Function at 0x816843
Capabilities:
Encode data using xor
Hash data with crc32

Disassembly:
push ebp
mov ebp, esp
push ecx
cmp dword [ebp + 8], 0
push ebx
push esi
push edi
not eax
mov ecx, 0xff
je 0x816873
test dl, 3
je 0x816873
movzx ebx, byte [edx]
xor ebx, eax
and ebx, ecx
shr eax, 8
xor eax, dword [ebx*4 + 0x85d3e0]
inc edx
dec dword [ebp + 8]
jne 0x816857
cmp dword [ebp + 8], 0x20
push 4
mov esi, edx
pop edi
jb 0x816a20
mov edx, dword [ebp + 8]
shr edx, 5
mov dword [ebp - 4], edx
xor eax, dword [esi]
add esi, edi
mov edx, eax
shr edx, 0x10
movzx ebx, ah
and edx, ecx
mov edx, dword [edx*4 + 0x85d7e0]
xor edx, dword [ebx*4 + 0x85dbe0]
mov ebx, eax
and eax, ecx
shr ebx, 0x18
xor edx, dword [ebx*4 + 0x85d3e0]
xor edx, dword [eax*4 + 0x85dfe0]
xor edx, dword [esi]
add esi, edi
mov eax, edx
shr eax, 0x10
and eax, ecx
mov eax, dword [eax*4 + 0x85d7e0]
movzx ebx, dh
xor eax, dword [ebx*4 + 0x85dbe0]
mov ebx, edx
and edx, ecx
shr ebx, 0x18
xor eax, dword [ebx*4 + 0x85d3e0]
xor eax, dword [edx*4 + 0x85dfe0]
xor eax, dword [esi]
add esi, edi
mov edx, eax
shr edx, 0x10
movzx ebx, ah
and edx, ecx
mov edx, dword [edx*4 + 0x85d7e0]
xor edx, dword [ebx*4 + 0x85dbe0]
mov ebx, eax
and eax, ecx
shr ebx, 0x18
xor edx, dword [ebx*4 + 0x85d3e0]
xor edx, dword [eax*4 + 0x85dfe0]
xor edx, dword [esi]
add esi, edi
mov eax, edx
shr eax, 0x10
and eax, ecx
mov eax, dword [eax*4 + 0x85d7e0]
movzx ebx, dh
xor eax, dword [ebx*4 + 0x85dbe0]
mov ebx, edx
and edx, ecx
shr ebx, 0x18
xor eax, dword [ebx*4 + 0x85d3e0]
xor eax, dword [edx*4 + 0x85dfe0]
xor eax, dword [esi]
add esi, edi
mov edx, eax
shr edx, 0x10
movzx ebx, ah
and edx, ecx
mov edx, dword [edx*4 + 0x85d7e0]
xor edx, dword [ebx*4 + 0x85dbe0]
mov ebx, eax
and eax, ecx
shr ebx, 0x18
xor edx, dword [ebx*4 + 0x85d3e0]
xor edx, dword [eax*4 + 0x85dfe0]
xor edx, dword [esi]
add esi, edi
mov eax, edx
shr eax, 0x10
and eax, ecx
mov eax, dword [eax*4 + 0x85d7e0]
movzx ebx, dh
xor eax, dword [ebx*4 + 0x85dbe0]
mov ebx, edx
shr ebx, 0x18
xor eax, dword [ebx*4 + 0x85d3e0]
and edx, ecx
xor eax, dword [edx*4 + 0x85dfe0]
xor eax, dword [esi]
add esi, edi
mov edx, eax
shr edx, 0x10
movzx ebx, ah
and edx, ecx
mov edx, dword [edx*4 + 0x85d7e0]
xor edx, dword [ebx*4 + 0x85dbe0]
mov ebx, eax
and eax, ecx
sub dword [ebp + 8], 0x20
shr ebx, 0x18
xor edx, dword [ebx*4 + 0x85d3e0]
xor edx, dword [eax*4 + 0x85dfe0]
xor edx, dword [esi]
add esi, edi
mov eax, edx
shr eax, 0x10
and eax, ecx
mov eax, dword [eax*4 + 0x85d7e0]
movzx ebx, dh
xor eax, dword [ebx*4 + 0x85dbe0]
mov ebx, edx
shr ebx, 0x18
xor eax, dword [ebx*4 + 0x85d3e0]
and edx, ecx
xor eax, dword [edx*4 + 0x85dfe0]
dec dword [ebp - 4]
jne 0x81688b
cmp dword [ebp + 8], edi
jb 0x816a69
mov edx, dword [ebp + 8]
shr edx, 2
mov dword [ebp - 4], edx
xor eax, dword [esi]
sub dword [ebp + 8], edi
mov edx, eax
shr edx, 0x10
and edx, ecx
mov edx, dword [edx*4 + 0x85d7e0]
movzx ebx, ah
xor edx, dword [ebx*4 + 0x85dbe0]
mov ebx, eax
shr ebx, 0x18
xor edx, dword [ebx*4 + 0x85d3e0]
and eax, ecx
xor edx, dword [eax*4 + 0x85dfe0]
add esi, edi
dec dword [ebp - 4]
mov eax, edx
jne 0x816a2e
cmp dword [ebp + 8], 0
je 0x816a86
movzx edx, byte [esi]
xor edx, eax
and edx, ecx
shr eax, 8
xor eax, dword [edx*4 + 0x85d3e0]
inc esi
dec dword [ebp + 8]
jne 0x816a6f
pop edi
pop esi
not eax
pop ebx
leave
ret