297b8c60e7
This breaks the dependency of libplugin on x/crypto, enabling people to use libplugin without having conflicts over the crypto module.
107 lines
2 KiB
Go
107 lines
2 KiB
Go
package main
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import (
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"bufio"
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"fmt"
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"os"
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"path"
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"regexp"
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"strings"
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"github.com/tg123/sshpiper/libplugin"
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)
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type workingdir struct {
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Path string
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NoCheckPerm bool
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Strict bool
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}
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// Base username validation on Debians default: https://sources.debian.net/src/adduser/3.113%2Bnmu3/adduser.conf/#L85
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// -> NAME_REGEX="^[a-z][-a-z0-9_]*\$"
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// The length is limited to 32 characters. See man 8 useradd: https://linux.die.net/man/8/useradd
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var usernameRule *regexp.Regexp = regexp.MustCompile("^[a-z_][-a-z0-9_]{0,31}$")
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const (
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userAuthorizedKeysFile = "authorized_keys"
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userKeyFile = "id_rsa"
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userUpstreamFile = "sshpiper_upstream"
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userKnownHosts = "known_hosts"
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)
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func isUsernameSecure(user string) bool {
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return usernameRule.MatchString(user)
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}
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func (w *workingdir) checkPerm(file string) error {
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filename := path.Join(w.Path, file)
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f, err := os.Open(filename)
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if err != nil {
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return err
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}
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defer f.Close()
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fi, err := f.Stat()
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if err != nil {
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return err
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}
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if w.NoCheckPerm {
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return nil
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}
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if fi.Mode().Perm()&0o077 != 0 {
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return fmt.Errorf("%v's perm is too open", filename)
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}
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return nil
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}
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func (w *workingdir) fullpath(file string) string {
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return path.Join(w.Path, file)
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}
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func (w *workingdir) Readfile(file string) ([]byte, error) {
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if err := w.checkPerm(file); err != nil {
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return nil, err
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}
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return os.ReadFile(w.fullpath(file))
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}
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func (w *workingdir) Exists(file string) bool {
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info, err := os.Stat(w.fullpath(file))
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if os.IsNotExist(err) {
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return false
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}
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return !info.IsDir()
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}
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// TODO refactor this
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func parseUpstreamFile(data string) (host string, user string, err error) {
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r := bufio.NewReader(strings.NewReader(data))
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for {
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host, err = r.ReadString('\n')
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if err != nil {
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break
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}
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host = strings.TrimSpace(host)
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if host != "" && host[0] != '#' {
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break
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}
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}
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t := strings.SplitN(host, "@", 2)
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if len(t) > 1 {
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user = t[0]
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host = t[1]
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}
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_, _, err = libplugin.SplitHostPortForSSH(host)
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return
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}
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