522 lines
18 KiB
Nix
522 lines
18 KiB
Nix
# This module provides configuration for the PAM (Pluggable
|
||
# Authentication Modules) system.
|
||
|
||
{ config, lib, pkgs, ... }:
|
||
|
||
with lib;
|
||
|
||
let
|
||
parentConfig = config;
|
||
|
||
pamOpts = { config, name, ... }: let cfg = config; in let config = parentConfig; in {
|
||
|
||
options = {
|
||
|
||
name = mkOption {
|
||
example = "sshd";
|
||
type = types.str;
|
||
description = "Name of the PAM service.";
|
||
};
|
||
|
||
unixAuth = mkOption {
|
||
default = true;
|
||
type = types.bool;
|
||
description = ''
|
||
Whether users can log in with passwords defined in
|
||
<filename>/etc/shadow</filename>.
|
||
'';
|
||
};
|
||
|
||
rootOK = mkOption {
|
||
default = false;
|
||
type = types.bool;
|
||
description = ''
|
||
If set, root doesn't need to authenticate (e.g. for the
|
||
<command>useradd</command> service).
|
||
'';
|
||
};
|
||
|
||
u2fAuth = mkOption {
|
||
default = config.security.pam.enableU2F;
|
||
type = types.bool;
|
||
description = ''
|
||
If set, users listed in
|
||
<filename>~/.yubico/u2f_keys</filename> are able to log in
|
||
with the associated U2F key.
|
||
'';
|
||
};
|
||
|
||
usbAuth = mkOption {
|
||
default = config.security.pam.usb.enable;
|
||
type = types.bool;
|
||
description = ''
|
||
If set, users listed in
|
||
<filename>/etc/pamusb.conf</filename> are able to log in
|
||
with the associated USB key.
|
||
'';
|
||
};
|
||
|
||
otpwAuth = mkOption {
|
||
default = config.security.pam.enableOTPW;
|
||
type = types.bool;
|
||
description = ''
|
||
If set, the OTPW system will be used (if
|
||
<filename>~/.otpw</filename> exists).
|
||
'';
|
||
};
|
||
|
||
fprintAuth = mkOption {
|
||
default = config.services.fprintd.enable;
|
||
type = types.bool;
|
||
description = ''
|
||
If set, fingerprint reader will be used (if exists and
|
||
your fingerprints are enrolled).
|
||
'';
|
||
};
|
||
|
||
oathAuth = mkOption {
|
||
default = config.security.pam.oath.enable;
|
||
type = types.bool;
|
||
description = ''
|
||
If set, the OATH Toolkit will be used.
|
||
'';
|
||
};
|
||
|
||
sshAgentAuth = mkOption {
|
||
default = false;
|
||
type = types.bool;
|
||
description = ''
|
||
If set, the calling user's SSH agent is used to authenticate
|
||
against the keys in the calling user's
|
||
<filename>~/.ssh/authorized_keys</filename>. This is useful
|
||
for <command>sudo</command> on password-less remote systems.
|
||
'';
|
||
};
|
||
|
||
startSession = mkOption {
|
||
default = false;
|
||
type = types.bool;
|
||
description = ''
|
||
If set, the service will register a new session with
|
||
systemd's login manager. For local sessions, this will give
|
||
the user access to audio devices, CD-ROM drives. In the
|
||
default PolicyKit configuration, it also allows the user to
|
||
reboot the system.
|
||
'';
|
||
};
|
||
|
||
setEnvironment = mkOption {
|
||
type = types.bool;
|
||
default = true;
|
||
description = ''
|
||
Whether the service should set the environment variables
|
||
listed in <option>environment.sessionVariables</option>
|
||
using <literal>pam_env.so</literal>.
|
||
'';
|
||
};
|
||
|
||
setLoginUid = mkOption {
|
||
type = types.bool;
|
||
description = ''
|
||
Set the login uid of the process
|
||
(<filename>/proc/self/loginuid</filename>) for auditing
|
||
purposes. The login uid is only set by ‘entry points’ like
|
||
<command>login</command> and <command>sshd</command>, not by
|
||
commands like <command>sudo</command>.
|
||
'';
|
||
};
|
||
|
||
forwardXAuth = mkOption {
|
||
default = false;
|
||
type = types.bool;
|
||
description = ''
|
||
Whether X authentication keys should be passed from the
|
||
calling user to the target user (e.g. for
|
||
<command>su</command>)
|
||
'';
|
||
};
|
||
|
||
pamMount = mkOption {
|
||
default = config.security.pam.mount.enable;
|
||
type = types.bool;
|
||
description = ''
|
||
Enable PAM mount (pam_mount) system to mount fileystems on user login.
|
||
'';
|
||
};
|
||
|
||
allowNullPassword = mkOption {
|
||
default = false;
|
||
type = types.bool;
|
||
description = ''
|
||
Whether to allow logging into accounts that have no password
|
||
set (i.e., have an empty password field in
|
||
<filename>/etc/passwd</filename> or
|
||
<filename>/etc/group</filename>). This does not enable
|
||
logging into disabled accounts (i.e., that have the password
|
||
field set to <literal>!</literal>). Note that regardless of
|
||
what the pam_unix documentation says, accounts with hashed
|
||
empty passwords are always allowed to log in.
|
||
'';
|
||
};
|
||
|
||
requireWheel = mkOption {
|
||
default = false;
|
||
type = types.bool;
|
||
description = ''
|
||
Whether to permit root access only to members of group wheel.
|
||
'';
|
||
};
|
||
|
||
limits = mkOption {
|
||
description = ''
|
||
Attribute set describing resource limits. Defaults to the
|
||
value of <option>security.pam.loginLimits</option>.
|
||
'';
|
||
};
|
||
|
||
showMotd = mkOption {
|
||
default = false;
|
||
type = types.bool;
|
||
description = "Whether to show the message of the day.";
|
||
};
|
||
|
||
makeHomeDir = mkOption {
|
||
default = false;
|
||
type = types.bool;
|
||
description = ''
|
||
Whether to try to create home directories for users
|
||
with <literal>$HOME</literal>s pointing to nonexistent
|
||
locations on session login.
|
||
'';
|
||
};
|
||
|
||
updateWtmp = mkOption {
|
||
default = false;
|
||
type = types.bool;
|
||
description = "Whether to update <filename>/var/log/wtmp</filename>.";
|
||
};
|
||
|
||
logFailures = mkOption {
|
||
default = false;
|
||
type = types.bool;
|
||
description = "Whether to log authentication failures in <filename>/var/log/faillog</filename>.";
|
||
};
|
||
|
||
enableAppArmor = mkOption {
|
||
default = false;
|
||
type = types.bool;
|
||
description = ''
|
||
Enable support for attaching AppArmor profiles at the
|
||
user/group level, e.g., as part of a role based access
|
||
control scheme.
|
||
'';
|
||
};
|
||
|
||
text = mkOption {
|
||
type = types.nullOr types.lines;
|
||
description = "Contents of the PAM service file.";
|
||
};
|
||
|
||
};
|
||
|
||
config = {
|
||
name = mkDefault name;
|
||
setLoginUid = mkDefault cfg.startSession;
|
||
limits = mkDefault config.security.pam.loginLimits;
|
||
|
||
# !!! TODO: move the LDAP stuff to the LDAP module, and the
|
||
# Samba stuff to the Samba module. This requires that the PAM
|
||
# module provides the right hooks.
|
||
text = mkDefault
|
||
(''
|
||
# Account management.
|
||
account sufficient pam_unix.so
|
||
${optionalString use_ldap
|
||
"account sufficient ${pam_ldap}/lib/security/pam_ldap.so"}
|
||
${optionalString config.services.sssd.enable
|
||
"account sufficient ${pkgs.sssd}/lib/security/pam_sss.so"}
|
||
${optionalString config.krb5.enable
|
||
"account sufficient ${pam_krb5}/lib/security/pam_krb5.so"}
|
||
|
||
# Authentication management.
|
||
${optionalString cfg.rootOK
|
||
"auth sufficient pam_rootok.so"}
|
||
${optionalString cfg.requireWheel
|
||
"auth required pam_wheel.so use_uid"}
|
||
${optionalString cfg.logFailures
|
||
"auth required pam_tally.so"}
|
||
${optionalString (config.security.pam.enableSSHAgentAuth && cfg.sshAgentAuth)
|
||
"auth sufficient ${pkgs.pam_ssh_agent_auth}/libexec/pam_ssh_agent_auth.so file=~/.ssh/authorized_keys:~/.ssh/authorized_keys2:/etc/ssh/authorized_keys.d/%u"}
|
||
${optionalString cfg.fprintAuth
|
||
"auth sufficient ${pkgs.fprintd}/lib/security/pam_fprintd.so"}
|
||
${optionalString cfg.u2fAuth
|
||
"auth sufficient ${pkgs.pam_u2f}/lib/security/pam_u2f.so"}
|
||
${optionalString cfg.usbAuth
|
||
"auth sufficient ${pkgs.pam_usb}/lib/security/pam_usb.so"}
|
||
${let oath = config.security.pam.oath; in optionalString cfg.oathAuth
|
||
"auth requisite ${pkgs.oathToolkit}/lib/security/pam_oath.so window=${toString oath.window} usersfile=${toString oath.usersFile} digits=${toString oath.digits}"}
|
||
'' +
|
||
# Modules in this block require having the password set in PAM_AUTHTOK.
|
||
# pam_unix is marked as 'sufficient' on NixOS which means nothing will run
|
||
# after it succeeds. Certain modules need to run after pam_unix
|
||
# prompts the user for password so we run it once with 'required' at an
|
||
# earlier point and it will run again with 'sufficient' further down.
|
||
# We use try_first_pass the second time to avoid prompting password twice
|
||
(optionalString (cfg.unixAuth && (config.security.pam.enableEcryptfs || cfg.pamMount)) ''
|
||
auth required pam_unix.so ${optionalString cfg.allowNullPassword "nullok"} likeauth
|
||
${optionalString config.security.pam.enableEcryptfs
|
||
"auth optional ${pkgs.ecryptfs}/lib/security/pam_ecryptfs.so unwrap"}
|
||
${optionalString cfg.pamMount
|
||
"auth optional ${pkgs.pam_mount}/lib/security/pam_mount.so"}
|
||
'') + ''
|
||
${optionalString cfg.unixAuth
|
||
"auth sufficient pam_unix.so ${optionalString cfg.allowNullPassword "nullok"} likeauth try_first_pass"}
|
||
${optionalString cfg.otpwAuth
|
||
"auth sufficient ${pkgs.otpw}/lib/security/pam_otpw.so"}
|
||
${optionalString use_ldap
|
||
"auth sufficient ${pam_ldap}/lib/security/pam_ldap.so use_first_pass"}
|
||
${optionalString config.services.sssd.enable
|
||
"auth sufficient ${pkgs.sssd}/lib/security/pam_sss.so use_first_pass"}
|
||
${optionalString config.krb5.enable ''
|
||
auth [default=ignore success=1 service_err=reset] ${pam_krb5}/lib/security/pam_krb5.so use_first_pass
|
||
auth [default=die success=done] ${pam_ccreds}/lib/security/pam_ccreds.so action=validate use_first_pass
|
||
auth sufficient ${pam_ccreds}/lib/security/pam_ccreds.so action=store use_first_pass
|
||
''}
|
||
auth required pam_deny.so
|
||
|
||
# Password management.
|
||
password requisite pam_unix.so nullok sha512
|
||
${optionalString config.security.pam.enableEcryptfs
|
||
"password optional ${pkgs.ecryptfs}/lib/security/pam_ecryptfs.so"}
|
||
${optionalString cfg.pamMount
|
||
"password optional ${pkgs.pam_mount}/lib/security/pam_mount.so"}
|
||
${optionalString use_ldap
|
||
"password sufficient ${pam_ldap}/lib/security/pam_ldap.so"}
|
||
${optionalString config.services.sssd.enable
|
||
"password sufficient ${pkgs.sssd}/lib/security/pam_sss.so use_authtok"}
|
||
${optionalString config.krb5.enable
|
||
"password sufficient ${pam_krb5}/lib/security/pam_krb5.so use_first_pass"}
|
||
${optionalString config.services.samba.syncPasswordsByPam
|
||
"password optional ${pkgs.samba}/lib/security/pam_smbpass.so nullok use_authtok try_first_pass"}
|
||
|
||
# Session management.
|
||
${optionalString cfg.setEnvironment ''
|
||
session required pam_env.so envfile=${config.system.build.pamEnvironment}
|
||
''}
|
||
session required pam_unix.so
|
||
${optionalString cfg.setLoginUid
|
||
"session ${
|
||
if config.boot.isContainer then "optional" else "required"
|
||
} pam_loginuid.so"}
|
||
${optionalString cfg.makeHomeDir
|
||
"session required ${pkgs.pam}/lib/security/pam_mkhomedir.so silent skel=${config.security.pam.makeHomeDir.skelDirectory} umask=0022"}
|
||
${optionalString cfg.updateWtmp
|
||
"session required ${pkgs.pam}/lib/security/pam_lastlog.so silent"}
|
||
${optionalString config.security.pam.enableEcryptfs
|
||
"session optional ${pkgs.ecryptfs}/lib/security/pam_ecryptfs.so"}
|
||
${optionalString use_ldap
|
||
"session optional ${pam_ldap}/lib/security/pam_ldap.so"}
|
||
${optionalString config.services.sssd.enable
|
||
"session optional ${pkgs.sssd}/lib/security/pam_sss.so"}
|
||
${optionalString config.krb5.enable
|
||
"session optional ${pam_krb5}/lib/security/pam_krb5.so"}
|
||
${optionalString cfg.otpwAuth
|
||
"session optional ${pkgs.otpw}/lib/security/pam_otpw.so"}
|
||
${optionalString cfg.startSession
|
||
"session optional ${pkgs.systemd}/lib/security/pam_systemd.so"}
|
||
${optionalString cfg.forwardXAuth
|
||
"session optional pam_xauth.so xauthpath=${pkgs.xorg.xauth}/bin/xauth systemuser=99"}
|
||
${optionalString (cfg.limits != [])
|
||
"session required ${pkgs.pam}/lib/security/pam_limits.so conf=${makeLimitsConf cfg.limits}"}
|
||
${optionalString (cfg.showMotd && config.users.motd != null)
|
||
"session optional ${pkgs.pam}/lib/security/pam_motd.so motd=${motd}"}
|
||
${optionalString cfg.pamMount
|
||
"session optional ${pkgs.pam_mount}/lib/security/pam_mount.so"}
|
||
${optionalString (cfg.enableAppArmor && config.security.apparmor.enable)
|
||
"session optional ${pkgs.apparmor-pam}/lib/security/pam_apparmor.so order=user,group,default debug"}
|
||
'');
|
||
};
|
||
|
||
};
|
||
|
||
|
||
inherit (pkgs) pam_krb5 pam_ccreds;
|
||
|
||
use_ldap = (config.users.ldap.enable && config.users.ldap.loginPam);
|
||
pam_ldap = if config.users.ldap.daemon.enable then pkgs.nss_pam_ldapd else pkgs.pam_ldap;
|
||
|
||
# Create a limits.conf(5) file.
|
||
makeLimitsConf = limits:
|
||
pkgs.writeText "limits.conf"
|
||
(concatMapStrings ({ domain, type, item, value }:
|
||
"${domain} ${type} ${item} ${toString value}\n")
|
||
limits);
|
||
|
||
motd = pkgs.writeText "motd" config.users.motd;
|
||
|
||
makePAMService = pamService:
|
||
{ source = pkgs.writeText "${pamService.name}.pam" pamService.text;
|
||
target = "pam.d/${pamService.name}";
|
||
};
|
||
|
||
in
|
||
|
||
{
|
||
|
||
###### interface
|
||
|
||
options = {
|
||
|
||
security.pam.loginLimits = mkOption {
|
||
default = [];
|
||
example =
|
||
[ { domain = "ftp";
|
||
type = "hard";
|
||
item = "nproc";
|
||
value = "0";
|
||
}
|
||
{ domain = "@student";
|
||
type = "-";
|
||
item = "maxlogins";
|
||
value = "4";
|
||
}
|
||
];
|
||
|
||
description =
|
||
'' Define resource limits that should apply to users or groups.
|
||
Each item in the list should be an attribute set with a
|
||
<varname>domain</varname>, <varname>type</varname>,
|
||
<varname>item</varname>, and <varname>value</varname>
|
||
attribute. The syntax and semantics of these attributes
|
||
must be that described in the limits.conf(5) man page.
|
||
'';
|
||
};
|
||
|
||
security.pam.services = mkOption {
|
||
default = [];
|
||
type = with types; loaOf (submodule pamOpts);
|
||
description =
|
||
''
|
||
This option defines the PAM services. A service typically
|
||
corresponds to a program that uses PAM,
|
||
e.g. <command>login</command> or <command>passwd</command>.
|
||
Each attribute of this set defines a PAM service, with the attribute name
|
||
defining the name of the service.
|
||
'';
|
||
};
|
||
|
||
security.pam.makeHomeDir.skelDirectory = mkOption {
|
||
type = types.str;
|
||
default = "/var/empty";
|
||
example = "/etc/skel";
|
||
description = ''
|
||
Path to skeleton directory whose contents are copied to home
|
||
directories newly created by <literal>pam_mkhomedir</literal>.
|
||
'';
|
||
};
|
||
|
||
security.pam.enableSSHAgentAuth = mkOption {
|
||
default = false;
|
||
description =
|
||
''
|
||
Enable sudo logins if the user's SSH agent provides a key
|
||
present in <filename>~/.ssh/authorized_keys</filename>.
|
||
This allows machines to exclusively use SSH keys instead of
|
||
passwords.
|
||
'';
|
||
};
|
||
|
||
security.pam.enableOTPW = mkOption {
|
||
default = false;
|
||
description = ''
|
||
Enable the OTPW (one-time password) PAM module.
|
||
'';
|
||
};
|
||
|
||
security.pam.enableU2F = mkOption {
|
||
default = false;
|
||
description = ''
|
||
Enable the U2F PAM module.
|
||
'';
|
||
};
|
||
|
||
security.pam.enableEcryptfs = mkOption {
|
||
default = false;
|
||
description = ''
|
||
Enable eCryptfs PAM module (mounting ecryptfs home directory on login).
|
||
'';
|
||
};
|
||
|
||
users.motd = mkOption {
|
||
default = null;
|
||
example = "Today is Sweetmorn, the 4th day of The Aftermath in the YOLD 3178.";
|
||
type = types.nullOr types.lines;
|
||
description = "Message of the day shown to users when they log in.";
|
||
};
|
||
|
||
};
|
||
|
||
|
||
###### implementation
|
||
|
||
config = {
|
||
|
||
environment.systemPackages =
|
||
# Include the PAM modules in the system path mostly for the manpages.
|
||
[ pkgs.pam ]
|
||
++ optional config.users.ldap.enable pam_ldap
|
||
++ optional config.services.sssd.enable pkgs.sssd
|
||
++ optionals config.krb5.enable [pam_krb5 pam_ccreds]
|
||
++ optionals config.security.pam.enableOTPW [ pkgs.otpw ]
|
||
++ optionals config.security.pam.oath.enable [ pkgs.oathToolkit ]
|
||
++ optionals config.security.pam.enableU2F [ pkgs.pam_u2f ]
|
||
++ optionals config.security.pam.enableEcryptfs [ pkgs.ecryptfs ];
|
||
|
||
security.setuidPrograms =
|
||
optionals config.security.pam.enableEcryptfs [ "mount.ecryptfs_private" "umount.ecryptfs_private" ];
|
||
|
||
environment.etc =
|
||
mapAttrsToList (n: v: makePAMService v) config.security.pam.services;
|
||
|
||
security.setuidOwners = [ {
|
||
program = "unix_chkpwd";
|
||
source = "${pkgs.pam}/sbin/unix_chkpwd.orig";
|
||
owner = "root";
|
||
setuid = true;
|
||
} ];
|
||
|
||
security.pam.services =
|
||
{ other.text =
|
||
''
|
||
auth required pam_warn.so
|
||
auth required pam_deny.so
|
||
account required pam_warn.so
|
||
account required pam_deny.so
|
||
password required pam_warn.so
|
||
password required pam_deny.so
|
||
session required pam_warn.so
|
||
session required pam_deny.so
|
||
'';
|
||
|
||
# Most of these should be moved to specific modules.
|
||
cups = {};
|
||
ftp = {};
|
||
i3lock = {};
|
||
i3lock-color = {};
|
||
screen = {};
|
||
vlock = {};
|
||
xlock = {};
|
||
xscreensaver = {};
|
||
|
||
runuser = { rootOK = true; unixAuth = false; setEnvironment = false; };
|
||
|
||
/* FIXME: should runuser -l start a systemd session? Currently
|
||
it complains "Cannot create session: Already running in a
|
||
session". */
|
||
runuser-l = { rootOK = true; unixAuth = false; };
|
||
};
|
||
|
||
};
|
||
|
||
}
|