1 /* $OpenBSD: auth.h,v 1.95 2018/03/03 03:15:51 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.
33 #include <openssl/rsa.h>
36 #include <login_cap.h>
51 typedef struct Authctxt Authctxt;
52 typedef struct Authmethod Authmethod;
53 typedef struct KbdintDevice KbdintDevice;
57 int authenticated; /* authenticated and alarms cancelled */
58 int postponed; /* authentication needs another step */
59 int valid; /* user exists and is allowed to login */
62 int server_caused_failure;
64 char *user; /* username sent by the client */
66 struct passwd *pw; /* set if 'valid' */
69 /* Method lists for multiple authentication */
70 char **auth_methods; /* modified from server config */
71 u_int num_auth_methods;
73 /* Authentication method-specific data */
80 krb5_context krb5_ctx;
81 krb5_ccache krb5_fwd_ccache;
82 krb5_principal krb5_user;
83 char *krb5_ticket_file;
86 struct sshbuf *loginmsg;
88 /* Authentication keys already used; these will be refused henceforth */
89 struct sshkey **prev_keys;
92 /* Last used key and ancilliary information from active auth method */
93 struct sshkey *auth_method_key;
94 char *auth_method_info;
96 /* Information exposed to session */
97 struct sshbuf *session_info; /* Auth info for environment */
101 * Every authentication method has to handle authentication requests for
102 * non-existing users, or for users that are not allowed to login. In this
103 * case 'valid' is set to 0, but 'user' points to the username requested by
109 int (*userauth)(struct ssh *);
114 * Keyboard interactive device:
115 * init_ctx returns: non NULL upon success
116 * query returns: 0 - success, otherwise failure
117 * respond returns: 0 - success, 1 - need further interaction,
118 * otherwise - failure
123 void* (*init_ctx)(Authctxt*);
124 int (*query)(void *ctx, char **name, char **infotxt,
125 u_int *numprompts, char ***prompts, u_int **echo_on);
126 int (*respond)(void *ctx, u_int numresp, char **responses);
127 void (*free_ctx)(void *ctx);
131 auth_rhosts2(struct passwd *, const char *, const char *, const char *);
133 int auth_password(struct ssh *, const char *);
135 int hostbased_key_allowed(struct passwd *, const char *, char *,
137 int user_key_allowed(struct ssh *, struct passwd *, struct sshkey *, int,
138 struct sshauthopt **);
139 int auth2_key_already_used(Authctxt *, const struct sshkey *);
142 * Handling auth method-specific information for logging and prevention
143 * of key reuse during multiple authentication.
145 void auth2_authctxt_reset_info(Authctxt *);
146 void auth2_record_key(Authctxt *, int, const struct sshkey *);
147 void auth2_record_info(Authctxt *authctxt, const char *, ...)
148 __attribute__((__format__ (printf, 2, 3)))
149 __attribute__((__nonnull__ (2)));
150 void auth2_update_session_info(Authctxt *, const char *, const char *);
153 int auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *);
154 int auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt);
155 int auth_krb5_password(Authctxt *authctxt, const char *password);
156 void krb5_cleanup_proc(Authctxt *authctxt);
159 #if defined(USE_SHADOW) && defined(HAS_SHADOW_EXPIRE)
161 int auth_shadow_acctexpired(struct spwd *);
162 int auth_shadow_pwexpired(Authctxt *);
165 #include "auth-pam.h"
167 void remove_kbdint_device(const char *);
169 void do_authentication2(Authctxt *);
171 void auth_log(Authctxt *, int, int, const char *, const char *);
172 void auth_maxtries_exceeded(Authctxt *) __attribute__((noreturn));
173 void userauth_finish(struct ssh *, int, const char *, const char *);
174 int auth_root_allowed(struct ssh *, const char *);
176 void userauth_send_banner(const char *);
178 char *auth2_read_banner(void);
179 int auth2_methods_valid(const char *, int);
180 int auth2_update_methods_lists(Authctxt *, const char *, const char *);
181 int auth2_setup_methods_lists(Authctxt *);
182 int auth2_method_allowed(Authctxt *, const char *, const char *);
184 void privsep_challenge_enable(void);
186 int auth2_challenge(struct ssh *, char *);
187 void auth2_challenge_stop(struct ssh *);
188 int bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **);
189 int bsdauth_respond(void *, u_int, char **);
190 int skey_query(void *, char **, char **, u_int *, char ***, u_int **);
191 int skey_respond(void *, u_int, char **);
193 int allowed_user(struct passwd *);
194 struct passwd * getpwnamallow(const char *user);
196 char *expand_authorized_keys(const char *, struct passwd *pw);
197 char *authorized_principals_file(struct passwd *);
199 FILE *auth_openkeyfile(const char *, struct passwd *, int);
200 FILE *auth_openprincipals(const char *, struct passwd *, int);
201 int auth_key_is_revoked(struct sshkey *);
203 const char *auth_get_canonical_hostname(struct ssh *, int);
206 check_key_in_hostfiles(struct passwd *, struct sshkey *, const char *,
207 const char *, const char *);
209 /* hostkey handling */
210 struct sshkey *get_hostkey_by_index(int);
211 struct sshkey *get_hostkey_public_by_index(int, struct ssh *);
212 struct sshkey *get_hostkey_public_by_type(int, int, struct ssh *);
213 struct sshkey *get_hostkey_private_by_type(int, int, struct ssh *);
214 int get_hostkey_index(struct sshkey *, int, struct ssh *);
215 int sshd_hostkey_sign(struct sshkey *, struct sshkey *, u_char **,
216 size_t *, const u_char *, size_t, const char *, u_int);
218 /* Key / cert options linkage to auth layer */
219 const struct sshauthopt *auth_options(struct ssh *);
220 int auth_activate_options(struct ssh *, struct sshauthopt *);
221 void auth_restrict_session(struct ssh *);
222 int auth_authorise_keyopts(struct ssh *, struct passwd *pw,
223 struct sshauthopt *, int, const char *);
224 void auth_log_authopts(const char *, const struct sshauthopt *, int);
226 /* debug messages during authentication */
227 void auth_debug_add(const char *fmt,...)
228 __attribute__((format(printf, 1, 2)));
229 void auth_debug_send(void);
230 void auth_debug_reset(void);
232 struct passwd *fakepw(void);
234 #define SSH_SUBPROCESS_STDOUT_DISCARD (1) /* Discard stdout */
235 #define SSH_SUBPROCESS_STDOUT_CAPTURE (1<<1) /* Redirect stdout */
236 #define SSH_SUBPROCESS_STDERR_DISCARD (1<<2) /* Discard stderr */
237 pid_t subprocess(const char *, struct passwd *,
238 const char *, int, char **, FILE **, u_int flags);
240 int sys_auth_passwd(struct ssh *, const char *);
242 #define SKEY_PROMPT "\nS/Key Password: "
244 #if defined(KRB5) && !defined(HEIMDAL)
246 krb5_error_code ssh_krb5_cc_gen(krb5_context, krb5_ccache *);