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package main
import (
"crypto/sha256"
"encoding/base64"
"encoding/json"
"flag"
"fmt"
"io/ioutil"
"log"
"math/rand"
"time"
)
type userDB struct {
User, Salt, Hash string
RW bool
}
var (
// you can also hardcode users here instead of loading password file
users = []userDB{}
)
func loadUsers() {
pwd, err := ioutil.ReadFile(*passwdDb)
if err != nil {
log.Fatal("unable to read password file: ", err)
}
err = json.Unmarshal(pwd, &users)
if err != nil {
log.Fatal("unable to parse password file: ", err)
}
log.Printf("Loaded %q (%d users)", *passwdDb, len(users))
}
func saveUsers() {
u, err := json.Marshal(users)
if err != nil {
log.Fatal(err)
}
// TODO: pretty format file
err = ioutil.WriteFile(*passwdDb, u, 600)
if err != nil {
log.Fatal(err)
}
log.Printf("Saved %q (%v users)", *passwdDb, len(users))
}
func manageUsers() {
switch flag.Arg(1) {
case "list":
listUsers()
case "newfile":
saveUsers()
case "add":
addUser(flag.Arg(2), rwStrBool(flag.Arg(3)))
case "delete":
delUser(flag.Arg(2))
case "passwd":
pwdUser(flag.Arg(2))
case "access":
setUser(flag.Arg(2), rwStrBool(flag.Arg(3)))
default:
fmt.Println("usage: user <list|add|delete|passwd|access|newfile> [username] [rw|ro]")
}
}
func listUsers() {
loadUsers()
for _, u := range users {
fmt.Printf("User: %q, RW: %v\n", u.User, u.RW)
}
}
func addUser(usr string, rw bool) {
if usr == "" {
log.Fatal("user add requires username and ro/rw\n")
}
loadUsers()
fmt.Print("Password: ")
var pwd string
fmt.Scanln(&pwd)
salt := rndStr(8)
hash := fmt.Sprintf("%x", sha256.Sum256([]byte(salt+pwd)))
users = append(users, userDB{User: usr, Salt: salt, Hash: hash, RW: rw})
saveUsers()
}
func delUser(usr string) {
loadUsers()
var udb []userDB
for _, u := range users {
if u.User == usr {
continue
}
udb = append(udb, u)
}
if len(users) == len(udb) {
log.Fatal("User not found / nothing changed")
}
users = udb
saveUsers()
}
func pwdUser(usr string) {
if usr == "" {
log.Fatal("user passwd requires username\n")
}
loadUsers()
fmt.Print("Password: ")
var pwd string
fmt.Scanln(&pwd)
salt := rndStr(8)
hash := fmt.Sprintf("%x", sha256.Sum256([]byte(salt+pwd)))
chg := false
for i, u := range users {
if u.User != usr {
continue
}
users[i].Salt = salt
users[i].Hash = hash
chg = true
}
if !chg {
log.Fatal("User not found / nothing changed")
}
saveUsers()
}
func setUser(usr string, rw bool) {
if usr == "" {
log.Fatal("user add requires username and ro/rw\n")
}
loadUsers()
chg := false
for i, u := range users {
if u.User != usr {
continue
}
users[i].RW = rw
chg = true
}
if !chg {
log.Fatal("User not found / nothing changed")
}
saveUsers()
}
func rwStrBool(acc string) bool {
var rw bool
switch acc {
case "rw":
rw = true
case "ro":
rw = false
default:
log.Fatal("access must be either 'ro' or 'rw'")
}
return rw
}
func rndStr(len int) string {
b := make([]byte, len)
rand.Seed(time.Now().Unix())
rand.Read(b)
return base64.StdEncoding.EncodeToString(b)[:len]
}
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