nixpkgs/nixos/modules/security/ipa.nix
2023-08-08 21:31:21 +08:00

259 lines
7.0 KiB
Nix

{
config,
lib,
pkgs,
...
}:
with lib; let
cfg = config.security.ipa;
pyBool = x:
if x
then "True"
else "False";
ldapConf = pkgs.writeText "ldap.conf" ''
# Turning this off breaks GSSAPI used with krb5 when rdns = false
SASL_NOCANON on
URI ldaps://${cfg.server}
BASE ${cfg.basedn}
TLS_CACERT /etc/ipa/ca.crt
'';
nssDb =
pkgs.runCommand "ipa-nssdb"
{
nativeBuildInputs = [pkgs.nss.tools];
} ''
mkdir -p $out
certutil -d $out -N --empty-password
certutil -d $out -A --empty-password -n "${cfg.realm} IPA CA" -t CT,C,C -i ${cfg.certificate}
'';
in {
options = {
security.ipa = {
enable = mkEnableOption (lib.mdDoc "FreeIPA domain integration");
certificate = mkOption {
type = types.package;
description = lib.mdDoc ''
IPA server CA certificate.
Use `nix-prefetch-url http://$server/ipa/config/ca.crt` to
obtain the file and the hash.
'';
example = literalExpression ''
pkgs.fetchurl {
url = http://ipa.example.com/ipa/config/ca.crt;
sha256 = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa";
};
'';
};
domain = mkOption {
type = types.str;
example = "example.com";
description = lib.mdDoc "Domain of the IPA server.";
};
realm = mkOption {
type = types.str;
example = "EXAMPLE.COM";
description = lib.mdDoc "Kerberos realm.";
};
server = mkOption {
type = types.str;
example = "ipa.example.com";
description = lib.mdDoc "IPA Server hostname.";
};
basedn = mkOption {
type = types.str;
example = "dc=example,dc=com";
description = lib.mdDoc "Base DN to use when performing LDAP operations.";
};
offlinePasswords = mkOption {
type = types.bool;
default = true;
description = lib.mdDoc "Whether to store offline passwords when the server is down.";
};
cacheCredentials = mkOption {
type = types.bool;
default = true;
description = lib.mdDoc "Whether to cache credentials.";
};
ifpAllowedUids = mkOption {
type = types.listOf types.str;
default = ["root"];
description = lib.mdDoc "A list of users allowed to access the ifp dbus interface.";
};
dyndns = {
enable = mkOption {
type = types.bool;
default = true;
description = lib.mdDoc "Whether to enable FreeIPA automatic hostname updates.";
};
interface = mkOption {
type = types.str;
example = "eth0";
default = "*";
description = lib.mdDoc "Network interface to perform hostname updates through.";
};
};
chromiumSupport = mkOption {
type = types.bool;
default = true;
description = lib.mdDoc "Whether to whitelist the FreeIPA domain in Chromium.";
};
};
};
config = mkIf cfg.enable {
assertions = [
{
assertion = !config.krb5.enable;
message = "krb5 must be disabled through `krb5.enable` for FreeIPA integration to work.";
}
{
assertion = !config.users.ldap.enable;
message = "ldap must be disabled through `users.ldap.enable` for FreeIPA integration to work.";
}
];
environment.systemPackages = with pkgs; [krb5Full freeipa];
environment.etc = {
"ipa/default.conf".text = ''
[global]
basedn = ${cfg.basedn}
realm = ${cfg.realm}
domain = ${cfg.domain}
server = ${cfg.server}
host = ${config.networking.hostName}
xmlrpc_uri = https://${cfg.server}/ipa/xml
enable_ra = True
'';
"ipa/nssdb".source = nssDb;
"krb5.conf".text = ''
[libdefaults]
default_realm = ${cfg.realm}
dns_lookup_realm = false
dns_lookup_kdc = true
rdns = false
ticket_lifetime = 24h
forwardable = true
udp_preference_limit = 0
[realms]
${cfg.realm} = {
kdc = ${cfg.server}:88
master_kdc = ${cfg.server}:88
admin_server = ${cfg.server}:749
default_domain = ${cfg.domain}
pkinit_anchors = FILE:/etc/ipa/ca.crt
}
[domain_realm]
.${cfg.domain} = ${cfg.realm}
${cfg.domain} = ${cfg.realm}
${cfg.server} = ${cfg.realm}
[dbmodules]
${cfg.realm} = {
db_library = ${pkgs.freeipa}/lib/krb5/plugins/kdb/ipadb.so
}
'';
"openldap/ldap.conf".source = ldapConf;
};
environment.etc."chromium/policies/managed/freeipa.json" = mkIf cfg.chromiumSupport {
text = ''
{ "AuthServerWhitelist": "*.${cfg.domain}" }
'';
};
system.activationScripts.ipa = stringAfter ["etc"] ''
# libcurl requires a hard copy of the certificate
if ! ${pkgs.diffutils}/bin/diff ${cfg.certificate} /etc/ipa/ca.crt > /dev/null 2>&1; then
rm -f /etc/ipa/ca.crt
cp ${cfg.certificate} /etc/ipa/ca.crt
fi
if [ ! -f /etc/krb5.keytab ]; then
cat <<EOF
In order to complete FreeIPA integration, please join the domain by completing the following steps:
1. Authenticate as an IPA user authorized to join new hosts, e.g. kinit admin@${cfg.realm}
2. Join the domain and obtain the keytab file: ipa-join
3. Install the keytab file: sudo install -m 600 krb5.keytab /etc/
4. Restart sssd systemd service: sudo systemctl restart sssd
EOF
fi
'';
services.sssd.config = ''
[domain/${cfg.domain}]
id_provider = ipa
auth_provider = ipa
access_provider = ipa
chpass_provider = ipa
ipa_domain = ${cfg.domain}
ipa_server = _srv_, ${cfg.server}
ipa_hostname = ${config.networking.hostName}.${cfg.domain}
cache_credentials = ${pyBool cfg.cacheCredentials}
krb5_store_password_if_offline = ${pyBool cfg.offlinePasswords}
${optionalString ((toLower cfg.domain) != (toLower cfg.realm))
"krb5_realm = ${cfg.realm}"}
dyndns_update = ${pyBool cfg.dyndns.enable}
dyndns_iface = ${cfg.dyndns.interface}
ldap_tls_cacert = /etc/ipa/ca.crt
ldap_user_extra_attrs = mail:mail, sn:sn, givenname:givenname, telephoneNumber:telephoneNumber, lock:nsaccountlock
[sssd]
debug_level = 65510
services = nss, sudo, pam, ssh, ifp
domains = ${cfg.domain}
[nss]
homedir_substring = /home
[pam]
pam_pwd_expiration_warning = 3
pam_verbosity = 3
[sudo]
debug_level = 65510
[autofs]
[ssh]
[pac]
[ifp]
user_attributes = +mail, +telephoneNumber, +givenname, +sn, +lock
allowed_uids = ${concatStringsSep ", " cfg.ifpAllowedUids}
'';
services.ntp.servers = singleton cfg.server;
services.sssd.enable = true;
services.ntp.enable = true;
security.pki.certificateFiles = singleton cfg.certificate;
};
}