/* Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

#define APR_WANT_STRFUNC

#include "apr_want.h"

#include "apr_strings.h"

#include "apr_dbm.h"

#include "apr_md5.h"

#include "httpd.h"

#include "http_config.h"

#include "ap_provider.h"

#include "http_core.h"

#include "http_log.h"

#include "http_protocol.h"

#include "http_request.h"   /* for ap_hook_(check_user_id | auth_checker)*/

#include "mod_auth.h"

#include "mod_authz_owner.h"

typedef struct {

    const char *grpfile;

    const char *dbmtype;

} authz_dbm_config_rec;

/* This should go into APR; perhaps with some nice

 * caching/locking/flocking of the open dbm file.

 */

static char *get_dbm_entry_as_str(apr_pool_t *pool, apr_dbm_t *f, char *key)

{

    apr_datum_t d, q;

    q.dptr = key;

#ifndef NETSCAPE_DBM_COMPAT

    q.dsize = strlen(q.dptr);

#else

    q.dsize = strlen(q.dptr) + 1;

#endif

    if (apr_dbm_fetch(f, q, &d) == APR_SUCCESS && d.dptr) {

        return apr_pstrmemdup(pool, d.dptr, d.dsize);

    }

    return NULL;

}

static void *create_authz_dbm_dir_config(apr_pool_t *p, char *d)

{

    authz_dbm_config_rec *conf = apr_palloc(p, sizeof(*conf));

    conf->grpfile = NULL;

    conf->dbmtype = "default";

    return conf;

}

static const command_rec authz_dbm_cmds[] =

{

    AP_INIT_TAKE1("AuthDBMGroupFile", ap_set_file_slot,

     (void *)APR_OFFSETOF(authz_dbm_config_rec, grpfile),

     OR_AUTHCFG, "database file containing group names and member user IDs"),

    AP_INIT_TAKE1("AuthzDBMType", ap_set_string_slot,

     (void *)APR_OFFSETOF(authz_dbm_config_rec, dbmtype),

     OR_AUTHCFG, "what type of DBM file the group file is"),

    {NULL}

};

module AP_MODULE_DECLARE_DATA authz_dbm_module;

/* We do something strange with the group file.  If the group file

 * contains any : we assume the format is

 *      key=username value=":"groupname [":"anything here is ignored]

 * otherwise we now (0.8.14+) assume that the format is

 *      key=username value=groupname

 * The first allows the password and group files to be the same

 * physical DBM file;   key=username value=password":"groupname[":"anything]

 *

 * mark@telescope.org, 22Sep95

 */

static apr_status_t get_dbm_grp(request_rec *r, char *key1, char *key2,

                                const char *dbmgrpfile, const char *dbtype,

                                const char ** out)

{

    char *grp_colon, *val;

    apr_status_t retval;

    apr_dbm_t *f;

    retval = apr_dbm_open_ex(&f, dbtype, dbmgrpfile, APR_DBM_READONLY,

                             APR_OS_DEFAULT, r->pool);

    if (retval != APR_SUCCESS) {

        return retval;

    }

    /* Try key2 only if key1 failed */

    if (!(val = get_dbm_entry_as_str(r->pool, f, key1))) {

        val = get_dbm_entry_as_str(r->pool, f, key2);

    }

    apr_dbm_close(f);

    if (val && (grp_colon = ap_strchr(val, ':')) != NULL) {

        char *grp_colon2 = ap_strchr(++grp_colon, ':');

        if (grp_colon2) {

            *grp_colon2 = '\0';

        }

        *out = grp_colon;

    }

    else {

        *out = val;

    }

    return retval;

}

static authz_status dbmgroup_check_authorization(request_rec *r,

                                                 const char *require_args,

                                                 const void *parsed_require_args)

{

    authz_dbm_config_rec *conf = ap_get_module_config(r->per_dir_config,

                                                      &authz_dbm_module);

    char *user = r->user;

    const char *err = NULL;

    const ap_expr_info_t *expr = parsed_require_args;

    const char *require;

    const char *t;

    char *w;

    const char *orig_groups = NULL;

    const char *realm = ap_auth_name(r);

    const char *groups;

    char *v;

    if (!user) {

        return AUTHZ_DENIED_NO_USER;

    }

    if (!conf->grpfile) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01798)

                        "No group file was specified in the configuration");

        return AUTHZ_DENIED;

    }

    /* fetch group data from dbm file only once. */

    if (!orig_groups) {

        apr_status_t status;

        status = get_dbm_grp(r, apr_pstrcat(r->pool, user, ":", realm, NULL),

                             user, conf->grpfile, conf->dbmtype, &groups);

        if (status != APR_SUCCESS) {

            ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(01799)

                          "could not open dbm (type %s) group access "

                          "file: %s", conf->dbmtype, conf->grpfile);

            return AUTHZ_GENERAL_ERROR;

        }

        if (groups == NULL) {

            /* no groups available, so exit immediately */

            ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01800)

                          "Authorization of user %s to access %s failed, reason: "

                          "user doesn't appear in DBM group file (%s).",

                          r->user, r->uri, conf->grpfile);

            return AUTHZ_DENIED;

        }

        orig_groups = groups;

    }

    require = ap_expr_str_exec(r, expr, &err;;

    if (err) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(02591)

                      "authz_dbm authorize: require dbm-group: Can't "

                      "evaluate require expression: %s", err);

        return AUTHZ_DENIED;

    }

    t = require;

    while ((w = ap_getword_white(r->pool, &t)) && w[0]) {

        groups = orig_groups;

        while (groups[0]) {

            v = ap_getword(r->pool, &groups, ',');

            if (!strcmp(v, w)) {

                return AUTHZ_GRANTED;

            }

        }

    }

    ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01801)

                  "Authorization of user %s to access %s failed, reason: "

                  "user is not part of the 'require'ed group(s).",

                  r->user, r->uri);

    return AUTHZ_DENIED;

}

static APR_OPTIONAL_FN_TYPE(authz_owner_get_file_group) *authz_owner_get_file_group;

static authz_status dbmfilegroup_check_authorization(request_rec *r,

                                                     const char *require_args,

                                                     const void *parsed_require_args)

{

    authz_dbm_config_rec *conf = ap_get_module_config(r->per_dir_config,

                                                      &authz_dbm_module);

    char *user = r->user;

    const char *realm = ap_auth_name(r);

    const char *filegroup = NULL;

    apr_status_t status;

    const char *groups;

    char *v;

    if (!user) {

        return AUTHZ_DENIED_NO_USER;

    }

    if (!conf->grpfile) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01802)

                        "No group file was specified in the configuration");

        return AUTHZ_DENIED;

    }

    /* fetch group data from dbm file. */

    status = get_dbm_grp(r, apr_pstrcat(r->pool, user, ":", realm, NULL),

                         user, conf->grpfile, conf->dbmtype, &groups);

    if (status != APR_SUCCESS) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(01803)

                      "could not open dbm (type %s) group access "

                      "file: %s", conf->dbmtype, conf->grpfile);

        return AUTHZ_DENIED;

    }

    if (groups == NULL) {

        /* no groups available, so exit immediately */

        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01804)

                      "Authorization of user %s to access %s failed, reason: "

                      "user doesn't appear in DBM group file (%s).",

                      r->user, r->uri, conf->grpfile);

        return AUTHZ_DENIED;

    }

    filegroup = authz_owner_get_file_group(r);

    if (filegroup) {

        while (groups[0]) {

            v = ap_getword(r->pool, &groups, ',');

            if (!strcmp(v, filegroup)) {

                return AUTHZ_GRANTED;

            }

        }

    }

    ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01805)

                  "Authorization of user %s to access %s failed, reason: "

                  "user is not part of the 'require'ed group(s).",

                  r->user, r->uri);

    return AUTHZ_DENIED;

}

static const char *dbm_parse_config(cmd_parms *cmd, const char *require_line,

                                     const void **parsed_require_line)

{

    const char *expr_err = NULL;

    ap_expr_info_t *expr;

    expr = ap_expr_parse_cmd(cmd, require_line, AP_EXPR_FLAG_STRING_RESULT,

            &expr_err, NULL);

    if (expr_err)

        return apr_pstrcat(cmd->temp_pool,

                           "Cannot parse expression in require line: ",

                           expr_err, NULL);

    *parsed_require_line = expr;

    return NULL;

}

static const authz_provider authz_dbmgroup_provider =

{

    &dbmgroup_check_authorization,

    &dbm_parse_config,

};

static const authz_provider authz_dbmfilegroup_provider =

{

    &dbmfilegroup_check_authorization,

    NULL,

};

static void authz_dbm_getfns(void)

{

    authz_owner_get_file_group = APR_RETRIEVE_OPTIONAL_FN(authz_owner_get_file_group);

}

static void register_hooks(apr_pool_t *p)

{

    ap_register_auth_provider(p, AUTHZ_PROVIDER_GROUP, "dbm-group",

                              AUTHZ_PROVIDER_VERSION,

                              &authz_dbmgroup_provider,

                              AP_AUTH_INTERNAL_PER_CONF);

    ap_register_auth_provider(p, AUTHZ_PROVIDER_GROUP, "dbm-file-group",

                              AUTHZ_PROVIDER_VERSION,

                              &authz_dbmfilegroup_provider,

                              AP_AUTH_INTERNAL_PER_CONF);

    ap_hook_optional_fn_retrieve(authz_dbm_getfns, NULL, NULL, APR_HOOK_MIDDLE);

}

AP_DECLARE_MODULE(authz_dbm) =

{

    STANDARD20_MODULE_STUFF,

    create_authz_dbm_dir_config, /* dir config creater */

    NULL,                        /* dir merger --- default is to override */

    NULL,                        /* server config */

    NULL,                        /* merge server config */

    authz_dbm_cmds,              /* command apr_table_t */

    register_hooks               /* register hooks */

};