string(pubArmor))

	keyBlobPath := path.Join(blobDir, bref.String()+".camli")
	if err = ioutil.WriteFile(keyBlobPath, pubArmor, 0644); err != nil {
		log.Fatalf("Error writing public key blob to %q: %v", keyBlobPath, err)
	}

	if ok, err := jsonsign.VerifyPublicKeyFile(keyBlobPath, keyId); !ok {
		log.Fatalf("Error verifying public key at %q: %v", keyBlobPath, err)
	}

	log.Printf("Your Camlistore identity (your GPG public key's blobref) is: %s", bref.String())

	_, err = os.Stat(client.ConfigFilePath())
	if err == nil {
		log.Fatalf("Config file %q already exists; quitting without touching it.", client.ConfigFilePath())
	}

	if f, err := os.OpenFile(client.ConfigFilePath(), os.O_CREATE|os.O_EXCL|os.O_WRONLY, 0600); err == nil {
		defer f.Close()
		m := make(map[string]interface{})
		m["keyId"] = keyId                    // TODO(bradfitz): make this 'identity' to match server config?
		m["publicKeyBlobref"] = bref.String() // TODO(bradfitz): not used anymore?
		m["server"] = "http://localhost:3179/"
		m["selfPubKeyDir"] = blobDir
		m["auth"] = "localhost"

		jsonBytes, err := json.MarshalIndent(m, "", "  ")
		if err != nil {
			log.Fatalf("JSON serialization error: %v", err)
		}
		_, err = f.Write(jsonBytes)
		if err != nil {
			log.Fatalf("Error writing to %q: %v", client.ConfigFilePath(), err)
		}
		log.Printf("Wrote %q; modify as necessary.", client.ConfigFilePath())
	}
	return nil
}