xref: /freebsd/crypto/openssh/auth.h (revision 2546665afcaf0d53dc2c7058fee96354b3680f5a)
1 /*	$OpenBSD: auth.h,v 1.49 2004/01/30 09:48:57 markus Exp $	*/
2 /*	$FreeBSD$	*/
3 
4 /*
5  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  *
27  */
28 
29 #ifndef AUTH_H
30 #define AUTH_H
31 
32 #include "key.h"
33 #include "hostfile.h"
34 #include <openssl/rsa.h>
35 
36 #ifdef HAVE_LOGIN_CAP
37 #include <login_cap.h>
38 #endif
39 #ifdef BSD_AUTH
40 #include <bsd_auth.h>
41 #endif
42 #ifdef KRB5
43 #include <krb5.h>
44 #endif
45 
46 typedef struct Authctxt Authctxt;
47 typedef struct Authmethod Authmethod;
48 typedef struct KbdintDevice KbdintDevice;
49 
50 struct Authctxt {
51 	int		 success;
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 	void		*methoddata;
73 };
74 /*
75  * Every authentication method has to handle authentication requests for
76  * non-existing users, or for users that are not allowed to login. In this
77  * case 'valid' is set to 0, but 'user' points to the username requested by
78  * the client.
79  */
80 
81 struct Authmethod {
82 	char	*name;
83 	int	(*userauth)(Authctxt *authctxt);
84 	int	*enabled;
85 };
86 
87 /*
88  * Keyboard interactive device:
89  * init_ctx	returns: non NULL upon success
90  * query	returns: 0 - success, otherwise failure
91  * respond	returns: 0 - success, 1 - need further interaction,
92  *		otherwise - failure
93  */
94 struct KbdintDevice
95 {
96 	const char *name;
97 	void*	(*init_ctx)(Authctxt*);
98 	int	(*query)(void *ctx, char **name, char **infotxt,
99 		    u_int *numprompts, char ***prompts, u_int **echo_on);
100 	int	(*respond)(void *ctx, u_int numresp, char **responses);
101 	void	(*free_ctx)(void *ctx);
102 };
103 
104 int      auth_rhosts(struct passwd *, const char *);
105 int
106 auth_rhosts2(struct passwd *, const char *, const char *, const char *);
107 
108 int	 auth_rhosts_rsa(Authctxt *, char *, Key *);
109 int      auth_password(Authctxt *, const char *);
110 int      auth_rsa(Authctxt *, BIGNUM *);
111 int      auth_rsa_challenge_dialog(Key *);
112 BIGNUM	*auth_rsa_generate_challenge(Key *);
113 int	 auth_rsa_verify_response(Key *, BIGNUM *, u_char[]);
114 int	 auth_rsa_key_allowed(struct passwd *, BIGNUM *, Key **);
115 
116 int	 auth_rhosts_rsa_key_allowed(struct passwd *, char *, char *, Key *);
117 int	 hostbased_key_allowed(struct passwd *, const char *, char *, Key *);
118 int	 user_key_allowed(struct passwd *, Key *);
119 
120 #ifdef KRB5
121 int	auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *);
122 int	auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt);
123 int	auth_krb5_password(Authctxt *authctxt, const char *password);
124 void	krb5_cleanup_proc(Authctxt *authctxt);
125 #endif /* KRB5 */
126 
127 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
128 #include <shadow.h>
129 int auth_shadow_acctexpired(struct spwd *);
130 int auth_shadow_pwexpired(Authctxt *);
131 #endif
132 
133 #include "auth-pam.h"
134 void disable_forwarding(void);
135 
136 void	do_authentication(Authctxt *);
137 void	do_authentication2(Authctxt *);
138 
139 void	auth_log(Authctxt *, int, char *, char *);
140 void	userauth_finish(Authctxt *, int, char *);
141 int	auth_root_allowed(char *);
142 
143 char	*auth2_read_banner(void);
144 
145 void	privsep_challenge_enable(void);
146 
147 int	auth2_challenge(Authctxt *, char *);
148 void	auth2_challenge_stop(Authctxt *);
149 int	bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **);
150 int	bsdauth_respond(void *, u_int, char **);
151 int	skey_query(void *, char **, char **, u_int *, char ***, u_int **);
152 int	skey_respond(void *, u_int, char **);
153 
154 int	allowed_user(struct passwd *);
155 struct passwd * getpwnamallow(const char *user);
156 
157 char	*get_challenge(Authctxt *);
158 int	verify_response(Authctxt *, const char *);
159 void	abandon_challenge_response(Authctxt *);
160 
161 char	*expand_filename(const char *, struct passwd *);
162 char	*authorized_keys_file(struct passwd *);
163 char	*authorized_keys_file2(struct passwd *);
164 
165 int
166 secure_filename(FILE *, const char *, struct passwd *, char *, size_t);
167 
168 HostStatus
169 check_key_in_hostfiles(struct passwd *, Key *, const char *,
170     const char *, const char *);
171 
172 /* hostkey handling */
173 Key	*get_hostkey_by_index(int);
174 Key	*get_hostkey_by_type(int);
175 int	 get_hostkey_index(Key *);
176 int	 ssh1_session_key(BIGNUM *);
177 
178 /* debug messages during authentication */
179 void	 auth_debug_add(const char *fmt,...) __attribute__((format(printf, 1, 2)));
180 void	 auth_debug_send(void);
181 void	 auth_debug_reset(void);
182 
183 struct passwd *fakepw(void);
184 
185 #define AUTH_FAIL_MAX 6
186 #define AUTH_FAIL_LOG (AUTH_FAIL_MAX/2)
187 #define AUTH_FAIL_MSG "Too many authentication failures for %.100s"
188 
189 #ifdef SKEY
190 #ifdef OPIE
191 #define SKEY_PROMPT "\nOPIE Password: "
192 #else
193 #define SKEY_PROMPT "\nS/Key Password: "
194 #endif
195 #endif
196 
197 #endif
198