dh_make_key and Fortuna

[Ron Aaron]

I'm having difficulty using 'dh_make_key' with any key size above 128.  The documentation says the size may be up to 512.

I initialize the fortuna PRNG with 64 bytes of random data and call dh_make_key with a size of anything above 129, then I get the return "CRYPT_ERROR_READPRNG" (it works for 128 and below).

Looking at the source, I believe the culprit is 'rng_make_prng', which doesn't accept bit sizes greater than 1024.

Is this a bug in the documentation, in the implementation, or in my usage?