writefreely/keys.go

93 lines
2.0 KiB
Go

/*
* Copyright © 2018 A Bunch Tell LLC.
*
* This file is part of WriteFreely.
*
* WriteFreely is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, included
* in the LICENSE file in this source code package.
*/
package writefreely
import (
"crypto/rand"
"github.com/writeas/web-core/log"
"io/ioutil"
"os"
"path/filepath"
)
const (
keysDir = "keys"
encKeysBytes = 32
)
var (
emailKeyPath = filepath.Join(keysDir, "email.aes256")
cookieAuthKeyPath = filepath.Join(keysDir, "cookies_auth.aes256")
cookieKeyPath = filepath.Join(keysDir, "cookies_enc.aes256")
)
type keychain struct {
emailKey, cookieAuthKey, cookieKey []byte
}
func initKeys(app *app) error {
var err error
app.keys = &keychain{}
app.keys.emailKey, err = ioutil.ReadFile(emailKeyPath)
if err != nil {
return err
}
app.keys.cookieAuthKey, err = ioutil.ReadFile(cookieAuthKeyPath)
if err != nil {
return err
}
app.keys.cookieKey, err = ioutil.ReadFile(cookieKeyPath)
if err != nil {
return err
}
return nil
}
// generateKey generates a key at the given path used for the encryption of
// certain user data. Because user data becomes unrecoverable without these
// keys, this won't overwrite any existing key, and instead outputs a message.
func generateKey(path string) error {
// Check if key file exists
if _, err := os.Stat(path); !os.IsNotExist(err) {
log.Info("%s already exists. rm the file if you understand the consquences.", path)
return nil
}
log.Info("Generating %s.", path)
b, err := generateBytes(encKeysBytes)
if err != nil {
log.Error("FAILED. %s. Run writefreely --gen-keys again.", err)
return err
}
err = ioutil.WriteFile(path, b, 0600)
if err != nil {
log.Error("FAILED writing file: %s", err)
return err
}
log.Info("Success.")
return nil
}
// generateBytes returns securely generated random bytes.
func generateBytes(n int) ([]byte, error) {
b := make([]byte, n)
_, err := rand.Read(b)
if err != nil {
return nil, err
}
return b, nil
}