1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
|
/* $OpenBSD: auth.h,v 1.106 2022/06/15 16:08:25 djm Exp $ */
/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#ifndef AUTH_H
#define AUTH_H
#include <signal.h>
#include <stdio.h>
#include <bsd_auth.h>
#ifdef KRB5
#include <krb5.h>
#endif
struct passwd;
struct ssh;
struct sshbuf;
struct sshkey;
struct sshkey_cert;
struct sshauthopt;
typedef struct Authctxt Authctxt;
typedef struct Authmethod Authmethod;
typedef struct KbdintDevice KbdintDevice;
struct Authctxt {
sig_atomic_t success;
int authenticated; /* authenticated and alarms cancelled */
int postponed; /* authentication needs another step */
int valid; /* user exists and is allowed to login */
int attempt;
int failures;
int server_caused_failure;
int force_pwchange;
char *user; /* username sent by the client */
char *service;
struct passwd *pw; /* set if 'valid' */
char *style;
/* Method lists for multiple authentication */
char **auth_methods; /* modified from server config */
u_int num_auth_methods;
/* Authentication method-specific data */
void *methoddata;
void *kbdintctxt;
auth_session_t *as;
#ifdef KRB5
krb5_context krb5_ctx;
krb5_ccache krb5_fwd_ccache;
krb5_principal krb5_user;
char *krb5_ticket_file;
#endif
/* Authentication keys already used; these will be refused henceforth */
struct sshkey **prev_keys;
u_int nprev_keys;
/* Last used key and ancillary information from active auth method */
struct sshkey *auth_method_key;
char *auth_method_info;
/* Information exposed to session */
struct sshbuf *session_info; /* Auth info for environment */
};
/*
* Every authentication method has to handle authentication requests for
* non-existing users, or for users that are not allowed to login. In this
* case 'valid' is set to 0, but 'user' points to the username requested by
* the client.
*/
struct Authmethod {
char *name;
char *synonym;
int (*userauth)(struct ssh *, const char *);
int *enabled;
};
/*
* Keyboard interactive device:
* init_ctx returns: non NULL upon success
* query returns: 0 - success, otherwise failure
* respond returns: 0 - success, 1 - need further interaction,
* otherwise - failure
*/
struct KbdintDevice
{
const char *name;
void* (*init_ctx)(Authctxt*);
int (*query)(void *ctx, char **name, char **infotxt,
u_int *numprompts, char ***prompts, u_int **echo_on);
int (*respond)(void *ctx, u_int numresp, char **responses);
void (*free_ctx)(void *ctx);
};
int
auth_rhosts2(struct passwd *, const char *, const char *, const char *);
int auth_password(struct ssh *, const char *);
int hostbased_key_allowed(struct ssh *, struct passwd *,
const char *, char *, struct sshkey *);
int user_key_allowed(struct ssh *ssh, struct passwd *, struct sshkey *,
int, struct sshauthopt **);
int auth2_key_already_used(Authctxt *, const struct sshkey *);
/*
* Handling auth method-specific information for logging and prevention
* of key reuse during multiple authentication.
*/
void auth2_authctxt_reset_info(Authctxt *);
void auth2_record_key(Authctxt *, int, const struct sshkey *);
void auth2_record_info(Authctxt *authctxt, const char *, ...)
__attribute__((__format__ (printf, 2, 3)))
__attribute__((__nonnull__ (2)));
void auth2_update_session_info(Authctxt *, const char *, const char *);
#ifdef KRB5
int auth_krb5(Authctxt *authctxt, krb5_data *auth, char **client, krb5_data *);
int auth_krb5_tgt(Authctxt *authctxt, krb5_data *tgt);
int auth_krb5_password(Authctxt *authctxt, const char *password);
void krb5_cleanup_proc(Authctxt *authctxt);
#endif /* KRB5 */
void do_authentication2(struct ssh *);
void auth_log(struct ssh *, int, int, const char *, const char *);
void auth_maxtries_exceeded(struct ssh *) __attribute__((noreturn));
void userauth_finish(struct ssh *, int, const char *, const char *);
int auth_root_allowed(struct ssh *, const char *);
char *auth2_read_banner(void);
int auth2_methods_valid(const char *, int);
int auth2_update_methods_lists(Authctxt *, const char *, const char *);
int auth2_setup_methods_lists(Authctxt *);
int auth2_method_allowed(Authctxt *, const char *, const char *);
void privsep_challenge_enable(void);
int auth2_challenge(struct ssh *, char *);
void auth2_challenge_stop(struct ssh *);
int bsdauth_query(void *, char **, char **, u_int *, char ***, u_int **);
int bsdauth_respond(void *, u_int, char **);
int allowed_user(struct ssh *, struct passwd *);
struct passwd * getpwnamallow(struct ssh *, const char *user);
char *expand_authorized_keys(const char *, struct passwd *pw);
char *authorized_principals_file(struct passwd *);
int auth_key_is_revoked(struct sshkey *);
const char *auth_get_canonical_hostname(struct ssh *, int);
HostStatus
check_key_in_hostfiles(struct passwd *, struct sshkey *, const char *,
const char *, const char *);
/* hostkey handling */
struct sshkey *get_hostkey_by_index(int);
struct sshkey *get_hostkey_public_by_index(int, struct ssh *);
struct sshkey *get_hostkey_public_by_type(int, int, struct ssh *);
struct sshkey *get_hostkey_private_by_type(int, int, struct ssh *);
int get_hostkey_index(struct sshkey *, int, struct ssh *);
int sshd_hostkey_sign(struct ssh *, struct sshkey *, struct sshkey *,
u_char **, size_t *, const u_char *, size_t, const char *);
/* Key / cert options linkage to auth layer */
const struct sshauthopt *auth_options(struct ssh *);
int auth_activate_options(struct ssh *, struct sshauthopt *);
void auth_restrict_session(struct ssh *);
void auth_log_authopts(const char *, const struct sshauthopt *, int);
/* debug messages during authentication */
void auth_debug_add(const char *fmt,...)
__attribute__((format(printf, 1, 2)));
void auth_debug_send(struct ssh *);
void auth_debug_reset(void);
struct passwd *fakepw(void);
/* auth2-pubkeyfile.c */
int auth_authorise_keyopts(struct passwd *, struct sshauthopt *, int,
const char *, const char *, const char *);
int auth_check_principals_line(char *, const struct sshkey_cert *,
const char *, struct sshauthopt **);
int auth_process_principals(FILE *, const char *,
const struct sshkey_cert *, struct sshauthopt **);
int auth_check_authkey_line(struct passwd *, struct sshkey *,
char *, const char *, const char *, const char *, struct sshauthopt **);
int auth_check_authkeys_file(struct passwd *, FILE *, char *,
struct sshkey *, const char *, const char *, struct sshauthopt **);
FILE *auth_openkeyfile(const char *, struct passwd *, int);
FILE *auth_openprincipals(const char *, struct passwd *, int);
#endif
|
