Merge pull request #22 from thomiceli/fix/ssh-keys

Fix SSH pubkey detection

internal/models/sshkey.go

@@ -48,7 +48,7 @@ func GetSSHKeyByID(sshKeyId uint) (*SSHKey, error) {
  return sshKey, err
 }
 
-func GetSSHKeyByContent(sshKeyContent string) (*SSHKey, error) {
+func SSHKeyDoesExists(sshKeyContent string) (*SSHKey, error) {
  sshKey := new(SSHKey)
  err := db.
  Where("content like ?", sshKeyContent+"%").
@@ -65,9 +65,9 @@ func (sshKey *SSHKey) Delete() error {
  return db.Delete(&sshKey).Error
 }
 
-func SSHKeyLastUsedNow(sshKeyID uint) error {
+func SSHKeyLastUsedNow(sshKeyContent string) error {
  return db.Model(&SSHKey{}).
- Where("id = ?", sshKeyID).
+ Where("content = ?", sshKeyContent).
  Update("last_used_at", time.Now().Unix()).Error
 }
 

internal/models/user.go

@@ -81,15 +81,14 @@ func GetUserById(userId uint) (*User, error) {
  return user, err
 }
 
-func GetUserBySSHKeyID(sshKeyId uint) (*User, error) {
- user := new(User)
+func SSHKeyExistsForUser(sshKey string, userId uint) (*SSHKey, error) {
+ key := new(SSHKey)
  err := db.
- Preload("SSHKeys").
- Joins("join ssh_keys on users.id = ssh_keys.user_id").
- Where("ssh_keys.id = ?", sshKeyId).
- First(&user).Error
+ Where("content = ?", sshKey).
+ Where("user_id = ?", userId).
+ First(&key).Error
 
- return user, err
+ return key, err
 }
 
 func GetUserByProvider(id string, provider string) (*User, error) {

internal/ssh/git_ssh.go

@@ -12,7 +12,7 @@ import (
  "strings"
 )
 
-func runGitCommand(ch ssh.Channel, gitCmd string, keyID uint, ip string) error {
+func runGitCommand(ch ssh.Channel, gitCmd string, key string, ip string) error {
  verb, args := parseCommand(gitCmd)
  if !strings.HasPrefix(verb, "git-") {
  verb = ""
@@ -43,7 +43,7 @@ func runGitCommand(ch ssh.Channel, gitCmd string, keyID uint, ip string) error {
  }
 
  if verb == "receive-pack" || requireLogin == "1" {
- user, err := models.GetUserBySSHKeyID(keyID)
+ pubKey, err := models.SSHKeyExistsForUser(key, gist.UserID)
  if err != nil {
  if errors.Is(err, gorm.ErrRecordNotFound) {
  log.Warn().Msg("Invalid SSH authentication attempt from " + ip)
@@ -52,15 +52,9 @@ func runGitCommand(ch ssh.Channel, gitCmd string, keyID uint, ip string) error {
  errorSsh("Failed to get user by SSH key id", err)
  return errors.New("internal server error")
  }
-
- if user.ID != gist.UserID {
- log.Warn().Msg("Invalid SSH authentication attempt from " + ip)
- return errors.New("unauthorized")
- }
+ _ = models.SSHKeyLastUsedNow(pubKey.Content)
  }
 
- _ = models.SSHKeyLastUsedNow(keyID)
-
  repositoryPath := git.RepositoryPath(gist.User.Username, gist.Uuid)
 
  cmd := exec.Command("git", verb, repositoryPath)

internal/ssh/run.go

@@ -12,7 +12,6 @@ import (
  "os"
  "os/exec"
  "path/filepath"
- "strconv"
  "strings"
  "syscall"
 )
@@ -24,7 +23,8 @@ func Start() {
 
  sshConfig := &ssh.ServerConfig{
  PublicKeyCallback: func(conn ssh.ConnMetadata, key ssh.PublicKey) (*ssh.Permissions, error) {
- pkey, err := models.GetSSHKeyByContent(strings.TrimSpace(string(ssh.MarshalAuthorizedKey(key))))
+ strKey := strings.TrimSpace(string(ssh.MarshalAuthorizedKey(key)))
+ _, err := models.SSHKeyDoesExists(strKey)
  if err != nil {
  if !errors.Is(err, gorm.ErrRecordNotFound) {
  return nil, err
@@ -33,7 +33,7 @@ func Start() {
  log.Warn().Msg("Invalid SSH authentication attempt from " + conn.RemoteAddr().String())
  return nil, errors.New("unknown public key")
  }
- return &ssh.Permissions{Extensions: map[string]string{"key-id": strconv.Itoa(int(pkey.ID))}}, nil
+ return &ssh.Permissions{Extensions: map[string]string{"key": strKey}}, nil
  },
  }
 
@@ -71,13 +71,12 @@ func listen(serverConfig *ssh.ServerConfig) {
  }
 
  go ssh.DiscardRequests(reqs)
- keyID, _ := strconv.Atoi(sConn.Permissions.Extensions["key-id"])
- go handleConnexion(channels, uint(keyID), sConn.RemoteAddr().String())
+ go handleConnexion(channels, sConn.Permissions.Extensions["key"], sConn.RemoteAddr().String())
  }()
  }
 }
 
-func handleConnexion(channels <-chan ssh.NewChannel, keyID uint, ip string) {
+func handleConnexion(channels <-chan ssh.NewChannel, key string, ip string) {
  for channel := range channels {
  if channel.ChannelType() != "session" {
  _ = channel.Reject(ssh.UnknownChannelType, "Unknown channel type")
@@ -109,7 +108,7 @@ func handleConnexion(channels <-chan ssh.NewChannel, keyID uint, ip string) {
  payloadCmd = payloadCmd[i:]
  }
 
- if err = runGitCommand(ch, payloadCmd, keyID, ip); err != nil {
+ if err = runGitCommand(ch, payloadCmd, key, ip); err != nil {
  _, _ = ch.Stderr().Write([]byte("Opengist: " + err.Error() + "\r\n"))
  }
  _, _ = ch.SendRequest("exit-status", false, []byte{0, 0, 0, 0})

internal/web/settings.go

@@ -74,11 +74,12 @@ func sshKeysProcess(ctx echo.Context) error {
 
  key.UserID = user.ID
 
- _, _, _, _, err := ssh.ParseAuthorizedKey([]byte(key.Content))
+ pubKey, _, _, _, err := ssh.ParseAuthorizedKey([]byte(key.Content))
  if err != nil {
  addFlash(ctx, "Invalid SSH key", "error")
  return redirect(ctx, "/settings")
  }
+ key.Content = strings.TrimSpace(string(ssh.MarshalAuthorizedKey(pubKey)))
 
  if err := key.Create(); err != nil {
  return errorRes(500, "Cannot add SSH key", err)

templates/pages/settings.html

@@ -83,7 +83,7 @@ <h2 class="text-md font-bold text-slate-300">
  Add SSH Key
  </h2>
  <h3 class="text-sm text-gray-400 italic mb-4">
- Used only to push gists using Git via SSH
+ Used only to pull/push gists using Git via SSH
  </h3>
  <form class="space-y-6" action="/settings/ssh-keys" method="post">
  <div>