open-vault/helper/pgpkeys/flag.go

142 lines
3.3 KiB
Go

package pgpkeys
import (
"bytes"
"encoding/base64"
"errors"
"fmt"
"os"
"strings"
"github.com/ProtonMail/go-crypto/openpgp"
)
// PubKeyFileFlag implements flag.Value and command.Example to receive exactly
// one PGP or keybase key via a flag.
type PubKeyFileFlag string
func (p *PubKeyFileFlag) String() string { return string(*p) }
func (p *PubKeyFileFlag) Set(val string) error {
if p != nil && *p != "" {
return errors.New("can only be specified once")
}
keys, err := ParsePGPKeys(strings.Split(val, ","))
if err != nil {
return err
}
if len(keys) > 1 {
return errors.New("can only specify one pgp key")
}
*p = PubKeyFileFlag(keys[0])
return nil
}
func (p *PubKeyFileFlag) Example() string { return "keybase:user" }
// PGPPubKeyFiles implements the flag.Value interface and allows parsing and
// reading a list of PGP public key files.
type PubKeyFilesFlag []string
func (p *PubKeyFilesFlag) String() string {
return fmt.Sprint(*p)
}
func (p *PubKeyFilesFlag) Set(val string) error {
if len(*p) > 0 {
return errors.New("can only be specified once")
}
keys, err := ParsePGPKeys(strings.Split(val, ","))
if err != nil {
return err
}
*p = PubKeyFilesFlag(keys)
return nil
}
func (p *PubKeyFilesFlag) Example() string { return "keybase:user1, keybase:user2, ..." }
// ParsePGPKeys takes a list of PGP keys and parses them either using keybase
// or reading them from disk and returns the "expanded" list of pgp keys in
// the same order.
func ParsePGPKeys(keyfiles []string) ([]string, error) {
keys := make([]string, len(keyfiles))
keybaseMap, err := FetchKeybasePubkeys(keyfiles)
if err != nil {
return nil, err
}
for i, keyfile := range keyfiles {
keyfile = strings.TrimSpace(keyfile)
if strings.HasPrefix(keyfile, kbPrefix) {
key, ok := keybaseMap[keyfile]
if !ok || key == "" {
return nil, fmt.Errorf("keybase user %q not found", strings.TrimPrefix(keyfile, kbPrefix))
}
keys[i] = key
continue
}
pgpStr, err := ReadPGPFile(keyfile)
if err != nil {
return nil, err
}
keys[i] = pgpStr
}
return keys, nil
}
// ReadPGPFile reads the given PGP file from disk.
func ReadPGPFile(path string) (string, error) {
if len(path) <= 0 {
return "", errors.New("empty path")
}
if path[0] == '@' {
path = path[1:]
}
f, err := os.Open(path)
if err != nil {
return "", err
}
defer f.Close()
buf := bytes.NewBuffer(nil)
_, err = buf.ReadFrom(f)
if err != nil {
return "", err
}
// First parse as an armored keyring file, if that doesn't work, treat it as a straight binary/b64 string
keyReader := bytes.NewReader(buf.Bytes())
entityList, err := openpgp.ReadArmoredKeyRing(keyReader)
if err == nil {
if len(entityList) != 1 {
return "", fmt.Errorf("more than one key found in file %q", path)
}
if entityList[0] == nil {
return "", fmt.Errorf("primary key was nil for file %q", path)
}
serializedEntity := bytes.NewBuffer(nil)
err = entityList[0].Serialize(serializedEntity)
if err != nil {
return "", fmt.Errorf("error serializing entity for file %q: %w", path, err)
}
return base64.StdEncoding.EncodeToString(serializedEntity.Bytes()), nil
}
_, err = base64.StdEncoding.DecodeString(buf.String())
if err == nil {
return buf.String(), nil
}
return base64.StdEncoding.EncodeToString(buf.Bytes()), nil
}