forgejo/models/asymkey/ssh_key_authorized_principals.go
Gusted f6c04d6b86
[GITEA] Make atomic ssh keys replacement robust
- After stumbling upon https://github.com/golang/go/issues/22397 and
reading the implementations I realized that Forgejo code doesn't have
`Sync()` and it doesn't properly error handle the `Close` function.
- (likely) Resolves https://codeberg.org/forgejo/forgejo/issues/1446

(cherry picked from commit 0efcb334c2)
(cherry picked from commit 04ef02c0dd)
(cherry picked from commit 85f2065c9b)
(cherry picked from commit 8d36b5cce6)
(cherry picked from commit 0f406dc4d2)
(cherry picked from commit 347a2e7372)
2023-10-30 14:44:21 +01:00

139 lines
4.1 KiB
Go

// Copyright 2021 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package asymkey
import (
"bufio"
"context"
"fmt"
"io"
"os"
"path/filepath"
"strings"
"time"
"code.gitea.io/gitea/models/db"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/setting"
"code.gitea.io/gitea/modules/util"
)
// _____ __ .__ .__ .___
// / _ \ __ ___/ |_| |__ ___________|__|_______ ____ __| _/
// / /_\ \| | \ __\ | \ / _ \_ __ \ \___ // __ \ / __ |
// / | \ | /| | | Y ( <_> ) | \/ |/ /\ ___// /_/ |
// \____|__ /____/ |__| |___| /\____/|__| |__/_____ \\___ >____ |
// \/ \/ \/ \/ \/
// __________ .__ .__ .__
// \______ _______|__| ____ ____ |_____________ | | ______
// | ___\_ __ | |/ \_/ ___\| \____ \__ \ | | / ___/
// | | | | \| | | \ \___| | |_> / __ \| |__\___ \
// |____| |__| |__|___| /\___ |__| __(____ |____/____ >
// \/ \/ |__| \/ \/
//
// This file contains functions for creating authorized_principals files
//
// There is a dependence on the database within RewriteAllPrincipalKeys & RegeneratePrincipalKeys
// The sshOpLocker is used from ssh_key_authorized_keys.go
const authorizedPrincipalsFile = "authorized_principals"
// RewriteAllPrincipalKeys removes any authorized principal and rewrite all keys from database again.
// Note: db.GetEngine(db.DefaultContext).Iterate does not get latest data after insert/delete, so we have to call this function
// outside any session scope independently.
func RewriteAllPrincipalKeys(ctx context.Context) error {
// Don't rewrite key if internal server
if setting.SSH.StartBuiltinServer || !setting.SSH.CreateAuthorizedPrincipalsFile {
return nil
}
sshOpLocker.Lock()
defer sshOpLocker.Unlock()
if setting.SSH.RootPath != "" {
// First of ensure that the RootPath is present, and if not make it with 0700 permissions
// This of course doesn't guarantee that this is the right directory for authorized_keys
// but at least if it's supposed to be this directory and it doesn't exist and we're the
// right user it will at least be created properly.
err := os.MkdirAll(setting.SSH.RootPath, 0o700)
if err != nil {
log.Error("Unable to MkdirAll(%s): %v", setting.SSH.RootPath, err)
return err
}
}
fPath := filepath.Join(setting.SSH.RootPath, authorizedPrincipalsFile)
tmpPath := fPath + ".tmp"
t, err := os.OpenFile(tmpPath, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o600)
if err != nil {
return err
}
defer func() {
t.Close()
os.Remove(tmpPath)
}()
if setting.SSH.AuthorizedPrincipalsBackup {
isExist, err := util.IsExist(fPath)
if err != nil {
log.Error("Unable to check if %s exists. Error: %v", fPath, err)
return err
}
if isExist {
bakPath := fmt.Sprintf("%s_%d.gitea_bak", fPath, time.Now().Unix())
if err = util.CopyFile(fPath, bakPath); err != nil {
return err
}
}
}
if err := regeneratePrincipalKeys(ctx, t); err != nil {
return err
}
if err := t.Sync(); err != nil {
return err
}
if err := t.Close(); err != nil {
return err
}
return util.Rename(tmpPath, fPath)
}
func regeneratePrincipalKeys(ctx context.Context, t io.StringWriter) error {
if err := db.GetEngine(ctx).Where("type = ?", KeyTypePrincipal).Iterate(new(PublicKey), func(idx int, bean any) (err error) {
_, err = t.WriteString((bean.(*PublicKey)).AuthorizedString())
return err
}); err != nil {
return err
}
fPath := filepath.Join(setting.SSH.RootPath, authorizedPrincipalsFile)
isExist, err := util.IsExist(fPath)
if err != nil {
log.Error("Unable to check if %s exists. Error: %v", fPath, err)
return err
}
if isExist {
f, err := os.Open(fPath)
if err != nil {
return err
}
scanner := bufio.NewScanner(f)
for scanner.Scan() {
line := scanner.Text()
if strings.HasPrefix(line, tplCommentPrefix) {
scanner.Scan()
continue
}
_, err = t.WriteString(line + "\n")
if err != nil {
f.Close()
return err
}
}
f.Close()
}
return nil
}