Function at 0x43da00
Capabilities:
Check if file exists
Encrypt or decrypt via wincrypt
Get file size
Read file on windows

Disassembly:
push 0xffffffffffffffff
push 0x49cdb6
mov eax, dword fs:[0]
push eax
sub esp, 0x474
mov eax, dword [0x4c2c40]
xor eax, esp
mov dword [esp + 0x470], eax
push ebx
push ebp
push esi
push edi
mov eax, dword [0x4c2c40]
xor eax, esp
push eax
lea eax, [esp + 0x488]
mov dword fs:[0], eax
mov eax, dword [esp + 0x49c]
mov ebp, dword [esp + 0x498]
xor ebx, ebx
lea ecx, [esp + 0x20]
push ecx
lea edi, [esp + 0x28]
lea esi, [esp + 0x2c]
mov dword [esp + 0x4c], eax
mov dword [esp + 0x2c], ebx
mov dword [esp + 0x24], ebx
mov dword [esp + 0x28], ebx
mov dword [esp + 0x34], ebx
call fcn.0043dd30
add esp, 4
cmp al, 1
jne 0x43dd04
cmp dword [ebp + 0x18], 8
jb 0x43da87
mov ebp, dword [ebp + 4]
jmp 0x43da8a
add ebp, 4
push ebx
push 0x80
push 3
push ebx
push 1
push SysReAllocStringLen
push ebp
call dword [sym.imp.KERNEL32.dll_CreateFileW]
mov esi, eax
cmp esi, ebx
mov dword [esp + 0x38], esi
je 0x43dce2
call dword [sym.imp.KERNEL32.dll_GetLastError]
cmp eax, 2
je 0x43dce2
lea edx, [esp + 0x34]
push edx
push esi
mov dword [esp + 0x3c], ebx
call dword [sym.imp.KERNEL32.dll_GetFileSize]
push 1
push ebx
mov edi, eax
mov eax, dword [esp + 0x3c]
push ebx
push eax
call fcn.004812b0
xor ecx, ecx
mov esi, eax
add esi, edi
push ebx
mov edi, edx
push 0x400
adc edi, ecx
push edi
push esi
call fcn.004812f0
push ebx
push 0x400
push edi
push esi
mov dword [esp + 0x24], eax
mov dword [esp + 0x28], edx
call fcn.0048ac70
or eax, edx
jne 0x43db19
or eax, 0xffffffff
add dword [esp + 0x14], eax
adc dword [esp + 0x18], eax
xor ebp, ebp
cmp dword [esp + 0x18], ebx
mov dword [esp + 0x2c], ebx
mov dword [esp + 0x40], ebx
jl 0x43dcab
jg 0x43db39
cmp dword [esp + 0x14], ebx
jb 0x43dcab
mov ecx, dword [esp + 0x38]
push ebx
lea edx, [esp + 0x30]
push edx
push 0x400
lea eax, [esp + 0x90]
push eax
push ecx
call dword [sym.imp.KERNEL32.dll_ReadFile]
cmp ebp, dword [esp + 0x14]
jne 0x43db6e
mov edx, dword [esp + 0x18]
cmp dword [esp + 0x40], edx
jne 0x43db6e
mov edi, 1
jmp 0x43db70
xor edi, edi
mov edx, dword [esp + 0x20]
lea eax, [esp + 0x2c]
push eax
lea ecx, [esp + 0x88]
push ecx
push ebx
push edi
push ebx
push edx
call dword [sym.imp.ADVAPI32.dll_CryptDecrypt]
mov dword [esp + 0x30], eax
mov eax, dword [esp + 0x2c]
push eax
lea ecx, [esp + 0x88]
push ecx
lea ecx, [esp + 0x70]
mov dword [esp + 0x88], 0xf
mov dword [esp + 0x84], ebx
mov byte [esp + 0x74], bl
call fcn.00401a10
mov dword [esp + 0x490], ebx
mov dword [esp + 0x64], 7
mov dword [esp + 0x60], ebx
mov word [esp + 0x50], bx
lea edx, [esp + 0x4c]
push edx
lea eax, [esp + 0x6c]
push eax
mov byte [esp + 0x498], 1
call fcn.00432b70
mov esi, dword [esp + 0x50]
add esp, 8
push ebx
lea ecx, [esp + 0x50]
push ecx
or eax, 0xffffffff
call fcn.004036a0
cmp edi, ebx
jne 0x43dc6f
cmp dword [esp + 0x64], 8
jb 0x43dc17
mov edx, dword [esp + 0x50]
push edx
call fcn.0045a870
add esp, 4
mov dword [esp + 0x490], 0xffffffff
cmp dword [esp + 0x80], 0x10
mov dword [esp + 0x64], 7
mov dword [esp + 0x60], ebx
mov word [esp + 0x50], bx
jb 0x43dc4a
mov eax, dword [esp + 0x6c]
push eax
call fcn.0045a870
add esp, 4
mov eax, dword [esp + 0x40]
add ebp, 1
adc eax, ebx
cmp eax, dword [esp + 0x18]
mov dword [esp + 0x40], eax
jl 0x43db39
jg 0x43dcab
cmp ebp, dword [esp + 0x14]
jbe 0x43db39
jmp 0x43dcab
cmp dword [esp + 0x64], 8
jb 0x43dc83
mov ecx, dword [esp + 0x50]
push ecx
call fcn.0045a870
add esp, 4
cmp dword [esp + 0x80], 0x10
mov dword [esp + 0x64], 7
mov dword [esp + 0x60], ebx
mov word [esp + 0x50], bx
jb 0x43dcab
mov edx, dword [esp + 0x6c]
push edx
call fcn.0045a870
add esp, 4
mov eax, dword [esp + 0x38]
push eax
call dword [sym.imp.KERNEL32.dll_CloseHandle]
mov ecx, dword [esp + 0x24]
push ecx
call dword [sym.imp.ADVAPI32.dll_CryptDestroyHash]
mov edx, dword [esp + 0x20]
push edx
call dword [sym.imp.ADVAPI32.dll_CryptDestroyKey]
mov eax, dword [esp + 0x28]
push ebx
push eax
call dword [sym.imp.ADVAPI32.dll_CryptReleaseContext]
cmp dword [esp + 0x30], 1
sete al
jmp 0x43dd06
mov ecx, dword [esp + 0x24]
push ecx
call dword [sym.imp.ADVAPI32.dll_CryptDestroyHash]
mov edx, dword [esp + 0x20]
push edx
call dword [sym.imp.ADVAPI32.dll_CryptDestroyKey]
mov eax, dword [esp + 0x28]
push ebx
push eax
call dword [sym.imp.ADVAPI32.dll_CryptReleaseContext]
xor al, al
mov ecx, dword [esp + 0x488]
mov dword fs:[0], ecx
pop ecx
pop edi
pop esi
pop ebp
pop ebx
mov ecx, dword [esp + 0x470]
xor ecx, esp
call fcn.00478599
add esp, 0x480
ret