Function at 0x403880
Capabilities:
Encode data using xor
Hash data with crc32

Disassembly:
push ebx
push edi
mov edi, dword [esp + 0xc]
mov ebx, edx
not ecx
test edi, edi
je 0x4038ad
mov edi, edi
test bl, 3
je 0x4038ad
movzx eax, byte [ebx]
inc ebx
xor eax, ecx
shr ecx, 8
and eax, 0xff
xor ecx, dword [eax*4 + 0x4277e0]
dec edi
jne 0x403890
push esi
cmp edi, 0x20
jb 0x403abf
push ebp
mov ebp, edi
shr ebp, 5
lea ecx, [ecx]
xor ecx, dword [ebx]
mov edx, ecx
mov eax, ecx
shr eax, 8
and eax, 0xff
shr edx, 0x10
and edx, 0xff
mov edx, dword [edx*4 + 0x427be0]
xor edx, dword [eax*4 + 0x427fe0]
mov eax, ecx
shr eax, 0x18
xor edx, dword [eax*4 + 0x4277e0]
movzx eax, cl
xor edx, dword [eax*4 + 0x4283e0]
xor edx, dword [ebx + 4]
add ebx, 8
mov ecx, edx
mov dword [esp + 0x14], ebx
mov esi, dword [esp + 0x14]
mov eax, edx
shr eax, 8
and eax, 0xff
shr ecx, 0x10
and ecx, 0xff
mov ebx, dword [ecx*4 + 0x427be0]
xor ebx, dword [eax*4 + 0x427fe0]
mov eax, edx
shr eax, 0x18
xor ebx, dword [eax*4 + 0x4277e0]
movzx eax, dl
xor ebx, dword [eax*4 + 0x4283e0]
xor ebx, dword [esi]
mov ecx, ebx
mov eax, ebx
shr eax, 8
and eax, 0xff
shr ecx, 0x10
and ecx, 0xff
mov edx, dword [ecx*4 + 0x427be0]
xor edx, dword [eax*4 + 0x427fe0]
mov eax, ebx
shr eax, 0x18
xor edx, dword [eax*4 + 0x4277e0]
movzx eax, bl
xor edx, dword [eax*4 + 0x4283e0]
xor edx, dword [esi + 4]
mov ecx, edx
mov eax, edx
shr eax, 8
and eax, 0xff
shr ecx, 0x10
and ecx, 0xff
mov ebx, dword [ecx*4 + 0x427be0]
xor ebx, dword [eax*4 + 0x427fe0]
mov eax, edx
shr eax, 0x18
xor ebx, dword [eax*4 + 0x4277e0]
movzx eax, dl
xor ebx, dword [eax*4 + 0x4283e0]
xor ebx, dword [esi + 8]
mov ecx, ebx
mov eax, ebx
shr ecx, 0x10
shr eax, 8
and ecx, 0xff
and eax, 0xff
mov edx, dword [ecx*4 + 0x427be0]
xor edx, dword [eax*4 + 0x427fe0]
mov eax, ebx
shr eax, 0x18
xor edx, dword [eax*4 + 0x4277e0]
movzx eax, bl
xor edx, dword [eax*4 + 0x4283e0]
xor edx, dword [esi + 0xc]
mov ecx, edx
mov eax, edx
shr ecx, 0x10
and ecx, 0xff
shr eax, 8
and eax, 0xff
mov ebx, dword [ecx*4 + 0x427be0]
xor ebx, dword [eax*4 + 0x427fe0]
sub edi, 0x20
mov eax, edx
shr eax, 0x18
xor ebx, dword [eax*4 + 0x4277e0]
movzx eax, dl
xor ebx, dword [eax*4 + 0x4283e0]
xor ebx, dword [esi + 0x10]
add esi, 0x14
mov ecx, ebx
mov dword [esp + 0x14], esi
shr ecx, 0x10
mov eax, ebx
shr eax, 8
and ecx, 0xff
and eax, 0xff
mov edx, dword [ecx*4 + 0x427be0]
xor edx, dword [eax*4 + 0x427fe0]
mov eax, ebx
shr eax, 0x18
xor edx, dword [eax*4 + 0x4277e0]
movzx eax, bl
mov ebx, esi
xor edx, dword [eax*4 + 0x4283e0]
xor edx, dword [ebx]
add ebx, 4
mov ecx, edx
mov eax, edx
shr ecx, 0x10
and ecx, 0xff
shr eax, 8
and eax, 0xff
mov ecx, dword [ecx*4 + 0x427be0]
xor ecx, dword [eax*4 + 0x427fe0]
mov eax, edx
shr eax, 0x18
xor ecx, dword [eax*4 + 0x4277e0]
movzx eax, dl
xor ecx, dword [eax*4 + 0x4283e0]
dec ebp
jne 0x4038c0
pop ebp
cmp edi, 4
jb 0x403b16
mov esi, edi
shr esi, 2
lea esp, [esp]
xor ecx, dword [ebx]
sub edi, 4
mov edx, ecx
mov eax, ecx
shr edx, 0x10
add ebx, 4
and edx, 0xff
shr eax, 8
and eax, 0xff
mov edx, dword [edx*4 + 0x427be0]
xor edx, dword [eax*4 + 0x427fe0]
mov eax, ecx
shr eax, 0x18
xor edx, dword [eax*4 + 0x4277e0]
movzx eax, cl
xor edx, dword [eax*4 + 0x4283e0]
mov ecx, edx
dec esi
jne 0x403ad0
pop esi
test edi, edi
je 0x403b3a
jmp 0x403b20
movzx eax, byte [ebx]
lea ebx, [ebx + 1]
xor eax, ecx
shr ecx, 8
and eax, 0xff
xor ecx, dword [eax*4 + 0x4277e0]
dec edi
jne 0x403b20
not ecx
pop edi
mov eax, ecx
pop ebx
ret