php-src/ext/random/randomizer.c
2023-03-20 16:19:05 +01:00

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/*
+----------------------------------------------------------------------+
| Copyright (c) The PHP Group |
+----------------------------------------------------------------------+
| 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: |
| https://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: Go Kudo <zeriyoshi@php.net> |
+----------------------------------------------------------------------+
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "php.h"
#include "php_random.h"
#include "ext/standard/php_array.h"
#include "ext/standard/php_string.h"
#include "Zend/zend_enum.h"
#include "Zend/zend_exceptions.h"
static inline void randomizer_common_init(php_random_randomizer *randomizer, zend_object *engine_object) {
if (engine_object->ce->type == ZEND_INTERNAL_CLASS) {
/* Internal classes always php_random_engine struct */
php_random_engine *engine = php_random_engine_from_obj(engine_object);
/* Copy engine pointers */
randomizer->algo = engine->algo;
randomizer->status = engine->status;
} else {
/* Self allocation */
randomizer->status = php_random_status_alloc(&php_random_algo_user, false);
php_random_status_state_user *state = randomizer->status->state;
zend_string *mname;
zend_function *generate_method;
mname = ZSTR_INIT_LITERAL("generate", 0);
generate_method = zend_hash_find_ptr(&engine_object->ce->function_table, mname);
zend_string_release(mname);
/* Create compatible state */
state->object = engine_object;
state->generate_method = generate_method;
/* Copy common pointers */
randomizer->algo = &php_random_algo_user;
/* Mark self-allocated for memory management */
randomizer->is_userland_algo = true;
}
}
/* {{{ Random\Randomizer::__construct() */
PHP_METHOD(Random_Randomizer, __construct)
{
php_random_randomizer *randomizer = Z_RANDOM_RANDOMIZER_P(ZEND_THIS);
zval engine;
zval *param_engine = NULL;
ZEND_PARSE_PARAMETERS_START(0, 1)
Z_PARAM_OPTIONAL
Z_PARAM_OBJECT_OF_CLASS_OR_NULL(param_engine, random_ce_Random_Engine);
ZEND_PARSE_PARAMETERS_END();
if (param_engine != NULL) {
ZVAL_COPY(&engine, param_engine);
} else {
/* Create default RNG instance */
object_init_ex(&engine, random_ce_Random_Engine_Secure);
}
zend_update_property(random_ce_Random_Randomizer, Z_OBJ_P(ZEND_THIS), "engine", strlen("engine"), &engine);
OBJ_RELEASE(Z_OBJ_P(&engine));
if (EG(exception)) {
RETURN_THROWS();
}
randomizer_common_init(randomizer, Z_OBJ_P(&engine));
}
/* }}} */
/* {{{ Generate a float in [0, 1) */
PHP_METHOD(Random_Randomizer, nextFloat)
{
php_random_randomizer *randomizer = Z_RANDOM_RANDOMIZER_P(ZEND_THIS);
uint64_t result;
size_t total_size;
ZEND_PARSE_PARAMETERS_NONE();
result = 0;
total_size = 0;
do {
uint64_t r = randomizer->algo->generate(randomizer->status);
result = result | (r << (total_size * 8));
total_size += randomizer->status->last_generated_size;
if (EG(exception)) {
RETURN_THROWS();
}
} while (total_size < sizeof(uint64_t));
/* A double has 53 bits of precision, thus we must not
* use the full 64 bits of the uint64_t, because we would
* introduce a bias / rounding error.
*/
#if DBL_MANT_DIG != 53
# error "Random_Randomizer::nextFloat(): Requires DBL_MANT_DIG == 53 to work."
#endif
const double step_size = 1.0 / (1ULL << 53);
/* Use the upper 53 bits, because some engine's lower bits
* are of lower quality.
*/
result = (result >> 11);
RETURN_DOUBLE(step_size * result);
}
/* }}} */
/* {{{ Generates a random float within a configurable interval.
*
* This method uses the γ-section algorithm by Frédéric Goualard.
*/
PHP_METHOD(Random_Randomizer, getFloat)
{
php_random_randomizer *randomizer = Z_RANDOM_RANDOMIZER_P(ZEND_THIS);
double min, max;
zend_object *bounds = NULL;
int bounds_type = 'C' + sizeof("ClosedOpen") - 1;
ZEND_PARSE_PARAMETERS_START(2, 3)
Z_PARAM_DOUBLE(min)
Z_PARAM_DOUBLE(max)
Z_PARAM_OPTIONAL
Z_PARAM_OBJ_OF_CLASS(bounds, random_ce_Random_IntervalBoundary);
ZEND_PARSE_PARAMETERS_END();
if (!zend_finite(min)) {
zend_argument_value_error(1, "must be finite");
RETURN_THROWS();
}
if (!zend_finite(max)) {
zend_argument_value_error(2, "must be finite");
RETURN_THROWS();
}
if (bounds) {
zval *case_name = zend_enum_fetch_case_name(bounds);
zend_string *bounds_name = Z_STR_P(case_name);
bounds_type = ZSTR_VAL(bounds_name)[0] + ZSTR_LEN(bounds_name);
}
switch (bounds_type) {
case 'C' + sizeof("ClosedOpen") - 1:
if (UNEXPECTED(max <= min)) {
zend_argument_value_error(2, "must be greater than argument #1 ($min)");
RETURN_THROWS();
}
RETURN_DOUBLE(php_random_gammasection_closed_open(randomizer->algo, randomizer->status, min, max));
case 'C' + sizeof("ClosedClosed") - 1:
if (UNEXPECTED(max < min)) {
zend_argument_value_error(2, "must be greater than or equal to argument #1 ($min)");
RETURN_THROWS();
}
RETURN_DOUBLE(php_random_gammasection_closed_closed(randomizer->algo, randomizer->status, min, max));
case 'O' + sizeof("OpenClosed") - 1:
if (UNEXPECTED(max <= min)) {
zend_argument_value_error(2, "must be greater than argument #1 ($min)");
RETURN_THROWS();
}
RETURN_DOUBLE(php_random_gammasection_open_closed(randomizer->algo, randomizer->status, min, max));
case 'O' + sizeof("OpenOpen") - 1:
if (UNEXPECTED(max <= min)) {
zend_argument_value_error(2, "must be greater than argument #1 ($min)");
RETURN_THROWS();
}
RETVAL_DOUBLE(php_random_gammasection_open_open(randomizer->algo, randomizer->status, min, max));
if (UNEXPECTED(isnan(Z_DVAL_P(return_value)))) {
zend_value_error("The given interval is empty, there are no floats between argument #1 ($min) and argument #2 ($max).");
RETURN_THROWS();
}
return;
default:
ZEND_UNREACHABLE();
}
}
/* }}} */
/* {{{ Generate positive random number */
PHP_METHOD(Random_Randomizer, nextInt)
{
php_random_randomizer *randomizer = Z_RANDOM_RANDOMIZER_P(ZEND_THIS);
uint64_t result;
ZEND_PARSE_PARAMETERS_NONE();
result = randomizer->algo->generate(randomizer->status);
if (EG(exception)) {
RETURN_THROWS();
}
if (randomizer->status->last_generated_size > sizeof(zend_long)) {
zend_throw_exception(random_ce_Random_RandomException, "Generated value exceeds size of int", 0);
RETURN_THROWS();
}
RETURN_LONG((zend_long) (result >> 1));
}
/* }}} */
/* {{{ Generate random number in range */
PHP_METHOD(Random_Randomizer, getInt)
{
php_random_randomizer *randomizer = Z_RANDOM_RANDOMIZER_P(ZEND_THIS);
uint64_t result;
zend_long min, max;
ZEND_PARSE_PARAMETERS_START(2, 2)
Z_PARAM_LONG(min)
Z_PARAM_LONG(max)
ZEND_PARSE_PARAMETERS_END();
if (UNEXPECTED(max < min)) {
zend_argument_value_error(2, "must be greater than or equal to argument #1 ($min)");
RETURN_THROWS();
}
if (UNEXPECTED(
randomizer->algo->range == php_random_algo_mt19937.range
&& ((php_random_status_state_mt19937 *) randomizer->status->state)->mode != MT_RAND_MT19937
)) {
uint64_t r = php_random_algo_mt19937.generate(randomizer->status) >> 1;
/* This is an inlined version of the RAND_RANGE_BADSCALING macro that does not invoke UB when encountering
* (max - min) > ZEND_LONG_MAX.
*/
zend_ulong offset = (double) ( (double) max - min + 1.0) * (r / (PHP_MT_RAND_MAX + 1.0));
result = (zend_long) (offset + min);
} else {
result = randomizer->algo->range(randomizer->status, min, max);
}
if (EG(exception)) {
RETURN_THROWS();
}
RETURN_LONG((zend_long) result);
}
/* }}} */
/* {{{ Generate random bytes string in ordered length */
PHP_METHOD(Random_Randomizer, getBytes)
{
php_random_randomizer *randomizer = Z_RANDOM_RANDOMIZER_P(ZEND_THIS);
zend_string *retval;
zend_long length;
size_t total_size = 0;
ZEND_PARSE_PARAMETERS_START(1, 1)
Z_PARAM_LONG(length)
ZEND_PARSE_PARAMETERS_END();
if (length < 1) {
zend_argument_value_error(1, "must be greater than 0");
RETURN_THROWS();
}
retval = zend_string_alloc(length, 0);
while (total_size < length) {
uint64_t result = randomizer->algo->generate(randomizer->status);
if (EG(exception)) {
zend_string_free(retval);
RETURN_THROWS();
}
for (size_t i = 0; i < randomizer->status->last_generated_size; i++) {
ZSTR_VAL(retval)[total_size++] = (result >> (i * 8)) & 0xff;
if (total_size >= length) {
break;
}
}
}
ZSTR_VAL(retval)[length] = '\0';
RETURN_STR(retval);
}
/* }}} */
/* {{{ Shuffling array */
PHP_METHOD(Random_Randomizer, shuffleArray)
{
php_random_randomizer *randomizer = Z_RANDOM_RANDOMIZER_P(ZEND_THIS);
zval *array;
ZEND_PARSE_PARAMETERS_START(1, 1)
Z_PARAM_ARRAY(array)
ZEND_PARSE_PARAMETERS_END();
ZVAL_DUP(return_value, array);
if (!php_array_data_shuffle(randomizer->algo, randomizer->status, return_value)) {
RETURN_THROWS();
}
}
/* }}} */
/* {{{ Shuffling binary */
PHP_METHOD(Random_Randomizer, shuffleBytes)
{
php_random_randomizer *randomizer = Z_RANDOM_RANDOMIZER_P(ZEND_THIS);
zend_string *bytes;
ZEND_PARSE_PARAMETERS_START(1, 1)
Z_PARAM_STR(bytes)
ZEND_PARSE_PARAMETERS_END();
if (ZSTR_LEN(bytes) < 2) {
RETURN_STR_COPY(bytes);
}
RETVAL_STRINGL(ZSTR_VAL(bytes), ZSTR_LEN(bytes));
if (!php_binary_string_shuffle(randomizer->algo, randomizer->status, Z_STRVAL_P(return_value), (zend_long) Z_STRLEN_P(return_value))) {
RETURN_THROWS();
}
}
/* }}} */
/* {{{ Pick keys */
PHP_METHOD(Random_Randomizer, pickArrayKeys)
{
php_random_randomizer *randomizer = Z_RANDOM_RANDOMIZER_P(ZEND_THIS);
zval *input, t;
zend_long num_req;
ZEND_PARSE_PARAMETERS_START(2, 2);
Z_PARAM_ARRAY(input)
Z_PARAM_LONG(num_req)
ZEND_PARSE_PARAMETERS_END();
if (!php_array_pick_keys(
randomizer->algo,
randomizer->status,
input,
num_req,
return_value,
false)
) {
RETURN_THROWS();
}
/* Keep compatibility, But the result is always an array */
if (Z_TYPE_P(return_value) != IS_ARRAY) {
ZVAL_COPY_VALUE(&t, return_value);
array_init(return_value);
zend_hash_next_index_insert(Z_ARRVAL_P(return_value), &t);
}
}
/* }}} */
/* {{{ Get Random Bytes for String */
PHP_METHOD(Random_Randomizer, getBytesFromString)
{
php_random_randomizer *randomizer = Z_RANDOM_RANDOMIZER_P(ZEND_THIS);
zend_long length;
zend_string *source, *retval;
size_t total_size = 0;
ZEND_PARSE_PARAMETERS_START(2, 2);
Z_PARAM_STR(source)
Z_PARAM_LONG(length)
ZEND_PARSE_PARAMETERS_END();
const size_t source_length = ZSTR_LEN(source);
const size_t max_offset = source_length - 1;
if (source_length < 1) {
zend_argument_value_error(1, "cannot be empty");
RETURN_THROWS();
}
if (length < 1) {
zend_argument_value_error(2, "must be greater than 0");
RETURN_THROWS();
}
retval = zend_string_alloc(length, 0);
if (max_offset > 0xff) {
while (total_size < length) {
uint64_t offset = randomizer->algo->range(randomizer->status, 0, max_offset);
if (EG(exception)) {
zend_string_free(retval);
RETURN_THROWS();
}
ZSTR_VAL(retval)[total_size++] = ZSTR_VAL(source)[offset];
}
} else {
uint64_t mask = max_offset;
// Copy the top-most bit into all lower bits.
// Shifting by 4 is sufficient, because max_offset
// is guaranteed to fit in an 8-bit integer at this
// point.
mask |= mask >> 1;
mask |= mask >> 2;
mask |= mask >> 4;
int failures = 0;
while (total_size < length) {
uint64_t result = randomizer->algo->generate(randomizer->status);
if (EG(exception)) {
zend_string_free(retval);
RETURN_THROWS();
}
for (size_t i = 0; i < randomizer->status->last_generated_size; i++) {
uint64_t offset = (result >> (i * 8)) & mask;
if (offset > max_offset) {
if (++failures > PHP_RANDOM_RANGE_ATTEMPTS) {
zend_string_free(retval);
zend_throw_error(random_ce_Random_BrokenRandomEngineError, "Failed to generate an acceptable random number in %d attempts", PHP_RANDOM_RANGE_ATTEMPTS);
RETURN_THROWS();
}
continue;
}
failures = 0;
ZSTR_VAL(retval)[total_size++] = ZSTR_VAL(source)[offset];
if (total_size >= length) {
break;
}
}
}
}
ZSTR_VAL(retval)[length] = '\0';
RETURN_STR(retval);
}
/* }}} */
/* {{{ Random\Randomizer::__serialize() */
PHP_METHOD(Random_Randomizer, __serialize)
{
php_random_randomizer *randomizer = Z_RANDOM_RANDOMIZER_P(ZEND_THIS);
zval t;
ZEND_PARSE_PARAMETERS_NONE();
array_init(return_value);
ZVAL_ARR(&t, zend_std_get_properties(&randomizer->std));
Z_TRY_ADDREF(t);
zend_hash_next_index_insert(Z_ARRVAL_P(return_value), &t);
}
/* }}} */
/* {{{ Random\Randomizer::__unserialize() */
PHP_METHOD(Random_Randomizer, __unserialize)
{
php_random_randomizer *randomizer = Z_RANDOM_RANDOMIZER_P(ZEND_THIS);
HashTable *d;
zval *members_zv;
zval *zengine;
ZEND_PARSE_PARAMETERS_START(1, 1)
Z_PARAM_ARRAY_HT(d);
ZEND_PARSE_PARAMETERS_END();
/* Verify the expected number of elements, this implicitly ensures that no additional elements are present. */
if (zend_hash_num_elements(d) != 1) {
zend_throw_exception(NULL, "Invalid serialization data for Random\\Randomizer object", 0);
RETURN_THROWS();
}
members_zv = zend_hash_index_find(d, 0);
if (!members_zv || Z_TYPE_P(members_zv) != IS_ARRAY) {
zend_throw_exception(NULL, "Invalid serialization data for Random\\Randomizer object", 0);
RETURN_THROWS();
}
object_properties_load(&randomizer->std, Z_ARRVAL_P(members_zv));
if (EG(exception)) {
zend_throw_exception(NULL, "Invalid serialization data for Random\\Randomizer object", 0);
RETURN_THROWS();
}
zengine = zend_read_property(randomizer->std.ce, &randomizer->std, "engine", strlen("engine"), 1, NULL);
if (Z_TYPE_P(zengine) != IS_OBJECT || !instanceof_function(Z_OBJCE_P(zengine), random_ce_Random_Engine)) {
zend_throw_exception(NULL, "Invalid serialization data for Random\\Randomizer object", 0);
RETURN_THROWS();
}
randomizer_common_init(randomizer, Z_OBJ_P(zengine));
}
/* }}} */