Looking a bit deeper ...
You can easily get the source code:
apt-get install hostap-source
Source file should appear in /usr/src directory.
Unpack it, as root of course:
tar zxvf hostap-driver_0.4.1.orig.tar.gz
In the new folder is the driver source code for cards with Prism chipsets. You will have to build a module from this code against your current kernel, for which you will also need the source code:
apt-get install kernel-source-$(uname -r)
Isn't it great being able to download all this source code?
Again, a new kernel-source folder will appear in /usr/src.
Make a sym link to it with this command:
ln -s /usr/src/kernel-source-WHATEVER /usr/src/linux
You will also need various tools for compiling:
binutils, e2fsprogs, gcc, make, module-init-tools, procps, util-linux, all available via APT.
I don't know if your card is PCI , USB or PCMCIA, but a stock Debian kernel has support for all these interfaces. They suggest you run a "configured" kernel but I haven't had any problems building drivers against stock kernel source. YMMV.
But, you will need to build the drivers. Now, goto driver source folder, open a root terminal and
make config, make all and make install.
Hopefully, your build was successful. You can load the drivers with
modprobe prism2_pci, prism2_usb or prism2_plx/prism2_cs, depending on the interface. Failing at that, reboot and let Discover try to detect and load it. Lastly, you can always add prism2_pci, prism2_usb, prism2_plx or prism2_cs to your /etc/modules file and they will be automatically loaded at boot time. This will sub for editing the rc.local file, which Debian doesn't have anyway.
Use something easy like KWiFiManager to setup your connection.