mod_session_cookie.c revision d6e81217d873dc3b87fc4ffa5fbac2fad4191a15
/* 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 "mod_session.h"
#include "apr_lib.h"
#include "apr_strings.h"
#include "http_log.h"
#include "util_cookies.h"
#define LOG_PREFIX "mod_session_cookie: "
#define MOD_SESSION_COOKIE "mod_session_cookie"
module AP_MODULE_DECLARE_DATA session_cookie_module;
/**
* Structure to carry the per-dir session config.
*/
typedef struct {
const char *name;
int name_set;
const char *name_attrs;
const char *name2;
int name2_set;
const char *name2_attrs;
int remove;
int remove_set;
} session_cookie_dir_conf;
/**
* Set the cookie and embed the session within it.
*
* This function adds an RFC2109 compliant Set-Cookie header for
* the cookie specified in SessionCookieName, and an RFC2965 compliant
* Set-Cookie2 header for the cookie specified in SessionCookieName2.
*
* If specified, the optional cookie attributes will be added to
* each cookie. If defaults are not specified, DEFAULT_ATTRS
* will be used.
*
* On success, this method will return APR_SUCCESS.
*
* @param r The request pointer.
* @param z A pointer to where the session will be written.
*/
AP_DECLARE(int) ap_session_cookie_save(request_rec * r, session_rec * z)
{
session_cookie_dir_conf *conf = ap_get_module_config(r->per_dir_config,
&session_cookie_module);
/* don't cache auth protected pages */
apr_table_addn(r->headers_out, "Cache-Control", "no-cache");
/* create RFC2109 compliant cookie */
if (conf->name_set) {
if (z->encoded && z->encoded[0]) {
ap_cookie_write(r, conf->name, z->encoded, conf->name_attrs, z->maxage);
}
else {
ap_cookie_remove(r, conf->name);
}
}
/* create RFC2965 compliant cookie */
if (conf->name2_set) {
if (z->encoded && z->encoded[0]) {
ap_cookie_write2(r, conf->name2, z->encoded, conf->name2_attrs, z->maxage);
}
else {
ap_cookie_remove2(r, conf->name2);
}
}
if (conf->name_set || conf->name2_set) {
return OK;
}
return DECLINED;
}
/**
* Isolate the cookie with the name "name", and if present, extract
* the payload from the cookie.
*
* If the cookie is found, the cookie and any other cookies with the
* same name are removed from the cookies passed in the request, so
* that credentials are not leaked to a backend server or process.
*
* A missing or malformed cookie will cause this function to return
* APR_EGENERAL.
*
* On success, this returns APR_SUCCESS.
*/
AP_DECLARE(int) ap_session_cookie_load(request_rec * r, session_rec ** z)
{
session_cookie_dir_conf *conf = ap_get_module_config(r->per_dir_config,
&session_cookie_module);
session_rec *zz = NULL;
const char *val = NULL;
const char *note = NULL;
const char *name = NULL;
request_rec *m = r->main ? r->main : r;
/* is our session in a cookie? */
if (conf->name2_set) {
name = conf->name2;
}
else if (conf->name_set) {
name = conf->name;
}
else {
return DECLINED;
}
/* first look in the notes */
note = apr_pstrcat(r->pool, MOD_SESSION_COOKIE, name, NULL);
zz = (session_rec *)apr_table_get(m->notes, note);
if (zz) {
*z = zz;
return OK;
}
/* otherwise, try parse the cookie */
ap_cookie_read(r, name, &val, conf->remove);
/* create a new session and return it */
zz = (session_rec *) apr_pcalloc(r->pool, sizeof(session_rec));
zz->pool = r->pool;
zz->entries = apr_table_make(r->pool, 10);
zz->encoded = val;
zz->uuid = (apr_uuid_t *) apr_pcalloc(r->pool, sizeof(apr_uuid_t));
*z = zz;
/* put the session in the notes so we don't have to parse it again */
apr_table_setn(m->notes, note, (char *)zz);
return OK;
}
static void *create_session_cookie_dir_config(apr_pool_t * p, char *dummy)
{
session_cookie_dir_conf *new =
(session_cookie_dir_conf *) apr_pcalloc(p, sizeof(session_cookie_dir_conf));
return (void *) new;
}
static void *merge_session_cookie_dir_config(apr_pool_t * p, void *basev, void *addv)
{
session_cookie_dir_conf *new = (session_cookie_dir_conf *) apr_pcalloc(p, sizeof(session_cookie_dir_conf));
session_cookie_dir_conf *add = (session_cookie_dir_conf *) addv;
session_cookie_dir_conf *base = (session_cookie_dir_conf *) basev;
new->name = (add->name_set == 0) ? base->name : add->name;
new->name_attrs = (add->name_set == 0) ? base->name_attrs : add->name_attrs;
new->name_set = add->name_set || base->name_set;
new->name2 = (add->name2_set == 0) ? base->name2 : add->name2;
new->name2_attrs = (add->name2_set == 0) ? base->name2_attrs : add->name2_attrs;
new->name2_set = add->name2_set || base->name2_set;
new->remove = (add->remove_set == 0) ? base->remove : add->remove;
new->remove_set = add->remove_set || base->remove_set;
return new;
}
/**
* Sanity check a given string that it exists, is not empty,
* and does not contain special characters.
*/
static const char *check_string(cmd_parms * cmd, const char *string)
{
if (!string || !*string || ap_strchr_c(string, '=') || ap_strchr_c(string, '&')) {
return apr_pstrcat(cmd->pool, cmd->directive->directive,
" cannot be empty, or contain '=' or '&'.",
NULL);
}
return NULL;
}
static const char *set_cookie_name(cmd_parms * cmd, void *config, const char *args)
{
char *last;
char *line = apr_pstrdup(cmd->pool, args);
session_cookie_dir_conf *conf = (session_cookie_dir_conf *) config;
char *cookie = apr_strtok(line, " \t", &last);
conf->name = cookie;
conf->name_set = 1;
while (apr_isspace(*last)) {
last++;
}
conf->name_attrs = last;
return check_string(cmd, cookie);
}
static const char *set_cookie_name2(cmd_parms * cmd, void *config, const char *args)
{
char *last;
char *line = apr_pstrdup(cmd->pool, args);
session_cookie_dir_conf *conf = (session_cookie_dir_conf *) config;
char *cookie = apr_strtok(line, " \t", &last);
conf->name2 = cookie;
conf->name2_set = 1;
while (apr_isspace(*last)) {
last++;
}
conf->name2_attrs = last;
return check_string(cmd, cookie);
}
static const char *
set_remove(cmd_parms * parms, void *dconf, int flag)
{
session_cookie_dir_conf *conf = dconf;
conf->remove = flag;
conf->remove_set = 1;
return NULL;
}
static const command_rec session_cookie_cmds[] =
{
AP_INIT_RAW_ARGS("SessionCookieName", set_cookie_name, NULL, OR_AUTHCFG,
"The name of the RFC2109 cookie carrying the session"),
AP_INIT_RAW_ARGS("SessionCookieName2", set_cookie_name2, NULL, OR_AUTHCFG,
"The name of the RFC2965 cookie carrying the session"),
AP_INIT_FLAG("SessionCookieRemove", set_remove, NULL, OR_AUTHCFG,
"Set to 'On' to remove the session cookie from the headers "
"and hide the cookie from a backend server or process"),
{NULL}
};
static void register_hooks(apr_pool_t * p)
{
ap_hook_session_load(ap_session_cookie_load, NULL, NULL, APR_HOOK_MIDDLE);
ap_hook_session_save(ap_session_cookie_save, NULL, NULL, APR_HOOK_MIDDLE);
}
module AP_MODULE_DECLARE_DATA session_cookie_module =
{
STANDARD20_MODULE_STUFF,
create_session_cookie_dir_config, /* dir config creater */
merge_session_cookie_dir_config, /* dir merger --- default is to
* override */
NULL, /* server config */
NULL, /* merge server config */
session_cookie_cmds, /* command apr_table_t */
register_hooks /* register hooks */
};