stockholm/lass/3modules/usershadow.nix
2021-12-08 11:30:42 +01:00

140 lines
4.4 KiB
Nix

{ config, lib, pkgs, ... }@args: with import <stockholm/lib>; let
cfg = config.lass.usershadow;
out = {
options.lass.usershadow = api;
config = lib.mkIf cfg.enable imp;
};
api = {
enable = mkEnableOption "usershadow";
pattern = mkOption {
type = types.str;
default = "/home/%/.shadow";
};
path = mkOption {
type = types.str;
};
};
imp = {
environment.systemPackages = [ usershadow ];
lass.usershadow.path = "${usershadow}";
security.pam.services.sshd.text = ''
auth required pam_exec.so expose_authtok /run/wrappers/bin/shadow_verify_pam ${cfg.pattern}
auth required pam_permit.so
account required pam_permit.so
session required pam_permit.so
'';
security.pam.services.dovecot2.text = ''
auth required pam_exec.so expose_authtok /run/wrappers/bin/shadow_verify_pam ${cfg.pattern}
auth required pam_permit.so
account required pam_permit.so
session required pam_permit.so
'';
security.wrappers.shadow_verify_pam = {
setuid = true;
source = "${usershadow}/bin/verify_pam";
owner = "root";
group = "root";
};
security.wrappers.shadow_verify_arg = {
setuid = true;
source = "${usershadow}/bin/verify_arg";
owner = "root";
group = "root";
};
};
usershadow = let {
deps = [
"pwstore-fast"
"bytestring"
];
body = pkgs.writeHaskellPackage "passwords" {
ghc-options = [
"-rtsopts"
"-Wall"
];
executables.verify_pam = {
extra-depends = deps;
text = ''
import System.IO
import Data.Char (chr)
import System.Environment (getEnv, getArgs)
import Crypto.PasswordStore (verifyPasswordWith, pbkdf2)
import qualified Data.ByteString.Char8 as BS8
import System.Exit (exitFailure, exitSuccess)
main :: IO ()
main = do
user <- getEnv "PAM_USER"
shadowFilePattern <- head <$> getArgs
let shadowFile = lhs <> user <> tail rhs
(lhs, rhs) = span (/= '%') shadowFilePattern
hash <- readFile shadowFile
password <- takeWhile (/= (chr 0)) <$> hGetLine stdin
let res = verifyPasswordWith pbkdf2 (2^) (BS8.pack password) (BS8.pack hash)
if res then exitSuccess else exitFailure
'';
};
executables.verify_arg = {
extra-depends = deps;
text = ''
import System.Environment (getArgs)
import Crypto.PasswordStore (verifyPasswordWith, pbkdf2)
import qualified Data.ByteString.Char8 as BS8
import System.Exit (exitFailure, exitSuccess)
main :: IO ()
main = do
argsList <- getArgs
let shadowFilePattern = argsList !! 0
let user = argsList !! 1
let password = argsList !! 2
let shadowFile = lhs <> user <> tail rhs
(lhs, rhs) = span (/= '%') shadowFilePattern
hash <- readFile shadowFile
let res = verifyPasswordWith pbkdf2 (2^) (BS8.pack password) (BS8.pack hash)
if res then do (putStr "yes") else exitFailure
'';
};
executables.passwd = {
extra-depends = deps;
text = ''
import System.Environment (getEnv)
import Crypto.PasswordStore (makePasswordWith, pbkdf2)
import qualified Data.ByteString.Char8 as BS8
import System.IO (stdin, stdout, hSetEcho, hFlush, putStr, putStrLn)
import Control.Exception (bracket_)
main :: IO ()
main = do
home <- getEnv "HOME"
mb_password <- bracket_ (hSetEcho stdin False) (hSetEcho stdin True) $ do
putStr "Enter new UNIX password: "
hFlush stdout
password <- BS8.hGetLine stdin
putStrLn ""
putStr "Retype new UNIX password: "
hFlush stdout
password2 <- BS8.hGetLine stdin
return $ if password == password2
then Just password
else Nothing
case mb_password of
Just password -> do
hash <- makePasswordWith pbkdf2 password 10
BS8.writeFile (home ++ "/.shadow") hash
putStrLn "passwd: all authentication tokens updated successfully."
Nothing -> putStrLn "Sorry, passwords do not match"
'';
};
};
};
in out