post_handler.c

/*
  +----------------------------------------------------------------------+
  | Suhosin Version 1                                                    |
  +----------------------------------------------------------------------+
  | Copyright (c) 2006-2007 The Hardened-PHP Project                     |
  | Copyright (c) 2007-2015 SektionEins GmbH                             |
  +----------------------------------------------------------------------+
  | This source file is subject to version 3.01 of the PHP license,      |
  | that is bundled with this package in the file LICENSE, and is        |
  | available through the world-wide-web at the following url:           |
  | http://www.php.net/license/3_01.txt                                  |
  | If you did not receive a copy of the PHP license and are unable to   |
  | obtain it through the world-wide-web, please send a note to          |
  | license@php.net so we can mail you a copy immediately.               |
  +----------------------------------------------------------------------+
  | Author: Stefan Esser <sesser@sektioneins.de>                         |
  +----------------------------------------------------------------------+
*/
/*
  $Id: post_handler.c,v 1.1.1.1 2007-11-28 01:15:35 sesser Exp $ 
*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include "php.h"
#include "php_ini.h"
#include "php_suhosin.h"
#include "SAPI.h"
#include "php_variables.h"
#include "php_content_types.h"
#include "suhosin_rfc1867.h"
#include "ext/standard/url.h"
#include "ext/standard/php_smart_str.h"

#if defined(PHP_WIN32) && PHP_VERSION_ID >= 50600
#include "win32/php_inttypes.h"
#endif

SAPI_POST_HANDLER_FUNC(suhosin_rfc1867_post_handler);


#if PHP_VERSION_ID < 50600
SAPI_POST_HANDLER_FUNC(suhosin_std_post_handler)
{
	char *var, *val, *e, *s, *p;
	zval *array_ptr = (zval *) arg;
	long count = 0;

	if (SG(request_info).post_data == NULL) {
		return;
	}	

	s = SG(request_info).post_data;
	e = s + SG(request_info).post_data_length;

	while (s < e && (p = memchr(s, '&', (e - s)))) {
last_value:
		if ((val = memchr(s, '=', (p - s)))) { /* have a value */
			unsigned int val_len, new_val_len;

			if (++count > PG(max_input_vars)) {
				php_error_docref(NULL TSRMLS_CC, E_WARNING, "Input variables exceeded %ld. To increase the limit change max_input_vars in php.ini.", PG(max_input_vars));
				return;
			}
			var = s;

			php_url_decode(var, (val - s));
			val++;
			val_len = php_url_decode(val, (p - val));
			val = estrndup(val, val_len);
			if (suhosin_input_filter(PARSE_POST, var, &val, val_len, &new_val_len TSRMLS_CC)) {
				if (sapi_module.input_filter(PARSE_POST, var, &val, new_val_len, &new_val_len TSRMLS_CC)) {
					php_register_variable_safe(var, val, new_val_len, array_ptr TSRMLS_CC);
				}
			} else {
				SUHOSIN_G(abort_request)=1;
			}
			efree(val);
		}
		s = p + 1;
	}
	if (s < e) {
		p = e;
		goto last_value;
	}
}
#else
typedef struct post_var_data {
	smart_str str;
	char *ptr;
	char *end;
	uint64_t cnt;
} post_var_data_t;

static zend_bool add_post_var(zval *arr, post_var_data_t *var, zend_bool eof TSRMLS_DC)
{
	char *ksep, *vsep, *val;
	size_t klen, vlen;
	/* FIXME: string-size_t */
	unsigned int new_vlen;

	if (var->ptr >= var->end) {
		return 0;
	}

	vsep = memchr(var->ptr, '&', var->end - var->ptr);
	if (!vsep) {
		if (!eof) {
			return 0;
		} else {
			vsep = var->end;
		}
	}

	ksep = memchr(var->ptr, '=', vsep - var->ptr);
	if (ksep) {
		*ksep = '\0';
		/* "foo=bar&" or "foo=&" */
		klen = ksep - var->ptr;
		vlen = vsep - ++ksep;
	} else {
		ksep = "";
		/* "foo&" */
		klen = vsep - var->ptr;
		vlen = 0;
	}

	/* do not forget that value needs to be allocated for the filters */
	val = estrndup(ksep, vlen);
	
	php_url_decode(var->ptr, klen);
	if (vlen) {
		vlen = php_url_decode(val, vlen);
	}

	if (suhosin_input_filter(PARSE_POST, var->ptr, &val, vlen, &new_vlen TSRMLS_CC)) {
		if (sapi_module.input_filter(PARSE_POST, var->ptr, &val, new_vlen, &new_vlen TSRMLS_CC)) {
			php_register_variable_safe(var->ptr, val, new_vlen, arr TSRMLS_CC);
		}
	} else {
		SUHOSIN_G(abort_request)=1;
	}
	efree(val);

	var->ptr = vsep + (vsep != var->end);
	return 1;
}

static inline int add_post_vars(zval *arr, post_var_data_t *vars, zend_bool eof TSRMLS_DC)
{
	uint64_t max_vars = PG(max_input_vars);

	vars->ptr = vars->str.c;
	vars->end = vars->str.c + vars->str.len;
	while (add_post_var(arr, vars, eof TSRMLS_CC)) {
		if (++vars->cnt > max_vars) {
			php_error_docref(NULL TSRMLS_CC, E_WARNING,
					"Input variables exceeded %" PRIu64 ". "
					"To increase the limit change max_input_vars in php.ini.",
					max_vars);
			return FAILURE;
		}
	}

	if (!eof) {
		memmove(vars->str.c, vars->ptr, vars->str.len = vars->end - vars->ptr);
	}
	return SUCCESS;
}

SAPI_POST_HANDLER_FUNC(suhosin_std_post_handler)
{
	zval *arr = (zval *) arg;
	php_stream *s = SG(request_info).request_body;
	post_var_data_t post_data;

	if (s && SUCCESS == php_stream_rewind(s)) {
		memset(&post_data, 0, sizeof(post_data));

		while (!php_stream_eof(s)) {
			char buf[BUFSIZ] = {0};
			size_t len = php_stream_read(s, buf, BUFSIZ);

			if (len && len != (size_t) -1) {
				smart_str_appendl(&post_data.str, buf, len);

				if (SUCCESS != add_post_vars(arr, &post_data, 0 TSRMLS_CC)) {
					if (post_data.str.c) {
						efree(post_data.str.c);
					}
					return;
				}
			}

			if (len != BUFSIZ){
				break;
			}
		}

		add_post_vars(arr, &post_data, 1 TSRMLS_CC);
		if (post_data.str.c) {
			efree(post_data.str.c);
		}
	}
}
#endif

static void suhosin_post_handler_modification(sapi_post_entry *spe)
{
	char *content_type = estrndup(spe->content_type, spe->content_type_len);
	suhosin_log(S_VARS, "some extension replaces the POST handler for %s - Suhosin's protection might be incomplete", content_type);
	efree(content_type);
}

static int (*old_OnUpdate_mbstring_encoding_translation)(zend_ini_entry *entry, char *new_value, uint new_value_length, void *mh_arg1, void *mh_arg2, void *mh_arg3, int stage TSRMLS_DC) = NULL;

/* {{{ static PHP_INI_MH(suhosin_OnUpdate_mbstring_encoding_translation) */
static PHP_INI_MH(suhosin_OnUpdate_mbstring_encoding_translation)
{
	zend_bool *p;
#ifndef ZTS
	char *base = (char *) mh_arg2;
#else
	char *base;

	base = (char *) ts_resource(*((int *) mh_arg2));
#endif

	p = (zend_bool *) (base+(size_t) mh_arg1);

	if (new_value_length == 2 && strcasecmp("on", new_value) == 0) {
			*p = (zend_bool) 1;
	}
	else if (new_value_length == 3 && strcasecmp("yes", new_value) == 0) {
		*p = (zend_bool) 1;
	}
	else if (new_value_length == 4 && strcasecmp("true", new_value) == 0) {
		*p = (zend_bool) 1;
	}
	else {
		*p = (zend_bool) atoi(new_value);
	}
	if (*p) {
		suhosin_log(S_VARS, "Dynamic configuration (maybe a .htaccess file) tried to activate mbstring.encoding_translation which is incompatible with suhosin");
	}
	return SUCCESS;
}
/* }}} */

/* {{{ php_post_entries[]
 */
static sapi_post_entry suhosin_post_entries[] = {
	{ DEFAULT_POST_CONTENT_TYPE, sizeof(DEFAULT_POST_CONTENT_TYPE)-1, sapi_read_standard_form_data,	suhosin_std_post_handler },
	{ MULTIPART_CONTENT_TYPE,    sizeof(MULTIPART_CONTENT_TYPE)-1,    NULL,                         suhosin_rfc1867_post_handler },
	{ NULL, 0, NULL, NULL }
};
/* }}} */

void suhosin_hook_post_handlers(TSRMLS_D)
{
	HashTable tempht;
	zend_ini_entry *ini_entry;
	
	sapi_unregister_post_entry(&suhosin_post_entries[0] TSRMLS_CC);
	sapi_unregister_post_entry(&suhosin_post_entries[1] TSRMLS_CC);
	sapi_register_post_entries(suhosin_post_entries TSRMLS_CC);

	/* we want to get notified if another extension deregisters the suhosin post handlers */

	/* we need to tell suhosin patch that there is a new valid destructor */
	/* therefore we have create HashTable that has this destructor */
	zend_hash_init(&tempht, 0, NULL, (dtor_func_t)suhosin_post_handler_modification, 0);
	zend_hash_destroy(&tempht);
	/* And now we can overwrite the destructor for post entries */
	SG(known_post_content_types).pDestructor = (dtor_func_t)suhosin_post_handler_modification;
	
	/* we have to stop mbstring from replacing our post handler */
	if (zend_hash_find(EG(ini_directives), "mbstring.encoding_translation", sizeof("mbstring.encoding_translation"), (void **) &ini_entry) == FAILURE) {
		return;
	}
	/* replace OnUpdate_mbstring_encoding_translation handler */
	old_OnUpdate_mbstring_encoding_translation = ini_entry->on_modify;
	ini_entry->on_modify = suhosin_OnUpdate_mbstring_encoding_translation;
}

void suhosin_unhook_post_handlers(TSRMLS_D)
{
	zend_ini_entry *ini_entry;

	/* Restore to an empty destructor */
	SG(known_post_content_types).pDestructor = NULL;

	/* Now restore the ini entry handler */
	if (zend_hash_find(EG(ini_directives), "mbstring.encoding_translation", sizeof("mbstring.encoding_translation"), (void **) &ini_entry) == FAILURE) {
		return;
	}
	/* replace OnUpdate_mbstring_encoding_translation handler */
	ini_entry->on_modify = old_OnUpdate_mbstring_encoding_translation;
	old_OnUpdate_mbstring_encoding_translation = NULL;
}

/*
 * Local variables:
 * tab-width: 4
 * c-basic-offset: 4
 * End:
 * vim600: noet sw=4 ts=4 fdm=marker
 * vim<600: noet sw=4 ts=4
 */