forked from tildetown/town
69 lines
1.4 KiB
Go
69 lines
1.4 KiB
Go
package main
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/*
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The purpose of this command is to be run via sudo as an arbitrary user by the "help" user. It is invoked as part of the "i need to add a new public key" flow from "ssh help@tilde.town".
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It's based on the createkeyfile helper and heavily copy pasta'd. They should probably share code or be a single command but I wanted to keep things simple for now.
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*/
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import (
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"fmt"
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"os"
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"os/user"
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"path"
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)
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const keyfileName = "authorized_keys2"
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func quit(msg string, code int) {
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// TODO print to stderr
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fmt.Println(msg)
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os.Exit(code)
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}
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func main() {
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username := os.Args[1]
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if username == "" {
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quit("expected username as argument", 1)
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}
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u, err := user.Current()
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if err != nil {
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quit(err.Error(), 2)
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}
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if u.Username != username {
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quit("that's my purse; I don't know you", 3)
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}
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sshPath := path.Join("/home", u.Username, ".ssh")
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keyfilePath := path.Join(sshPath, keyfileName)
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f, err := os.OpenFile(keyfilePath, os.O_APPEND|os.O_WRONLY, 0600)
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if err != nil {
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quit(fmt.Sprintf("failed to open %s: %s", keyfilePath, err.Error()), 5)
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}
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defer f.Close()
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stdin := make([]byte, 90000) // arbitrary limit
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n, err := os.Stdin.Read(stdin)
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if err != nil {
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quit(err.Error(), 6)
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} else if n == 0 {
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quit("nothing passed on STDIN", 7)
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}
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stdin = stdin[0:n]
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n, err = f.Write(stdin)
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if err != nil {
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quit(err.Error(), 9)
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} else if n == 0 {
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quit("wrote nothing to keyfile", 10)
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}
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}
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