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jcs's openbsd hax
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1/*
2 * Copyright (c) 2012,2023 Damien Miller <djm@mindrot.org>
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16
17#include <sys/types.h>
18
19#include <stdlib.h>
20#include <string.h>
21
22#include "log.h"
23#include "misc.h"
24#include "servconf.h"
25#include "xmalloc.h"
26#include "hostfile.h"
27#include "auth.h"
28
29extern ServerOptions options;
30
31/*
32 * Configuration of enabled authentication methods. Separate from the rest of
33 * auth2-*.c because we want to query it during server configuration validity
34 * checking in the sshd listener process without pulling all the auth code in
35 * too.
36 */
37
38/* "none" is allowed only one time and it is cleared by userauth_none() later */
39int none_enabled = 1;
40struct authmethod_cfg methodcfg_none = {
41 "none",
42 NULL,
43 &none_enabled
44};
45struct authmethod_cfg methodcfg_pubkey = {
46 "publickey",
47 "publickey-hostbound-v00@openssh.com",
48 &options.pubkey_authentication
49};
50#ifdef GSSAPI
51struct authmethod_cfg methodcfg_gssapi = {
52 "gssapi-with-mic",
53 NULL,
54 &options.gss_authentication
55};
56#endif
57struct authmethod_cfg methodcfg_passwd = {
58 "password",
59 NULL,
60 &options.password_authentication
61};
62struct authmethod_cfg methodcfg_kbdint = {
63 "keyboard-interactive",
64 NULL,
65 &options.kbd_interactive_authentication
66};
67struct authmethod_cfg methodcfg_hostbased = {
68 "hostbased",
69 NULL,
70 &options.hostbased_authentication
71};
72
73static struct authmethod_cfg *authmethod_cfgs[] = {
74 &methodcfg_none,
75 &methodcfg_pubkey,
76#ifdef GSSAPI
77 &methodcfg_gssapi,
78#endif
79 &methodcfg_passwd,
80 &methodcfg_kbdint,
81 &methodcfg_hostbased,
82 NULL
83};
84
85/*
86 * Check a comma-separated list of methods for validity. If need_enable is
87 * non-zero, then also require that the methods are enabled.
88 * Returns 0 on success or -1 if the methods list is invalid.
89 */
90int
91auth2_methods_valid(const char *_methods, int need_enable)
92{
93 char *methods, *omethods, *method, *p;
94 u_int i, found;
95 int ret = -1;
96 const struct authmethod_cfg *cfg;
97
98 if (*_methods == '\0') {
99 error("empty authentication method list");
100 return -1;
101 }
102 omethods = methods = xstrdup(_methods);
103 while ((method = strsep(&methods, ",")) != NULL) {
104 for (found = i = 0; !found && authmethod_cfgs[i] != NULL; i++) {
105 cfg = authmethod_cfgs[i];
106 if ((p = strchr(method, ':')) != NULL)
107 *p = '\0';
108 if (strcmp(method, cfg->name) != 0)
109 continue;
110 if (need_enable) {
111 if (cfg->enabled == NULL ||
112 *(cfg->enabled) == 0) {
113 error("Disabled method \"%s\" in "
114 "AuthenticationMethods list \"%s\"",
115 method, _methods);
116 goto out;
117 }
118 }
119 found = 1;
120 break;
121 }
122 if (!found) {
123 error("Unknown authentication method \"%s\" in list",
124 method);
125 goto out;
126 }
127 }
128 ret = 0;
129 out:
130 free(omethods);
131 return ret;
132}