/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2000 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * Portions of this software are based upon public domain software
 * originally written at the National Center for Supercomputing Applications,
 * University of Illinois, Urbana-Champaign.
 */
/*
 * http_auth: authentication
 * 
 * Rob McCool & Brian Behlendorf.
 * 
 * Adapted to Apache by rst.
 *
 * dirkx - Added Authoritative control to allow passing on to lower  
 *         modules if and only if the user-id is not known to this
 *         module. A known user with a faulty or absent password still
 *         causes an AuthRequired. The default is 'Authoritative', i.e.
 *         no control is passed along.
 */
#include "httpd.h"
#include "http_config.h"
#include "http_core.h"
#include "http_log.h"
#include "http_protocol.h"
#if (defined(WIN32) || defined(NETWARE))
#include <sdbm.h>
#define dbm_open sdbm_open
#define dbm_fetch sdbm_fetch
#define dbm_close sdbm_close
#else
#include <ndbm.h>
#endif
/*
 * Module definition information - the part between the -START and -END
 * lines below is used by Configure. This could be stored in a separate
 * instead.
 *
 * MODULE-DEFINITION-START
 * Name: dbm_auth_module
 * ConfigStart
    . ./helpers/find-dbm-lib
 * ConfigEnd
 * MODULE-DEFINITION-END
 */
typedef struct {
    char *auth_dbmpwfile;
    char *auth_dbmgrpfile;
    int auth_dbmauthoritative;
} dbm_auth_config_rec;
static void *create_dbm_auth_dir_config(pool *p, char *d)
{
    dbm_auth_config_rec *sec
    = (dbm_auth_config_rec *) ap_pcalloc(p, sizeof(dbm_auth_config_rec));
    sec->auth_dbmpwfile = NULL;
    sec->auth_dbmgrpfile = NULL;
    sec->auth_dbmauthoritative = 1;  /* fortress is secure by default */
    return sec;
}
static const char *set_dbm_slot(cmd_parms *cmd, void *offset, char *f, char *t)
{
    if (!t || strcmp(t, "dbm"))
        return DECLINE_CMD;
    return ap_set_file_slot(cmd, offset, f);
}
static const command_rec dbm_auth_cmds[] =
{
    {"AuthDBMUserFile", ap_set_file_slot,
     (void *) XtOffsetOf(dbm_auth_config_rec, auth_dbmpwfile),
     OR_AUTHCFG, TAKE1, NULL},
    {"AuthDBMGroupFile", ap_set_file_slot,
     (void *) XtOffsetOf(dbm_auth_config_rec, auth_dbmgrpfile),
     OR_AUTHCFG, TAKE1, NULL},
    {"AuthUserFile", set_dbm_slot,
     (void *) XtOffsetOf(dbm_auth_config_rec, auth_dbmpwfile),
     OR_AUTHCFG, TAKE12, NULL},
    {"AuthGroupFile", set_dbm_slot,
     (void *) XtOffsetOf(dbm_auth_config_rec, auth_dbmgrpfile),
     OR_AUTHCFG, TAKE12, NULL},
    {"AuthDBMAuthoritative", ap_set_flag_slot,
     (void *) XtOffsetOf(dbm_auth_config_rec, auth_dbmauthoritative),
     OR_AUTHCFG, FLAG, "Set to 'no' to allow access control to be passed along to lower modules, if the UserID is not known in this module"},
    {NULL}
};
module MODULE_VAR_EXPORT dbm_auth_module;
static char *get_dbm_pw(request_rec *r, char *user, char *auth_dbmpwfile)
{
    DBM *f;
    datum d, q;
    char *pw = NULL;
    q.dptr = user;
#ifndef NETSCAPE_DBM_COMPAT
    q.dsize = strlen(q.dptr);
#else
    q.dsize = strlen(q.dptr) + 1;
#endif
    if (!(f = dbm_open(auth_dbmpwfile, O_RDONLY, 0664))) {
        ap_log_rerror(APLOG_MARK, APLOG_ERR, r,
                    "could not open dbm auth file: %s", auth_dbmpwfile);
        return NULL;
    }
    d = dbm_fetch(f, q);
    if (d.dptr) {
        pw = ap_palloc(r->pool, d.dsize + 1);
        strncpy(pw, d.dptr, d.dsize);
        pw[d.dsize] = '\0';     /* Terminate the string */
    }
    dbm_close(f);
    return pw;
}
/* 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 char *get_dbm_grp(request_rec *r, char *user, char *auth_dbmgrpfile)
{
    char *grp_data = get_dbm_pw(r, user, auth_dbmgrpfile);
    char *grp_colon;
    char *grp_colon2;
    if (grp_data == NULL)
        return NULL;
    if ((grp_colon = strchr(grp_data, ':')) != NULL) {
        grp_colon2 = strchr(++grp_colon, ':');
        if (grp_colon2)
            *grp_colon2 = '\0';
        return grp_colon;
    }
    return grp_data;
}
static int dbm_authenticate_basic_user(request_rec *r)
{
    dbm_auth_config_rec *sec =
    (dbm_auth_config_rec *) ap_get_module_config(r->per_dir_config,
                                              &dbm_auth_module);
    conn_rec *c = r->connection;
    const char *sent_pw;
    char *real_pw, *colon_pw;
    char *invalid_pw;
    int res;
    if ((res = ap_get_basic_auth_pw(r, &sent_pw)))
        return res;
    if (!sec->auth_dbmpwfile)
        return DECLINED;
    if (!(real_pw = get_dbm_pw(r, c->user, sec->auth_dbmpwfile))) {
        if (!(sec->auth_dbmauthoritative))
            return DECLINED;
        ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
                    "DBM user %s not found: %s", c->user, r->filename);
        ap_note_basic_auth_failure(r);
        return AUTH_REQUIRED;
    }
    /* Password is up to first : if exists */
    colon_pw = strchr(real_pw, ':');
    if (colon_pw) {
        *colon_pw = '\0';
    }
    invalid_pw = ap_validate_password(sent_pw, real_pw);
    if (invalid_pw != NULL) {
        ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
                      "DBM user %s: authentication failure for \"%s\": %s",
                      c->user, r->uri, invalid_pw);
        ap_note_basic_auth_failure(r);
        return AUTH_REQUIRED;
    }
    return OK;
}
/* Checking ID */
static int dbm_check_auth(request_rec *r)
{
    dbm_auth_config_rec *sec =
    (dbm_auth_config_rec *) ap_get_module_config(r->per_dir_config,
                                              &dbm_auth_module);
    char *user = r->connection->user;
    int m = r->method_number;
    const array_header *reqs_arr = ap_requires(r);
    require_line *reqs = reqs_arr ? (require_line *) reqs_arr->elts : NULL;
    register int x;
    const char *t;
    char *w;
    if (!sec->auth_dbmgrpfile)
        return DECLINED;
    if (!reqs_arr)
        return DECLINED;
    for (x = 0; x < reqs_arr->nelts; x++) {
        if (!(reqs[x].method_mask & (1 << m)))
            continue;
        t = reqs[x].requirement;
        w = ap_getword_white(r->pool, &t);
        if (!strcmp(w, "group") && sec->auth_dbmgrpfile) {
            const char *orig_groups, *groups;
            char *v;
            if (!(groups = get_dbm_grp(r, user, sec->auth_dbmgrpfile))) {
                if (!(sec->auth_dbmauthoritative))
                    return DECLINED;
                ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
                            "user %s not in DBM group file %s: %s",
                            user, sec->auth_dbmgrpfile, r->filename);
                ap_note_basic_auth_failure(r);
                return AUTH_REQUIRED;
            }
            orig_groups = groups;
            while (t[0]) {
                w = ap_getword_white(r->pool, &t);
                groups = orig_groups;
                while (groups[0]) {
                    v = ap_getword(r->pool, &groups, ',');
                    if (!strcmp(v, w))
                        return OK;
                }
            }
            ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
                        "user %s not in right group: %s",
                        user, r->filename);
            ap_note_basic_auth_failure(r);
            return AUTH_REQUIRED;
        }
    }
    return DECLINED;
}
module MODULE_VAR_EXPORT dbm_auth_module =
{
    STANDARD_MODULE_STUFF,
    NULL,                       /* initializer */
    create_dbm_auth_dir_config, /* dir config creater */
    NULL,                       /* dir merger --- default is to override */
    NULL,                       /* server config */
    NULL,                       /* merge server config */
    dbm_auth_cmds,              /* command table */
    NULL,                       /* handlers */
    NULL,                       /* filename translation */
    dbm_authenticate_basic_user,        /* check_user_id */
    dbm_check_auth,             /* check auth */
    NULL,                       /* check access */
    NULL,                       /* type_checker */
    NULL,                       /* fixups */
    NULL,                       /* logger */
    NULL,                       /* header parser */
    NULL,                       /* child_init */
    NULL,                       /* child_exit */
    NULL                        /* post read-request */
};