Function at 0x591b00
Capabilities:
Encode data using xor

Disassembly:
mov eax, 0x10
call fcn.004c47c0
cmp dword [esp + 0x2c], 0
push ebx
push ebp
push esi
mov esi, dword [esp + 0x34]
push edi
mov esi, dword [esi]
je 0x591c35
mov edi, dword [esp + 0x2c]
mov ebx, dword [esp + 0x28]
mov ebp, dword [esp + 0x24]
test esi, esi
je 0x591b4d
mov ecx, dword [esp + 0x34]
test edi, edi
je 0x591b4d
movzx eax, byte [ebp]
dec edi
xor byte [esi + ecx], al
inc ebp
movzx eax, byte [esi + ecx]
inc esi
mov byte [ebx], al
inc ebx
and esi, 0xf
jne 0x591b33
mov edx, dword [esp + 0x40]
cmp edi, 0x10
jb 0x591be8
mov ecx, dword [esp + 0x34]
mov eax, ebx
sub eax, ecx
mov dword [esp + 0x1c], eax
mov eax, ebp
sub eax, ecx
mov dword [esp + 0x18], eax
mov eax, edi
shr eax, 4
mov dword [esp + 0x3c], eax
shl eax, 4
add ebx, eax
add ebp, eax
mov dword [esp + 0x14], ebx
mov ebx, dword [esp + 0x1c]
mov dword [esp + 0x10], ebp
mov ebp, dword [esp + 0x18]
jmp 0x591b94
mov ecx, dword [esp + 0x34]
push dword [esp + 0x30]
push ecx
push ecx
call edx
add esp, 0xc
cmp esi, 0x10
jae 0x591bca
mov ecx, dword [esp + 0x34]
mov edx, 0xf
sub edx, esi
add ecx, esi
shr edx, 2
inc edx
mov eax, dword [ecx + ebp]
lea ecx, [ecx + 4]
xor dword [ecx - 4], eax
mov eax, dword [ecx - 4]
mov dword [ebx + ecx - 4], eax
sub edx, 1
jne 0x591bb5
mov edx, dword [esp + 0x40]
sub edi, 0x10
add ebx, 0x10
add ebp, 0x10
xor esi, esi
sub dword [esp + 0x3c], 1
jne 0x591b90
mov ebx, dword [esp + 0x14]
mov ebp, dword [esp + 0x10]
test edi, edi
je 0x591d5f
push dword [esp + 0x30]
mov eax, dword [esp + 0x38]
push eax
push eax
call edx
mov eax, dword [esp + 0x40]
add esp, 0xc
sub ebp, eax
sub ebx, eax
lea ecx, [esi + eax]
add esi, edi
nop dword [eax]
movzx eax, byte [ecx + ebp]
lea ecx, [ecx + 1]
xor byte [ecx - 1], al
movzx eax, byte [ecx - 1]
mov byte [ecx + ebx - 1], al
sub edi, 1
jne 0x591c10
mov eax, dword [esp + 0x38]
pop edi
mov dword [eax], esi
pop esi
pop ebp
pop ebx
add esp, 0x10
ret
mov ebx, dword [esp + 0x2c]
mov ebp, dword [esp + 0x28]
mov edi, dword [esp + 0x24]
mov dword [esp + 0x10], ebx
mov dword [esp + 0x14], ebp
mov dword [esp + 0x3c], edi
test esi, esi
je 0x591c7b
mov edx, dword [esp + 0x34]
test ebx, ebx
je 0x591c7b
mov al, byte [esi + edx]
dec ebx
mov cl, byte [edi]
inc edi
xor al, cl
mov dword [esp + 0x3c], edi
mov byte [ebp], al
inc ebp
mov byte [esi + edx], cl
inc esi
mov dword [esp + 0x14], ebp
mov dword [esp + 0x10], ebx
and esi, 0xf
jne 0x591c55
mov edx, dword [esp + 0x40]
cmp ebx, 0x10
jb 0x591d1a
mov ecx, dword [esp + 0x34]
mov eax, ebp
sub eax, ecx
mov dword [esp + 0x18], eax
mov eax, ebx
shr eax, 4
mov dword [esp + 0x1c], eax
jmp 0x591ca4
mov ecx, dword [esp + 0x34]
push dword [esp + 0x30]
push ecx
push ecx
call edx
add esp, 0xc
cmp esi, 0x10
jae 0x591cf3
mov ebx, dword [esp + 0x3c]
mov edi, dword [esp + 0x34]
sub ebx, ebp
mov ebp, 0xf
add edi, esi
sub ebp, esi
mov esi, dword [esp + 0x18]
shr ebp, 2
inc ebp
nop
mov eax, dword [edi]
lea ecx, [esi + edi]
mov edx, dword [ecx + ebx]
lea edi, [edi + 4]
xor eax, edx
mov dword [ecx], eax
mov dword [edi - 4], edx
sub ebp, 1
jne 0x591cd0
mov ebx, dword [esp + 0x10]
mov ebp, dword [esp + 0x14]
mov edi, dword [esp + 0x3c]
add dword [esp + 0x18], 0x10
sub ebx, 0x10
mov edx, dword [esp + 0x40]
add ebp, 0x10
add edi, 0x10
mov dword [esp + 0x10], ebx
xor esi, esi
mov dword [esp + 0x14], ebp
sub dword [esp + 0x1c], 1
mov dword [esp + 0x3c], edi
jne 0x591ca0
test ebx, ebx
je 0x591d5f
push dword [esp + 0x30]
mov eax, dword [esp + 0x38]
push eax
push eax
call edx
mov ecx, dword [esp + 0x40]
sub edi, ebp
add esp, 0xc
sub ebp, ecx
lea eax, [esi + ecx]
add esi, ebx
mov dword [esp + 0x1c], esi
mov esi, eax
mov dword [esp + 0x3c], eax
mov al, byte [esi]
lea ecx, [esi + ebp]
mov dl, byte [ecx + edi]
lea esi, [esi + 1]
xor al, dl
mov byte [ecx], al
mov byte [esi - 1], dl
sub ebx, 1
jne 0x591d44
mov esi, dword [esp + 0x1c]
mov eax, dword [esp + 0x38]
pop edi
mov dword [eax], esi
pop esi
pop ebp
pop ebx
add esp, 0x10
ret