1/* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements.  See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License.  You may obtain a copy of the License at
7 *
8 *     http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#define APR_WANT_STRFUNC
18#include "apr_want.h"
19#include "apr_strings.h"
20#include "apr_dbm.h"
21#include "apr_md5.h"
22
23#include "httpd.h"
24#include "http_config.h"
25#include "ap_provider.h"
26#include "http_core.h"
27#include "http_log.h"
28#include "http_protocol.h"
29#include "http_request.h"   /* for ap_hook_(check_user_id | auth_checker)*/
30
31#include "mod_auth.h"
32
33typedef struct {
34    const char *grpfile;
35    const char *dbmtype;
36} authz_dbm_config_rec;
37
38APR_DECLARE_OPTIONAL_FN(char*, authz_owner_get_file_group, (request_rec *r));
39
40
41/* This should go into APR; perhaps with some nice
42 * caching/locking/flocking of the open dbm file.
43 */
44static char *get_dbm_entry_as_str(apr_pool_t *pool, apr_dbm_t *f, char *key)
45{
46    apr_datum_t d, q;
47    q.dptr = key;
48
49#ifndef NETSCAPE_DBM_COMPAT
50    q.dsize = strlen(q.dptr);
51#else
52    q.dsize = strlen(q.dptr) + 1;
53#endif
54
55    if (apr_dbm_fetch(f, q, &d) == APR_SUCCESS && d.dptr) {
56        return apr_pstrmemdup(pool, d.dptr, d.dsize);
57    }
58
59    return NULL;
60}
61
62static void *create_authz_dbm_dir_config(apr_pool_t *p, char *d)
63{
64    authz_dbm_config_rec *conf = apr_palloc(p, sizeof(*conf));
65
66    conf->grpfile = NULL;
67    conf->dbmtype = "default";
68
69    return conf;
70}
71
72static const command_rec authz_dbm_cmds[] =
73{
74    AP_INIT_TAKE1("AuthDBMGroupFile", ap_set_file_slot,
75     (void *)APR_OFFSETOF(authz_dbm_config_rec, grpfile),
76     OR_AUTHCFG, "database file containing group names and member user IDs"),
77    AP_INIT_TAKE1("AuthzDBMType", ap_set_string_slot,
78     (void *)APR_OFFSETOF(authz_dbm_config_rec, dbmtype),
79     OR_AUTHCFG, "what type of DBM file the group file is"),
80    {NULL}
81};
82
83module AP_MODULE_DECLARE_DATA authz_dbm_module;
84
85/* We do something strange with the group file.  If the group file
86 * contains any : we assume the format is
87 *      key=username value=":"groupname [":"anything here is ignored]
88 * otherwise we now (0.8.14+) assume that the format is
89 *      key=username value=groupname
90 * The first allows the password and group files to be the same
91 * physical DBM file;   key=username value=password":"groupname[":"anything]
92 *
93 * mark@telescope.org, 22Sep95
94 */
95
96static apr_status_t get_dbm_grp(request_rec *r, char *key1, char *key2,
97                                const char *dbmgrpfile, const char *dbtype,
98                                const char ** out)
99{
100    char *grp_colon, *val;
101    apr_status_t retval;
102    apr_dbm_t *f;
103
104    retval = apr_dbm_open_ex(&f, dbtype, dbmgrpfile, APR_DBM_READONLY,
105                             APR_OS_DEFAULT, r->pool);
106
107    if (retval != APR_SUCCESS) {
108        return retval;
109    }
110
111    /* Try key2 only if key1 failed */
112    if (!(val = get_dbm_entry_as_str(r->pool, f, key1))) {
113        val = get_dbm_entry_as_str(r->pool, f, key2);
114    }
115
116    apr_dbm_close(f);
117
118    if (val && (grp_colon = ap_strchr(val, ':')) != NULL) {
119        char *grp_colon2 = ap_strchr(++grp_colon, ':');
120
121        if (grp_colon2) {
122            *grp_colon2 = '\0';
123        }
124        *out = grp_colon;
125    }
126    else {
127        *out = val;
128    }
129
130    return retval;
131}
132
133static authz_status dbmgroup_check_authorization(request_rec *r,
134                                                 const char *require_args,
135                                                 const void *parsed_require_args)
136{
137    authz_dbm_config_rec *conf = ap_get_module_config(r->per_dir_config,
138                                                      &authz_dbm_module);
139    char *user = r->user;
140
141    const char *err = NULL;
142    const ap_expr_info_t *expr = parsed_require_args;
143    const char *require;
144
145    const char *t;
146    char *w;
147    const char *orig_groups = NULL;
148    const char *realm = ap_auth_name(r);
149    const char *groups;
150    char *v;
151
152    if (!user) {
153        return AUTHZ_DENIED_NO_USER;
154    }
155
156    if (!conf->grpfile) {
157        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01798)
158                        "No group file was specified in the configuration");
159        return AUTHZ_DENIED;
160    }
161
162    /* fetch group data from dbm file only once. */
163    if (!orig_groups) {
164        apr_status_t status;
165
166        status = get_dbm_grp(r, apr_pstrcat(r->pool, user, ":", realm, NULL),
167                             user, conf->grpfile, conf->dbmtype, &groups);
168
169        if (status != APR_SUCCESS) {
170            ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(01799)
171                          "could not open dbm (type %s) group access "
172                          "file: %s", conf->dbmtype, conf->grpfile);
173            return AUTHZ_GENERAL_ERROR;
174        }
175
176        if (groups == NULL) {
177            /* no groups available, so exit immediately */
178            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01800)
179                          "Authorization of user %s to access %s failed, reason: "
180                          "user doesn't appear in DBM group file (%s).",
181                          r->user, r->uri, conf->grpfile);
182            return AUTHZ_DENIED;
183        }
184
185        orig_groups = groups;
186    }
187
188    require = ap_expr_str_exec(r, expr, &err);
189    if (err) {
190        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02591)
191                      "authz_dbm authorize: require dbm-group: Can't "
192                      "evaluate require expression: %s", err);
193        return AUTHZ_DENIED;
194    }
195
196    t = require;
197    while ((w = ap_getword_white(r->pool, &t)) && w[0]) {
198        groups = orig_groups;
199        while (groups[0]) {
200            v = ap_getword(r->pool, &groups, ',');
201            if (!strcmp(v, w)) {
202                return AUTHZ_GRANTED;
203            }
204        }
205    }
206
207    ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01801)
208                  "Authorization of user %s to access %s failed, reason: "
209                  "user is not part of the 'require'ed group(s).",
210                  r->user, r->uri);
211
212    return AUTHZ_DENIED;
213}
214
215APR_OPTIONAL_FN_TYPE(authz_owner_get_file_group) *authz_owner_get_file_group;
216
217static authz_status dbmfilegroup_check_authorization(request_rec *r,
218                                                     const char *require_args,
219                                                     const void *parsed_require_args)
220{
221    authz_dbm_config_rec *conf = ap_get_module_config(r->per_dir_config,
222                                                      &authz_dbm_module);
223    char *user = r->user;
224    const char *realm = ap_auth_name(r);
225    const char *filegroup = NULL;
226    apr_status_t status;
227    const char *groups;
228    char *v;
229
230    if (!user) {
231        return AUTHZ_DENIED_NO_USER;
232    }
233
234    if (!conf->grpfile) {
235        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01802)
236                        "No group file was specified in the configuration");
237        return AUTHZ_DENIED;
238    }
239
240    /* fetch group data from dbm file. */
241    status = get_dbm_grp(r, apr_pstrcat(r->pool, user, ":", realm, NULL),
242                         user, conf->grpfile, conf->dbmtype, &groups);
243
244    if (status != APR_SUCCESS) {
245        ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(01803)
246                      "could not open dbm (type %s) group access "
247                      "file: %s", conf->dbmtype, conf->grpfile);
248        return AUTHZ_DENIED;
249    }
250
251    if (groups == NULL) {
252        /* no groups available, so exit immediately */
253        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01804)
254                      "Authorization of user %s to access %s failed, reason: "
255                      "user doesn't appear in DBM group file (%s).",
256                      r->user, r->uri, conf->grpfile);
257        return AUTHZ_DENIED;
258    }
259
260    filegroup = authz_owner_get_file_group(r);
261
262    if (filegroup) {
263        while (groups[0]) {
264            v = ap_getword(r->pool, &groups, ',');
265            if (!strcmp(v, filegroup)) {
266                return AUTHZ_GRANTED;
267            }
268        }
269    }
270
271    ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01805)
272                  "Authorization of user %s to access %s failed, reason: "
273                  "user is not part of the 'require'ed group(s).",
274                  r->user, r->uri);
275
276    return AUTHZ_DENIED;
277}
278
279static const char *dbm_parse_config(cmd_parms *cmd, const char *require_line,
280                                     const void **parsed_require_line)
281{
282    const char *expr_err = NULL;
283    ap_expr_info_t *expr;
284
285    expr = ap_expr_parse_cmd(cmd, require_line, AP_EXPR_FLAG_STRING_RESULT,
286            &expr_err, NULL);
287
288    if (expr_err)
289        return apr_pstrcat(cmd->temp_pool,
290                           "Cannot parse expression in require line: ",
291                           expr_err, NULL);
292
293    *parsed_require_line = expr;
294
295    return NULL;
296}
297
298static const authz_provider authz_dbmgroup_provider =
299{
300    &dbmgroup_check_authorization,
301    &dbm_parse_config,
302};
303
304static const authz_provider authz_dbmfilegroup_provider =
305{
306    &dbmfilegroup_check_authorization,
307    NULL,
308};
309
310
311static void register_hooks(apr_pool_t *p)
312{
313    authz_owner_get_file_group = APR_RETRIEVE_OPTIONAL_FN(authz_owner_get_file_group);
314
315    ap_register_auth_provider(p, AUTHZ_PROVIDER_GROUP, "dbm-group",
316                              AUTHZ_PROVIDER_VERSION,
317                              &authz_dbmgroup_provider,
318                              AP_AUTH_INTERNAL_PER_CONF);
319    ap_register_auth_provider(p, AUTHZ_PROVIDER_GROUP, "dbm-file-group",
320                              AUTHZ_PROVIDER_VERSION,
321                              &authz_dbmfilegroup_provider,
322                              AP_AUTH_INTERNAL_PER_CONF);
323}
324
325AP_DECLARE_MODULE(authz_dbm) =
326{
327    STANDARD20_MODULE_STUFF,
328    create_authz_dbm_dir_config, /* dir config creater */
329    NULL,                        /* dir merger --- default is to override */
330    NULL,                        /* server config */
331    NULL,                        /* merge server config */
332    authz_dbm_cmds,              /* command apr_table_t */
333    register_hooks               /* register hooks */
334};
335