diff options
author | Colin Watson <cjwatson@debian.org> | 2003-09-23 18:08:35 +0000 |
---|---|---|
committer | Colin Watson <cjwatson@debian.org> | 2003-09-23 18:08:35 +0000 |
commit | d59fd3e421aa81b8e5e118f3f806081df2aca879 (patch) | |
tree | 356a4e607edc979c625bb33db63c656d771478bd /gss-serv.c | |
parent | 7505658c58e96b8d270f1928a0e1fa7f3e0c266b (diff) | |
parent | 45431c9b4677608680cd071768cbf156b316a7e8 (diff) |
Merge 3.7.1p2 to the trunk. I have absolutely no idea yet whether this will
work.
Diffstat (limited to 'gss-serv.c')
-rw-r--r-- | gss-serv.c | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/gss-serv.c b/gss-serv.c new file mode 100644 index 000000000..8fd1d63f0 --- /dev/null +++ b/gss-serv.c | |||
@@ -0,0 +1,292 @@ | |||
1 | /* $OpenBSD: gss-serv.c,v 1.3 2003/08/31 13:31:57 markus Exp $ */ | ||
2 | |||
3 | /* | ||
4 | * Copyright (c) 2001-2003 Simon Wilkinson. All rights reserved. | ||
5 | * | ||
6 | * Redistribution and use in source and binary forms, with or without | ||
7 | * modification, are permitted provided that the following conditions | ||
8 | * are met: | ||
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. | ||
14 | * | ||
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. | ||
25 | */ | ||
26 | |||
27 | #include "includes.h" | ||
28 | |||
29 | #ifdef GSSAPI | ||
30 | |||
31 | #include "bufaux.h" | ||
32 | #include "compat.h" | ||
33 | #include "auth.h" | ||
34 | #include "log.h" | ||
35 | #include "channels.h" | ||
36 | #include "session.h" | ||
37 | #include "servconf.h" | ||
38 | #include "monitor_wrap.h" | ||
39 | #include "xmalloc.h" | ||
40 | #include "getput.h" | ||
41 | |||
42 | #include "ssh-gss.h" | ||
43 | |||
44 | extern ServerOptions options; | ||
45 | |||
46 | static ssh_gssapi_client gssapi_client = | ||
47 | { GSS_C_EMPTY_BUFFER, GSS_C_EMPTY_BUFFER, | ||
48 | GSS_C_NO_CREDENTIAL, NULL, {NULL, NULL, NULL}}; | ||
49 | |||
50 | ssh_gssapi_mech gssapi_null_mech = | ||
51 | { NULL, NULL, {0, NULL}, NULL, NULL, NULL, NULL}; | ||
52 | |||
53 | #ifdef KRB5 | ||
54 | extern ssh_gssapi_mech gssapi_kerberos_mech; | ||
55 | #endif | ||
56 | |||
57 | ssh_gssapi_mech* supported_mechs[]= { | ||
58 | #ifdef KRB5 | ||
59 | &gssapi_kerberos_mech, | ||
60 | #endif | ||
61 | &gssapi_null_mech, | ||
62 | }; | ||
63 | |||
64 | /* Unpriviledged */ | ||
65 | void | ||
66 | ssh_gssapi_supported_oids(gss_OID_set *oidset) | ||
67 | { | ||
68 | int i = 0; | ||
69 | OM_uint32 min_status; | ||
70 | int present; | ||
71 | gss_OID_set supported; | ||
72 | |||
73 | gss_create_empty_oid_set(&min_status, oidset); | ||
74 | gss_indicate_mechs(&min_status, &supported); | ||
75 | |||
76 | while (supported_mechs[i]->name != NULL) { | ||
77 | if (GSS_ERROR(gss_test_oid_set_member(&min_status, | ||
78 | &supported_mechs[i]->oid, supported, &present))) | ||
79 | present = 0; | ||
80 | if (present) | ||
81 | gss_add_oid_set_member(&min_status, | ||
82 | &supported_mechs[i]->oid, oidset); | ||
83 | i++; | ||
84 | } | ||
85 | } | ||
86 | |||
87 | |||
88 | /* Wrapper around accept_sec_context | ||
89 | * Requires that the context contains: | ||
90 | * oid | ||
91 | * credentials (from ssh_gssapi_acquire_cred) | ||
92 | */ | ||
93 | /* Priviledged */ | ||
94 | OM_uint32 | ||
95 | ssh_gssapi_accept_ctx(Gssctxt *ctx, gss_buffer_desc *recv_tok, | ||
96 | gss_buffer_desc *send_tok, OM_uint32 *flags) | ||
97 | { | ||
98 | OM_uint32 status; | ||
99 | gss_OID mech; | ||
100 | |||
101 | ctx->major = gss_accept_sec_context(&ctx->minor, | ||
102 | &ctx->context, ctx->creds, recv_tok, | ||
103 | GSS_C_NO_CHANNEL_BINDINGS, &ctx->client, &mech, | ||
104 | send_tok, flags, NULL, &ctx->client_creds); | ||
105 | |||
106 | if (GSS_ERROR(ctx->major)) | ||
107 | ssh_gssapi_error(ctx); | ||
108 | |||
109 | if (ctx->client_creds) | ||
110 | debug("Received some client credentials"); | ||
111 | else | ||
112 | debug("Got no client credentials"); | ||
113 | |||
114 | status = ctx->major; | ||
115 | |||
116 | /* Now, if we're complete and we have the right flags, then | ||
117 | * we flag the user as also having been authenticated | ||
118 | */ | ||
119 | |||
120 | if (((flags == NULL) || ((*flags & GSS_C_MUTUAL_FLAG) && | ||
121 | (*flags & GSS_C_INTEG_FLAG))) && (ctx->major == GSS_S_COMPLETE)) { | ||
122 | if (ssh_gssapi_getclient(ctx, &gssapi_client)) | ||
123 | fatal("Couldn't convert client name"); | ||
124 | } | ||
125 | |||
126 | return (status); | ||
127 | } | ||
128 | |||
129 | /* | ||
130 | * This parses an exported name, extracting the mechanism specific portion | ||
131 | * to use for ACL checking. It verifies that the name belongs the mechanism | ||
132 | * originally selected. | ||
133 | */ | ||
134 | static OM_uint32 | ||
135 | ssh_gssapi_parse_ename(Gssctxt *ctx, gss_buffer_t ename, gss_buffer_t name) | ||
136 | { | ||
137 | char *tok; | ||
138 | OM_uint32 offset; | ||
139 | OM_uint32 oidl; | ||
140 | |||
141 | tok=ename->value; | ||
142 | |||
143 | /* | ||
144 | * Check that ename is long enough for all of the fixed length | ||
145 | * header, and that the initial ID bytes are correct | ||
146 | */ | ||
147 | |||
148 | if (ename->length<6 || memcmp(tok,"\x04\x01", 2)!=0) | ||
149 | return GSS_S_FAILURE; | ||
150 | |||
151 | /* | ||
152 | * Extract the OID, and check it. Here GSSAPI breaks with tradition | ||
153 | * and does use the OID type and length bytes. To confuse things | ||
154 | * there are two lengths - the first including these, and the | ||
155 | * second without. | ||
156 | */ | ||
157 | |||
158 | oidl = GET_16BIT(tok+2); /* length including next two bytes */ | ||
159 | oidl = oidl-2; /* turn it into the _real_ length of the variable OID */ | ||
160 | |||
161 | /* | ||
162 | * Check the BER encoding for correct type and length, that the | ||
163 | * string is long enough and that the OID matches that in our context | ||
164 | */ | ||
165 | if (tok[4] != 0x06 || tok[5] != oidl || | ||
166 | ename->length < oidl+6 || | ||
167 | !ssh_gssapi_check_oid(ctx,tok+6,oidl)) | ||
168 | return GSS_S_FAILURE; | ||
169 | |||
170 | offset = oidl+6; | ||
171 | |||
172 | if (ename->length < offset+4) | ||
173 | return GSS_S_FAILURE; | ||
174 | |||
175 | name->length = GET_32BIT(tok+offset); | ||
176 | offset += 4; | ||
177 | |||
178 | if (ename->length < offset+name->length) | ||
179 | return GSS_S_FAILURE; | ||
180 | |||
181 | name->value = xmalloc(name->length+1); | ||
182 | memcpy(name->value,tok+offset,name->length); | ||
183 | ((char *)name->value)[name->length] = 0; | ||
184 | |||
185 | return GSS_S_COMPLETE; | ||
186 | } | ||
187 | |||
188 | /* Extract the client details from a given context. This can only reliably | ||
189 | * be called once for a context */ | ||
190 | |||
191 | /* Priviledged (called from accept_secure_ctx) */ | ||
192 | OM_uint32 | ||
193 | ssh_gssapi_getclient(Gssctxt *ctx, ssh_gssapi_client *client) | ||
194 | { | ||
195 | int i = 0; | ||
196 | |||
197 | gss_buffer_desc ename; | ||
198 | |||
199 | client->mech = NULL; | ||
200 | |||
201 | while (supported_mechs[i]->name != NULL) { | ||
202 | if (supported_mechs[i]->oid.length == ctx->oid->length && | ||
203 | (memcmp(supported_mechs[i]->oid.elements, | ||
204 | ctx->oid->elements, ctx->oid->length) == 0)) | ||
205 | client->mech = supported_mechs[i]; | ||
206 | i++; | ||
207 | } | ||
208 | |||
209 | if (client->mech == NULL) | ||
210 | return GSS_S_FAILURE; | ||
211 | |||
212 | if ((ctx->major = gss_display_name(&ctx->minor, ctx->client, | ||
213 | &client->displayname, NULL))) { | ||
214 | ssh_gssapi_error(ctx); | ||
215 | return (ctx->major); | ||
216 | } | ||
217 | |||
218 | if ((ctx->major = gss_export_name(&ctx->minor, ctx->client, | ||
219 | &ename))) { | ||
220 | ssh_gssapi_error(ctx); | ||
221 | return (ctx->major); | ||
222 | } | ||
223 | |||
224 | if ((ctx->major = ssh_gssapi_parse_ename(ctx,&ename, | ||
225 | &client->exportedname))) { | ||
226 | return (ctx->major); | ||
227 | } | ||
228 | |||
229 | /* We can't copy this structure, so we just move the pointer to it */ | ||
230 | client->creds = ctx->client_creds; | ||
231 | ctx->client_creds = GSS_C_NO_CREDENTIAL; | ||
232 | return (ctx->major); | ||
233 | } | ||
234 | |||
235 | /* As user - called through fatal cleanup hook */ | ||
236 | void | ||
237 | ssh_gssapi_cleanup_creds(void *ignored) | ||
238 | { | ||
239 | if (gssapi_client.store.filename != NULL) { | ||
240 | /* Unlink probably isn't sufficient */ | ||
241 | debug("removing gssapi cred file\"%s\"", gssapi_client.store.filename); | ||
242 | unlink(gssapi_client.store.filename); | ||
243 | } | ||
244 | } | ||
245 | |||
246 | /* As user */ | ||
247 | void | ||
248 | ssh_gssapi_storecreds(void) | ||
249 | { | ||
250 | if (gssapi_client.mech && gssapi_client.mech->storecreds) { | ||
251 | (*gssapi_client.mech->storecreds)(&gssapi_client); | ||
252 | if (options.gss_cleanup_creds) | ||
253 | fatal_add_cleanup(ssh_gssapi_cleanup_creds, NULL); | ||
254 | } else | ||
255 | debug("ssh_gssapi_storecreds: Not a GSSAPI mechanism"); | ||
256 | } | ||
257 | |||
258 | /* This allows GSSAPI methods to do things to the childs environment based | ||
259 | * on the passed authentication process and credentials. | ||
260 | */ | ||
261 | /* As user */ | ||
262 | void | ||
263 | ssh_gssapi_do_child(char ***envp, u_int *envsizep) | ||
264 | { | ||
265 | |||
266 | if (gssapi_client.store.envvar != NULL && | ||
267 | gssapi_client.store.envval != NULL) { | ||
268 | |||
269 | debug("Setting %s to %s", gssapi_client.store.envvar, | ||
270 | gssapi_client.store.envval); | ||
271 | child_set_env(envp, envsizep, gssapi_client.store.envvar, | ||
272 | gssapi_client.store.envval); | ||
273 | } | ||
274 | } | ||
275 | |||
276 | /* Priviledged */ | ||
277 | int | ||
278 | ssh_gssapi_userok(char *user) | ||
279 | { | ||
280 | if (gssapi_client.exportedname.length == 0 || | ||
281 | gssapi_client.exportedname.value == NULL) { | ||
282 | debug("No suitable client data"); | ||
283 | return 0; | ||
284 | } | ||
285 | if (gssapi_client.mech && gssapi_client.mech->userok) | ||
286 | return ((*gssapi_client.mech->userok)(&gssapi_client, user)); | ||
287 | else | ||
288 | debug("ssh_gssapi_userok: Unknown GSSAPI mechanism"); | ||
289 | return (0); | ||
290 | } | ||
291 | |||
292 | #endif | ||