feat(sftp-server): do not generate host key until first enabled (#7734)

server/sftp/sftp.go

@@ -0,0 +1,123 @@
+package sftp
+
+import (
+	"github.com/KirCute/sftpd-alist"
+	"github.com/alist-org/alist/v3/internal/errs"
+	"github.com/alist-org/alist/v3/internal/model"
+	"github.com/alist-org/alist/v3/pkg/utils"
+	"github.com/alist-org/alist/v3/server/ftp"
+	"os"
+)
+
+type DriverAdapter struct {
+	FtpDriver *ftp.AferoAdapter
+}
+
+func (s *DriverAdapter) OpenFile(_ string, _ uint32, _ *sftpd.Attr) (sftpd.File, error) {
+	// See also GetHandle
+	return nil, errs.NotImplement
+}
+
+func (s *DriverAdapter) OpenDir(_ string) (sftpd.Dir, error) {
+	// See also GetHandle
+	return nil, errs.NotImplement
+}
+
+func (s *DriverAdapter) Remove(name string) error {
+	return s.FtpDriver.Remove(name)
+}
+
+func (s *DriverAdapter) Rename(old, new string, _ uint32) error {
+	return s.FtpDriver.Rename(old, new)
+}
+
+func (s *DriverAdapter) Mkdir(name string, attr *sftpd.Attr) error {
+	return s.FtpDriver.Mkdir(name, attr.Mode)
+}
+
+func (s *DriverAdapter) Rmdir(name string) error {
+	return s.Remove(name)
+}
+
+func (s *DriverAdapter) Stat(name string, _ bool) (*sftpd.Attr, error) {
+	stat, err := s.FtpDriver.Stat(name)
+	if err != nil {
+		return nil, err
+	}
+	return fileInfoToSftpAttr(stat), nil
+}
+
+func (s *DriverAdapter) SetStat(_ string, _ *sftpd.Attr) error {
+	return errs.NotSupport
+}
+
+func (s *DriverAdapter) ReadLink(_ string) (string, error) {
+	return "", errs.NotSupport
+}
+
+func (s *DriverAdapter) CreateLink(_, _ string, _ uint32) error {
+	return errs.NotSupport
+}
+
+func (s *DriverAdapter) RealPath(path string) (string, error) {
+	return utils.FixAndCleanPath(path), nil
+}
+
+func (s *DriverAdapter) GetHandle(name string, flags uint32, _ *sftpd.Attr, offset uint64) (sftpd.FileTransfer, error) {
+	return s.FtpDriver.GetHandle(name, sftpFlagToOpenMode(flags), int64(offset))
+}
+
+func (s *DriverAdapter) ReadDir(name string) ([]sftpd.NamedAttr, error) {
+	dir, err := s.FtpDriver.ReadDir(name)
+	if err != nil {
+		return nil, err
+	}
+	ret := make([]sftpd.NamedAttr, len(dir))
+	for i, d := range dir {
+		ret[i] = *fileInfoToSftpNamedAttr(d)
+	}
+	return ret, nil
+}
+
+// From leffss/sftpd
+func sftpFlagToOpenMode(flags uint32) int {
+	mode := 0
+	if (flags & SSH_FXF_READ) != 0 {
+		mode |= os.O_RDONLY
+	}
+	if (flags & SSH_FXF_WRITE) != 0 {
+		mode |= os.O_WRONLY
+	}
+	if (flags & SSH_FXF_APPEND) != 0 {
+		mode |= os.O_APPEND
+	}
+	if (flags & SSH_FXF_CREAT) != 0 {
+		mode |= os.O_CREATE
+	}
+	if (flags & SSH_FXF_TRUNC) != 0 {
+		mode |= os.O_TRUNC
+	}
+	if (flags & SSH_FXF_EXCL) != 0 {
+		mode |= os.O_EXCL
+	}
+	return mode
+}
+
+func fileInfoToSftpAttr(stat os.FileInfo) *sftpd.Attr {
+	ret := &sftpd.Attr{}
+	ret.Flags |= sftpd.ATTR_SIZE
+	ret.Size = uint64(stat.Size())
+	ret.Flags |= sftpd.ATTR_MODE
+	ret.Mode = stat.Mode()
+	ret.Flags |= sftpd.ATTR_TIME
+	ret.ATime = stat.Sys().(model.Obj).CreateTime()
+	ret.MTime = stat.ModTime()
+	return ret
+}
+
+func fileInfoToSftpNamedAttr(stat os.FileInfo) *sftpd.NamedAttr {
+	return &sftpd.NamedAttr{
+		Name: stat.Name(),
+		Attr: *fileInfoToSftpAttr(stat),
+	}
+}