/**
* If the libsodium PHP extension is loaded, we'll use it above any other
* solution.
*
* libsodium-php project:
* @ref https://github.com/jedisct1/libsodium-php
*
* @param int $bytes
*
* @throws Exception
*
* @return string
*/
function random_bytes($bytes)
{
try {
$bytes = RandomCompat_intval($bytes);
} catch (TypeError $ex) {
throw new TypeError('random_bytes(): $bytes must be an integer');
}
if ($bytes < 1) {
throw new Error('Length must be greater than 0');
}
/**
* \Sodium\randombytes_buf() doesn't allow more than 2147483647 bytes to be
* generated in one invocation.
*/
if ($bytes > 2147483647) {
$buf = '';
for ($i = 0; $i < $bytes; $i += 1073741824) {
$n = $bytes - $i > 1073741824 ? 1073741824 : $bytes - $i;
$buf .= \Sodium\randombytes_buf($n);
}
} else {
$buf = \Sodium\randombytes_buf($bytes);
}
if ($buf !== false) {
if (RandomCompat_strlen($buf) === $bytes) {
return $buf;
}
}
/**
* If we reach here, PHP has failed us.
*/
throw new Exception('Could not gather sufficient random data');
}
public function testStrlen()
{
if (!function_exists('RandomCompat_strlen')) {
return $this->markTestSkipped('We don\' need to test this in PHP 7.');
}
$this->assertEquals(RandomCompat_strlen("𝒳"), 4);
}
/**
* Windows with PHP < 5.3.0 will not have the function
* openssl_random_pseudo_bytes() available, so let's use
* CAPICOM to work around this deficiency.
*
* @param int $bytes
*
* @throws Exception
*
* @return string
*/
function random_bytes($bytes)
{
if (!is_int($bytes)) {
throw new TypeError('Length must be an integer');
}
if ($bytes < 1) {
throw new Error('Length must be greater than 0');
}
$buf = '';
$util = new COM('CAPICOM.Utilities.1');
$execCount = 0;
/**
* Let's not let it loop forever. If we run N times and fail to
* get N bytes of random data, then CAPICOM has failed us.
*/
do {
$buf .= base64_decode($util->GetRandom($bytes, 0));
if (RandomCompat_strlen($buf) >= $bytes) {
/**
* Return our random entropy buffer here:
*/
return RandomCompat_substr($buf, 0, $bytes);
}
++$execCount;
} while ($execCount < $bytes);
/**
* If we reach here, PHP has failed us.
*/
throw new Exception('PHP failed to generate random data.');
}
/**
* Since openssl_random_pseudo_bytes() uses openssl's
* RAND_pseudo_bytes() API, which has been marked as deprecated by the
* OpenSSL team, this is our last resort before failure.
*
* @ref https://www.openssl.org/docs/crypto/RAND_bytes.html
*
* @param int $bytes
*
* @throws Exception
*
* @return string
*/
function random_bytes($bytes)
{
try {
$bytes = RandomCompat_intval($bytes);
} catch (TypeError $ex) {
throw new TypeError('random_bytes(): $bytes must be an integer');
}
if ($bytes < 1) {
throw new Error('Length must be greater than 0');
}
$secure = true;
/**
* $secure is passed by reference. If it's set to false, fail. Note
* that this will only return false if this function fails to return
* any data.
*
* @ref https://github.com/paragonie/random_compat/issues/6#issuecomment-119564973
*/
$buf = openssl_random_pseudo_bytes($bytes, $secure);
if ($buf !== false && $secure) {
if (RandomCompat_strlen($buf) === $bytes) {
return $buf;
}
}
/**
* If we reach here, PHP has failed us.
*/
throw new Exception('Could not gather sufficient random data');
}
/**
* Powered by ext/mcrypt (and thankfully NOT libmcrypt)
*
* @ref https://bugs.php.net/bug.php?id=55169
* @ref https://github.com/php/php-src/blob/c568ffe5171d942161fc8dda066bce844bdef676/ext/mcrypt/mcrypt.c#L1321-L1386
*
* @param int $bytes
*
* @throws Exception
*
* @return string
*/
function random_bytes($bytes)
{
if (!is_int($bytes)) {
throw new TypeError('Length must be an integer');
}
if ($bytes < 1) {
throw new Error('Length must be greater than 0');
}
$buf = mcrypt_create_iv($bytes, MCRYPT_DEV_URANDOM);
if ($buf !== false) {
if (RandomCompat_strlen($buf) === $bytes) {
/**
* Return our random entropy buffer here:
*/
return $buf;
}
}
/**
* If we reach here, PHP has failed us.
*/
throw new Exception('PHP failed to generate random data.');
}
/**
* Powered by ext/mcrypt (and thankfully NOT libmcrypt)
*
* @ref https://bugs.php.net/bug.php?id=55169
* @ref https://github.com/php/php-src/blob/c568ffe5171d942161fc8dda066bce844bdef676/ext/mcrypt/mcrypt.c#L1321-L1386
*
* @param int $bytes
*
* @throws Exception
*
* @return string
*/
function random_bytes($bytes)
{
try {
$bytes = RandomCompat_intval($bytes);
} catch (TypeError $ex) {
throw new TypeError('random_bytes(): $bytes must be an integer');
}
if ($bytes < 1) {
throw new Error('Length must be greater than 0');
}
$buf = @mcrypt_create_iv($bytes, MCRYPT_DEV_URANDOM);
if ($buf !== false && RandomCompat_strlen($buf) === $bytes) {
/**
* Return our random entropy buffer here:
*/
return $buf;
}
/**
* If we reach here, PHP has failed us.
*/
throw new Exception('Could not gather sufficient random data');
}
/**
* Since openssl_random_pseudo_bytes() uses openssl's
* RAND_pseudo_bytes() API, which has been marked as deprecated by the
* OpenSSL team, this is our last resort before failure.
*
* @ref https://www.openssl.org/docs/crypto/RAND_bytes.html
*
* @param int $bytes
* @return string
*/
function random_bytes($bytes)
{
$secure = true;
$buf = openssl_random_pseudo_bytes($bytes, $secure);
if ($buf !== false && $secure) {
if (RandomCompat_strlen($buf) === $bytes) {
return $buf;
}
}
}
/**
* Unless open_basedir is enabled, use /dev/urandom for
* random numbers in accordance with best practices
*
* Why we use /dev/urandom and not /dev/random
* @ref http://sockpuppet.org/blog/2014/02/25/safely-generate-random-numbers
*
* @param int $bytes
*
* @throws Exception
*
* @return string
*/
function random_bytes($bytes)
{
static $fp = null;
/**
* This block should only be run once
*/
if (empty($fp)) {
/**
* We use /dev/urandom if it is a char device.
* We never fall back to /dev/random
*/
$fp = fopen('/dev/urandom', 'rb');
if (!empty($fp)) {
$st = fstat($fp);
if (($st['mode'] & 0170000) !== 020000) {
fclose($fp);
$fp = false;
}
}
if (!empty($fp)) {
/**
* stream_set_read_buffer() does not exist in HHVM
*
* If we don't set the stream's read buffer to 0, PHP will
* internally buffer 8192 bytes, which can waste entropy
*
* stream_set_read_buffer returns 0 on success
*/
if (function_exists('stream_set_read_buffer')) {
stream_set_read_buffer($fp, RANDOM_COMPAT_READ_BUFFER);
}
if (function_exists('stream_set_chunk_size')) {
stream_set_chunk_size($fp, RANDOM_COMPAT_READ_BUFFER);
}
}
}
try {
$bytes = RandomCompat_intval($bytes);
} catch (TypeError $ex) {
throw new TypeError('random_bytes(): $bytes must be an integer');
}
if ($bytes < 1) {
throw new Error('Length must be greater than 0');
}
/**
* This if() block only runs if we managed to open a file handle
*
* It does not belong in an else {} block, because the above
* if (empty($fp)) line is logic that should only be run once per
* page load.
*/
if (!empty($fp)) {
$remaining = $bytes;
$buf = '';
/**
* We use fread() in a loop to protect against partial reads
*/
do {
$read = fread($fp, $remaining);
if ($read === false) {
/**
* We cannot safely read from the file. Exit the
* do-while loop and trigger the exception condition
*/
$buf = false;
break;
}
/**
* Decrease the number of bytes returned from remaining
*/
$remaining -= RandomCompat_strlen($read);
$buf .= $read;
} while ($remaining > 0);
/**
* Is our result valid?
*/
if ($buf !== false) {
if (RandomCompat_strlen($buf) === $bytes) {
/**
* Return our random entropy buffer here:
*/
return $buf;
}
}
}
/**
* If we reach here, PHP has failed us.
*/
throw new Exception('Error reading from source device');
}
/**
* substr() implementation that isn't brittle to mbstring.func_overload
*
* This version uses mb_substr() in '8bit' mode to treat strings as raw
* binary rather than UTF-8, ISO-8859-1, etc
*
* @param string $binary_string
* @param int $start
* @param int $length (optional)
*
* @throws TypeError
*
* @return string
*/
function RandomCompat_substr($binary_string, $start, $length = null)
{
if (!is_string($binary_string)) {
throw new TypeError('RandomCompat_substr(): First argument should be a string');
}
if (!is_int($start)) {
throw new TypeError('RandomCompat_substr(): Second argument should be an integer');
}
if ($length === null) {
/**
* mb_substr($str, 0, NULL, '8bit') returns an empty string on
* PHP 5.3, so we have to find the length ourselves.
*/
$length = RandomCompat_strlen($length) - $start;
} elseif (!is_int($length)) {
throw new TypeError('RandomCompat_substr(): Third argument should be an integer, or omitted');
}
// Consistency with PHP's behavior
if ($start === RandomCompat_strlen($binary_string) && $length === 0) {
return '';
}
if ($start > RandomCompat_strlen($binary_string)) {
return false;
}
return mb_substr($binary_string, $start, $length, '8bit');
}
/**
* substr() implementation that isn't brittle to mbstring.func_overload
*
* This version uses mb_substr() in '8bit' mode to treat strings as raw
* binary rather than UTF-8, ISO-8859-1, etc
*
* @param string $binary_string
* @param int $start
* @param int $length (optional)
*
* @throws InvalidArgumentException
*
* @return string
*/
function RandomCompat_substr($binary_string, $start, $length = null)
{
if (!is_string($binary_string)) {
throw new InvalidArgumentException('RandomCompat_substr(): First argument should be a string');
}
if (!is_int($start)) {
throw new InvalidArgumentException('RandomCompat_substr(): Second argument should be an integer');
}
if ($length === null) {
/**
* mb_substr($str, 0, NULL, '8bit') returns an empty string on
* PHP 5.3, so we have to find the length ourselves.
*/
$length = RandomCompat_strlen($length) - $start;
} elseif (!is_int($length)) {
throw new InvalidArgumentException('RandomCompat_substr(): Third argument should be an integer, or omitted');
}
return mb_substr($binary_string, $start, $length, '8bit');
}
