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djm@openbsd.org04c091f2019-01-19 21:43:56 +00001/* $OpenBSD: auth.h,v 1.99 2019/01/19 21:43:56 djm Exp $ */
Ben Lindstrom05764b92002-03-05 01:53:02 +00002
Damien Millere4340be2000-09-16 13:29:08 +11003/*
4 * Copyright (c) 2000 Markus Friedl. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Ben Lindstrom4dccfa52000-12-28 16:40:05 +000025 *
Damien Millere4340be2000-09-16 13:29:08 +110026 */
Ben Lindstrom05764b92002-03-05 01:53:02 +000027
Damien Millerb38eff82000-04-01 11:09:21 +100028#ifndef AUTH_H
29#define AUTH_H
30
Damien Miller9f2abc42006-07-10 20:53:08 +100031#include <signal.h>
Damien Miller9f2abc42006-07-10 20:53:08 +100032
Ben Lindstrom226cfa02001-01-22 05:34:40 +000033#include <openssl/rsa.h>
34
Damien Miller60396b02001-02-18 17:01:00 +110035#ifdef HAVE_LOGIN_CAP
36#include <login_cap.h>
37#endif
38#ifdef BSD_AUTH
39#include <bsd_auth.h>
40#endif
Ben Lindstromec95ed92001-07-04 04:21:14 +000041#ifdef KRB5
42#include <krb5.h>
43#endif
Damien Miller60396b02001-02-18 17:01:00 +110044
djm@openbsd.org7c856852018-03-03 03:15:51 +000045struct passwd;
markus@openbsd.org57d10cb2015-01-19 20:16:15 +000046struct ssh;
djm@openbsd.org8f574952017-06-24 06:34:38 +000047struct sshbuf;
djm@openbsd.org7c856852018-03-03 03:15:51 +000048struct sshkey;
49struct sshauthopt;
djm@openbsd.orgf69b69b2014-12-22 07:51:30 +000050
Damien Miller874d77b2000-10-14 16:23:11 +110051typedef struct Authctxt Authctxt;
Ben Lindstrom511bb242002-06-06 20:52:37 +000052typedef struct Authmethod Authmethod;
Ben Lindstrom551ea372001-06-05 18:56:16 +000053typedef struct KbdintDevice KbdintDevice;
54
Damien Miller874d77b2000-10-14 16:23:11 +110055struct Authctxt {
Damien Miller97c91f62006-04-23 12:08:37 +100056 sig_atomic_t success;
Damien Miller3f8123c2006-08-19 00:32:46 +100057 int authenticated; /* authenticated and alarms cancelled */
Damien Miller8ce778a2003-05-14 13:43:25 +100058 int postponed; /* authentication needs another step */
59 int valid; /* user exists and is allowed to login */
Ben Lindstromec95ed92001-07-04 04:21:14 +000060 int attempt;
61 int failures;
djm@openbsd.org2b64c492015-05-08 06:41:56 +000062 int server_caused_failure;
Darren Tucker23bc8d02004-02-06 16:24:31 +110063 int force_pwchange;
Damien Miller8ce778a2003-05-14 13:43:25 +100064 char *user; /* username sent by the client */
Ben Lindstromec95ed92001-07-04 04:21:14 +000065 char *service;
Damien Miller8ce778a2003-05-14 13:43:25 +100066 struct passwd *pw; /* set if 'valid' */
Ben Lindstromec95ed92001-07-04 04:21:14 +000067 char *style;
djm@openbsd.org8f574952017-06-24 06:34:38 +000068
69 /* Method lists for multiple authentication */
70 char **auth_methods; /* modified from server config */
71 u_int num_auth_methods;
72
73 /* Authentication method-specific data */
74 void *methoddata;
Ben Lindstromec95ed92001-07-04 04:21:14 +000075 void *kbdintctxt;
Damien Miller60396b02001-02-18 17:01:00 +110076#ifdef BSD_AUTH
Ben Lindstromec95ed92001-07-04 04:21:14 +000077 auth_session_t *as;
78#endif
Ben Lindstromec95ed92001-07-04 04:21:14 +000079#ifdef KRB5
80 krb5_context krb5_ctx;
Ben Lindstromec95ed92001-07-04 04:21:14 +000081 krb5_ccache krb5_fwd_ccache;
82 krb5_principal krb5_user;
83 char *krb5_ticket_file;
Damien Miller9c870f92004-04-16 22:47:55 +100084 char *krb5_ccname;
Damien Miller60396b02001-02-18 17:01:00 +110085#endif
djm@openbsd.org8f574952017-06-24 06:34:38 +000086 struct sshbuf *loginmsg;
djm@openbsd.orgf69b69b2014-12-22 07:51:30 +000087
djm@openbsd.org8f574952017-06-24 06:34:38 +000088 /* Authentication keys already used; these will be refused henceforth */
89 struct sshkey **prev_keys;
90 u_int nprev_keys;
91
djm@openbsd.org001aa552018-04-10 00:10:49 +000092 /* Last used key and ancillary information from active auth method */
djm@openbsd.org8f574952017-06-24 06:34:38 +000093 struct sshkey *auth_method_key;
94 char *auth_method_info;
95
96 /* Information exposed to session */
97 struct sshbuf *session_info; /* Auth info for environment */
Damien Miller874d77b2000-10-14 16:23:11 +110098};
djm@openbsd.org8f574952017-06-24 06:34:38 +000099
Damien Miller8ce778a2003-05-14 13:43:25 +1000100/*
101 * Every authentication method has to handle authentication requests for
102 * non-existing users, or for users that are not allowed to login. In this
103 * case 'valid' is set to 0, but 'user' points to the username requested by
104 * the client.
105 */
Damien Miller874d77b2000-10-14 16:23:11 +1100106
Ben Lindstrom511bb242002-06-06 20:52:37 +0000107struct Authmethod {
108 char *name;
markus@openbsd.orgeb272ea2017-05-30 14:29:59 +0000109 int (*userauth)(struct ssh *);
Ben Lindstrom511bb242002-06-06 20:52:37 +0000110 int *enabled;
111};
112
Ben Lindstrom226cfa02001-01-22 05:34:40 +0000113/*
Ben Lindstrom551ea372001-06-05 18:56:16 +0000114 * Keyboard interactive device:
Damien Miller9f0f5c62001-12-21 14:45:46 +1100115 * init_ctx returns: non NULL upon success
116 * query returns: 0 - success, otherwise failure
Ben Lindstrom551ea372001-06-05 18:56:16 +0000117 * respond returns: 0 - success, 1 - need further interaction,
118 * otherwise - failure
119 */
120struct KbdintDevice
121{
122 const char *name;
Damien Millerb0462112002-02-19 15:24:43 +1100123 void* (*init_ctx)(Authctxt*);
Damien Millera93c6d82002-02-19 15:25:29 +1100124 int (*query)(void *ctx, char **name, char **infotxt,
125 u_int *numprompts, char ***prompts, u_int **echo_on);
Damien Millerb0462112002-02-19 15:24:43 +1100126 int (*respond)(void *ctx, u_int numresp, char **responses);
127 void (*free_ctx)(void *ctx);
Ben Lindstrom551ea372001-06-05 18:56:16 +0000128};
129
Ben Lindstrom5eabda32001-04-12 23:34:34 +0000130int
Ben Lindstrom16ae3d02001-07-04 04:02:36 +0000131auth_rhosts2(struct passwd *, const char *, const char *, const char *);
Ben Lindstrom5eabda32001-04-12 23:34:34 +0000132
djm@openbsd.org7c856852018-03-03 03:15:51 +0000133int auth_password(struct ssh *, const char *);
Ben Lindstrom08105192002-03-22 02:50:06 +0000134
djm@openbsd.org04c091f2019-01-19 21:43:56 +0000135int hostbased_key_allowed(struct ssh *, struct passwd *,
136 const char *, char *, struct sshkey *);
djm@openbsd.org7c856852018-03-03 03:15:51 +0000137int user_key_allowed(struct ssh *, struct passwd *, struct sshkey *, int,
138 struct sshauthopt **);
djm@openbsd.org8f574952017-06-24 06:34:38 +0000139int auth2_key_already_used(Authctxt *, const struct sshkey *);
140
141/*
142 * Handling auth method-specific information for logging and prevention
143 * of key reuse during multiple authentication.
144 */
145void auth2_authctxt_reset_info(Authctxt *);
146void auth2_record_key(Authctxt *, int, const struct sshkey *);
147void auth2_record_info(Authctxt *authctxt, const char *, ...)
148 __attribute__((__format__ (printf, 2, 3)))
149 __attribute__((__nonnull__ (2)));
150void auth2_update_session_info(Authctxt *, const char *, const char *);
Ben Lindstrom226cfa02001-01-22 05:34:40 +0000151
Ben Lindstromec95ed92001-07-04 04:21:14 +0000152#ifdef KRB5
Damien Miller25162f22002-09-12 09:47:29 +1000153int auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *);
Ben Lindstromec95ed92001-07-04 04:21:14 +0000154int auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt);
155int auth_krb5_password(Authctxt *authctxt, const char *password);
Darren Tucker3e33cec2003-10-02 16:12:36 +1000156void krb5_cleanup_proc(Authctxt *authctxt);
Ben Lindstromec95ed92001-07-04 04:21:14 +0000157#endif /* KRB5 */
158
Darren Tucker15ee7482004-02-22 09:43:15 +1100159#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
Darren Tuckeraa0aeca2004-02-22 10:22:05 +1100160#include <shadow.h>
Darren Tucker15ee7482004-02-22 09:43:15 +1100161int auth_shadow_acctexpired(struct spwd *);
Darren Tucker9df3def2004-02-10 13:01:14 +1100162int auth_shadow_pwexpired(Authctxt *);
163#endif
164
Damien Millerb8481582000-12-03 11:51:51 +1100165#include "auth-pam.h"
Darren Tucker269a1ea2005-02-03 00:20:53 +1100166#include "audit.h"
Darren Tucker3c660802005-01-20 22:20:50 +1100167void remove_kbdint_device(const char *);
168
Damien Miller5ebce132019-01-20 09:44:53 +1100169void do_authentication2(struct ssh *);
Damien Millerefb4afe2000-04-12 18:45:05 +1000170
djm@openbsd.org3a00a922019-01-19 21:41:18 +0000171void auth_log(struct ssh *, int, int, const char *, const char *);
172void auth_maxtries_exceeded(struct ssh *) __attribute__((noreturn));
markus@openbsd.orgeb272ea2017-05-30 14:29:59 +0000173void userauth_finish(struct ssh *, int, const char *, const char *);
djm@openbsd.org7c856852018-03-03 03:15:51 +0000174int auth_root_allowed(struct ssh *, const char *);
Damien Miller15b05cf2012-12-03 09:53:20 +1100175
Damien Miller5ad9fd92002-05-13 11:07:41 +1000176char *auth2_read_banner(void);
Damien Millera6e3f012012-11-04 23:21:40 +1100177int auth2_methods_valid(const char *, int);
Damien Miller91a55f22013-04-23 15:18:10 +1000178int auth2_update_methods_lists(Authctxt *, const char *, const char *);
Damien Millera6e3f012012-11-04 23:21:40 +1100179int auth2_setup_methods_lists(Authctxt *);
Damien Miller91a55f22013-04-23 15:18:10 +1000180int auth2_method_allowed(Authctxt *, const char *, const char *);
Damien Miller5ad9fd92002-05-13 11:07:41 +1000181
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000182void privsep_challenge_enable(void);
183
markus@openbsd.orgeb272ea2017-05-30 14:29:59 +0000184int auth2_challenge(struct ssh *, char *);
185void auth2_challenge_stop(struct ssh *);
Ben Lindstrom08105192002-03-22 02:50:06 +0000186int bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **);
187int bsdauth_respond(void *, u_int, char **);
Damien Miller874d77b2000-10-14 16:23:11 +1100188
djm@openbsd.org3a00a922019-01-19 21:41:18 +0000189int allowed_user(struct ssh *, struct passwd *);
190struct passwd * getpwnamallow(struct ssh *, const char *user);
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000191
Damien Millerd8478b62011-05-29 21:39:36 +1000192char *expand_authorized_keys(const char *, struct passwd *pw);
Damien Miller30da3442010-05-10 11:58:03 +1000193char *authorized_principals_file(struct passwd *);
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000194
Darren Tucker33c787f2008-07-02 22:37:30 +1000195FILE *auth_openkeyfile(const char *, struct passwd *, int);
Damien Miller30da3442010-05-10 11:58:03 +1000196FILE *auth_openprincipals(const char *, struct passwd *, int);
markus@openbsd.org54d90ac2017-05-30 08:52:19 +0000197int auth_key_is_revoked(struct sshkey *);
Ben Lindstrombfb3a0e2001-06-05 20:25:05 +0000198
djm@openbsd.org95767262016-03-07 19:02:43 +0000199const char *auth_get_canonical_hostname(struct ssh *, int);
200
Ben Lindstrom83647ce2001-06-25 04:30:16 +0000201HostStatus
markus@openbsd.org54d90ac2017-05-30 08:52:19 +0000202check_key_in_hostfiles(struct passwd *, struct sshkey *, const char *,
Ben Lindstrom16ae3d02001-07-04 04:02:36 +0000203 const char *, const char *);
Ben Lindstrom83647ce2001-06-25 04:30:16 +0000204
Ben Lindstrom08105192002-03-22 02:50:06 +0000205/* hostkey handling */
markus@openbsd.org54d90ac2017-05-30 08:52:19 +0000206struct sshkey *get_hostkey_by_index(int);
207struct sshkey *get_hostkey_public_by_index(int, struct ssh *);
208struct sshkey *get_hostkey_public_by_type(int, int, struct ssh *);
209struct sshkey *get_hostkey_private_by_type(int, int, struct ssh *);
210int get_hostkey_index(struct sshkey *, int, struct ssh *);
djm@openbsd.org04c091f2019-01-19 21:43:56 +0000211int sshd_hostkey_sign(struct ssh *, struct sshkey *, struct sshkey *,
212 u_char **, size_t *, const u_char *, size_t, const char *);
Ben Lindstrom08105192002-03-22 02:50:06 +0000213
djm@openbsd.org7c856852018-03-03 03:15:51 +0000214/* Key / cert options linkage to auth layer */
215const struct sshauthopt *auth_options(struct ssh *);
216int auth_activate_options(struct ssh *, struct sshauthopt *);
217void auth_restrict_session(struct ssh *);
218int auth_authorise_keyopts(struct ssh *, struct passwd *pw,
219 struct sshauthopt *, int, const char *);
220void auth_log_authopts(const char *, const struct sshauthopt *, int);
221
Ben Lindstroma574cda2002-05-15 16:16:14 +0000222/* debug messages during authentication */
djm@openbsd.org7c856852018-03-03 03:15:51 +0000223void auth_debug_add(const char *fmt,...)
224 __attribute__((format(printf, 1, 2)));
djm@openbsd.org3a00a922019-01-19 21:41:18 +0000225void auth_debug_send(struct ssh *);
Ben Lindstroma574cda2002-05-15 16:16:14 +0000226void auth_debug_reset(void);
227
Damien Miller856f0be2003-09-03 07:32:45 +1000228struct passwd *fakepw(void);
229
markus@openbsd.org25cf9102018-01-08 15:21:49 +0000230#define SSH_SUBPROCESS_STDOUT_DISCARD (1) /* Discard stdout */
231#define SSH_SUBPROCESS_STDOUT_CAPTURE (1<<1) /* Redirect stdout */
232#define SSH_SUBPROCESS_STDERR_DISCARD (1<<2) /* Discard stderr */
233pid_t subprocess(const char *, struct passwd *,
234 const char *, int, char **, FILE **, u_int flags);
235
djm@openbsd.org7c856852018-03-03 03:15:51 +0000236int sys_auth_passwd(struct ssh *, const char *);
Darren Tuckerf3bb4342005-03-31 21:39:25 +1000237
Darren Tuckera916d142005-07-07 11:50:20 +1000238#if defined(KRB5) && !defined(HEIMDAL)
239#include <krb5.h>
240krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *);
241#endif
Damien Millerb38eff82000-04-01 11:09:21 +1000242#endif