Function at 0x43f4c4
Capabilities:
Encode data using xor
Generate random numbers using a mersenne twister

Disassembly:
push ebp
push ebx
push edi
push esi
sub esp, 8
mov ebp, dword [esp + 0x20]
mov eax, 0x80000000
mov edi, dword [esp + 0x24]
xor edi, eax
mov ecx, dword [esp + 0x28]
xor ecx, eax
sub ecx, edi
cmp ecx, 0xffffffff
je 0x43f6cf
mov dword [esp], edi
lea ebx, [ecx + 1]
mov edi, ecx
mov dword [esp + 4], edi
nop word cs:[eax + eax]
test edi, edi
je 0x43f574
mov eax, dword [ebp]
cmp eax, 0x270
jne 0x43f584
mov ecx, dword [ebp + 4]
mov eax, 0xfffffd90
nop word cs:[eax + eax]
and ecx, 0x80000000
mov edx, dword [ebp + eax*4 + 0x9c8]
mov esi, edx
and esi, 0x7ffffffe
or esi, ecx
shr esi, 1
mov ecx, edx
and edx, 1
neg edx
and edx, 0x9908b0df
xor edx, dword [ebp + eax*4 + 0xff8]
xor edx, esi
mov dword [ebp + eax*4 + 0x1384], edx
inc eax
jne 0x43f524
mov eax, dword [ebp]
jmp 0x43f65f
xor ecx, ecx
xor esi, esi
jmp 0x43f69b
cmp eax, 0x4e0
jb 0x43f65f
mov ecx, dword [ebp + 0x9c4]
xor eax, eax
nop word cs:[eax + eax]
and ecx, 0x80000000
mov edx, dword [ebp + eax*4 + 0x9c8]
mov esi, edx
and esi, 0x7ffffffe
or esi, ecx
shr esi, 1
mov ecx, edx
and edx, 1
neg edx
and edx, 0x9908b0df
xor edx, dword [ebp + eax*4 + 0xff8]
xor edx, esi
mov dword [ebp + eax*4 + 4], edx
inc eax
cmp eax, 0xe3
jne 0x43f5a4
mov ecx, dword [ebp + 0xd50]
mov eax, 0x80000000
and ecx, eax
xor eax, eax
nop word [eax + eax]
mov edx, dword [ebp + eax*4 + 0xd54]
mov esi, edx
and esi, 0x7ffffffe
or esi, ecx
shr esi, 1
mov ecx, edx
and edx, 1
neg edx
and edx, 0x9908b0df
xor edx, dword [ebp + eax*4 + 4]
xor edx, esi
mov dword [ebp + eax*4 + 0x390], edx
and ecx, 0x80000000
inc eax
cmp eax, 0x18c
jne 0x43f5f4
mov eax, dword [ebp + 4]
mov edx, eax
and edx, 0x7ffffffe
or edx, ecx
shr edx, 1
and eax, 1
neg eax
and eax, 0x9908b0df
xor eax, dword [ebp + 0x634]
xor eax, edx
mov dword [ebp + 0x9c0], eax
mov dword [ebp], 0
xor eax, eax
lea ecx, [eax + 1]
mov dword [ebp], ecx
mov eax, dword [ebp + eax*4 + 4]
mov ecx, eax
shr ecx, 0xb
and ecx, dword [ebp + 0x1384]
xor ecx, eax
mov eax, ecx
shl eax, 7
and eax, 0x9d2c5680
xor eax, ecx
mov edx, eax
shl edx, 0xf
and edx, 0xefc60000
xor edx, eax
mov ecx, edx
shr ecx, 0x12
xor ecx, edx
mov esi, 0xffffffff
xor edx, edx
mov eax, ecx
div ebx
mov edi, eax
xor edx, edx
mov eax, esi
div ebx
cmp edi, eax
mov edi, dword [esp + 4]
jb 0x43f6bf
xor edx, edx
mov eax, esi
div ebx
cmp edx, edi
jne 0x43f504
xor edx, edx
mov eax, ecx
div ebx
mov eax, edx
mov edi, dword [esp]
jmp 0x43f836
mov eax, dword [ebp]
cmp eax, 0x270
jne 0x43f725
mov ecx, dword [ebp + 4]
mov eax, 0xfffffd90
nop dword [eax]
and ecx, 0x80000000
mov edx, dword [ebp + eax*4 + 0x9c8]
mov esi, edx
and esi, 0x7ffffffe
or esi, ecx
shr esi, 1
mov ecx, edx
and edx, 1
neg edx
and edx, 0x9908b0df
xor edx, dword [ebp + eax*4 + 0xff8]
xor edx, esi
mov dword [ebp + eax*4 + 0x1384], edx
inc eax
jne 0x43f6e4
mov eax, dword [ebp]
jmp 0x43f7ff
cmp eax, 0x4e0
jb 0x43f7ff
mov ecx, dword [ebp + 0x9c4]
xor eax, eax
nop word cs:[eax + eax]
and ecx, 0x80000000
mov edx, dword [ebp + eax*4 + 0x9c8]
mov esi, edx
and esi, 0x7ffffffe
or esi, ecx
shr esi, 1
mov ecx, edx
and edx, 1
neg edx
and edx, 0x9908b0df
xor edx, dword [ebp + eax*4 + 0xff8]
xor edx, esi
mov dword [ebp + eax*4 + 4], edx
inc eax
cmp eax, 0xe3
jne 0x43f744
mov ecx, 0x80000000
and ecx, dword [ebp + 0xd50]
xor eax, eax
nop dword [eax + eax]
mov edx, dword [ebp + eax*4 + 0xd54]
mov esi, edx
and esi, 0x7ffffffe
or esi, ecx
shr esi, 1
mov ecx, edx
and edx, 1
neg edx
and edx, 0x9908b0df
xor edx, dword [ebp + eax*4 + 4]
xor edx, esi
mov dword [ebp + eax*4 + 0x390], edx
and ecx, 0x80000000
inc eax
cmp eax, 0x18c
jne 0x43f794
mov eax, dword [ebp + 4]
mov edx, eax
and edx, 0x7ffffffe
or edx, ecx
shr edx, 1
and eax, 1
neg eax
and eax, 0x9908b0df
xor eax, dword [ebp + 0x634]
xor eax, edx
mov dword [ebp + 0x9c0], eax
mov dword [ebp], 0
xor eax, eax
lea ecx, [eax + 1]
mov dword [ebp], ecx
mov eax, dword [ebp + eax*4 + 4]
mov ecx, eax
shr ecx, 0xb
and ecx, dword [ebp + 0x1384]
xor ecx, eax
mov eax, ecx
shl eax, 7
and eax, 0x9d2c5680
xor eax, ecx
mov ecx, eax
shl ecx, 0xf
and ecx, 0xefc60000
xor ecx, eax
mov eax, ecx
shr eax, 0x12
xor eax, ecx
add eax, edi
xor eax, 0x80000000
add esp, 8
pop esi
pop edi
pop ebx
pop ebp
ret