OpenID in PHP

[meepbear *]

>Is BCMath better than BigInt? I was under the impression it wasn't. As
>for compatibility, BCMath would be better anyway, claims to be bundled
>with PHP 4.0.4 onward. The most desirable option would be using
>whatever is available in order of efficiency such as:

In the context of PHP "bundled" only means that it doesn't depend on an 
external library, but whether or not it's there and useable depends on how 
PHP was compiled (with --enable-bcmath). I checked with the hosts I'm with, 
and I asked others to check a phpinfo(); and none of them had either BCMath 
or GMP so my sense so far is that you can't rely on them being there and 
most likely neither of them will be there.
To further add to the fun, the BCMath that comes with Windows doesn't yield 
the same results as it does on UNIX.

BigInt is my own "pure PHP" implementation so you're probably thinking of 
something else, although I probably would really like to know about what you 
thought it is. I asked on the list a days back for a native implementation 
of big integers but never heard back so I started my own. It works right 
now, but it's just too slow to use with numbers as big as DH requires so I 
pulled it back out.
GMP doesn't work on Windows so I can't test that easily.

HMAC also requires the mhash extension which isn't necessarily there by 
default, but at least you can get around that one easily.