mirror of https://github.com/perkeep/perkeep.git
153 lines
3.6 KiB
Go
153 lines
3.6 KiB
Go
/*
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Copyright 2011 The Perkeep Authors
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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// Package pinentry interfaces with the pinentry(1) command to securely
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// prompt the user for a password using whichever user interface the
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// user is currently using.
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package pinentry // import "perkeep.org/internal/pinentry"
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import (
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"bufio"
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"errors"
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"fmt"
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"os"
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"os/exec"
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"strings"
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)
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// ErrCancel is returned when the user explicitly aborts the password
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// request.
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var ErrCancel = errors.New("pinentry: Cancel")
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// Request describes what the user should see during the request for
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// their password.
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type Request struct {
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Desc, Prompt, OK, Cancel, Error string
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}
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func catch(err *error) {
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rerr := recover()
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if rerr == nil {
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return
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}
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if e, ok := rerr.(string); ok {
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*err = errors.New(e)
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}
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if e, ok := rerr.(error); ok {
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*err = e
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}
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}
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func check(err error) {
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if err != nil {
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panic(err)
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}
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}
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func (r *Request) GetPIN() (pin string, outerr error) {
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defer catch(&outerr)
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bin, err := exec.LookPath("pinentry")
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if err != nil {
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return r.getPINNaïve()
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}
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cmd := exec.Command(bin)
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stdin, _ := cmd.StdinPipe()
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stdout, _ := cmd.StdoutPipe()
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check(cmd.Start())
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defer cmd.Wait()
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defer stdin.Close()
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br := bufio.NewReader(stdout)
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lineb, _, err := br.ReadLine()
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if err != nil {
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return "", fmt.Errorf("Failed to get getpin greeting")
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}
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line := string(lineb)
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if !strings.HasPrefix(line, "OK") {
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return "", fmt.Errorf("getpin greeting said %q", line)
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}
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set := func(cmd string, val string) {
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if val == "" {
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return
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}
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fmt.Fprintf(stdin, "%s %s\n", cmd, val)
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line, _, err := br.ReadLine()
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if err != nil {
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panic("Failed to " + cmd)
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}
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if string(line) != "OK" {
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panic("Response to " + cmd + " was " + string(line))
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}
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}
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set("SETPROMPT", r.Prompt)
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set("SETDESC", r.Desc)
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set("SETOK", r.OK)
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set("SETCANCEL", r.Cancel)
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set("SETERROR", r.Error)
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set("OPTION", "ttytype="+os.Getenv("TERM"))
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tty, err := os.Readlink("/proc/self/fd/0")
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if err == nil {
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set("OPTION", "ttyname="+tty)
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}
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fmt.Fprintf(stdin, "GETPIN\n")
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lineb, _, err = br.ReadLine()
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if err != nil {
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return "", fmt.Errorf("Failed to read line after GETPIN: %v", err)
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}
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line = string(lineb)
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if strings.HasPrefix(line, "D ") {
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return line[2:], nil
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}
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if strings.HasPrefix(line, "ERR 83886179 ") {
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return "", ErrCancel
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}
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return "", fmt.Errorf("GETPIN response didn't start with D; got %q", line)
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}
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func runPass(bin string, args ...string) error {
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cmd := exec.Command(bin, args...)
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cmd.Stdin = os.Stdin
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if out, err := cmd.CombinedOutput(); err != nil {
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return fmt.Errorf("%v error: %v, %s", bin, err, out)
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}
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return nil
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}
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func (r *Request) getPINNaïve() (string, error) {
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stty, err := exec.LookPath("stty")
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if err != nil {
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return "", errors.New("no pinentry or stty found")
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}
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if err := runPass(stty, "-echo"); err != nil {
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return "", err
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}
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defer runPass(stty, "echo")
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if r.Desc != "" {
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fmt.Printf("%s\n\n", r.Desc)
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}
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prompt := r.Prompt
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if prompt == "" {
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prompt = "Password"
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}
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fmt.Printf("%s: ", prompt)
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br := bufio.NewReader(os.Stdin)
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line, _, err := br.ReadLine()
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if err != nil {
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return "", err
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}
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return string(line), nil
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}
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