• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /* $OpenBSD: auth.h,v 1.89 2016/08/13 17:47:41 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 
45 struct ssh;
46 struct sshkey;
47 
48 typedef struct Authctxt Authctxt;
49 typedef struct Authmethod Authmethod;
50 typedef struct KbdintDevice KbdintDevice;
51 
52 struct 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 
92 struct 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  */
105 struct 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 
115 int
116 auth_rhosts2(struct passwd *, const char *, const char *, const char *);
117 
118 int      auth_password(Authctxt *, const char *);
119 
120 int	 hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
121 int	 user_key_allowed(struct passwd *, Key *, int);
122 void	 pubkey_auth_info(Authctxt *, const Key *, const char *, ...)
123 	    __attribute__((__format__ (printf, 3, 4)));
124 void	 auth2_record_userkey(Authctxt *, struct sshkey *);
125 int	 auth2_userkey_already_used(Authctxt *, struct sshkey *);
126 
127 struct stat;
128 int	 auth_secure_path(const char *, struct stat *, const char *, uid_t,
129     char *, size_t);
130 
131 #ifdef KRB5
132 int	auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *);
133 int	auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt);
134 int	auth_krb5_password(Authctxt *authctxt, const char *password);
135 void	krb5_cleanup_proc(Authctxt *authctxt);
136 #endif /* KRB5 */
137 
138 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
139 #include <shadow.h>
140 int auth_shadow_acctexpired(struct spwd *);
141 int auth_shadow_pwexpired(Authctxt *);
142 #endif
143 
144 #include "auth-pam.h"
145 #include "audit.h"
146 void remove_kbdint_device(const char *);
147 
148 void disable_forwarding(void);
149 
150 void	do_authentication2(Authctxt *);
151 
152 void	auth_info(Authctxt *authctxt, const char *, ...)
153 	    __attribute__((__format__ (printf, 2, 3)))
154 	    __attribute__((__nonnull__ (2)));
155 void	auth_log(Authctxt *, int, int, const char *, const char *);
156 void	auth_maxtries_exceeded(Authctxt *) __attribute__((noreturn));
157 void	userauth_finish(Authctxt *, int, const char *, const char *);
158 int	auth_root_allowed(const char *);
159 
160 void	userauth_send_banner(const char *);
161 
162 char	*auth2_read_banner(void);
163 int	 auth2_methods_valid(const char *, int);
164 int	 auth2_update_methods_lists(Authctxt *, const char *, const char *);
165 int	 auth2_setup_methods_lists(Authctxt *);
166 int	 auth2_method_allowed(Authctxt *, const char *, const char *);
167 
168 void	privsep_challenge_enable(void);
169 
170 int	auth2_challenge(Authctxt *, char *);
171 void	auth2_challenge_stop(Authctxt *);
172 int	bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **);
173 int	bsdauth_respond(void *, u_int, char **);
174 int	skey_query(void *, char **, char **, u_int *, char ***, u_int **);
175 int	skey_respond(void *, u_int, char **);
176 
177 int	allowed_user(struct passwd *);
178 struct passwd * getpwnamallow(const char *user);
179 
180 char	*expand_authorized_keys(const char *, struct passwd *pw);
181 char	*authorized_principals_file(struct passwd *);
182 
183 FILE	*auth_openkeyfile(const char *, struct passwd *, int);
184 FILE	*auth_openprincipals(const char *, struct passwd *, int);
185 int	 auth_key_is_revoked(Key *);
186 
187 const char	*auth_get_canonical_hostname(struct ssh *, int);
188 
189 HostStatus
190 check_key_in_hostfiles(struct passwd *, Key *, const char *,
191     const char *, const char *);
192 
193 /* hostkey handling */
194 Key	*get_hostkey_by_index(int);
195 Key	*get_hostkey_public_by_index(int, struct ssh *);
196 Key	*get_hostkey_public_by_type(int, int, struct ssh *);
197 Key	*get_hostkey_private_by_type(int, int, struct ssh *);
198 int	 get_hostkey_index(Key *, int, struct ssh *);
199 int	 sshd_hostkey_sign(Key *, Key *, u_char **, size_t *,
200 	     const u_char *, size_t, const char *, u_int);
201 
202 /* debug messages during authentication */
203 void	 auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2)));
204 void	 auth_debug_send(void);
205 void	 auth_debug_reset(void);
206 
207 struct passwd *fakepw(void);
208 
209 int	 sys_auth_passwd(Authctxt *, const char *);
210 
211 #define SKEY_PROMPT "\nS/Key Password: "
212 
213 #if defined(KRB5) && !defined(HEIMDAL)
214 #include <krb5.h>
215 krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *);
216 #endif
217 #endif
218