Function at 0x421020
Capabilities:
Encode data using xor

Disassembly:
push ebp
mov ebp, esp
push ebx
push edi
push esi
and esp, 0xfffffff8
sub esp, 0x20
cmp dword [ecx], 0xffffffff
je 0x421072
movzx eax, byte [ebp + 0x14]
movzx edx, byte [ebp + 0x10]
mov ebx, dword [ebp + 0xc]
and dl, 0xf
shl al, 7
or al, dl
mov byte [esp + 6], al
movzx eax, byte [ecx + 4]
shl al, 7
mov dword [esp + 0xc], 0
mov dword [esp + 8], 0
cmp ebx, 0x7d
mov dword [esp + 0x14], ecx
ja 0x421079
or al, bl
mov byte [esp + 7], al
xor esi, esi
jmp 0x4210be
xor ebx, ebx
jmp 0x4212a4
cmp ebx, 0xffff
ja 0x4210a3
or al, 0x7e
mov byte [esp + 7], al
mov eax, ebx
rol ax, 8
movzx eax, ax
mov dword [esp + 8], eax
mov dword [esp + 0xc], 0
mov esi, 2
jmp 0x4210be
or al, 0x7f
mov byte [esp + 7], al
mov eax, ebx
bswap eax
mov dword [esp + 0xc], eax
mov dword [esp + 8], 0
mov esi, 8
lea eax, [ebx + 0xe]
push eax
call fcn.004088e0
add esp, 4
mov ebx, eax
lea eax, [esp + 6]
mov edx, eax
mov edi, ebx
xor ecx, ecx
xchg esi, edx
rep movsd dword es:[edi], dword [esi]
xchg esi, edx
mov edi, ebx
mov ecx, 1
xchg esi, eax
rep movsw word es:[edi], word [esi]
xchg esi, eax
mov dword [esp + 0x10], ebx
lea eax, [ebx + 2]
mov ebx, dword [ebp + 0xc]
cmp ebx, 0x7e
jb 0x42112a
mov ecx, esi
shr ecx, 2
lea edx, [esp + 8]
mov edi, eax
xchg esi, edx
rep movsd dword es:[edi], dword [esi]
xchg esi, edx
mov ecx, esi
and ecx, 0xfffffff8
add eax, ecx
lea edx, [esp + ecx]
add edx, 8
mov ecx, esi
shr ecx, 1
and ecx, 1
mov edi, eax
xchg esi, edx
rep movsw word es:[edi], word [esi]
xchg esi, edx
and esi, 2
add eax, esi
mov esi, dword [ebp + 8]
mov ecx, dword [esp + 0x14]
cmp byte [ecx + 4], 0
je 0x421198
mov edx, dword [ebp + 0x18]
mov ebx, edx
mov edi, eax
mov ecx, 1
xchg esi, ebx
rep movsd dword es:[edi], dword [esi]
xchg esi, ebx
lea ebx, [eax + 4]
lea esi, [edx + 4]
mov edi, ebx
xor ecx, ecx
xchg esi, esi
rep movsw word es:[edi], word [esi]
xchg esi, esi
cmp byte [edx], 0
jne 0x421175
cmp byte [edx + 1], 0
jne 0x421175
cmp byte [edx + 2], 0
jne 0x421175
cmp byte [edx + 3], 0
je 0x4212b0
mov edx, dword [ebp + 0xc]
mov dword [esp + 0x18], edx
test edx, edx
je 0x421230
movzx ecx, byte [ebx]
mov edi, edx
and edi, 3
cmp edx, 4
jae 0x4211dd
xor esi, esi
jmp 0x421216
mov ecx, ebx
shr ecx, 2
mov edx, esi
mov edi, eax
xchg esi, edx
rep movsd dword es:[edi], dword [esi]
xchg esi, edx
mov edx, ebx
and edx, 0xfffffffc
add eax, edx
add edx, esi
mov ecx, ebx
shr ecx, 1
and ecx, 1
mov esi, edx
mov edi, eax
xchg esi, esi
rep movsw word es:[edi], word [esi]
xchg esi, esi
mov ecx, ebx
and ecx, 2
mov esi, ebx
mov ebx, eax
add ebx, ecx
mov eax, esi
test al, 1
je 0x421230
add edx, ecx
movzx eax, byte [edx]
mov byte [ebx], al
inc ebx
jmp 0x421230
and dword [esp + 0x18], 0xfffffffc
xor esi, esi
mov edx, dword [ebp + 0x18]
nop
nop
nop
nop
nop
nop
nop
nop
nop
xor cl, byte [edx]
mov byte [eax + esi + 5], cl
xor cl, byte [edx + 1]
mov byte [eax + esi + 6], cl
xor cl, byte [edx + 2]
mov byte [eax + esi + 7], cl
xor cl, byte [edx + 3]
mov byte [eax + esi + 8], cl
add esi, 4
cmp dword [esp + 0x18], esi
jne 0x4211f0
add ebx, esi
test edi, edi
mov edx, dword [ebp + 0x18]
je 0x421230
nop
nop
nop
mov eax, esi
and eax, 3
xor cl, byte [edx + eax]
mov byte [ebx + 1], cl
inc ebx
inc esi
dec edi
jne 0x421220
mov esi, dword [esp + 0x10]
sub ebx, esi
push 0xd0026952
push dword [0x44fdc0]
call fcn.004431d0
add esp, 8
push 0
push ebx
push esi
mov esi, dword [esp + 0x20]
push dword [esi]
call eax
cmp eax, 0xffffffff
setne bl
jne 0x421298
cmp dword [esi], 0xffffffff
je 0x421298
push 0x59ea2086
push dword [0x44fdc0]
call fcn.004431d0
add esp, 8
push 2
push dword [esi]
call eax
push 0x2e775759
push dword [0x44fdc0]
call fcn.004431d0
add esp, 8
push dword [esi]
call eax
mov dword [esi], 0xffffffff
push dword [esp + 0x10]
call fcn.004088f0
add esp, 4
mov eax, ebx
lea esp, [ebp - 0xc]
pop esi
pop edi
pop ebx
pop ebp
ret 0x14
mov eax, dword [ebp + 0xc]
mov ecx, eax
mov edx, eax
shr ecx, 2
mov esi, dword [ebp + 8]
mov eax, esi
mov edi, ebx
xchg esi, eax
rep movsd dword es:[edi], dword [esi]
xchg esi, eax
mov eax, edx
and edx, 0xfffffffc
add ebx, edx
add edx, esi
mov ecx, eax
mov esi, eax
shr ecx, 1
and ecx, 1
mov eax, edx
mov edi, ebx
xchg esi, eax
rep movsw word es:[edi], word [esi]
xchg esi, eax
mov ecx, esi
mov eax, esi
and eax, 2
add ebx, eax
test cl, 1
je 0x421230
add edx, eax
jmp 0x4211d5