/* ====================================================================
 * 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.
 */
/*
 * mod_auth_db: authentication
 * 
 * Original work by Rob McCool & Brian Behlendorf.
 * 
 * Adapted to Apache by rst (mod_auth_dbm)
 *
 * Adapted for Berkeley DB by Andrew Cohen 
 *
 * mod_auth_db was based on mod_auth_dbm.
 * 
 * Warning, this is not a drop in replacement for mod_auth_dbm, 
 * for people wanting to switch from dbm to Berkeley DB.
 * It requires the use of AuthDBUserFile and AuthDBGroupFile
 *           instead of   AuthDBMUserFile    AuthDBMGroupFile
 *
 * Also, in the configuration file you need to specify
 *  db_auth_module rather than dbm_auth_module
 *
 * On some BSD systems (e.g. FreeBSD and NetBSD) dbm is automatically
 * mapped to Berkeley DB. You can use either mod_auth_dbm or
 * mod_auth_db. The latter makes it more obvious that it's Berkeley.
 * On other platforms where you want to use the DB library you
 * usually have to install it first. See http://www.sleepycat.com/
 * for the distribution. The interface this module uses is the
 * one from DB version 1.85 and 1.86, but DB version 2.x
 * can also be used when compatibility mode is enabled.
 *
 * 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"
#include <db.h>
#if defined(DB_VERSION_MAJOR)
#if (DB_VERSION_MAJOR == 2)
#define DB2
#endif
#if (DB_VERSION_MAJOR == 3)
#define DB3
#endif
#endif
typedef struct {
    char *auth_dbpwfile;
    char *auth_dbgrpfile;
    int auth_dbauthoritative;
} db_auth_config_rec;
static void *create_db_auth_dir_config(pool *p, char *d)
{
    db_auth_config_rec *sec
    = (db_auth_config_rec *) ap_pcalloc(p, sizeof(db_auth_config_rec));
    sec->auth_dbpwfile = NULL;
    sec->auth_dbgrpfile = NULL;
    sec->auth_dbauthoritative = 1;   /* fortress is secure by default */
    return sec;
}
static const char *set_db_slot(cmd_parms *cmd, void *offset, char *f, char *t)
{
    if (!t || strcmp(t, "db"))
        return DECLINE_CMD;
    return ap_set_file_slot(cmd, offset, f);
}
static const command_rec db_auth_cmds[] =
{
    {"AuthDBUserFile", ap_set_file_slot,
     (void *) XtOffsetOf(db_auth_config_rec, auth_dbpwfile),
     OR_AUTHCFG, TAKE1, NULL},
    {"AuthDBGroupFile", ap_set_file_slot,
     (void *) XtOffsetOf(db_auth_config_rec, auth_dbgrpfile),
     OR_AUTHCFG, TAKE1, NULL},
    {"AuthUserFile", set_db_slot,
     (void *) XtOffsetOf(db_auth_config_rec, auth_dbpwfile),
     OR_AUTHCFG, TAKE12, NULL},
    {"AuthGroupFile", set_db_slot,
     (void *) XtOffsetOf(db_auth_config_rec, auth_dbgrpfile),
     OR_AUTHCFG, TAKE12, NULL},
    {"AuthDBAuthoritative", ap_set_flag_slot,
     (void *) XtOffsetOf(db_auth_config_rec, auth_dbauthoritative),
     OR_AUTHCFG, FLAG,
     "Set to 'no' to allow access control to be passed along to lower modules if the userID is not known to this module"},
    {NULL}
};
module db_auth_module;
static char *get_db_pw(request_rec *r, char *user, const char *auth_dbpwfile)
{
    DB *f;
    DBT d, q;
    char *pw = NULL;
    memset(&d, 0, sizeof(d));
    memset(&q, 0, sizeof(q));
    q.data = user;
    q.size = strlen(q.data);
#if defined(DB3)
    if (   db_create(&f, NULL, 0) != 0 
        || f->open(f, auth_dbpwfile, NULL, DB_HASH, DB_RDONLY, 0664) != 0) {
#elif defined(DB2)
    if (db_open(auth_dbpwfile, DB_HASH, DB_RDONLY, 0664, NULL, NULL, &f) != 0) {
#else
    if (!(f = dbopen(auth_dbpwfile, O_RDONLY, 0664, DB_HASH, NULL))) {
#endif
        ap_log_rerror(APLOG_MARK, APLOG_ERR, r,
                    "could not open db auth file: %s", auth_dbpwfile);
        return NULL;
    }
#if defined(DB2) || defined(DB3)
    if (!((f->get) (f, NULL, &q, &d, 0))) {
#else
    if (!((f->get) (f, &q, &d, 0))) {
#endif
        pw = ap_palloc(r->pool, d.size + 1);
        strncpy(pw, d.data, d.size);
        pw[d.size] = '\0';      /* Terminate the string */
    }
#if defined(DB2) || defined(DB3)
    (f->close) (f, 0);
#else
    (f->close) (f);
#endif
    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 DB file;   key=username value=password":"groupname[":"anything]
 *
 * mark@telescope.org, 22Sep95
 */
static char *get_db_grp(request_rec *r, char *user, const char *auth_dbgrpfile)
{
    char *grp_data = get_db_pw(r, user, auth_dbgrpfile);
    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 db_authenticate_basic_user(request_rec *r)
{
    db_auth_config_rec *sec =
    (db_auth_config_rec *) ap_get_module_config(r->per_dir_config,
                                             &db_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_dbpwfile)
        return DECLINED;
    if (!(real_pw = get_db_pw(r, c->user, sec->auth_dbpwfile))) {
        if (!(sec->auth_dbauthoritative))
            return DECLINED;
        ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
                    "DB 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,
                      "DB 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 db_check_auth(request_rec *r)
{
    db_auth_config_rec *sec =
    (db_auth_config_rec *) ap_get_module_config(r->per_dir_config,
                                             &db_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_dbgrpfile)
        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_dbgrpfile) {
            const char *orig_groups, *groups;
            char *v;
            if (!(groups = get_db_grp(r, user, sec->auth_dbgrpfile))) {
                if (!(sec->auth_dbauthoritative))
                    return DECLINED;
                ap_log_rerror(APLOG_MARK, APLOG_NOERRNO|APLOG_ERR, r,
                            "user %s not in DB group file %s: %s",
                            user, sec->auth_dbgrpfile, 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 db_auth_module =
{
    STANDARD_MODULE_STUFF,
    NULL,                       /* initializer */
    create_db_auth_dir_config,  /* dir config creater */
    NULL,                       /* dir merger --- default is to override */
    NULL,                       /* server config */
    NULL,                       /* merge server config */
    db_auth_cmds,               /* command table */
    NULL,                       /* handlers */
    NULL,                       /* filename translation */
    db_authenticate_basic_user, /* check_user_id */
    db_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 */
};