diff options
author | Ben Lindstrom <mouring@eviladmin.org> | 2002-06-06 20:27:55 +0000 |
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committer | Ben Lindstrom <mouring@eviladmin.org> | 2002-06-06 20:27:55 +0000 |
commit | 855bf3ac3cf395b282600700c1fd792af1f3fdcb (patch) | |
tree | effce712ac4bb1d7ef46cc3db4fdda2b74756298 /auth2-hostbased.c | |
parent | 4887da222b5dec4e36f85f724d836dfbb6d434c7 (diff) |
- markus@cvs.openbsd.org 2002/05/25 18:51:07
[auth.h auth2.c auth2-hostbased.c auth2-kbdint.c auth2-none.c
auth2-passwd.c auth2-pubkey.c Makefile.in]
split auth2.c into one file per method; ok provos@/deraadt@
NOTE: Merged back noticable cygwin and pam stuff. May need review to
ensure I did not miss anything.
Diffstat (limited to 'auth2-hostbased.c')
-rw-r--r-- | auth2-hostbased.c | 182 |
1 files changed, 182 insertions, 0 deletions
diff --git a/auth2-hostbased.c b/auth2-hostbased.c new file mode 100644 index 000000000..2bde7bb79 --- /dev/null +++ b/auth2-hostbased.c | |||
@@ -0,0 +1,182 @@ | |||
1 | /* | ||
2 | * Copyright (c) 2000 Markus Friedl. All rights reserved. | ||
3 | * | ||
4 | * Redistribution and use in source and binary forms, with or without | ||
5 | * modification, are permitted provided that the following conditions | ||
6 | * are met: | ||
7 | * 1. Redistributions of source code must retain the above copyright | ||
8 | * notice, this list of conditions and the following disclaimer. | ||
9 | * 2. Redistributions in binary form must reproduce the above copyright | ||
10 | * notice, this list of conditions and the following disclaimer in the | ||
11 | * documentation and/or other materials provided with the distribution. | ||
12 | * | ||
13 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | ||
14 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | ||
15 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | ||
16 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | ||
17 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | ||
18 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | ||
19 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | ||
20 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | ||
21 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | ||
22 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | ||
23 | */ | ||
24 | |||
25 | #include "includes.h" | ||
26 | RCSID("$OpenBSD: auth2-hostbased.c,v 1.2 2002/05/31 11:35:15 markus Exp $"); | ||
27 | |||
28 | #include "ssh2.h" | ||
29 | #include "xmalloc.h" | ||
30 | #include "packet.h" | ||
31 | #include "buffer.h" | ||
32 | #include "log.h" | ||
33 | #include "servconf.h" | ||
34 | #include "compat.h" | ||
35 | #include "bufaux.h" | ||
36 | #include "auth.h" | ||
37 | #include "key.h" | ||
38 | #include "canohost.h" | ||
39 | #include "monitor_wrap.h" | ||
40 | #include "pathnames.h" | ||
41 | |||
42 | /* import */ | ||
43 | extern ServerOptions options; | ||
44 | extern u_char *session_id2; | ||
45 | extern int session_id2_len; | ||
46 | |||
47 | static int | ||
48 | userauth_hostbased(Authctxt *authctxt) | ||
49 | { | ||
50 | Buffer b; | ||
51 | Key *key = NULL; | ||
52 | char *pkalg, *cuser, *chost, *service; | ||
53 | u_char *pkblob, *sig; | ||
54 | u_int alen, blen, slen; | ||
55 | int pktype; | ||
56 | int authenticated = 0; | ||
57 | |||
58 | if (!authctxt->valid) { | ||
59 | debug2("userauth_hostbased: disabled because of invalid user"); | ||
60 | return 0; | ||
61 | } | ||
62 | pkalg = packet_get_string(&alen); | ||
63 | pkblob = packet_get_string(&blen); | ||
64 | chost = packet_get_string(NULL); | ||
65 | cuser = packet_get_string(NULL); | ||
66 | sig = packet_get_string(&slen); | ||
67 | |||
68 | debug("userauth_hostbased: cuser %s chost %s pkalg %s slen %d", | ||
69 | cuser, chost, pkalg, slen); | ||
70 | #ifdef DEBUG_PK | ||
71 | debug("signature:"); | ||
72 | buffer_init(&b); | ||
73 | buffer_append(&b, sig, slen); | ||
74 | buffer_dump(&b); | ||
75 | buffer_free(&b); | ||
76 | #endif | ||
77 | pktype = key_type_from_name(pkalg); | ||
78 | if (pktype == KEY_UNSPEC) { | ||
79 | /* this is perfectly legal */ | ||
80 | log("userauth_hostbased: unsupported " | ||
81 | "public key algorithm: %s", pkalg); | ||
82 | goto done; | ||
83 | } | ||
84 | key = key_from_blob(pkblob, blen); | ||
85 | if (key == NULL) { | ||
86 | error("userauth_hostbased: cannot decode key: %s", pkalg); | ||
87 | goto done; | ||
88 | } | ||
89 | if (key->type != pktype) { | ||
90 | error("userauth_hostbased: type mismatch for decoded key " | ||
91 | "(received %d, expected %d)", key->type, pktype); | ||
92 | goto done; | ||
93 | } | ||
94 | service = datafellows & SSH_BUG_HBSERVICE ? "ssh-userauth" : | ||
95 | authctxt->service; | ||
96 | buffer_init(&b); | ||
97 | buffer_put_string(&b, session_id2, session_id2_len); | ||
98 | /* reconstruct packet */ | ||
99 | buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST); | ||
100 | buffer_put_cstring(&b, authctxt->user); | ||
101 | buffer_put_cstring(&b, service); | ||
102 | buffer_put_cstring(&b, "hostbased"); | ||
103 | buffer_put_string(&b, pkalg, alen); | ||
104 | buffer_put_string(&b, pkblob, blen); | ||
105 | buffer_put_cstring(&b, chost); | ||
106 | buffer_put_cstring(&b, cuser); | ||
107 | #ifdef DEBUG_PK | ||
108 | buffer_dump(&b); | ||
109 | #endif | ||
110 | /* test for allowed key and correct signature */ | ||
111 | authenticated = 0; | ||
112 | if (PRIVSEP(hostbased_key_allowed(authctxt->pw, cuser, chost, key)) && | ||
113 | PRIVSEP(key_verify(key, sig, slen, buffer_ptr(&b), | ||
114 | buffer_len(&b))) == 1) | ||
115 | authenticated = 1; | ||
116 | |||
117 | buffer_clear(&b); | ||
118 | done: | ||
119 | debug2("userauth_hostbased: authenticated %d", authenticated); | ||
120 | if (key != NULL) | ||
121 | key_free(key); | ||
122 | xfree(pkalg); | ||
123 | xfree(pkblob); | ||
124 | xfree(cuser); | ||
125 | xfree(chost); | ||
126 | xfree(sig); | ||
127 | return authenticated; | ||
128 | } | ||
129 | |||
130 | /* return 1 if given hostkey is allowed */ | ||
131 | int | ||
132 | hostbased_key_allowed(struct passwd *pw, const char *cuser, char *chost, | ||
133 | Key *key) | ||
134 | { | ||
135 | const char *resolvedname, *ipaddr, *lookup; | ||
136 | HostStatus host_status; | ||
137 | int len; | ||
138 | |||
139 | resolvedname = get_canonical_hostname(options.verify_reverse_mapping); | ||
140 | ipaddr = get_remote_ipaddr(); | ||
141 | |||
142 | debug2("userauth_hostbased: chost %s resolvedname %s ipaddr %s", | ||
143 | chost, resolvedname, ipaddr); | ||
144 | |||
145 | if (options.hostbased_uses_name_from_packet_only) { | ||
146 | if (auth_rhosts2(pw, cuser, chost, chost) == 0) | ||
147 | return 0; | ||
148 | lookup = chost; | ||
149 | } else { | ||
150 | if (((len = strlen(chost)) > 0) && chost[len - 1] == '.') { | ||
151 | debug2("stripping trailing dot from chost %s", chost); | ||
152 | chost[len - 1] = '\0'; | ||
153 | } | ||
154 | if (strcasecmp(resolvedname, chost) != 0) | ||
155 | log("userauth_hostbased mismatch: " | ||
156 | "client sends %s, but we resolve %s to %s", | ||
157 | chost, ipaddr, resolvedname); | ||
158 | if (auth_rhosts2(pw, cuser, resolvedname, ipaddr) == 0) | ||
159 | return 0; | ||
160 | lookup = resolvedname; | ||
161 | } | ||
162 | debug2("userauth_hostbased: access allowed by auth_rhosts2"); | ||
163 | |||
164 | host_status = check_key_in_hostfiles(pw, key, lookup, | ||
165 | _PATH_SSH_SYSTEM_HOSTFILE, | ||
166 | options.ignore_user_known_hosts ? NULL : _PATH_SSH_USER_HOSTFILE); | ||
167 | |||
168 | /* backward compat if no key has been found. */ | ||
169 | if (host_status == HOST_NEW) | ||
170 | host_status = check_key_in_hostfiles(pw, key, lookup, | ||
171 | _PATH_SSH_SYSTEM_HOSTFILE2, | ||
172 | options.ignore_user_known_hosts ? NULL : | ||
173 | _PATH_SSH_USER_HOSTFILE2); | ||
174 | |||
175 | return (host_status == HOST_OK); | ||
176 | } | ||
177 | |||
178 | Authmethod method_hostbased = { | ||
179 | "hostbased", | ||
180 | userauth_hostbased, | ||
181 | &options.hostbased_authentication | ||
182 | }; | ||