Function at 0x57e850
Capabilities:
Encode data using xor
Encrypt data using rc4 prga

Disassembly:
sub esp, 0xc
push ebx
mov ebx, dword [esp + 0x18]
mov eax, ebx
push ebp
push esi
push edi
mov edi, dword [esp + 0x20]
sub eax, edi
and eax, 0xfffffffe
cmp eax, 0x40
jle 0x57e8dd
mov ecx, dword [esp + 0x2c]
mov esi, dword [esp + 0x28]
test esi, esi
jle 0x57e948
push ecx
push ebx
lea eax, [esp + 0x1c]
push edi
push eax
call fcn.0057cf40
mov edx, dword [esp + 0x24]
mov eax, esi
mov ebp, dword [esp + 0x28]
mov ecx, ebx
sar eax, 2
add esp, 0x10
sar esi, 1
sub ecx, ebp
add esi, eax
and ecx, 0xfffffffe
mov eax, edx
sub eax, edi
and eax, 0xfffffffe
cmp eax, ecx
mov eax, dword [esp + 0x2c]
push eax
push esi
jge 0x57e8bf
push edx
push edi
call fcn.0057e850
mov edi, ebp
jmp 0x57e8ca
push ebx
push ebp
call fcn.0057e850
mov ebx, dword [esp + 0x24]
mov ecx, dword [esp + 0x3c]
mov eax, ebx
sub eax, edi
add esp, 0x10
and eax, 0xfffffffe
cmp eax, 0x40
jg 0x57e873
cmp edi, ebx
je 0x57ead3
lea esi, [edi + 2]
cmp esi, ebx
je 0x57ead3
mov ecx, 2
sub ecx, edi
mov dword [esp + 0x20], ecx
nop dword [eax + eax]
movzx ebp, word [esi]
mov edx, esi
movsx eax, bp
mov dword [esp + 0x24], ebp
movd xmm1, eax
movsx eax, word [edi]
cvtdq2pd xmm1, xmm1
movd xmm0, eax
cvtdq2pd xmm0, xmm0
comisd xmm1, xmm0
jbe 0x57ea81
add ecx, 0xfffffffe
mov eax, esi
add ecx, esi
push ecx
sub eax, ecx
add eax, 2
push edi
push eax
call fcn.0086cdf0
add esp, 0xc
mov word [edi], bp
jmp 0x57eac4
sub ebx, edi
mov eax, ebx
mov dword [esp + 0x24], ebx
sar eax, 1
mov esi, eax
mov dword [esp + 0x10], eax
sar esi, 1
test esi, esi
jle 0x57ea32
mov ebx, eax
lea ebp, [ebx - 1]
sar ebp, 1
mov dword [esp + 0x14], ebp
nop dword [eax]
movzx eax, word [edi + esi*2 - 2]
dec esi
mov dword [esp + 0x20], eax
mov edx, esi
mov ecx, esi
cmp esi, ebp
jge 0x57e9bb
add ecx, ecx
movsx eax, word [edi + ecx*2 + 4]
movd xmm1, eax
movsx eax, word [edi + ecx*2 + 2]
cvtdq2pd xmm1, xmm1
movd xmm0, eax
xor eax, eax
cvtdq2pd xmm0, xmm0
comisd xmm1, xmm0
seta al
inc ecx
xor eax, 1
add ecx, eax
mov ax, word [edi + ecx*2]
mov word [edi + edx*2], ax
mov edx, ecx
cmp ecx, ebp
jl 0x57e982
cmp edx, ebp
jne 0x57e9d0
test bl, 1
jne 0x57e9d0
mov ax, word [edi + ebx*2 - 2]
mov word [edi + edx*2], ax
lea edx, [ebx - 1]
lea ecx, [edx - 1]
sar ecx, 1
cmp esi, edx
jge 0x57ea16
mov eax, dword [esp + 0x20]
cwde
movd xmm1, eax
cvtdq2pd xmm1, xmm1
nop word [eax + eax]
movzx ebp, word [edi + ecx*2]
movsx eax, bp
movd xmm0, eax
cvtdq2pd xmm0, xmm0
comisd xmm0, xmm1
jbe 0x57ea12
mov word [edi + edx*2], bp
mov edx, ecx
dec ecx
sar ecx, 1
cmp esi, edx
jl 0x57e9f0
mov ebp, dword [esp + 0x14]
mov eax, dword [esp + 0x20]
mov word [edi + edx*2], ax
test esi, esi
jg 0x57e970
mov ebx, dword [esp + 0x24]
mov ecx, dword [esp + 0x2c]
mov eax, dword [esp + 0x10]
cmp eax, 2
jl 0x57ead3
nop dword [eax + eax]
movzx eax, word [edi + ebx - 2]
mov dword [esp + 0x24], eax
mov ax, word [edi]
mov word [edi + ebx - 2], ax
lea eax, [esp + 0x24]
push ecx
push eax
lea eax, [ebx - 2]
sar eax, 1
push eax
push 0
push edi
call fcn.0057d920
mov ecx, dword [esp + 0x40]
add ebx, 0xfffffffe
mov eax, ebx
add esp, 0x14
and eax, 0xfffffffe
cmp eax, 4
jge 0x57ea40
pop edi
pop esi
pop ebp
pop ebx
add esp, 0xc
ret
movzx eax, word [esi - 2]
lea ecx, [esi - 2]
cwde
movd xmm0, eax
cvtdq2pd xmm0, xmm0
comisd xmm1, xmm0
jbe 0x57eac1
movzx ebp, word [ecx]
nop word [eax + eax]
mov word [edx], bp
mov edx, ecx
movzx eax, word [ecx - 2]
sub ecx, 2
mov ebp, eax
cwde
movd xmm0, eax
cvtdq2pd xmm0, xmm0
comisd xmm1, xmm0
ja 0x57eaa0
mov ebp, dword [esp + 0x24]
mov word [edx], bp
mov ecx, dword [esp + 0x20]
add esi, 2
cmp esi, ebx
jne 0x57e900
pop edi
pop esi
pop ebp
pop ebx
add esp, 0xc
ret