xref: /freebsd/crypto/openssh/auth.h (revision 4c8945a06b01a5c8122cdeb402af36bb46a06acc)
1 /* $OpenBSD: auth.h,v 1.66 2010/05/07 11:30:29 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		 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 	void		*jpake_ctx;
63 #ifdef BSD_AUTH
64 	auth_session_t	*as;
65 #endif
66 #ifdef KRB5
67 	krb5_context	 krb5_ctx;
68 	krb5_ccache	 krb5_fwd_ccache;
69 	krb5_principal	 krb5_user;
70 	char		*krb5_ticket_file;
71 	char		*krb5_ccname;
72 #endif
73 	Buffer		*loginmsg;
74 	void		*methoddata;
75 };
76 /*
77  * Every authentication method has to handle authentication requests for
78  * non-existing users, or for users that are not allowed to login. In this
79  * case 'valid' is set to 0, but 'user' points to the username requested by
80  * the client.
81  */
82 
83 struct Authmethod {
84 	char	*name;
85 	int	(*userauth)(Authctxt *authctxt);
86 	int	*enabled;
87 };
88 
89 /*
90  * Keyboard interactive device:
91  * init_ctx	returns: non NULL upon success
92  * query	returns: 0 - success, otherwise failure
93  * respond	returns: 0 - success, 1 - need further interaction,
94  *		otherwise - failure
95  */
96 struct KbdintDevice
97 {
98 	const char *name;
99 	void*	(*init_ctx)(Authctxt*);
100 	int	(*query)(void *ctx, char **name, char **infotxt,
101 		    u_int *numprompts, char ***prompts, u_int **echo_on);
102 	int	(*respond)(void *ctx, u_int numresp, char **responses);
103 	void	(*free_ctx)(void *ctx);
104 };
105 
106 int      auth_rhosts(struct passwd *, const char *);
107 int
108 auth_rhosts2(struct passwd *, const char *, const char *, const char *);
109 
110 int	 auth_rhosts_rsa(Authctxt *, char *, Key *);
111 int      auth_password(Authctxt *, const char *);
112 int      auth_rsa(Authctxt *, BIGNUM *);
113 int      auth_rsa_challenge_dialog(Key *);
114 BIGNUM	*auth_rsa_generate_challenge(Key *);
115 int	 auth_rsa_verify_response(Key *, BIGNUM *, u_char[]);
116 int	 auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **);
117 
118 int	 auth_rhosts_rsa_key_allowed(struct passwd *, char *, char *, Key *);
119 int	 hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
120 int	 user_key_allowed(struct passwd *, Key *);
121 
122 #ifdef KRB5
123 int	auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *);
124 int	auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt);
125 int	auth_krb5_password(Authctxt *authctxt, const char *password);
126 void	krb5_cleanup_proc(Authctxt *authctxt);
127 #endif /* KRB5 */
128 
129 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
130 #include <shadow.h>
131 int auth_shadow_acctexpired(struct spwd *);
132 int auth_shadow_pwexpired(Authctxt *);
133 #endif
134 
135 #include "auth-pam.h"
136 #include "audit.h"
137 void remove_kbdint_device(const char *);
138 
139 void disable_forwarding(void);
140 
141 void	do_authentication(Authctxt *);
142 void	do_authentication2(Authctxt *);
143 
144 void	auth_log(Authctxt *, int, char *, char *);
145 void	userauth_finish(Authctxt *, int, char *);
146 void	userauth_send_banner(const char *);
147 int	auth_root_allowed(char *);
148 
149 char	*auth2_read_banner(void);
150 
151 void	privsep_challenge_enable(void);
152 
153 int	auth2_challenge(Authctxt *, char *);
154 void	auth2_challenge_stop(Authctxt *);
155 int	bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **);
156 int	bsdauth_respond(void *, u_int, char **);
157 int	skey_query(void *, char **, char **, u_int *, char ***, u_int **);
158 int	skey_respond(void *, u_int, char **);
159 
160 void	auth2_jpake_get_pwdata(Authctxt *, BIGNUM **, char **, char **);
161 void	auth2_jpake_stop(Authctxt *);
162 
163 int	allowed_user(struct passwd *);
164 struct passwd * getpwnamallow(const char *user);
165 
166 char	*get_challenge(Authctxt *);
167 int	verify_response(Authctxt *, const char *);
168 void	abandon_challenge_response(Authctxt *);
169 
170 char	*authorized_keys_file(struct passwd *);
171 char	*authorized_keys_file2(struct passwd *);
172 char	*authorized_principals_file(struct passwd *);
173 
174 FILE	*auth_openkeyfile(const char *, struct passwd *, int);
175 FILE	*auth_openprincipals(const char *, struct passwd *, int);
176 int	 auth_key_is_revoked(Key *);
177 
178 HostStatus
179 check_key_in_hostfiles(struct passwd *, Key *, const char *,
180     const char *, const char *);
181 
182 /* hostkey handling */
183 Key	*get_hostkey_by_index(int);
184 Key	*get_hostkey_public_by_type(int);
185 Key	*get_hostkey_private_by_type(int);
186 int	 get_hostkey_index(Key *);
187 int	 ssh1_session_key(BIGNUM *);
188 
189 /* debug messages during authentication */
190 void	 auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2)));
191 void	 auth_debug_send(void);
192 void	 auth_debug_reset(void);
193 
194 struct passwd *fakepw(void);
195 
196 int	 sys_auth_passwd(Authctxt *, const char *);
197 
198 #define AUTH_FAIL_MSG "Too many authentication failures for %.100s"
199 
200 #define SKEY_PROMPT "\nS/Key Password: "
201 
202 #if defined(KRB5) && !defined(HEIMDAL)
203 #include <krb5.h>
204 krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *);
205 #endif
206 #endif
207