Function at 0x5987a3
Capabilities:
Encode data using xor

Disassembly:
push ebp
mov ebp, esp
mov eax, dword [ebp + 0x1c]
sub esp, 0x1c
cmp dword [ebp + 0x20], 0
push ebx
push esi
mov esi, dword [eax]
push edi
mov edi, dword [ebp + 0x10]
je 0x598895
mov ebx, dword [ebp + 0x18]
test esi, esi
mov ecx, dword [ebp + 0xc]
mov edx, dword [ebp + 8]
mov dword [ebp + 0x20], edx
mov dword [ebp - 4], ecx
je 0x5987e8
test edi, edi
je 0x5987e8
mov al, byte [edx]
xor byte [esi + ebx], al
mov al, byte [esi + ebx]
mov byte [ecx], al
inc ecx
inc edx
dec edi
inc esi
and esi, 0xf
jmp 0x5987c9
cmp edi, 0x10
jb 0x59885a
mov eax, ecx
sub eax, ebx
mov dword [ebp - 8], eax
mov eax, edx
sub eax, ebx
mov dword [ebp - 0xc], eax
mov eax, edi
shr eax, 4
mov dword [ebp - 0x10], eax
shl eax, 4
add ecx, eax
add edx, eax
mov dword [ebp - 4], ecx
mov dword [ebp + 0x20], edx
push dword [ebp + 0x14]
push ebx
push ebx
call dword [ebp + 0x24]
add esp, 0xc
cmp esi, 0x10
jae 0x598847
push 0xf
pop edx
sub edx, esi
lea ecx, [esi + ebx]
mov esi, dword [ebp - 8]
mov ebx, dword [ebp - 0xc]
shr edx, 2
inc edx
mov eax, dword [ebx + ecx]
xor dword [ecx], eax
mov eax, dword [ecx]
mov dword [esi + ecx], eax
lea ecx, [ecx + 4]
sub edx, 1
jne 0x598832
mov ebx, dword [ebp + 0x18]
add dword [ebp - 8], 0x10
sub edi, 0x10
add dword [ebp - 0xc], 0x10
xor esi, esi
sub dword [ebp - 0x10], 1
jne 0x598810
test edi, edi
je 0x5989ad
push dword [ebp + 0x14]
push ebx
push ebx
call dword [ebp + 0x24]
mov edx, dword [ebp - 4]
lea ecx, [esi + ebx]
sub dword [ebp + 0x20], ebx
add esp, 0xc
sub edx, ebx
add esi, edi
mov dword [ebp - 8], esi
mov esi, dword [ebp + 0x20]
mov al, byte [ecx + esi]
xor byte [ecx], al
mov al, byte [ecx]
mov byte [ecx + edx], al
inc ecx
sub edi, 1
jne 0x598880
jmp 0x5989aa
mov ebx, dword [ebp + 0xc]
mov dword [ebp - 4], edi
mov dword [ebp - 8], ebx
test esi, esi
je 0x5988d2
mov edx, dword [ebp + 8]
mov eax, dword [ebp + 0x18]
mov dword [ebp + 0x20], edx
test edi, edi
je 0x5988d8
mov al, byte [esi + eax]
mov cl, byte [edx]
xor al, cl
mov byte [ebx], al
inc ebx
mov eax, dword [ebp + 0x18]
inc edx
dec edi
mov dword [ebp - 8], ebx
mov dword [ebp + 0x20], edx
mov dword [ebp - 4], edi
mov byte [esi + eax], cl
inc esi
and esi, 0xf
jne 0x5988ab
jmp 0x5988d8
mov eax, dword [ebp + 8]
mov dword [ebp + 0x20], eax
cmp edi, 0x10
jb 0x598966
mov eax, dword [ebp + 0x18]
mov ecx, ebx
sub ecx, eax
mov dword [ebp - 0xc], ecx
mov ecx, edi
shr ecx, 4
mov dword [ebp - 0x10], ecx
jmp 0x5988f8
mov eax, dword [ebp + 0x18]
push dword [ebp + 0x14]
push eax
push eax
call dword [ebp + 0x24]
add esp, 0xc
cmp esi, 0x10
jae 0x59894a
mov eax, dword [ebp + 0x18]
mov edx, dword [ebp + 0x20]
add eax, esi
mov edi, dword [ebp - 0xc]
sub edx, ebx
mov dword [ebp - 0x18], eax
mov ebx, eax
push 0xf
pop eax
sub eax, esi
mov dword [ebp - 0x1c], edx
shr eax, 2
inc eax
mov dword [ebp - 0x14], eax
mov esi, eax
mov eax, dword [ebx]
lea ecx, [edi + ebx]
mov edx, dword [ecx + edx]
xor eax, edx
mov dword [ecx], eax
mov dword [ebx], edx
lea ebx, [ebx + 4]
mov edx, dword [ebp - 0x1c]
sub esi, 1
jne 0x59892b
mov edi, dword [ebp - 4]
mov ebx, dword [ebp - 8]
add dword [ebp - 0xc], 0x10
sub edi, 0x10
add dword [ebp + 0x20], 0x10
add ebx, 0x10
xor esi, esi
mov dword [ebp - 4], edi
sub dword [ebp - 0x10], 1
mov dword [ebp - 8], ebx
jne 0x5988f5
test edi, edi
je 0x5989ad
push dword [ebp + 0x14]
mov eax, dword [ebp + 0x18]
push eax
push eax
call dword [ebp + 0x24]
mov eax, dword [ebp + 0x18]
add esp, 0xc
sub dword [ebp + 0x20], ebx
sub ebx, eax
lea ecx, [esi + eax]
add esi, edi
mov dword [ebp - 8], esi
mov esi, dword [ebp + 0x20]
mov dword [ebp - 0xc], ecx
mov eax, dword [ebp - 0xc]
add ecx, ebx
mov dl, byte [ecx + esi]
mov al, byte [eax]
xor al, dl
mov byte [ecx], al
mov ecx, dword [ebp - 0xc]
mov byte [ecx], dl
inc ecx
mov dword [ebp - 0xc], ecx
sub edi, 1
jne 0x59898e
mov esi, dword [ebp - 8]
mov eax, dword [ebp + 0x1c]
pop edi
mov dword [eax], esi
pop esi
pop ebx
leave
ret