Function at 0x41bb31
Capabilities:
Validate payment card number using luhn algorithm

Disassembly:
sub esp, 0xdb4
mov eax, dword [0x4c0390]
xor eax, esp
mov dword [esp + 0xdb0], eax
push edi
mov edi, dword [esp + 0xdbc]
push 0x40
push 0x4b1c28
push 0xffffffffffffffff
call fcn.00420760
cmp eax, 0x26e831b8
je 0x41bb2b
xor al, al
pop edi
mov ecx, dword [esp + 0xdb0]
xor ecx, esp
call fcn.0049eaa6
add esp, 0xdb4
ret 8
push ebx
push 0x604
push 0
push 0x4c8d58
call fcn.0049f060
add esp, 0xc
push 0x400
lea eax, [esp + 0x13c]
push eax
mov ecx, edi
call fcn.004666d0
test al, al
je 0x41bb81
mov bl, 0x23
lea ebx, [ebx]
cmp byte [esp + 0x138], bl
jne 0x41bb81
push 0x400
lea ecx, [esp + 0x13c]
push ecx
mov ecx, edi
call fcn.004666d0
test al, al
jne 0x41bb60
push esi
push 0x100
push 0x4c8d58
mov ecx, edi
call fcn.004666d0
push 0x100
push 0x4c8e58
mov ecx, edi
call fcn.004666d0
push 0x80
lea edx, [esp + 0x940]
push edx
mov ecx, edi
call fcn.004666d0
xor esi, esi
lea ebx, [ebx]
mov eax, 0x400
sub eax, esi
push eax
lea ecx, [esp + esi + 0x140]
push ecx
mov ecx, edi
call fcn.004666d0
add esi, 0x36
cmp esi, 0x17a
jl 0x41bbc0
xor edi, edi
xor esi, esi
jmp 0x41bbf0
movsx edx, byte [esp + esi + 0x13c]
push edx
call fcn.00465d30
test al, al
je 0x41bc17
movsx ecx, byte [esp + esi + 0x13c]
inc esi
cmp esi, 2
lea eax, [edi + edi*4]
lea edi, [ecx + eax*2 - 0x30]
jl 0x41bbf0
push ebp
xor ebp, ebp
mov dword [esp + 0x18], edi
xor esi, esi
movsx edx, byte [esp + esi + 0x142]
push edx
call fcn.00465d30
test al, al
je 0x41bc48
movsx ecx, byte [esp + esi + 0x142]
inc esi
cmp esi, 3
lea eax, [ebp + ebp*4]
lea ebp, [ecx + eax*2 - 0x30]
jl 0x41bc20
xor ebx, ebx
mov dword [esp + 0x14], ebp
xor esi, esi
movsx edx, byte [esp + esi + 0x145]
push edx
call fcn.00465d30
test al, al
je 0x41bc77
movsx ecx, byte [esp + esi + 0x145]
inc esi
cmp esi, 3
lea eax, [ebx + ebx*4]
lea ebx, [ecx + eax*2 - 0x30]
jl 0x41bc50
xor edi, edi
xor esi, esi
jmp 0x41bc80
movsx edx, byte [esp + esi + 0x148]
push edx
call fcn.00465d30
test al, al
je 0x41bca7
movsx ecx, byte [esp + esi + 0x148]
inc esi
cmp esi, 2
lea eax, [edi + edi*4]
lea edi, [ecx + eax*2 - 0x30]
jl 0x41bc80
cmp ebp, 0x100
jg 0x41bee9
cmp ebx, 0x100
jg 0x41bee9
mov ebp, 0x4be338
xor esi, esi
push 8
lea edx, [esp + 0x44]
push edx
push ebp
call fcn.00465e00
push 8
lea eax, [esp + 0x44]
push eax
lea ecx, [esp + 0x152]
push ecx
call fcn.00465c50
test eax, eax
je 0x41bee9
add esi, 8
add ebp, 8
cmp esi, 0x8f0
jb 0x41bcc6
xor esi, esi
nop
lea edx, [esp + 0x40]
push edx
call fcn.00464de0
mov eax, 0x4c8d58
lea edx, [eax + 1]
mov cl, byte [eax]
inc eax
test cl, cl
jne 0x41bd12
push 1
sub eax, edx
push eax
push 0x4c8d58
lea eax, [esp + 0x4c]
push eax
call fcn.00464e20
push 1
lea ecx, [esp + 0x20]
push ecx
lea edx, [esp + 0x48]
push edx
call fcn.00464ee0
mov eax, dword [esp + 0x1c]
cmp eax, dword [esi + 0x4be2f8]
jne 0x41bd5a
mov ecx, dword [esp + 0x20]
cmp ecx, dword [esi + 0x4be2fc]
je 0x41bee9
add esi, 8
cmp esi, 0x40
jb 0x41bd00
mov esi, dword [esp + 0x18]
push esi
lea edx, [esp + 0x14e]
push edx
push 0x4c8f58
call fcn.0049fe90
mov ebp, dword [esp + 0x20]
push ebp
lea esi, [esp + esi + 0x15a]
push esi
push 0x4c9258
call fcn.0049fe90
push ebx
add esi, ebp
push esi
push 0x4c9158
call fcn.0049fe90
push edi
add esi, ebx
push esi
push 0x4c9058
call fcn.0049fe90
push 0xa
push 0
add edi, esi
push edi
call fcn.004a0f51
mov dword [0x4c9358], eax
mov eax, 0x4c8e58
add esp, 0x3c
lea ecx, [eax + 1]
mov dl, byte [eax]
inc eax
test dl, dl
jne 0x41bdc8
sub eax, ecx
push eax
push 0x4c8e58
push 0xffffffffffffffff
call fcn.00420760
mov ecx, 0x4c8d58
lea esi, [ecx + 1]
mov dl, byte [ecx]
inc ecx
test dl, dl
jne 0x41bde6
sub ecx, esi
push ecx
push 0x4c8d58
push eax
call fcn.00420760
mov ecx, 0x4c8f58
lea esi, [ecx + 1]
mov dl, byte [ecx]
inc ecx
test dl, dl
jne 0x41be03
sub ecx, esi
push ecx
push 0x4c8f58
push eax
call fcn.00420760
mov ecx, 0x4c9258
lea esi, [ecx + 1]
mov dl, byte [ecx]
inc ecx
test dl, dl
jne 0x41be20
sub ecx, esi
push ecx
push 0x4c9258
push eax
call fcn.00420760
mov ecx, 0x4c9158
lea esi, [ecx + 1]
lea ecx, [ecx]
mov dl, byte [ecx]
inc ecx
test dl, dl
jne 0x41be40
sub ecx, esi
push ecx
push 0x4c9158
push eax
call fcn.00420760
mov ecx, 0x4c9058
lea esi, [ecx + 1]
lea ecx, [ecx]
mov dl, byte [ecx]
inc ecx
test dl, dl
jne 0x41be60
sub ecx, esi
push ecx
push 0x4c9058
push eax
call fcn.00420760
cmp eax, dword [0x4c9358]
jne 0x41bee9
cmp byte [0x4c8e58], 0
je 0x41c042
mov ebp, 0x4c8e61
mov dword [esp + 0x14], ebp
push 9
push 0x4b1d24
lea ebx, [ebp - 9]
push ebx
call fcn.00465c50
test eax, eax
je 0x41bebc
push 9
push 0x4b1d18
push ebx
call fcn.00465c50
test eax, eax
jne 0x41bf75
cmp byte [ebp], 0
mov byte [esp + 0x13], 0
mov esi, ebp
je 0x41bee9
lea esp, [esp]
cmp byte [esi - 1], 0x20
jne 0x41bee3
movsx eax, byte [esi]
push eax
call fcn.00465d30
test al, al
jne 0x41bf06
inc esi
cmp byte [esi], 0
jne 0x41bed0
xor al, al
mov ecx, dword [esp + 0xdc0]
pop ebp
pop esi
pop ebx
pop edi
xor ecx, esp
call fcn.0049eaa6
add esp, 0xdb4
ret 8
push esi
call fcn.004a0cf6
push 0x2e
push esi
mov edi, eax
call fcn.0049e710
add esp, 0xc
test eax, eax
je 0x41bf30
inc eax
cmp byte [eax], 0x2a
je 0x41bf30
push eax
call fcn.004a0cf6
add esp, 4
mov ecx, eax
jmp 0x41bf33
or ecx, 0xffffffff
cmp edi, 3
jne 0x41bf57
cmp ecx, 0xffffffff
je 0x41bf53
mov eax, 0x66666667
imul ecx
sar edx, 2
mov eax, edx
shr eax, 0x1f
add eax, edx
cmp eax, 9
jne 0x41bf57
mov al, 1
jmp 0x41bf5b
mov al, byte [esp + 0x13]
cmp byte [ebp - 5], 0x4d
jne 0x41bf6d
cmp edi, 3
jg 0x41bf75
jne 0x41bf6d
cmp ecx, 0x5a
jge 0x41bf75
test al, al
je 0x41bee9
push 9
push 0x4b1d0c
push ebx
call fcn.00465c50
test eax, eax
jne 0x41c02f
mov esi, ebp
cmp byte [ebp], al
je 0x41bee9
cmp byte [esi - 1], 0x20
jne 0x41bfa8
movsx ecx, byte [esi]
push ecx
call fcn.00465d30
test al, al
jne 0x41bfb3
inc esi
cmp byte [esi], 0
jne 0x41bf95
jmp 0x41bee9
mov edi, 1
push esi
mov ebx, edi
call fcn.004a0cf6
push 0x2e
push esi
mov ebp, eax
call fcn.0049e710
add esp, 0xc
test eax, eax
je 0x41bff7
lea esi, [eax + 1]
push esi
call fcn.004a0cf6
push 0x2e
push esi
mov edi, eax
call fcn.0049e710
add esp, 0xc
test eax, eax
je 0x41bff7
inc eax
push eax
call fcn.004a0cf6
add esp, 4
mov ebx, eax
lea ecx, [esp + 0x1c]
call fcn.00468ca0
lea ecx, [esp + 0x1c]
call fcn.00468f60
mov eax, dword [esp + 0x1c]
cmp ebp, eax
ja 0x41c02f
jne 0x41bee9
mov eax, dword [esp + 0x20]
cmp edi, eax
ja 0x41c02f
jne 0x41bee9
cmp ebx, dword [esp + 0x24]
jb 0x41bee9
mov ebp, dword [esp + 0x14]
inc ebp
cmp byte [ebp - 9], 0
mov dword [esp + 0x14], ebp
jne 0x41be93
cmp byte [esp + 0xdcc], 0
je 0x41c183
mov eax, 0x4c8e58
lea edx, [eax + 1]
mov cl, byte [eax]
inc eax
test cl, cl
jne 0x41c058
push 0x4c9258
push 0x4b1c28
sub eax, edx
push eax
push 0x4c8e58
call fcn.004261a0
test eax, eax
je 0x41bee9
xor eax, eax
mov cl, byte [eax + 0x4c8d58]
mov byte [esp + eax + 0x540], cl
inc eax
test cl, cl
jne 0x41c080
mov eax, 0x4c8f58
mov edx, eax
lea esp, [esp]
mov cl, byte [eax]
inc eax
test cl, cl
jne 0x41c0a0
lea edi, [esp + 0x540]
sub eax, edx
dec edi
mov cl, byte [edi + 1]
inc edi
test cl, cl
jne 0x41c0b1
mov ecx, eax
shr ecx, 2
mov esi, edx
rep movsd dword es:[edi], dword [esi]
mov ecx, eax
and ecx, 3
rep movsb byte es:[edi], byte [esi]
xor eax, eax
jmp 0x41c0d0
mov cl, byte [esp + eax + 0x540]
mov byte [esp + eax + 0x9c0], cl
inc eax
test cl, cl
jne 0x41c0d0
lea eax, [esp + 0x540]
lea edx, [eax + 1]
lea ecx, [ecx]
mov cl, byte [eax]
inc eax
test cl, cl
jne 0x41c0f0
push 0x4c9158
sub eax, edx
push 0x4b1c28
mov esi, eax
push esi
lea edx, [esp + 0x54c]
push edx
call fcn.004261a0
test eax, eax
je 0x41bee9
xor eax, eax
lea ecx, [ecx]
mov cl, byte [esp + eax + 0x9c0]
mov byte [esp + eax + 0x540], cl
inc eax
test cl, cl
jne 0x41c120
lea eax, [esp + 0x40]
push eax
push 0x4c9058
push esi
lea ecx, [esp + 0x54c]
push ecx
call fcn.00425fa0
xor eax, eax
lea ecx, [ecx]
mov cl, byte [esp + eax + 0x9c0]
mov byte [esp + eax + 0x540], cl
inc eax
test cl, cl
jne 0x41c150
lea edx, [esp + 0x40]
push edx
push 0x4c8f58
push esi
lea eax, [esp + 0x54c]
push eax
call fcn.004261a0
test eax, eax
je 0x41bee9
mov al, 1
jmp 0x41beeb