;;; GNU Guix --- Functional package management for GNU ;;; Copyright © 2018 Danny Milosavljevic ;;; Copyright © 2018, 2019 Ricardo Wurmus ;;; Copyright © 2021 Maxime Devos ;;; ;;; This file is part of GNU Guix. ;;; ;;; GNU Guix is free software; you can redistribute it and/or modify it ;;; under the terms of the GNU General Public License as published by ;;; the Free Software Foundation; either version 3 of the License, or (at ;;; your option) any later version. ;;; ;;; GNU Guix is distributed in the hope that it will be useful, but ;;; WITHOUT ANY WARRANTY; without even the implied warranty of ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ;;; GNU General Public License for more details. ;;; ;;; You should have received a copy of the GNU General Public License ;;; along with GNU Guix. If not, see . (define-module (gnu services authentication) #:use-module (gnu services) #:use-module (gnu services base) #:use-module (gnu services configuration) #:use-module (gnu services dbus) #:use-module (gnu services shepherd) #:use-module (gnu system pam) #:use-module (gnu system shadow) #:use-module (gnu packages admin) #:use-module (gnu packages freedesktop) #:use-module (gnu packages openldap) #:use-module (guix gexp) #:use-module (guix records) #:use-module (guix packages) #:use-module (guix modules) #:use-module (ice-9 match) #:use-module (srfi srfi-1) #:use-module (srfi srfi-26) #:export (fprintd-configuration fprintd-configuration? fprintd-service-type nslcd-configuration nslcd-configuration? nslcd-service-type)) (define-configuration fprintd-configuration (fprintd (file-like fprintd) "The fprintd package")) (define (fprintd-dbus-service config) (list (fprintd-configuration-fprintd config))) (define fprintd-service-type (service-type (name 'fprintd) (extensions (list (service-extension dbus-root-service-type fprintd-dbus-service) (service-extension polkit-service-type fprintd-dbus-service))) (default-value (fprintd-configuration)) (description "Run fprintd, a fingerprint management daemon."))) ;;; ;;; NSS Pam LDAP service (nslcd) ;;; (define (uglify-field-name name) (match name ('filters "filter") ('maps "map") (_ (string-map (match-lambda (#\- #\_) (chr chr)) (symbol->string name))))) (define (value->string val) (cond ((boolean? val) (if val "on" "off")) ((number? val) (number->string val)) ((symbol? val) (string-map (match-lambda (#\- #\_) (chr chr)) (symbol->string val))) (else val))) (define (serialize-field field-name val) (if (eq? field-name 'pam-services) #t (format #t "~a ~a\n" (uglify-field-name field-name) (value->string val)))) (define serialize-string serialize-field) (define serialize-boolean serialize-field) (define serialize-number serialize-field) (define (serialize-list field-name val) (map (cut serialize-field field-name <>) val)) (define-maybe string) (define-maybe boolean) (define-maybe number) (define (ssl-option? val) (or (boolean? val) (eq? val 'start-tls2022-11-04nls: Update translations....ybe tls-reqcert-option) (define (deref-option? val) (member val '(never searching finding always))) (define serialize-deref-option serialize-field) (define-maybe deref-option) (define (comma-separated-list-of-strings? val) (and (list? val) (every string? val))) (define (ignore-users-option? val) (or (comma-separated-list-of-strings? val) (eq? 'all-local val))) (define (serialize-ignore-users-option field-name val) (serialize-field field-name (if (eq? 'all-local val) val (string-join val ",")))) (define-maybe ignore-users-option) (define (log-option? val) (let ((valid-scheme? (lambda (scheme) (or (string? scheme) (member scheme '(none syslog)))))) (match val ((scheme level) (and (valid-scheme? scheme) (member level '(crit error warning notice info debug)))) ((scheme) (valid-scheme? scheme))))) (define (serialize-log-option field-name val) (serialize-field field-name (string-join (map (cut format #f "~a" <>) val)))) (define (valid-map? val) "Is VAL a supported map name?" (member val '(alias aliases ether ethers group host hosts netgroup network networks passwd protocol protocols rpc service services shadow))) (define (scope-option? val) (let ((valid-scopes '(subtree onelevel base children))) (match val ((map-name scope) (and (valid-map? map-name) (member scope valid-scopes))) ((scope) (member scope valid-scopes))))) (define (serialize-scope-option field-name val) (serialize-field field-name (string-join (map (cut format #f "~a" <>) val)))) (define (map-entry? val) (match val (((? valid-map? map-name) (? string? attribute) (? string? new-attribute)) #t) (_ #f))) (define (list-of-map-entries? val) (and (list? val) (every map-entry? val))) (define (filter-entry? val) (match val (((? valid-map? map-name) (? string? filter-expression)) #t) (_ #f))) (define (list-of-filter-entries? val) (and (list? val) (every filter-entry? val))) (define (serialize-filter-entry field-name val) (serialize-field 'filter (match val (((? valid-map? map-name) (? string? filter-expression)) (string-append (symbol->string map-name) " " filter-expression))))) (define (serialize-list-of-filter-entries field-name val) (for-each (cut serialize-filter-entry field-name <>) val)) (define (serialize-map-entry field-name val) (serialize-field 'map (match val (((? valid-map? map-name) (? string? attribute) (? string? new-attribute)) (string-append (symbol->string map-name) " " attribute " " new-attribute))))) (define (serialize-list-of-map-entries field-name val) (for-each (cut serialize-map-entry field-name <>) val)) (define-configuration nslcd-configuration (nss-pam-ldapd (file-like nss-pam-ldapd) "The NSS-PAM-LDAPD package to use.") ;; Runtime options (threads maybe-number "The number of threads to start that can handle requests and perform LDAP queries. Each thread opens a separate connection to the LDAP server. The default is to start 5 threads.") (uid (string "nslcd") "This specifies the user id with which the daemon should be run.") (gid (string "nslcd") "This specifies the group id with which the daemon should be run.") (log (log-option '("/var/log/nslcd" info)) "This option controls the way logging is done via a list containing SCHEME and LEVEL. The SCHEME argument may either be the symbols \"none\" or \"syslog\", or an absolute file name. The LEVEL argument is optional and specifies the log level. The log level may be one of the following symbols: \"crit\", \"error\", \"warning\", \"notice\", \"info\" or \"debug\". All messages with the specified log level or higher are logged.") ;; LDAP connection settings (uri (list '("ldap://localhost:389/")) "The list of LDAP server URIs. Normally, only the first server will be used with the following servers as fall-back.") (ldap-version maybe-string "The version of the LDAP protocol to use. The default is to use the maximum version supported by the LDAP library.") (binddn maybe-string "Specifies the distinguished name with which to bind to the directory server for lookups. The default is to bind anonymously.") (bindpw maybe-string "Specifies the credentials with which to bind. This option is only applicable when used with binddn.") (rootpwmoddn maybe-string "Specifies the distinguished name to use when the root user tries to modify a user's password using the PAM module.") (rootpwmodpw maybe-string "Specifies the credentials with which to bind if the root user tries to change a user's password. This option is only applicable when used with rootpwmoddn") ;; SASL authentication options (sasl-mech maybe-string "Specifies the SASL mechanism to be used when performing SASL authentication.") (sasl-realm maybe-string "Specifies the SASL realm to be used when performing SASL authentication.") (sasl-authcid maybe-string "Specifies the authentication identity to be used when performing SASL authentication.") (sasl-authzid maybe-string "Specifies the authorization identity to be used when performing SASL authentication.") (sasl-canonicalize? maybe-boolean "Determines whether the LDAP server host name should be canonicalised. If this is enabled the LDAP library will do a reverse host name lookup. By default, it is left up to the LDAP library whether this check is performed or not.") ;; Kerberos authentication options (krb5-ccname maybe-string "Set the name for the GSS-API Kerberos credentials cache.") ;; Search / mapping options (base (string "dc=example,dc=com") "The directory search base.") (scope (scope-option '(subtree)) "Specifies the search scope (subtree, onelevel, base or children). The default scope is subtree; base scope is almost never useful for name service lookups; children scope is not supported on all servers.") (deref maybe-deref-option "Specifies the policy for dereferencing aliases. The default policy is to never dereference aliases.") (referrals maybe-boolean "Specifies whether automatic referral chasing should be enabled. The default behaviour is to chase referrals.") (maps (list-of-map-entries '()) "This option allows for custom attributes to be looked up instead of the default RFC 2307 attributes. It is a list of maps, each consisting of the name of a map, the RFC 2307 attribute to match and the query expression for the attribute as it is available in the directory.") (filters (list-of-filter-entries '()) "A list of filters consisting of the name of a map to which the filter applies and an LDAP search filter expression.") ;; Timing / reconnect options (bind-timelimit maybe-number "Specifies the time limit in seconds to use when connecting to the directory server. The default value is 10 seconds.") (timelimit maybe-number "Specifies the time limit (in seconds) to wait for a response from the LDAP server. A value of zero, which is the default, is to wait indefinitely for searches to be completed.") (idle-timelimit maybe-number "Specifies the period if inactivity (in seconds) after which the con‐ nection to the LDAP server will be closed. The default is not to time out connections.") (reconnect-sleeptime maybe-number "Specifies the number of seconds to sleep when connecting to all LDAP servers fails. By default one second is waited between the first failure and the first retry.") (reconnect-retrytime maybe-number "Specifies the time after which the LDAP server is considered to be permanently unavailable. Once this time is reached retries will be done only once per this time period. The default value is 10 seconds.") ;; TLS options (ssl maybe-ssl-option "Specifies whether to use SSL/TLS or not (the default is not to). If 'start-tls is specified then StartTLS is used rather than raw LDAP over SSL.") (tls-reqcert maybe-tls-reqcert-option "Specifies what checks to perform on a server-supplied certificate. The meaning of the values is described in the ldap.conf(5) manual page.") (tls-cacertdir maybe-string "Specifies the directory containing X.509 certificates for peer authen‐ tication. This parameter is ignored when using GnuTLS.") (tls-cacertfile maybe-string "Specifies the path to the X.509 certificate for peer authentication.") (tls-randfile maybe-string "Specifies the path to an entropy source. This parameter is ignored when using GnuTLS.") (tls-ciphers maybe-string "Specifies the ciphers to use for TLS as a string.") (tls-cert maybe-string "Specifies the path to the file containing the local certificate for client TLS authentication.") (tls-key maybe-string "Specifies the path to the file containing the private key for client TLS authentication.") ;; Other options (pagesize maybe-number "Set this to a number greater than 0 to request paged results from the LDAP server in accordance with RFC2696. The default (0) is to not request paged results.") (nss-initgroups-ignoreusers maybe-ignore-users-option "This option prevents group membership lookups through LDAP for the specified users. Alternatively, the value 'all-local may be used. With that value nslcd builds a full list of non-LDAP users on startup.") (nss-min-uid maybe-number "This option ensures that LDAP users with a numeric user id lower than the specified value are ignored.") (nss-uid-offset maybe-number "This option specifies an offset that is added to all LDAP numeric user ids. This can be used to avoid user id collisions with local users.") (nss-gid-offset maybe-number "This option specifies an offset that is added to all LDAP numeric group ids. This can be used to avoid user id collisions with local groups.") (nss-nested-groups maybe-boolean "If this option is set, the member attribute of a group may point to another group. Members of nested groups are also returned in the higher level group and parent groups are returned when finding groups for a specific user. The default is not to perform extra searches for nested groups.") (nss-getgrent-skipmembers maybe-boolean "If this option is set, the group member list is not retrieved when looking up groups. Lookups for finding which groups a user belongs to will remain functional so the user will likely still get the correct groups assigned on login.") (nss-disable-enumeration maybe-boolean "If this option is set, functions which cause all user/group entries to be loaded from the directory will not succeed in doing so. This can dramatically reduce LDAP server load in situations where there are a great number of users and/or groups. This option is not recommended for most configurations.") (validnames maybe-string "This option can be used to specify how user and group names are verified within the system. This pattern is used to check all user and group names that are requested and returned from LDAP.") (ignorecase maybe-boolean "This specifies whether or not to perform searches using case-insensitive matching. Enabling this could open up the system to authorization bypass vulnerabilities and introduce nscd cache poisoning vulnerabilities which allow denial of service.") (pam-authc-ppolicy maybe-boolean "This option specifies whether password policy controls are requested and handled from the LDAP server when performing user authentication.") (pam-authc-search maybe-string "By default nslcd performs an LDAP search with the user's credentials after BIND (authentication) to ensure that the BIND operation was successful. The default search is a simple check to see if the user's DN exists. A search filter can be specified that will be used instead. It should return at least one entry.") (pam-authz-search maybe-string "This option allows flexible fine tuning of the authorisation check that should be performed. The search filter specified is executed and if any entries match, access is granted, otherwise access is denied.") (pam-password-prohibit-message maybe-string "If this option is set password modification using pam_ldap will be denied and the specified message will be presented to the user instead. The message can be used to direct the user to an alternative means of changing their password.") ;; Options for extension of pam-root-service-type. (pam-services (list '()) "List of pam service names for which LDAP authentication should suffice.")) (define %nslcd-accounts (list (user-group (name "nslcd") (system? #t)) (user-account (name "nslcd") (group "nslcd") (comment "NSLCD service account") (home-directory "/var/empty") (shell (file-append shadow "/sbin/nologin")) (system? #t)))) (define (nslcd-config-file config) "Return an NSLCD configuration file." (plain-file "nslcd.conf" (with-output-to-string (lambda () (serialize-configuration config nslcd-configuration-fields) ;; The file must end with a newline character. (format #t "\n"))))) ;; XXX: The file should only be readable by root if it contains a "bindpw" ;; declaration. Unfortunately, this etc-service-type extension does not ;; support setting file modes, so we do this in the activation service. (define (nslcd-etc-service config) `(("nslcd.conf" ,(nslcd-config-file config)))) (define (nslcd-shepherd-service config) (list (shepherd-service (documentation "Run the nslcd service for resolving names from LDAP.") (provision '(nslcd)) (requirement '(networking user-processes)) (start #~(make-forkexec-constructor (list (string-append #$(nslcd-configuration-nss-pam-ldapd config) "/sbin/nslcd") "--nofork") #:pid-file "/var/run/nslcd/nslcd.pid" #:environment-variables (list (string-append "LD_LIBRARY_PATH=" #$(nslcd-configuration-nss-pam-ldapd config) "/lib")))) (stop #~(make-kill-destructor))))) (define (pam-ldap-pam-service config) "Return a PAM service for LDAP authentication." (define pam-ldap-module #~(string-append #$(nslcd-configuration-nss-pam-ldapd config) "/lib/security/pam_ldap.so")) (pam-extension (transformer (lambda (pam) (if (member (pam-service-name pam) (nslcd-configuration-pam-services config)) (let ((sufficient (pam-entry (control "sufficient") (module pam-ldap-module)))) (pam-service (inherit pam) (auth (cons sufficient (pam-service-auth pam))) (session (cons sufficient (pam-service-session pam))) (account (cons sufficient (pam-service-account pam))))) pam))))) (define (pam-ldap-pam-services config) (list (pam-ldap-pam-service config))) (define %nslcd-activation (with-imported-modules (source-module-closure '((gnu build activation))) #~(begin (use-modules (gnu build activation)) (let ((rundir "/var/run/nslcd") (user (getpwnam "nslcd"))) (mkdir-p/perms rundir user #o755) (when (file-exists? "/etc/nslcd.conf") (chmod "/etc/nslcd.conf" #o400)))))) (define nslcd-service-type (service-type (name 'nslcd) (description "Run the NSLCD service for looking up names from LDAP.") (extensions (list (service-extension account-service-type (const %nslcd-accounts)) (service-extension etc-service-type nslcd-etc-service) (service-extension activation-service-type (const %nslcd-activation)) (service-extension pam-root-service-type pam-ldap-pam-services) (service-extension nscd-service-type (const (list nss-pam-ldapd))) (service-extension shepherd-root-service-type nslcd-shepherd-service))) (default-value (nslcd-configuration)))) (define (generate-nslcd-documentation) (generate-documentation `((nslcd-configuration ,nslcd-configuration-fields)) 'nslcd-configuration))