Line data Source code
1 : /*
2 : * Copyright (c) 1997 - 1999, 2002 - 2003 Kungliga Tekniska Högskolan
3 : * (Royal Institute of Technology, Stockholm, Sweden).
4 : * 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 : *
10 : * 1. Redistributions of source code must retain the above copyright
11 : * notice, this list of conditions and the following disclaimer.
12 : *
13 : * 2. Redistributions in binary form must reproduce the above copyright
14 : * notice, this list of conditions and the following disclaimer in the
15 : * documentation and/or other materials provided with the distribution.
16 : *
17 : * 3. Neither the name of the Institute nor the names of its contributors
18 : * may be used to endorse or promote products derived from this software
19 : * without specific prior written permission.
20 : *
21 : * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 : * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 : * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 : * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 : * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 : * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 : * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 : * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 : * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 : * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 : * SUCH DAMAGE.
32 : */
33 :
34 : #include <string.h>
35 : #include "krb5_locl.h"
36 : #include "an2ln_plugin.h"
37 : #include "db_plugin.h"
38 :
39 : /* Default plugin (DB using binary search of sorted text file) follows */
40 : static krb5_error_code KRB5_LIB_CALL an2ln_def_plug_init(krb5_context, void **);
41 : static void KRB5_LIB_CALL an2ln_def_plug_fini(void *);
42 : static krb5_error_code KRB5_LIB_CALL an2ln_def_plug_an2ln(void *, krb5_context, const char *,
43 : krb5_const_principal, set_result_f,
44 : void *);
45 :
46 : static krb5plugin_an2ln_ftable an2ln_def_plug = {
47 : 0,
48 : an2ln_def_plug_init,
49 : an2ln_def_plug_fini,
50 : an2ln_def_plug_an2ln,
51 : };
52 :
53 : /* Plugin engine code follows */
54 : struct plctx {
55 : krb5_const_principal aname;
56 : heim_string_t luser;
57 : const char *rule;
58 : };
59 :
60 : static krb5_error_code KRB5_LIB_CALL
61 0 : set_res(void *userctx, const char *res)
62 : {
63 0 : struct plctx *plctx = userctx;
64 0 : plctx->luser = heim_string_create(res);
65 0 : if (plctx->luser == NULL)
66 0 : return ENOMEM;
67 0 : return 0;
68 : }
69 :
70 : static krb5_error_code KRB5_LIB_CALL
71 0 : plcallback(krb5_context context,
72 : const void *plug, void *plugctx, void *userctx)
73 : {
74 0 : const krb5plugin_an2ln_ftable *locate = plug;
75 0 : struct plctx *plctx = userctx;
76 :
77 0 : if (plctx->luser)
78 0 : return 0;
79 :
80 0 : return locate->an2ln(plugctx, context, plctx->rule, plctx->aname, set_res, plctx);
81 : }
82 :
83 : static const char *an2ln_plugin_deps[] = { "krb5", NULL };
84 :
85 : static struct heim_plugin_data
86 : an2ln_plugin_data = {
87 : "krb5",
88 : KRB5_PLUGIN_AN2LN,
89 : KRB5_PLUGIN_AN2LN_VERSION_0,
90 : an2ln_plugin_deps,
91 : krb5_get_instance
92 : };
93 :
94 : static krb5_error_code
95 0 : an2ln_plugin(krb5_context context, const char *rule, krb5_const_principal aname,
96 : size_t lnsize, char *lname)
97 : {
98 : krb5_error_code ret;
99 : struct plctx ctx;
100 :
101 0 : ctx.rule = rule;
102 0 : ctx.aname = aname;
103 0 : ctx.luser = NULL;
104 :
105 : /*
106 : * Order of plugin invocation is non-deterministic, but there should
107 : * really be no more than one plugin that can handle any given kind
108 : * rule, so the effect should be deterministic anyways.
109 : */
110 0 : ret = _krb5_plugin_run_f(context, &an2ln_plugin_data,
111 : 0, &ctx, plcallback);
112 0 : if (ret != 0) {
113 0 : heim_release(ctx.luser);
114 0 : return ret;
115 : }
116 :
117 0 : if (ctx.luser == NULL)
118 0 : return KRB5_PLUGIN_NO_HANDLE;
119 :
120 0 : if (strlcpy(lname, heim_string_get_utf8(ctx.luser), lnsize) >= lnsize)
121 0 : ret = KRB5_CONFIG_NOTENUFSPACE;
122 :
123 0 : heim_release(ctx.luser);
124 0 : return ret;
125 : }
126 :
127 : static void
128 0 : reg_def_plugins_once(void *ctx)
129 : {
130 0 : krb5_context context = ctx;
131 :
132 0 : krb5_plugin_register(context, PLUGIN_TYPE_DATA, KRB5_PLUGIN_AN2LN,
133 : &an2ln_def_plug);
134 0 : }
135 :
136 : static int
137 0 : princ_realm_is_default(krb5_context context,
138 : krb5_const_principal aname)
139 : {
140 : krb5_error_code ret;
141 0 : krb5_realm *lrealms = NULL;
142 : krb5_realm *r;
143 : int valid;
144 :
145 0 : ret = krb5_get_default_realms(context, &lrealms);
146 0 : if (ret)
147 0 : return 0;
148 :
149 0 : valid = 0;
150 0 : for (r = lrealms; *r != NULL; ++r) {
151 0 : if (strcmp (*r, aname->realm) == 0) {
152 0 : valid = 1;
153 0 : break;
154 : }
155 : }
156 0 : krb5_free_host_realm (context, lrealms);
157 0 : return valid;
158 : }
159 :
160 : /*
161 : * This function implements MIT's auth_to_local_names configuration for
162 : * configuration compatibility. Specifically:
163 : *
164 : * [realms]
165 : * <realm-name> = {
166 : * auth_to_local_names = {
167 : * <unparsed-principal-name> = <username>
168 : * }
169 : * }
170 : *
171 : * If multiple usernames are configured then the last one is taken.
172 : *
173 : * The configuration can only be expected to hold a relatively small
174 : * number of mappings. For lots of mappings use a DB.
175 : */
176 : static krb5_error_code
177 0 : an2ln_local_names(krb5_context context,
178 : krb5_const_principal aname,
179 : size_t lnsize,
180 : char *lname)
181 : {
182 : krb5_error_code ret;
183 : char *unparsed;
184 : char **values;
185 : char *res;
186 : size_t i;
187 :
188 0 : if (!princ_realm_is_default(context, aname))
189 0 : return KRB5_PLUGIN_NO_HANDLE;
190 :
191 0 : ret = krb5_unparse_name_flags(context, aname,
192 : KRB5_PRINCIPAL_UNPARSE_NO_REALM,
193 : &unparsed);
194 0 : if (ret)
195 0 : return ret;
196 :
197 0 : ret = KRB5_PLUGIN_NO_HANDLE;
198 0 : values = krb5_config_get_strings(context, NULL, "realms", aname->realm,
199 : "auth_to_local_names", unparsed, NULL);
200 0 : free(unparsed);
201 0 : if (!values)
202 0 : return ret;
203 : /* Take the last value, just like MIT */
204 0 : for (res = NULL, i = 0; values[i]; i++)
205 0 : res = values[i];
206 0 : if (res) {
207 0 : ret = 0;
208 0 : if (strlcpy(lname, res, lnsize) >= lnsize)
209 0 : ret = KRB5_CONFIG_NOTENUFSPACE;
210 :
211 0 : if (!*res || strcmp(res, ":") == 0)
212 0 : ret = KRB5_NO_LOCALNAME;
213 : }
214 :
215 0 : krb5_config_free_strings(values);
216 0 : return ret;
217 : }
218 :
219 : /*
220 : * Heimdal's default aname2lname mapping.
221 : */
222 : static krb5_error_code
223 0 : an2ln_default(krb5_context context,
224 : char *rule,
225 : krb5_const_principal aname,
226 : size_t lnsize, char *lname)
227 : {
228 : krb5_error_code ret;
229 : const char *res;
230 : int root_princs_ok;
231 :
232 0 : if (strcmp(rule, "NONE") == 0)
233 0 : return KRB5_NO_LOCALNAME;
234 :
235 0 : if (strcmp(rule, "DEFAULT") == 0)
236 0 : root_princs_ok = 0;
237 0 : else if (strcmp(rule, "HEIMDAL_DEFAULT") == 0)
238 0 : root_princs_ok = 1;
239 : else
240 0 : return KRB5_PLUGIN_NO_HANDLE;
241 :
242 0 : if (!princ_realm_is_default(context, aname))
243 0 : return KRB5_PLUGIN_NO_HANDLE;
244 :
245 0 : if (aname->name.name_string.len == 1) {
246 : /*
247 : * One component principal names in default realm -> the one
248 : * component is the username.
249 : */
250 0 : res = aname->name.name_string.val[0];
251 0 : } else if (root_princs_ok && aname->name.name_string.len == 2 &&
252 0 : strcmp (aname->name.name_string.val[1], "root") == 0) {
253 : /*
254 : * Two-component principal names in default realm where the
255 : * first component is "root" -> root IFF the principal is in
256 : * root's .k5login (or whatever krb5_kuserok() does).
257 : */
258 : krb5_principal rootprinc;
259 : krb5_boolean userok;
260 :
261 0 : res = "root";
262 :
263 0 : ret = krb5_copy_principal(context, aname, &rootprinc);
264 0 : if (ret)
265 0 : return ret;
266 :
267 0 : userok = _krb5_kuserok(context, rootprinc, res, FALSE);
268 0 : krb5_free_principal(context, rootprinc);
269 0 : if (!userok)
270 0 : return KRB5_NO_LOCALNAME;
271 : } else {
272 0 : return KRB5_PLUGIN_NO_HANDLE;
273 : }
274 :
275 0 : if (strlcpy(lname, res, lnsize) >= lnsize)
276 0 : return KRB5_CONFIG_NOTENUFSPACE;
277 :
278 0 : return 0;
279 : }
280 :
281 : /**
282 : * Map a principal name to a local username.
283 : *
284 : * Returns 0 on success, KRB5_NO_LOCALNAME if no mapping was found, or
285 : * some Kerberos or system error.
286 : *
287 : * Inputs:
288 : *
289 : * @param context A krb5_context
290 : * @param aname A principal name
291 : * @param lnsize The size of the buffer into which the username will be written
292 : * @param lname The buffer into which the username will be written
293 : *
294 : * @ingroup krb5_support
295 : */
296 : KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
297 0 : krb5_aname_to_localname(krb5_context context,
298 : krb5_const_principal aname,
299 : size_t lnsize,
300 : char *lname)
301 : {
302 : static heim_base_once_t reg_def_plugins = HEIM_BASE_ONCE_INIT;
303 : krb5_error_code ret;
304 : krb5_realm realm;
305 : size_t i;
306 0 : char **rules = NULL;
307 : char *rule;
308 :
309 0 : if (lnsize)
310 0 : lname[0] = '\0';
311 :
312 0 : heim_base_once_f(®_def_plugins, context, reg_def_plugins_once);
313 :
314 : /* Try MIT's auth_to_local_names config first */
315 0 : ret = an2ln_local_names(context, aname, lnsize, lname);
316 0 : if (ret != KRB5_PLUGIN_NO_HANDLE)
317 0 : return ret;
318 :
319 0 : ret = krb5_get_default_realm(context, &realm);
320 0 : if (ret)
321 0 : return ret;
322 :
323 0 : rules = krb5_config_get_strings(context, NULL, "realms", realm,
324 : "auth_to_local", NULL);
325 0 : krb5_xfree(realm);
326 0 : if (!rules) {
327 : /* Heimdal's default rule */
328 0 : ret = an2ln_default(context, "HEIMDAL_DEFAULT", aname, lnsize, lname);
329 0 : if (ret == KRB5_PLUGIN_NO_HANDLE)
330 0 : return KRB5_NO_LOCALNAME;
331 0 : return ret;
332 : }
333 :
334 : /*
335 : * MIT rules.
336 : *
337 : * Note that RULEs and DBs only have white-list functionality,
338 : * thus RULEs and DBs that we don't understand we simply ignore.
339 : *
340 : * This means that plugins that implement black-lists are
341 : * dangerous: if a black-list plugin isn't found, the black-list
342 : * won't be enforced. But black-lists are dangerous anyways.
343 : */
344 0 : for (ret = KRB5_PLUGIN_NO_HANDLE, i = 0; rules[i]; i++) {
345 0 : rule = rules[i];
346 :
347 : /* Try NONE, DEFAULT, and HEIMDAL_DEFAULT rules */
348 0 : ret = an2ln_default(context, rule, aname, lnsize, lname);
349 0 : if (ret == KRB5_PLUGIN_NO_HANDLE)
350 : /* Try DB, RULE, ... plugins */
351 0 : ret = an2ln_plugin(context, rule, aname, lnsize, lname);
352 :
353 0 : if (ret == 0 && lnsize && !lname[0])
354 0 : continue; /* Success but no lname?! lies! */
355 0 : else if (ret != KRB5_PLUGIN_NO_HANDLE)
356 0 : break;
357 : }
358 :
359 0 : if (ret == KRB5_PLUGIN_NO_HANDLE) {
360 0 : if (lnsize)
361 0 : lname[0] = '\0';
362 0 : ret = KRB5_NO_LOCALNAME;
363 : }
364 :
365 0 : krb5_config_free_strings(rules);
366 0 : return ret;
367 : }
368 :
369 : static krb5_error_code KRB5_LIB_CALL
370 0 : an2ln_def_plug_init(krb5_context context, void **ctx)
371 : {
372 0 : *ctx = NULL;
373 0 : return 0;
374 : }
375 :
376 : static void KRB5_LIB_CALL
377 0 : an2ln_def_plug_fini(void *ctx)
378 : {
379 0 : }
380 :
381 : static heim_base_once_t sorted_text_db_init_once = HEIM_BASE_ONCE_INIT;
382 :
383 : static void
384 0 : sorted_text_db_init_f(void *arg)
385 : {
386 0 : (void) heim_db_register("sorted-text", NULL, &heim_sorted_text_file_dbtype);
387 0 : }
388 :
389 : static krb5_error_code KRB5_LIB_CALL
390 0 : an2ln_def_plug_an2ln(void *plug_ctx, krb5_context context,
391 : const char *rule,
392 : krb5_const_principal aname,
393 : set_result_f set_res_f, void *set_res_ctx)
394 : {
395 : krb5_error_code ret;
396 : const char *an2ln_db_fname;
397 0 : heim_db_t dbh = NULL;
398 : heim_dict_t db_options;
399 : heim_data_t k, v;
400 : heim_error_t error;
401 0 : char *unparsed = NULL;
402 0 : char *value = NULL;
403 :
404 0 : _krb5_load_db_plugins(context);
405 0 : heim_base_once_f(&sorted_text_db_init_once, NULL, sorted_text_db_init_f);
406 :
407 0 : if (strncmp(rule, "DB:", strlen("DB:")) != 0)
408 0 : return KRB5_PLUGIN_NO_HANDLE;
409 :
410 0 : an2ln_db_fname = &rule[strlen("DB:")];
411 0 : if (!*an2ln_db_fname)
412 0 : return KRB5_PLUGIN_NO_HANDLE;
413 :
414 0 : ret = krb5_unparse_name(context, aname, &unparsed);
415 0 : if (ret)
416 0 : return ret;
417 :
418 0 : db_options = heim_dict_create(11);
419 0 : if (db_options != NULL)
420 0 : heim_dict_set_value(db_options, HSTR("read-only"),
421 0 : heim_number_create(1));
422 0 : dbh = heim_db_create(NULL, an2ln_db_fname, db_options, &error);
423 0 : if (dbh == NULL) {
424 0 : krb5_set_error_message(context, heim_error_get_code(error),
425 0 : N_("Couldn't open aname2lname-text-db", ""));
426 0 : ret = KRB5_PLUGIN_NO_HANDLE;
427 0 : goto cleanup;
428 : }
429 :
430 : /* Binary search; file should be sorted (in C locale) */
431 0 : k = heim_data_ref_create(unparsed, strlen(unparsed), NULL);
432 0 : if (k == NULL) {
433 0 : ret = krb5_enomem(context);
434 0 : goto cleanup;
435 : }
436 0 : v = heim_db_copy_value(dbh, NULL, k, &error);
437 0 : heim_release(k);
438 0 : if (v == NULL && error != NULL) {
439 0 : krb5_set_error_message(context, heim_error_get_code(error),
440 0 : N_("Lookup in aname2lname-text-db failed", ""));
441 0 : ret = heim_error_get_code(error);
442 0 : goto cleanup;
443 0 : } else if (v == NULL) {
444 0 : ret = KRB5_PLUGIN_NO_HANDLE;
445 0 : goto cleanup;
446 : } else {
447 : /* found */
448 0 : if (heim_data_get_length(v) == 0) {
449 0 : krb5_set_error_message(context, ret,
450 0 : N_("Principal mapped to empty username", ""));
451 0 : ret = KRB5_NO_LOCALNAME;
452 0 : goto cleanup;
453 : }
454 0 : value = strndup(heim_data_get_ptr(v), heim_data_get_length(v));
455 0 : heim_release(v);
456 0 : if (value == NULL) {
457 0 : ret = krb5_enomem(context);
458 0 : goto cleanup;
459 : }
460 0 : ret = set_res_f(set_res_ctx, value);
461 : }
462 :
463 0 : cleanup:
464 0 : heim_release(dbh);
465 0 : free(unparsed);
466 0 : free(value);
467 0 : return ret;
468 : }
469 :
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