How can I know to which ubuntu package does a specified file (not on my fs) belongs?

[Kevin Wilson]

Hi,
I want to know how can I find (with apt-get), to which ubuntu package
does a certain file (which **does not** exist on my filesystem)
belong.
For example, crypto.h header file belongs to libssl-devel; but I found
it only after googling.
With fedore you have:
yum provides "*/crypto.h"  (which , BTW, returns openssl-deve and not
libssl-devel)

rgs,
Kevin