Function at 0x402880
Capabilities:
Encode data using xor
Hash data with crc32

Disassembly:
push esi
mov esi, edx
not eax
test esi, esi
je 0x4028ae
lea esp, [esp]
test cl, 3
je 0x4028ae
movzx edx, byte [ecx]
xor edx, eax
and edx, 0xff
shr eax, 8
xor eax, dword [edx*4 + 0x55de68]
inc ecx
dec esi
jne 0x402890
push ebx
push edi
cmp esi, 0x20
jb 0x402ac4
mov edi, esi
shr edi, 5
mov edi, edi
xor eax, dword [ecx]
mov edx, eax
shr edx, 0x10
mov ebx, eax
shr ebx, 8
and ebx, 0xff
and edx, 0xff
mov edx, dword [edx*4 + 0x55e268]
xor edx, dword [ebx*4 + 0x55e668]
mov ebx, eax
shr ebx, 0x18
xor edx, dword [ebx*4 + 0x55de68]
and eax, 0xff
xor edx, dword [eax*4 + 0x55ea68]
xor edx, dword [ecx + 4]
mov eax, edx
shr eax, 0x10
and eax, 0xff
mov eax, dword [eax*4 + 0x55e268]
mov ebx, edx
shr ebx, 8
and ebx, 0xff
xor eax, dword [ebx*4 + 0x55e668]
mov ebx, edx
shr ebx, 0x18
xor eax, dword [ebx*4 + 0x55de68]
and edx, 0xff
xor eax, dword [edx*4 + 0x55ea68]
xor eax, dword [ecx + 8]
mov edx, eax
shr edx, 0x10
mov ebx, eax
shr ebx, 8
and ebx, 0xff
and edx, 0xff
mov edx, dword [edx*4 + 0x55e268]
xor edx, dword [ebx*4 + 0x55e668]
mov ebx, eax
shr ebx, 0x18
xor edx, dword [ebx*4 + 0x55de68]
and eax, 0xff
xor edx, dword [eax*4 + 0x55ea68]
xor edx, dword [ecx + 0xc]
mov eax, edx
shr eax, 0x10
and eax, 0xff
mov eax, dword [eax*4 + 0x55e268]
mov ebx, edx
shr ebx, 8
and ebx, 0xff
xor eax, dword [ebx*4 + 0x55e668]
mov ebx, edx
shr ebx, 0x18
xor eax, dword [ebx*4 + 0x55de68]
and edx, 0xff
xor eax, dword [edx*4 + 0x55ea68]
xor eax, dword [ecx + 0x10]
mov edx, eax
shr edx, 0x10
mov ebx, eax
shr ebx, 8
and edx, 0xff
mov edx, dword [edx*4 + 0x55e268]
and ebx, 0xff
xor edx, dword [ebx*4 + 0x55e668]
mov ebx, eax
shr ebx, 0x18
xor edx, dword [ebx*4 + 0x55de68]
and eax, 0xff
xor edx, dword [eax*4 + 0x55ea68]
xor edx, dword [ecx + 0x14]
mov eax, edx
shr eax, 0x10
and eax, 0xff
mov eax, dword [eax*4 + 0x55e268]
mov ebx, edx
shr ebx, 8
and ebx, 0xff
xor eax, dword [ebx*4 + 0x55e668]
mov ebx, edx
shr ebx, 0x18
xor eax, dword [ebx*4 + 0x55de68]
and edx, 0xff
xor eax, dword [edx*4 + 0x55ea68]
add ecx, 0x20
xor eax, dword [ecx - 8]
sub esi, 0x20
mov edx, eax
mov ebx, eax
shr edx, 0x10
shr ebx, 8
and edx, 0xff
mov edx, dword [edx*4 + 0x55e268]
and ebx, 0xff
xor edx, dword [ebx*4 + 0x55e668]
mov ebx, eax
shr ebx, 0x18
xor edx, dword [ebx*4 + 0x55de68]
and eax, 0xff
xor edx, dword [eax*4 + 0x55ea68]
xor edx, dword [ecx - 4]
mov eax, edx
shr eax, 0x10
and eax, 0xff
mov eax, dword [eax*4 + 0x55e268]
mov ebx, edx
shr ebx, 8
and ebx, 0xff
xor eax, dword [ebx*4 + 0x55e668]
mov ebx, edx
shr ebx, 0x18
xor eax, dword [ebx*4 + 0x55de68]
and edx, 0xff
xor eax, dword [edx*4 + 0x55ea68]
dec edi
jne 0x4028c0
cmp esi, 4
jb 0x402b19
mov edx, esi
shr edx, 2
mov edi, edi
xor eax, dword [ecx]
add ecx, 4
mov edi, eax
shr edi, 0x10
and edi, 0xff
mov edi, dword [edi*4 + 0x55e268]
mov ebx, eax
shr ebx, 8
and ebx, 0xff
xor edi, dword [ebx*4 + 0x55e668]
mov ebx, eax
shr ebx, 0x18
xor edi, dword [ebx*4 + 0x55de68]
and eax, 0xff
xor edi, dword [eax*4 + 0x55ea68]
sub esi, 4
dec edx
mov eax, edi
jne 0x402ad0
pop edi
pop ebx
test esi, esi
je 0x402b39
nop
movzx edx, byte [ecx]
xor edx, eax
and edx, 0xff
shr eax, 8
xor eax, dword [edx*4 + 0x55de68]
inc ecx
dec esi
jne 0x402b20
not eax
pop esi
ret