auth.h revision 323121
1/* $OpenBSD: auth.h,v 1.86 2015/12/04 16:41:28 markus Exp $ */
2
3/*
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.
25 *
26 */
27
28#ifndef AUTH_H
29#define AUTH_H
30
31#include <signal.h>
32
33#include <openssl/rsa.h>
34
35#ifdef HAVE_LOGIN_CAP
36#include <login_cap.h>
37#endif
38#ifdef BSD_AUTH
39#include <bsd_auth.h>
40#endif
41#ifdef KRB5
42#include <krb5.h>
43#endif
44
45struct ssh;
46struct sshkey;
47
48typedef struct Authctxt Authctxt;
49typedef struct Authmethod Authmethod;
50typedef struct KbdintDevice KbdintDevice;
51
52struct Authctxt {
53	sig_atomic_t	 success;
54	int		 authenticated;	/* authenticated and alarms cancelled */
55	int		 postponed;	/* authentication needs another step */
56	int		 valid;		/* user exists and is allowed to login */
57	int		 attempt;
58	int		 failures;
59	int		 server_caused_failure;
60	int		 force_pwchange;
61	char		*user;		/* username sent by the client */
62	char		*service;
63	struct passwd	*pw;		/* set if 'valid' */
64	char		*style;
65	void		*kbdintctxt;
66	char		*info;		/* Extra info for next auth_log */
67#ifdef BSD_AUTH
68	auth_session_t	*as;
69#endif
70	char		**auth_methods;	/* modified from server config */
71	u_int		 num_auth_methods;
72#ifdef KRB5
73	krb5_context	 krb5_ctx;
74	krb5_ccache	 krb5_fwd_ccache;
75	krb5_principal	 krb5_user;
76	char		*krb5_ticket_file;
77	char		*krb5_ccname;
78#endif
79	Buffer		*loginmsg;
80	void		*methoddata;
81
82	struct sshkey	**prev_userkeys;
83	u_int		 nprev_userkeys;
84};
85/*
86 * Every authentication method has to handle authentication requests for
87 * non-existing users, or for users that are not allowed to login. In this
88 * case 'valid' is set to 0, but 'user' points to the username requested by
89 * the client.
90 */
91
92struct Authmethod {
93	char	*name;
94	int	(*userauth)(Authctxt *authctxt);
95	int	*enabled;
96};
97
98/*
99 * Keyboard interactive device:
100 * init_ctx	returns: non NULL upon success
101 * query	returns: 0 - success, otherwise failure
102 * respond	returns: 0 - success, 1 - need further interaction,
103 *		otherwise - failure
104 */
105struct KbdintDevice
106{
107	const char *name;
108	void*	(*init_ctx)(Authctxt*);
109	int	(*query)(void *ctx, char **name, char **infotxt,
110		    u_int *numprompts, char ***prompts, u_int **echo_on);
111	int	(*respond)(void *ctx, u_int numresp, char **responses);
112	void	(*free_ctx)(void *ctx);
113};
114
115int      auth_rhosts(struct passwd *, const char *);
116int
117auth_rhosts2(struct passwd *, const char *, const char *, const char *);
118
119int	 auth_rhosts_rsa(Authctxt *, char *, Key *);
120int      auth_password(Authctxt *, const char *);
121int      auth_rsa(Authctxt *, BIGNUM *);
122int      auth_rsa_challenge_dialog(Key *);
123BIGNUM	*auth_rsa_generate_challenge(Key *);
124int	 auth_rsa_verify_response(Key *, BIGNUM *, u_char[]);
125int	 auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **);
126
127int	 auth_rhosts_rsa_key_allowed(struct passwd *, char *, char *, Key *);
128int	 hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
129int	 user_key_allowed(struct passwd *, Key *, int);
130void	 pubkey_auth_info(Authctxt *, const Key *, const char *, ...)
131	    __attribute__((__format__ (printf, 3, 4)));
132void	 auth2_record_userkey(Authctxt *, struct sshkey *);
133int	 auth2_userkey_already_used(Authctxt *, struct sshkey *);
134
135struct stat;
136int	 auth_secure_path(const char *, struct stat *, const char *, uid_t,
137    char *, size_t);
138
139#ifdef KRB5
140int	auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *);
141int	auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt);
142int	auth_krb5_password(Authctxt *authctxt, const char *password);
143void	krb5_cleanup_proc(Authctxt *authctxt);
144#endif /* KRB5 */
145
146#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
147#include <shadow.h>
148int auth_shadow_acctexpired(struct spwd *);
149int auth_shadow_pwexpired(Authctxt *);
150#endif
151
152#include "auth-pam.h"
153#include "audit.h"
154void remove_kbdint_device(const char *);
155
156void disable_forwarding(void);
157
158void	do_authentication(Authctxt *);
159void	do_authentication2(Authctxt *);
160
161void	auth_info(Authctxt *authctxt, const char *, ...)
162	    __attribute__((__format__ (printf, 2, 3)))
163	    __attribute__((__nonnull__ (2)));
164void	auth_log(Authctxt *, int, int, const char *, const char *);
165void	auth_maxtries_exceeded(Authctxt *) __attribute__((noreturn));
166void	userauth_finish(Authctxt *, int, const char *, const char *);
167int	auth_root_allowed(const char *);
168
169void	userauth_send_banner(const char *);
170
171char	*auth2_read_banner(void);
172int	 auth2_methods_valid(const char *, int);
173int	 auth2_update_methods_lists(Authctxt *, const char *, const char *);
174int	 auth2_setup_methods_lists(Authctxt *);
175int	 auth2_method_allowed(Authctxt *, const char *, const char *);
176
177void	privsep_challenge_enable(void);
178
179int	auth2_challenge(Authctxt *, char *);
180void	auth2_challenge_stop(Authctxt *);
181int	bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **);
182int	bsdauth_respond(void *, u_int, char **);
183int	skey_query(void *, char **, char **, u_int *, char ***, u_int **);
184int	skey_respond(void *, u_int, char **);
185
186int	allowed_user(struct passwd *);
187struct passwd * getpwnamallow(const char *user);
188
189char	*get_challenge(Authctxt *);
190int	verify_response(Authctxt *, const char *);
191void	abandon_challenge_response(Authctxt *);
192
193char	*expand_authorized_keys(const char *, struct passwd *pw);
194char	*authorized_principals_file(struct passwd *);
195
196FILE	*auth_openkeyfile(const char *, struct passwd *, int);
197FILE	*auth_openprincipals(const char *, struct passwd *, int);
198int	 auth_key_is_revoked(Key *);
199
200HostStatus
201check_key_in_hostfiles(struct passwd *, Key *, const char *,
202    const char *, const char *);
203
204/* hostkey handling */
205Key	*get_hostkey_by_index(int);
206Key	*get_hostkey_public_by_index(int, struct ssh *);
207Key	*get_hostkey_public_by_type(int, int, struct ssh *);
208Key	*get_hostkey_private_by_type(int, int, struct ssh *);
209int	 get_hostkey_index(Key *, int, struct ssh *);
210int	 ssh1_session_key(BIGNUM *);
211int	 sshd_hostkey_sign(Key *, Key *, u_char **, size_t *,
212	     const u_char *, size_t, const char *, u_int);
213
214/* debug messages during authentication */
215void	 auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2)));
216void	 auth_debug_send(void);
217void	 auth_debug_reset(void);
218
219struct passwd *fakepw(void);
220
221int	 sys_auth_passwd(Authctxt *, const char *);
222
223#define SKEY_PROMPT "\nS/Key Password: "
224
225#if defined(KRB5) && !defined(HEIMDAL)
226#include <krb5.h>
227krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *);
228#endif
229#endif
230