/* 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.

 */

#include "apr_strings.h"

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

#include "ap_config.h"

#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"

#include "mod_auth.h"

typedef struct {

    char *pwfile;

} authn_file_config_rec;

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), "file", (user), (realm), (data))

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

{

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

    conf->pwfile = NULL;     /* just to illustrate the default really */

    return conf;

}

static const command_rec authn_file_cmds[] =

{

    AP_INIT_TAKE1("AuthUserFile", ap_set_file_slot,

                  (void *)APR_OFFSETOF(authn_file_config_rec, pwfile),

                  OR_AUTHCFG, "text file containing user IDs and passwords"),

    {NULL}

};

module AP_MODULE_DECLARE_DATA authn_file_module;

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

                                   const char *password)

{

    authn_file_config_rec *conf = ap_get_module_config(r->per_dir_config,

                                                       &authn_file_module);

    ap_configfile_t *f;

    char l[MAX_STRING_LEN];

    apr_status_t status;

    char *file_password = NULL;

    if (!conf->pwfile) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01619)

                      "AuthUserFile not specified in the configuration");

        return AUTH_GENERAL_ERROR;

    }

    status = ap_pcfg_openfile(&f, r->pool, conf->pwfile);

    if (status != APR_SUCCESS) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(01620)

                      "Could not open password file: %s", conf->pwfile);

        return AUTH_GENERAL_ERROR;

    }

    while (!(ap_cfg_getline(l, MAX_STRING_LEN, f))) {

        const char *rpw, *w;

        /* Skip # or blank lines. */

        if ((l[0] == '#') || (!l[0])) {

            continue;

        }

        rpw = l;

        w = ap_getword(r->pool, &rpw, ':');

        if (!strcmp(user, w)) {

            file_password = ap_getword(r->pool, &rpw, ':');

            break;

        }

    }

    ap_cfg_closefile(f);

    if (!file_password) {

        return AUTH_USER_NOT_FOUND;

    }

    AUTHN_CACHE_STORE(r, user, NULL, file_password);

    status = apr_password_validate(password, file_password);

    if (status != APR_SUCCESS) {

        return AUTH_DENIED;

    }

    return AUTH_GRANTED;

}

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

                                   const char *realm, char **rethash)

{

    authn_file_config_rec *conf = ap_get_module_config(r->per_dir_config,

                                                       &authn_file_module);

    ap_configfile_t *f;

    char l[MAX_STRING_LEN];

    apr_status_t status;

    char *file_hash = NULL;

    if (!conf->pwfile) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, 0, r, APLOGNO(01621)

                      "AuthUserFile not specified in the configuration");

        return AUTH_GENERAL_ERROR;

    }

    status = ap_pcfg_openfile(&f, r->pool, conf->pwfile);

    if (status != APR_SUCCESS) {

        ap_log_rerror(APLOG_MARK, APLOG_ERR, status, r, APLOGNO(01622)

                      "Could not open password file: %s", conf->pwfile);

        return AUTH_GENERAL_ERROR;

    }

    while (!(ap_cfg_getline(l, MAX_STRING_LEN, f))) {

        const char *rpw, *w, *x;

        /* Skip # or blank lines. */

        if ((l[0] == '#') || (!l[0])) {

            continue;

        }

        rpw = l;

        w = ap_getword(r->pool, &rpw, ':');

        x = ap_getword(r->pool, &rpw, ':');

        if (x && w && !strcmp(user, w) && !strcmp(realm, x)) {

            /* Remember that this is a md5 hash of user:realm:password.  */

            file_hash = ap_getword(r->pool, &rpw, ':');

            break;

        }

    }

    ap_cfg_closefile(f);

    if (!file_hash) {

        return AUTH_USER_NOT_FOUND;

    }

    *rethash = file_hash;

    AUTHN_CACHE_STORE(r, user, realm, file_hash);

    return AUTH_USER_FOUND;

}

static const authn_provider authn_file_provider =

{

    &check_password,

    &get_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, "file",

                              AUTHN_PROVIDER_VERSION,

                              &authn_file_provider, AP_AUTH_INTERNAL_PER_CONF);

    ap_hook_optional_fn_retrieve(opt_retr, NULL, NULL, APR_HOOK_MIDDLE);

}

AP_DECLARE_MODULE(authn_file) =

{

    STANDARD20_MODULE_STUFF,

    create_authn_file_dir_config,    /* dir config creater */

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

    NULL,                            /* server config */

    NULL,                            /* merge server config */

    authn_file_cmds,                 /* command apr_table_t */

    register_hooks                   /* register hooks */

};