ParagonIE_Sodium_Crypto::generichash_init( string $key = '', int $outputLength = 32 ): string

761    public static function generichash_init($key = '', $outputLength = 32)762    {763        // This ensures that ParagonIE_Sodium_Core_BLAKE2b::$iv is initialized764        ParagonIE_Sodium_Core_BLAKE2b::pseudoConstructor();765 766        $k = null;767        if (!empty($key)) {768            $k = ParagonIE_Sodium_Core_BLAKE2b::stringToSplFixedArray($key);769            if ($k->count() > ParagonIE_Sodium_Core_BLAKE2b::KEYBYTES) {770                throw new RangeException('Invalid key size');771            }772        }773 774        /** @var SplFixedArray $ctx */775        $ctx = ParagonIE_Sodium_Core_BLAKE2b::init($k, $outputLength);776 777        return ParagonIE_Sodium_Core_BLAKE2b::contextToString($ctx);778    }