simsam:
I have attached the map file.
sha.obj is the only module bound to the executable: 1953 bytes (Pentium class processor). There are at least three SHA implementations for AVR processors so it is not too surprising that something named "sha" would be small enough to fit in an Uno's memory. The rest (memory management, pbc, and floating-point) is dynamically linked.
The program uses structured exceptions which will be troublesome in the best case and non-existent in the worst case. I believe the libraries are "pure C" in which case structured exceptions can be easily managed / avoided.