wal-g

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package crypto
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import (
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	"bytes"
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	"encoding/json"
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	"fmt"
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	"os"
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	"os/exec"
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	"os/user"
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	"path/filepath"
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	"strings"
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	"github.com/pkg/errors"
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	"github.com/wal-g/tracelog"
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)
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type GpgKeyExportError struct {
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	error
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}
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func NewGpgKeyExportError(text string) GpgKeyExportError {
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	return GpgKeyExportError{errors.Errorf("Got error while exporting gpg key: '%s'", text)}
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}
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func (err GpgKeyExportError) Error() string {
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	return fmt.Sprintf(tracelog.GetErrorFormatter(), err.error)
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}
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const GpgBin = "gpg"
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// CachedKey is the data transfer object describing format of key ring cache
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type CachedKey struct {
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	KeyID string `json:"keyId"`
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	Body  []byte `json:"body"`
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}
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// TODO : unit tests
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// Here we read armored version of Key by calling GPG process
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func GetPubRingArmor(keyID string) ([]byte, error) {
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	var cache CachedKey
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	var cacheFilename string
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	usr, err := user.Current()
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	if err == nil {
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		cacheFilename = filepath.Join(usr.HomeDir, ".walg_key_cache")
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		file, err := os.ReadFile(cacheFilename)
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		// here we ignore whatever error can occur
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		if err == nil {
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			err = json.Unmarshal(file, &cache)
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			tracelog.ErrorLogger.PrintOnError(err)
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			if err == nil && cache.KeyID == keyID && len(cache.Body) > 0 { // don't return an empty cached value
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				return cache.Body, nil
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			}
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		}
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	}
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	cmd := exec.Command(GpgBin, "-a", "--export", keyID)
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	var stderr bytes.Buffer
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	cmd.Stderr = &stderr
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	out, err := cmd.Output()
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	if err != nil {
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		return nil, err
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	}
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	if stderr.Len() > 0 { // gpg -a --export <key-id> reports error on stderr and exits == 0 if the key isn't found
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		return nil, NewGpgKeyExportError(strings.TrimSpace(stderr.String()))
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	}
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	cache.KeyID = keyID
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	cache.Body = out
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	marshal, err := json.Marshal(&cache)
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	if err == nil && len(cacheFilename) > 0 {
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		err = os.WriteFile(cacheFilename, marshal, 0644)
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		tracelog.ErrorLogger.PrintOnError(err)
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	}
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	return out, nil
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}
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func GetSecretRingArmor(keyID string) ([]byte, error) {
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	out, err := exec.Command(GpgBin, "-a", "--export-secret-key", keyID).Output()
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	if err != nil {
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		return nil, err
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	}
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	return out, nil
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}
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