php-src/ext/random/engine_user.c
Tim Düsterhus 60f149f7ad
Improve error reporting in random extension (#9071)
* Use `php_random_bytes_throw()` in Secure engine's generate()

This exposes the underlying exception, improving debugging:

    Fatal error: Uncaught Exception: Cannot open source device in php-src/test.php:5
    Stack trace:
    #0 php-src/test.php(5): Random\Engine\Secure->generate()
    #1 {main}

    Next RuntimeException: Random number generation failed in php-src/test.php:5
    Stack trace:
    #0 php-src/test.php(5): Random\Engine\Secure->generate()
    #1 {main}
      thrown in php-src/test.php on line 5

* Use `php_random_int_throw()` in Secure engine's range()

This exposes the underlying exception, improving debugging:

    Exception: Cannot open source device in php-src/test.php:17
    Stack trace:
    #0 php-src/test.php(17): Random\Randomizer->getInt(1, 3)
    #1 {main}

    Next RuntimeException: Random number generation failed in php-src/test.php:17
    Stack trace:
    #0 php-src/test.php(17): Random\Randomizer->getInt(1, 3)
    #1 {main}

* Throw exception when a user engine returns an empty string

This improves debugging, because the actual reason for the failure is available
as a previous Exception:

    DomainException: The returned string must not be empty in php-src/test.php:17
    Stack trace:
    #0 php-src/test.php(17): Random\Randomizer->getBytes(123)
    #1 {main}

    Next RuntimeException: Random number generation failed in php-src/test.php:17
    Stack trace:
    #0 php-src/test.php(17): Random\Randomizer->getBytes(123)
    #1 {main}

* Throw exception when the range selector fails to get acceptable numbers in 50 attempts

This improves debugging, because the actual reason for the failure is available
as a previous Exception:

    RuntimeException: Failed to generate an acceptable random number in 50 attempts in php-src/test.php:17
    Stack trace:
    #0 php-src/test.php(17): Random\Randomizer->getInt(1, 3)
    #1 {main}

    Next RuntimeException: Random number generation failed in php-src/test.php:17
    Stack trace:
    #0 php-src/test.php(17): Random\Randomizer->getInt(1, 3)
    #1 {main}

* Improve user_unsafe test

Select parameters for ->getInt() that will actually lead to unsafe behavior.

* Fix user_unsafe test

If an engine fails once it will be permanently poisoned by setting
`->last_unsafe`. This is undesirable for the test, because it skews the
results.

Fix this by creating a fresh engine for each "assertion".

* Remove duplication in user_unsafe.phpt

* Catch `Throwable` in user_unsafe.phpt

As we print the full stringified exception we implicitly assert the type of the
exception. No need to be overly specific in the catch block.

* Throw an error if an engine returns an empty string

* Throw an Error if range fails to find an acceptable number in 50 attempts
2022-07-25 09:00:49 +02:00

76 lines
2.2 KiB
C

/*
+----------------------------------------------------------------------+
| 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"
static uint64_t generate(php_random_status *status)
{
php_random_status_state_user *s = status->state;
uint64_t result = 0;
size_t size;
zval retval;
zend_call_known_instance_method_with_0_params(s->generate_method, s->object, &retval);
if (EG(exception)) {
status->last_unsafe = true;
return 0;
}
/* Store generated size in a state */
size = Z_STRLEN(retval);
/* Guard for over 64-bit results */
if (size > sizeof(uint64_t)) {
size = sizeof(uint64_t);
}
status->last_generated_size = size;
if (size > 0) {
/* Endianness safe copy */
for (size_t i = 0; i < size; i++) {
result += ((uint64_t) (unsigned char) Z_STRVAL(retval)[i]) << (8 * i);
}
} else {
zend_throw_error(NULL, "A random engine must return a non-empty string");
status->last_unsafe = true;
return 0;
}
zval_ptr_dtor(&retval);
return result;
}
static zend_long range(php_random_status *status, zend_long min, zend_long max)
{
return php_random_range(&php_random_algo_user, status, min, max);
}
const php_random_algo php_random_algo_user = {
0,
sizeof(php_random_status_state_user),
NULL,
generate,
range,
NULL,
NULL,
};