xref: /freebsd/crypto/openssh/auth.h (revision a0ee8cc636cd5c2374ec44ca71226564ea0bca95)
1 /* $OpenBSD: auth.h,v 1.78 2014/07/03 11:16:55 djm 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		 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 #ifdef BSD_AUTH
65 	auth_session_t	*as;
66 #endif
67 	char		**auth_methods;	/* modified from server config */
68 	u_int		 num_auth_methods;
69 #ifdef KRB5
70 	krb5_context	 krb5_ctx;
71 	krb5_ccache	 krb5_fwd_ccache;
72 	krb5_principal	 krb5_user;
73 	char		*krb5_ticket_file;
74 	char		*krb5_ccname;
75 #endif
76 	Buffer		*loginmsg;
77 	void		*methoddata;
78 };
79 /*
80  * Every authentication method has to handle authentication requests for
81  * non-existing users, or for users that are not allowed to login. In this
82  * case 'valid' is set to 0, but 'user' points to the username requested by
83  * the client.
84  */
85 
86 struct Authmethod {
87 	char	*name;
88 	int	(*userauth)(Authctxt *authctxt);
89 	int	*enabled;
90 };
91 
92 /*
93  * Keyboard interactive device:
94  * init_ctx	returns: non NULL upon success
95  * query	returns: 0 - success, otherwise failure
96  * respond	returns: 0 - success, 1 - need further interaction,
97  *		otherwise - failure
98  */
99 struct KbdintDevice
100 {
101 	const char *name;
102 	void*	(*init_ctx)(Authctxt*);
103 	int	(*query)(void *ctx, char **name, char **infotxt,
104 		    u_int *numprompts, char ***prompts, u_int **echo_on);
105 	int	(*respond)(void *ctx, u_int numresp, char **responses);
106 	void	(*free_ctx)(void *ctx);
107 };
108 
109 int      auth_rhosts(struct passwd *, const char *);
110 int
111 auth_rhosts2(struct passwd *, const char *, const char *, const char *);
112 
113 int	 auth_rhosts_rsa(Authctxt *, char *, Key *);
114 int      auth_password(Authctxt *, const char *);
115 int      auth_rsa(Authctxt *, BIGNUM *);
116 int      auth_rsa_challenge_dialog(Key *);
117 BIGNUM	*auth_rsa_generate_challenge(Key *);
118 int	 auth_rsa_verify_response(Key *, BIGNUM *, u_char[]);
119 int	 auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **);
120 
121 int	 auth_rhosts_rsa_key_allowed(struct passwd *, char *, char *, Key *);
122 int	 hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
123 int	 user_key_allowed(struct passwd *, Key *);
124 void	 pubkey_auth_info(Authctxt *, const Key *, const char *, ...)
125 	    __attribute__((__format__ (printf, 3, 4)));
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_authentication(Authctxt *);
151 void	do_authentication2(Authctxt *);
152 
153 void	auth_info(Authctxt *authctxt, const char *, ...)
154 	    __attribute__((__format__ (printf, 2, 3)))
155 	    __attribute__((__nonnull__ (2)));
156 void	auth_log(Authctxt *, int, int, const char *, const char *);
157 void	auth_maxtries_exceeded(Authctxt *) __attribute__((noreturn));
158 void	userauth_finish(Authctxt *, int, const char *, const char *);
159 int	auth_root_allowed(const char *);
160 
161 void	userauth_send_banner(const char *);
162 
163 char	*auth2_read_banner(void);
164 int	 auth2_methods_valid(const char *, int);
165 int	 auth2_update_methods_lists(Authctxt *, const char *, const char *);
166 int	 auth2_setup_methods_lists(Authctxt *);
167 int	 auth2_method_allowed(Authctxt *, const char *, const char *);
168 
169 void	privsep_challenge_enable(void);
170 
171 int	auth2_challenge(Authctxt *, char *);
172 void	auth2_challenge_stop(Authctxt *);
173 int	bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **);
174 int	bsdauth_respond(void *, u_int, char **);
175 int	skey_query(void *, char **, char **, u_int *, char ***, u_int **);
176 int	skey_respond(void *, u_int, char **);
177 
178 int	allowed_user(struct passwd *);
179 struct passwd * getpwnamallow(const char *user);
180 
181 char	*get_challenge(Authctxt *);
182 int	verify_response(Authctxt *, const char *);
183 void	abandon_challenge_response(Authctxt *);
184 
185 char	*expand_authorized_keys(const char *, struct passwd *pw);
186 char	*authorized_principals_file(struct passwd *);
187 
188 FILE	*auth_openkeyfile(const char *, struct passwd *, int);
189 FILE	*auth_openprincipals(const char *, struct passwd *, int);
190 int	 auth_key_is_revoked(Key *);
191 
192 HostStatus
193 check_key_in_hostfiles(struct passwd *, Key *, const char *,
194     const char *, const char *);
195 
196 /* hostkey handling */
197 Key	*get_hostkey_by_index(int);
198 Key	*get_hostkey_public_by_index(int);
199 Key	*get_hostkey_public_by_type(int);
200 Key	*get_hostkey_private_by_type(int);
201 int	 get_hostkey_index(Key *);
202 int	 ssh1_session_key(BIGNUM *);
203 void	 sshd_hostkey_sign(Key *, Key *, u_char **, u_int *, u_char *, u_int);
204 
205 /* debug messages during authentication */
206 void	 auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2)));
207 void	 auth_debug_send(void);
208 void	 auth_debug_reset(void);
209 
210 struct passwd *fakepw(void);
211 
212 int	 sys_auth_passwd(Authctxt *, const char *);
213 
214 #define SKEY_PROMPT "\nS/Key Password: "
215 
216 #if defined(KRB5) && !defined(HEIMDAL)
217 #include <krb5.h>
218 krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *);
219 #endif
220 #endif
221