if this is RC4

[Martin Minow]

The strange line in the posted RC4 (assuming that's what it is):
>         xorIndex = state[x] + (state[y]) % 256;
might be an intentional do-nothing statement that could be used to show
that the original was stolen source code, rather than a decompilation
of an executable or object module. An expert could point out that the
statement cannot be derived from any distribution of RC4, but was in
the source licensed to Company X, and therefore an employee of Company X
violated the source code agreement.

Just speculating.

Martin Minow
minow at apple.com
The above does not represent the position of Apple Computer Inc.