Installation
There is no installation needed to use these
functions; they are part of the PHP core.
However, to enable Argon2 password hashing, PHP must be built either with
libargon2 support using the
--with-password-argon2 configure option
or, starting from PHP 8.4.0, with OpenSSL using
--with-openssl and
--with-openssl-argon2.
Prior to PHP 8.1.0, it was possible to specify the argon2 directory with
--with-password-argon2[=DIR].