/* 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.

 */

/*

 * http_auth: authentication

 *

 * Rob McCool & Brian Behlendorf.

 *

 * Adapted to Apache by rst.

 *

 */

#define APR_WANT_STRFUNC

#include "apr_want.h"

#include "apr_strings.h"

#include "apr_dbm.h"

#include "apr_md5.h"        /* for apr_password_validate */

#include "ap_provider.h"

#include "httpd.h"

#include "http_config.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"

static APR_OPTIONAL_FN_TYPE(ap_authn_cache_store) *authn_cache_store = NULL;

#define AUTHN_CACHE_STORE(r,user,realm,data) \

    if (authn_cache_store != NULL) \

        authn_cache_store((r), "dbm", (user), (realm), (data))

typedef struct {

    const char *pwfile;

    const char *dbmtype;

} authn_dbm_config_rec;

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

{

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

    conf->pwfile = NULL;

    conf->dbmtype = "default";

    return conf;

}

static const command_rec authn_dbm_cmds[] =

{

    AP_INIT_TAKE1("AuthDBMUserFile", ap_set_file_slot,

     (void *)APR_OFFSETOF(authn_dbm_config_rec, pwfile),

     OR_AUTHCFG, "dbm database file containing user IDs and passwords"),

    AP_INIT_TAKE1("AuthDBMType", ap_set_string_slot,

     (void *)APR_OFFSETOF(authn_dbm_config_rec, dbmtype),

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

    {NULL}

};

module AP_MODULE_DECLARE_DATA authn_dbm_module;

static apr_status_t fetch_dbm_value(const char *dbmtype, const char *dbmfile,

                                    const char *user, char **value,

                                    apr_pool_t *pool)

{

    apr_dbm_t *f;

    apr_datum_t key, val;

    apr_status_t rv;

    rv = apr_dbm_open_ex(&f, dbmtype, dbmfile, APR_DBM_READONLY,

                         APR_OS_DEFAULT, pool);

    if (rv != APR_SUCCESS) {

        return rv;

    }

    key.dptr = (char*)user;

#ifndef NETSCAPE_DBM_COMPAT

    key.dsize = strlen(key.dptr);

#else

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

#endif

    *value = NULL;

    if (apr_dbm_fetch(f, key, &val) == APR_SUCCESS && val.dptr) {

        *value = apr_pstrmemdup(pool, val.dptr, val.dsize);

    }

    apr_dbm_close(f);

    return rv;

}

static authn_status check_dbm_pw(request_rec *r, const char *user,

                                 const char *password)

{

    authn_dbm_config_rec *conf = ap_get_module_config(r->per_dir_config,

                                                      &authn_dbm_module);

    apr_status_t rv;

    char *dbm_password;

    char *colon_pw;

    rv = fetch_dbm_value(conf->dbmtype, conf->pwfile, user, &dbm_password,

                         r->pool);

    if (rv != APR_SUCCESS) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01754)

                      "could not open dbm (type %s) auth file: %s",

                      conf->dbmtype, conf->pwfile);

        return AUTH_GENERAL_ERROR;

    }

    if (!dbm_password) {

        return AUTH_USER_NOT_FOUND;

    }

    colon_pw = ap_strchr(dbm_password, ':');

    if (colon_pw) {

        *colon_pw = '\0';

    }

    AUTHN_CACHE_STORE(r, user, NULL, dbm_password);

    rv = apr_password_validate(password, dbm_password);

    if (rv != APR_SUCCESS) {

        return AUTH_DENIED;

    }

    return AUTH_GRANTED;

}

static authn_status get_dbm_realm_hash(request_rec *r, const char *user,

                                       const char *realm, char **rethash)

{

    authn_dbm_config_rec *conf = ap_get_module_config(r->per_dir_config,

                                                      &authn_dbm_module);

    apr_status_t rv;

    char *dbm_hash;

    char *colon_hash;

    rv = fetch_dbm_value(conf->dbmtype, conf->pwfile,

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

                         &dbm_hash, r->pool);

    if (rv != APR_SUCCESS) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, rv, r, APLOGNO(01755)

                      "Could not open dbm (type %s) hash file: %s",

                      conf->dbmtype, conf->pwfile);

        return AUTH_GENERAL_ERROR;

    }

    if (!dbm_hash) {

        return AUTH_USER_NOT_FOUND;

    }

    colon_hash = ap_strchr(dbm_hash, ':');

    if (colon_hash) {

        *colon_hash = '\0';

    }

    *rethash = dbm_hash;

    AUTHN_CACHE_STORE(r, user, realm, dbm_hash);

    return AUTH_USER_FOUND;

}

static const authn_provider authn_dbm_provider =

{

    &check_dbm_pw,

    &get_dbm_realm_hash,

};

static void opt_retr(void)

{

    authn_cache_store = APR_RETRIEVE_OPTIONAL_FN(ap_authn_cache_store);

}

static void register_hooks(apr_pool_t *p)

{

    ap_register_auth_provider(p, AUTHN_PROVIDER_GROUP, "dbm",

                              AUTHN_PROVIDER_VERSION,

                              &authn_dbm_provider, AP_AUTH_INTERNAL_PER_CONF);

    ap_hook_optional_fn_retrieve(opt_retr, NULL, NULL, APR_HOOK_MIDDLE);

}

AP_DECLARE_MODULE(authn_dbm) =

{

    STANDARD20_MODULE_STUFF,

    create_authn_dbm_dir_config, /* dir config creater */

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

    NULL,                        /* server config */

    NULL,                        /* merge server config */

    authn_dbm_cmds,              /* command apr_table_t */

    register_hooks               /* register hooks */

};