Random\Engine\Secure::generate

Description

Returns cryptographically secure randomness.

The sources of randomness in the order of priority are as follows:

• Linux: » getrandom(), /dev/urandom

• FreeBSD >= 12 (PHP >= 7.3): » getrandom(), /dev/urandom

• Windows (PHP >= 7.2): » CNG-API

  Windows: » CryptGenRandom

• macOS (PHP >= 8.2; >= 8.1.9; >= 8.0.22 if CCRandomGenerateBytes is available at compile time): CCRandomGenerateBytes()

  macOS (PHP >= 8.1; >= 8.0.2): arc4random_buf(), /dev/urandom

• NetBSD >= 7 (PHP >= 7.1; >= 7.0.1): arc4random_buf(), /dev/urandom

• OpenBSD >= 5.5 (PHP >= 7.1; >= 7.0.1): arc4random_buf(), /dev/urandom

• DragonflyBSD (PHP >= 8.1): » getrandom(), /dev/urandom

• Solaris (PHP >= 8.1): » getrandom(), /dev/urandom

• Any combination of operating system and PHP version not previously mentioned: /dev/urandom
• If none of the sources are available or they all fail to generate randomness, then a Random\RandomException will be thrown.