xref: /freebsd/crypto/openssh/auth.h (revision 39beb93c3f8bdbf72a61fda42300b5ebed7390c8)
1 /* $OpenBSD: auth.h,v 1.61 2008/07/02 12:03:51 dtucker 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 
45 typedef struct Authctxt Authctxt;
46 typedef struct Authmethod Authmethod;
47 typedef struct KbdintDevice KbdintDevice;
48 
49 struct 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		 force_pwchange;
57 	char		*user;		/* username sent by the client */
58 	char		*service;
59 	struct passwd	*pw;		/* set if 'valid' */
60 	char		*style;
61 	void		*kbdintctxt;
62 #ifdef BSD_AUTH
63 	auth_session_t	*as;
64 #endif
65 #ifdef KRB5
66 	krb5_context	 krb5_ctx;
67 	krb5_ccache	 krb5_fwd_ccache;
68 	krb5_principal	 krb5_user;
69 	char		*krb5_ticket_file;
70 	char		*krb5_ccname;
71 #endif
72 	Buffer		*loginmsg;
73 	void		*methoddata;
74 };
75 /*
76  * Every authentication method has to handle authentication requests for
77  * non-existing users, or for users that are not allowed to login. In this
78  * case 'valid' is set to 0, but 'user' points to the username requested by
79  * the client.
80  */
81 
82 struct Authmethod {
83 	char	*name;
84 	int	(*userauth)(Authctxt *authctxt);
85 	int	*enabled;
86 };
87 
88 /*
89  * Keyboard interactive device:
90  * init_ctx	returns: non NULL upon success
91  * query	returns: 0 - success, otherwise failure
92  * respond	returns: 0 - success, 1 - need further interaction,
93  *		otherwise - failure
94  */
95 struct KbdintDevice
96 {
97 	const char *name;
98 	void*	(*init_ctx)(Authctxt*);
99 	int	(*query)(void *ctx, char **name, char **infotxt,
100 		    u_int *numprompts, char ***prompts, u_int **echo_on);
101 	int	(*respond)(void *ctx, u_int numresp, char **responses);
102 	void	(*free_ctx)(void *ctx);
103 };
104 
105 int      auth_rhosts(struct passwd *, const char *);
106 int
107 auth_rhosts2(struct passwd *, const char *, const char *, const char *);
108 
109 int	 auth_rhosts_rsa(Authctxt *, char *, Key *);
110 int      auth_password(Authctxt *, const char *);
111 int      auth_rsa(Authctxt *, BIGNUM *);
112 int      auth_rsa_challenge_dialog(Key *);
113 BIGNUM	*auth_rsa_generate_challenge(Key *);
114 int	 auth_rsa_verify_response(Key *, BIGNUM *, u_char[]);
115 int	 auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **);
116 
117 int	 auth_rhosts_rsa_key_allowed(struct passwd *, char *, char *, Key *);
118 int	 hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
119 int	 user_key_allowed(struct passwd *, Key *);
120 
121 #ifdef KRB5
122 int	auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *);
123 int	auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt);
124 int	auth_krb5_password(Authctxt *authctxt, const char *password);
125 void	krb5_cleanup_proc(Authctxt *authctxt);
126 #endif /* KRB5 */
127 
128 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
129 #include <shadow.h>
130 int auth_shadow_acctexpired(struct spwd *);
131 int auth_shadow_pwexpired(Authctxt *);
132 #endif
133 
134 #include "auth-pam.h"
135 #include "audit.h"
136 void remove_kbdint_device(const char *);
137 
138 void disable_forwarding(void);
139 
140 void	do_authentication(Authctxt *);
141 void	do_authentication2(Authctxt *);
142 
143 void	auth_log(Authctxt *, int, char *, char *);
144 void	userauth_finish(Authctxt *, int, char *);
145 void	userauth_send_banner(const char *);
146 int	auth_root_allowed(char *);
147 
148 char	*auth2_read_banner(void);
149 
150 void	privsep_challenge_enable(void);
151 
152 int	auth2_challenge(Authctxt *, char *);
153 void	auth2_challenge_stop(Authctxt *);
154 int	bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **);
155 int	bsdauth_respond(void *, u_int, char **);
156 int	skey_query(void *, char **, char **, u_int *, char ***, u_int **);
157 int	skey_respond(void *, u_int, char **);
158 
159 int	allowed_user(struct passwd *);
160 struct passwd * getpwnamallow(const char *user);
161 
162 char	*get_challenge(Authctxt *);
163 int	verify_response(Authctxt *, const char *);
164 void	abandon_challenge_response(Authctxt *);
165 
166 char	*authorized_keys_file(struct passwd *);
167 char	*authorized_keys_file2(struct passwd *);
168 
169 FILE	*auth_openkeyfile(const char *, struct passwd *, int);
170 
171 HostStatus
172 check_key_in_hostfiles(struct passwd *, Key *, const char *,
173     const char *, const char *);
174 
175 /* hostkey handling */
176 Key	*get_hostkey_by_index(int);
177 Key	*get_hostkey_by_type(int);
178 int	 get_hostkey_index(Key *);
179 int	 ssh1_session_key(BIGNUM *);
180 
181 /* debug messages during authentication */
182 void	 auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2)));
183 void	 auth_debug_send(void);
184 void	 auth_debug_reset(void);
185 
186 struct passwd *fakepw(void);
187 
188 int	 sys_auth_passwd(Authctxt *, const char *);
189 
190 #define AUTH_FAIL_MSG "Too many authentication failures for %.100s"
191 
192 #define SKEY_PROMPT "\nS/Key Password: "
193 
194 #if defined(KRB5) && !defined(HEIMDAL)
195 #include <krb5.h>
196 krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *);
197 #endif
198 #endif
199