1 /* $OpenBSD: auth.h,v 1.101 2020/12/22 00:12:22 djm Exp $ */
4 * Copyright (c) 2000 Markus Friedl. All rights reserved.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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.
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.
34 #include <login_cap.h>
49 typedef struct Authctxt Authctxt;
50 typedef struct Authmethod Authmethod;
51 typedef struct KbdintDevice KbdintDevice;
55 int authenticated; /* authenticated and alarms cancelled */
56 int postponed; /* authentication needs another step */
57 int valid; /* user exists and is allowed to login */
60 int server_caused_failure;
62 char *user; /* username sent by the client */
64 struct passwd *pw; /* set if 'valid' */
67 /* Method lists for multiple authentication */
68 char **auth_methods; /* modified from server config */
69 u_int num_auth_methods;
71 /* Authentication method-specific data */
78 krb5_context krb5_ctx;
79 krb5_ccache krb5_fwd_ccache;
80 krb5_principal krb5_user;
81 char *krb5_ticket_file;
84 struct sshbuf *loginmsg;
86 /* Authentication keys already used; these will be refused henceforth */
87 struct sshkey **prev_keys;
90 /* Last used key and ancillary information from active auth method */
91 struct sshkey *auth_method_key;
92 char *auth_method_info;
94 /* Information exposed to session */
95 struct sshbuf *session_info; /* Auth info for environment */
99 * Every authentication method has to handle authentication requests for
100 * non-existing users, or for users that are not allowed to login. In this
101 * case 'valid' is set to 0, but 'user' points to the username requested by
107 int (*userauth)(struct ssh *);
112 * Keyboard interactive device:
113 * init_ctx returns: non NULL upon success
114 * query returns: 0 - success, otherwise failure
115 * respond returns: 0 - success, 1 - need further interaction,
116 * otherwise - failure
121 void* (*init_ctx)(Authctxt*);
122 int (*query)(void *ctx, char **name, char **infotxt,
123 u_int *numprompts, char ***prompts, u_int **echo_on);
124 int (*respond)(void *ctx, u_int numresp, char **responses);
125 void (*free_ctx)(void *ctx);
129 auth_rhosts2(struct passwd *, const char *, const char *, const char *);
131 int auth_password(struct ssh *, const char *);
133 int hostbased_key_allowed(struct ssh *, struct passwd *,
134 const char *, char *, struct sshkey *);
135 int user_key_allowed(struct ssh *, struct passwd *, struct sshkey *, int,
136 struct sshauthopt **);
137 int auth2_key_already_used(Authctxt *, const struct sshkey *);
140 * Handling auth method-specific information for logging and prevention
141 * of key reuse during multiple authentication.
143 void auth2_authctxt_reset_info(Authctxt *);
144 void auth2_record_key(Authctxt *, int, const struct sshkey *);
145 void auth2_record_info(Authctxt *authctxt, const char *, ...)
146 __attribute__((__format__ (printf, 2, 3)))
147 __attribute__((__nonnull__ (2)));
148 void auth2_update_session_info(Authctxt *, const char *, const char *);
151 int auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *);
152 int auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt);
153 int auth_krb5_password(Authctxt *authctxt, const char *password);
154 void krb5_cleanup_proc(Authctxt *authctxt);
157 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
159 int auth_shadow_acctexpired(struct spwd *);
160 int auth_shadow_pwexpired(Authctxt *);
163 #include "auth-pam.h"
165 void remove_kbdint_device(const char *);
167 void do_authentication2(struct ssh *);
169 void auth_log(struct ssh *, int, int, const char *, const char *);
170 void auth_maxtries_exceeded(struct ssh *) __attribute__((noreturn));
171 void userauth_finish(struct ssh *, int, const char *, const char *);
172 int auth_root_allowed(struct ssh *, const char *);
174 char *auth2_read_banner(void);
175 int auth2_methods_valid(const char *, int);
176 int auth2_update_methods_lists(Authctxt *, const char *, const char *);
177 int auth2_setup_methods_lists(Authctxt *);
178 int auth2_method_allowed(Authctxt *, const char *, const char *);
180 void privsep_challenge_enable(void);
182 int auth2_challenge(struct ssh *, char *);
183 void auth2_challenge_stop(struct ssh *);
184 int bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **);
185 int bsdauth_respond(void *, u_int, char **);
187 int allowed_user(struct ssh *, struct passwd *);
188 struct passwd * getpwnamallow(struct ssh *, const char *user);
190 char *expand_authorized_keys(const char *, struct passwd *pw);
191 char *authorized_principals_file(struct passwd *);
193 FILE *auth_openkeyfile(const char *, struct passwd *, int);
194 FILE *auth_openprincipals(const char *, struct passwd *, int);
195 int auth_key_is_revoked(struct sshkey *);
197 const char *auth_get_canonical_hostname(struct ssh *, int);
200 check_key_in_hostfiles(struct passwd *, struct sshkey *, const char *,
201 const char *, const char *);
203 /* hostkey handling */
204 struct sshkey *get_hostkey_by_index(int);
205 struct sshkey *get_hostkey_public_by_index(int, struct ssh *);
206 struct sshkey *get_hostkey_public_by_type(int, int, struct ssh *);
207 struct sshkey *get_hostkey_private_by_type(int, int, struct ssh *);
208 int get_hostkey_index(struct sshkey *, int, struct ssh *);
209 int sshd_hostkey_sign(struct ssh *, struct sshkey *, struct sshkey *,
210 u_char **, size_t *, const u_char *, size_t, const char *);
212 /* Key / cert options linkage to auth layer */
213 const struct sshauthopt *auth_options(struct ssh *);
214 int auth_activate_options(struct ssh *, struct sshauthopt *);
215 void auth_restrict_session(struct ssh *);
216 int auth_authorise_keyopts(struct ssh *, struct passwd *pw,
217 struct sshauthopt *, int, const char *);
218 void auth_log_authopts(const char *, const struct sshauthopt *, int);
220 /* debug messages during authentication */
221 void auth_debug_add(const char *fmt,...)
222 __attribute__((format(printf, 1, 2)));
223 void auth_debug_send(struct ssh *);
224 void auth_debug_reset(void);
226 struct passwd *fakepw(void);
228 int sys_auth_passwd(struct ssh *, const char *);
230 #if defined(KRB5) && !defined(HEIMDAL)
231 krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *);