section .data
    len equ 255

section .bss
    string1 resb len
    string2 resb 255
    prov resb 255
    key1 resb 255
    strlen resb 4
    key2 resd 1

section .text
global _start

KeyA:
    mov esi, 0
    .Cycle1:
        mov dl, byte [eax+esi]
        cmp dl, 0
        je Ret
        add [key2], dword 1
        inc esi
        loop .Cycle1

Key:
    mov esi,0
    mov edi, 0
    mov ecx, [strlen]

        Cycle2:
        mov bl, [eax+esi]
        mov [key1 + edi], bl
        inc esi
        inc edi
        dec ecx
        cmp ecx, 0
        je Ret
        cmp esi, [key2]
        jge Zero
        jmp Cycle2

            Zero:
            mov esi, 0
            jmp Cycle2


Encrypt:
    mov ecx, [strlen]
    mov esi, 0
    mov edi, 0
    mov ebx, 0

        Cikl:


            xor dx, dx
            movzx bp, byte [key1 + esi]
            movzx di, byte [string1 + esi]
            mov [prov + esi], di

            cmp di, 'A'
            jl Copy

            movzx di, byte [prov + esi]
            cmp di, 'Z'
            jle EncA

            movzx di, byte [prov + esi]
            cmp di, 'a'
            jl Copy

            movzx di, byte [prov + esi]
            cmp di, 'z'
            jle Enca

            movzx di, byte [prov + esi]
            cmp di, 'z'
            jg Copy


                Metka:
                    cmp ecx, 0
                    je Ret
                    dec ecx
                    inc esi
                    jmp Cikl

                Copy:
                    mov dl, byte [prov + esi]
                    mov [string2 + esi], dl
                    jmp Metka

                EncA:
                    movzx di, byte [prov + esi]
                    sub di, 'A'
                    sub bp, 'a'
                    add bp, di
                    mov ax, bp
                    mov bx, 26
                    div bx

                    add dl, 1*'A'
                    mov [string2 + esi], dl
                    jmp Metka

                Enca:
                    movzx di, byte [prov + esi]
                    add bp, di
                    sub bp, 2*'a'

                    mov ax, bp
                    mov bx, 26
                    div bx

                    add dl, 1*'a'
                    mov [string2 + esi], dl
                    jmp Metka

        ret

Ret:
    ret
Exit:
    mov eax, 1
    int 80h
_start:


mov eax, 3
mov ebx, 0
mov ecx, string1
mov edx, len
int 80h

cmp eax, 0
je Exit

mov [strlen], eax
xor eax,eax
mov eax, [esp+8]

call KeyA
call Key
call Encrypt

mov eax, 4
mov ebx, 1
mov ecx, string2
mov edx, [strlen]
int 80h

mov eax, 1
int 80h