1/* $OpenBSD: auth.h,v 1.76 2013/07/19 07:37:48 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
45typedef struct Authctxt Authctxt;
46typedef struct Authmethod Authmethod;
47typedef struct KbdintDevice KbdintDevice;
48
49struct Authctxt {
50	sig_atomic_t	 success;
51	int		 authenticated;	/* authenticated and alarms cancelled */
52	int		 postponed;	/* authentication needs another step */
53	int		 valid;		/* user exists and is allowed to login */
54	int		 attempt;
55	int		 failures;
56	int		 server_caused_failure;
57	int		 force_pwchange;
58	char		*user;		/* username sent by the client */
59	char		*service;
60	struct passwd	*pw;		/* set if 'valid' */
61	char		*style;
62	void		*kbdintctxt;
63	char		*info;		/* Extra info for next auth_log */
64	void		*jpake_ctx;
65#ifdef BSD_AUTH
66	auth_session_t	*as;
67#endif
68	char		**auth_methods;	/* modified from server config */
69	u_int		 num_auth_methods;
70#ifdef KRB5
71	krb5_context	 krb5_ctx;
72	krb5_ccache	 krb5_fwd_ccache;
73	krb5_principal	 krb5_user;
74	char		*krb5_ticket_file;
75	char		*krb5_ccname;
76#endif
77	Buffer		*loginmsg;
78	void		*methoddata;
79};
80/*
81 * Every authentication method has to handle authentication requests for
82 * non-existing users, or for users that are not allowed to login. In this
83 * case 'valid' is set to 0, but 'user' points to the username requested by
84 * the client.
85 */
86
87struct Authmethod {
88	char	*name;
89	int	(*userauth)(Authctxt *authctxt);
90	int	*enabled;
91};
92
93/*
94 * Keyboard interactive device:
95 * init_ctx	returns: non NULL upon success
96 * query	returns: 0 - success, otherwise failure
97 * respond	returns: 0 - success, 1 - need further interaction,
98 *		otherwise - failure
99 */
100struct KbdintDevice
101{
102	const char *name;
103	void*	(*init_ctx)(Authctxt*);
104	int	(*query)(void *ctx, char **name, char **infotxt,
105		    u_int *numprompts, char ***prompts, u_int **echo_on);
106	int	(*respond)(void *ctx, u_int numresp, char **responses);
107	void	(*free_ctx)(void *ctx);
108};
109
110int      auth_rhosts(struct passwd *, const char *);
111int
112auth_rhosts2(struct passwd *, const char *, const char *, const char *);
113
114int	 auth_rhosts_rsa(Authctxt *, char *, Key *);
115int      auth_password(Authctxt *, const char *);
116int      auth_rsa(Authctxt *, BIGNUM *);
117int      auth_rsa_challenge_dialog(Key *);
118BIGNUM	*auth_rsa_generate_challenge(Key *);
119int	 auth_rsa_verify_response(Key *, BIGNUM *, u_char[]);
120int	 auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **);
121
122int	 auth_rhosts_rsa_key_allowed(struct passwd *, char *, char *, Key *);
123int	 hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
124int	 user_key_allowed(struct passwd *, Key *);
125void	 pubkey_auth_info(Authctxt *, const Key *, const char *, ...)
126	    __attribute__((__format__ (printf, 3, 4)));
127
128struct stat;
129int	 auth_secure_path(const char *, struct stat *, const char *, uid_t,
130    char *, size_t);
131
132#ifdef KRB5
133int	auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *);
134int	auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt);
135int	auth_krb5_password(Authctxt *authctxt, const char *password);
136void	krb5_cleanup_proc(Authctxt *authctxt);
137#endif /* KRB5 */
138
139#if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
140#include <shadow.h>
141int auth_shadow_acctexpired(struct spwd *);
142int auth_shadow_pwexpired(Authctxt *);
143#endif
144
145#include "auth-pam.h"
146#include "audit.h"
147void remove_kbdint_device(const char *);
148
149void disable_forwarding(void);
150
151void	do_authentication(Authctxt *);
152void	do_authentication2(Authctxt *);
153
154void	auth_info(Authctxt *authctxt, const char *, ...)
155	    __attribute__((__format__ (printf, 2, 3)))
156	    __attribute__((__nonnull__ (2)));
157void	auth_log(Authctxt *, int, int, const char *, const char *);
158void	userauth_finish(Authctxt *, int, const char *, const char *);
159int	auth_root_allowed(const char *);
160
161void	userauth_send_banner(const char *);
162
163char	*auth2_read_banner(void);
164int	 auth2_methods_valid(const char *, int);
165int	 auth2_update_methods_lists(Authctxt *, const char *, const char *);
166int	 auth2_setup_methods_lists(Authctxt *);
167int	 auth2_method_allowed(Authctxt *, const char *, const char *);
168
169void	privsep_challenge_enable(void);
170
171int	auth2_challenge(Authctxt *, char *);
172void	auth2_challenge_stop(Authctxt *);
173int	bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **);
174int	bsdauth_respond(void *, u_int, char **);
175int	skey_query(void *, char **, char **, u_int *, char ***, u_int **);
176int	skey_respond(void *, u_int, char **);
177
178void	auth2_jpake_get_pwdata(Authctxt *, BIGNUM **, char **, char **);
179void	auth2_jpake_stop(Authctxt *);
180
181int	allowed_user(struct passwd *);
182struct passwd * getpwnamallow(const char *user);
183
184char	*get_challenge(Authctxt *);
185int	verify_response(Authctxt *, const char *);
186void	abandon_challenge_response(Authctxt *);
187
188char	*expand_authorized_keys(const char *, struct passwd *pw);
189char	*authorized_principals_file(struct passwd *);
190
191FILE	*auth_openkeyfile(const char *, struct passwd *, int);
192FILE	*auth_openprincipals(const char *, struct passwd *, int);
193int	 auth_key_is_revoked(Key *);
194
195HostStatus
196check_key_in_hostfiles(struct passwd *, Key *, const char *,
197    const char *, const char *);
198
199/* hostkey handling */
200Key	*get_hostkey_by_index(int);
201Key	*get_hostkey_public_by_index(int);
202Key	*get_hostkey_public_by_type(int);
203Key	*get_hostkey_private_by_type(int);
204int	 get_hostkey_index(Key *);
205int	 ssh1_session_key(BIGNUM *);
206void	 sshd_hostkey_sign(Key *, Key *, u_char **, u_int *, u_char *, u_int);
207
208/* debug messages during authentication */
209void	 auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2)));
210void	 auth_debug_send(void);
211void	 auth_debug_reset(void);
212
213struct passwd *fakepw(void);
214
215int	 sys_auth_passwd(Authctxt *, const char *);
216
217#define AUTH_FAIL_MSG "Too many authentication failures for %.100s"
218
219#define SKEY_PROMPT "\nS/Key Password: "
220
221#if defined(KRB5) && !defined(HEIMDAL)
222#include <krb5.h>
223krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *);
224#endif
225#endif
226