utils.asm

; =============================================================================
; Windows x64 Assembly - System Utilities
; =============================================================================
; Author: Dominik Karczewski (ogur.dev)
; Build: nasm -f win64 utils.asm -o utils.obj
;        link utils.obj /subsystem:console /entry:main kernel32.lib advapi32.lib ws2_32.lib iphlpapi.lib
; =============================================================================

bits 64
default rel

; Win32 API
extern ExitProcess
extern GetStdHandle
extern WriteConsoleA
extern ReadConsoleA
extern GetComputerNameA
extern GetUserNameA
extern GetCurrentDirectoryA
extern FindFirstFileA
extern FindNextFileA
extern FindClose
extern SetConsoleTitleA
extern GetTickCount64
extern Sleep
extern GetConsoleScreenBufferInfo
extern SetConsoleCursorPosition
extern FillConsoleOutputCharacterA
extern FillConsoleOutputAttribute

; Winsock API
extern WSAStartup
extern WSACleanup
extern socket
extern connect
extern send
extern recv
extern closesocket
extern inet_addr
extern htons
extern gethostbyname

; IPHLPAPI
extern IcmpCreateFile
extern IcmpSendEcho
extern IcmpCloseHandle

; Constants
STD_OUTPUT_HANDLE equ -11
STD_INPUT_HANDLE equ -10
MAX_PATH equ 260
AF_INET equ 2
SOCK_STREAM equ 1
IPPROTO_TCP equ 6

section .data
    title       db "System Utilities", 0
    
    banner      db 0x0A, 0x0D
                db "=================================", 0x0A, 0x0D
                db "  System Utilities - ogur.dev", 0x0A, 0x0D
                db "=================================", 0x0A, 0x0D, 0x0A, 0x0D, 0
    
    menu        db "Select utility:", 0x0A, 0x0D
                db "  [1] System Info", 0x0A, 0x0D
                db "  [2] Directory Tree", 0x0A, 0x0D
                db "  [3] HTTP Request (curl-like)", 0x0A, 0x0D
                db "  [4] Ping Host", 0x0A, 0x0D
                db "  [5] Port Scanner", 0x0A, 0x0D
                db "  [6] Exit", 0x0A, 0x0D, 0x0A, 0x0D
                db "Choice: ", 0
    
    ; System info
    sys_header  db 0x0A, 0x0D, "=== System Info ===", 0x0A, 0x0D, 0
    sys_comp    db "Computer: ", 0
    sys_user    db "User: ", 0
    sys_dir     db "Directory: ", 0
    
    ; Directory tree
    tree_header db 0x0A, 0x0D, "=== Directory Tree ===", 0x0A, 0x0D, 0
    tree_file   db "  |- ", 0
    tree_dir    db "  [+] ", 0
    tree_slash  db "/", 0x0A, 0x0D, 0
    search_pattern db "*", 0
    
    ; HTTP request
    http_header db 0x0A, 0x0D, "=== HTTP Request ===", 0x0A, 0x0D, 0
    http_prompt db "Enter hostname (e.g., example.com): ", 0
    http_connecting db "Connecting to ", 0
    http_port   db ":80...", 0x0A, 0x0D, 0
    http_sent   db "Request sent, waiting for response...", 0x0A, 0x0D, 0x0A, 0x0D, 0
    http_response_header db "=== Response ===", 0x0A, 0x0D, 0
    wsa_error_msg db "WSA initialization failed!", 0x0A, 0x0D, 0
    
    ; Ping
    ping_header db 0x0A, 0x0D, "=== Ping ===", 0x0A, 0x0D, 0
    ping_prompt db "Enter hostname or IP (e.g., 8.8.8.8): ", 0
    ping_sending db "Pinging ", 0
    ping_dots   db "...", 0x0A, 0x0D, 0
    ping_reply  db "Reply from ", 0
    ping_time   db ": time=", 0
    ping_ms     db "ms", 0x0A, 0x0D, 0
    ping_timeout db "Request timed out.", 0x0A, 0x0D, 0
    ping_resolve_error db "Could not resolve hostname.", 0x0A, 0x0D, 0
    
    ; Port scanner
    scan_header db 0x0A, 0x0D, "=== Port Scanner ===", 0x0A, 0x0D, 0
    scan_ip_prompt db "Enter hostname or IP (e.g., 127.0.0.1): ", 0
    scan_start_prompt db "Start port (e.g., 20): ", 0
    scan_end_prompt db "End port (e.g., 100): ", 0
    scan_scanning db "Scanning ", 0
    scan_ports  db " ports ", 0
    scan_to     db "-", 0
    scan_ellipsis db "...", 0x0A, 0x0D, 0
    scan_open   db "Port ", 0
    scan_open_suffix db " is OPEN", 0x0A, 0x0D, 0
    scan_done   db "Scan complete.", 0x0A, 0x0D, 0
    
    ; Common
    newline     db 0x0A, 0x0D, 0
    error_socket db "Socket error!", 0x0A, 0x0D, 0
    error_connect db "Connection failed!", 0x0A, 0x0D, 0
    press_key   db 0x0A, 0x0D, "Press Enter to continue...", 0

    ; Debug strings
    debug_resolving db "DEBUG: Resolving: ", 0
    debug_got_hostent db "DEBUG: Got hostent", 0x0A, 0x0D, 0
    debug_got_addrlist db "DEBUG: Got addr_list", 0x0A, 0x0D, 0
    debug_got_firstaddr db "DEBUG: Got first addr", 0x0A, 0x0D, 0
    debug_success db "DEBUG: Success, IP = ", 0
    debug_err_null db "DEBUG: ERROR - gethostbyname returned NULL", 0x0A, 0x0D, 0
    debug_err_addrlist db "DEBUG: ERROR - h_addr_list is NULL", 0x0A, 0x0D, 0
    debug_err_firstaddr db "DEBUG: ERROR - first address is NULL", 0x0A, 0x0D, 0
    debug_err_ip db "DEBUG: ERROR - IP is zero", 0x0A, 0x0D, 0

section .bss
    hStdOut     resq 1
    hStdIn      resq 1
    bytesWritten resq 1
    bytesRead   resq 1
    choice      resb 10
    computerName resb 256
    userName    resb 256
    currentDir  resb MAX_PATH
    nameSize    resd 1
    findData    resb 592
    
    ; Console
    consoleInfo resb 22
    
    ; Network
    wsaData     resb 400
    sockfd      resq 1
    sockaddr    resb 16
    recvBuffer  resb 4096
    numBuffer   resb 20
    
    ; User input buffers
    input_host  resb 256
    input_ip    resb 64
    input_port_start resb 10
    input_port_end resb 10
    
    ; HTTP request building
    http_full_req resb 1024
    
    ; Ping
    icmpHandle  resq 1
    pingData    resb 32
    replyBuffer resb 256
    resolved_ip resd 1

section .text
global main

main:
    push rbp
    mov rbp, rsp
    sub rsp, 32
    
    lea rcx, [title]
    call SetConsoleTitleA
    
    mov rcx, STD_OUTPUT_HANDLE
    call GetStdHandle
    mov [hStdOut], rax
    
    mov rcx, STD_INPUT_HANDLE
    call GetStdHandle
    mov [hStdIn], rax
    
    ; Initialize Winsock
    mov rcx, 0x0202
    lea rdx, [wsaData]
    call WSAStartup
    
    ; CHECK IF WSA WORKED
    test eax, eax
    jnz .wsa_failed
    
.menu_loop:
    call clear_screen
    
    lea rdx, [banner]
    call print_str
    
    lea rdx, [menu]
    call print_str
    
    mov rcx, [hStdIn]
    lea rdx, [choice]
    mov r8, 10
    lea r9, [bytesRead]
    call ReadConsoleA
    
    movzx eax, byte [choice]
    sub eax, '0'
    
    cmp eax, 1
    je .opt_sysinfo
    cmp eax, 2
    je .opt_tree
    cmp eax, 3
    je .opt_http
    cmp eax, 4
    je .opt_ping
    cmp eax, 5
    je .opt_portscan
    cmp eax, 6
    je .exit
    jmp .menu_loop

.opt_sysinfo:
    call show_system_info
    call pause_screen
    jmp .menu_loop

.opt_tree:
    call show_directory_tree
    call pause_screen
    jmp .menu_loop

.opt_http:
    call do_http_request
    call pause_screen
    jmp .menu_loop

.opt_ping:
    call do_ping
    call pause_screen
    jmp .menu_loop

.opt_portscan:
    call do_port_scan
    call pause_screen
    jmp .menu_loop

.wsa_failed:
    lea rdx, [wsa_error_msg]
    call print_str
    call pause_screen
    jmp .exit

.exit:
    call WSACleanup
    xor rcx, rcx
    call ExitProcess

; =============================================================================
; clear_screen - Clear console using Win32 API
; =============================================================================
clear_screen:
    push rbp
    mov rbp, rsp
    sub rsp, 64

    ; Get console info
    mov rcx, [hStdOut]
    lea rdx, [consoleInfo]
    call GetConsoleScreenBufferInfo

    ; Calculate console size
    movzx eax, word [consoleInfo + 0]   ; dwSize.X
    movzx ecx, word [consoleInfo + 2]   ; dwSize.Y
    mul ecx
    mov r12d, eax  ; Total chars

    ; Fill with spaces
    mov rcx, [hStdOut]
    mov edx, 0x20  ; Space character
    mov r8d, r12d
    xor r9d, r9d   ; Top-left (0, 0)
    lea rax, [bytesWritten]
    mov [rsp+32], rax
    call FillConsoleOutputCharacterA

    ; Reset cursor to 0,0
    mov rcx, [hStdOut]
    xor edx, edx   ; COORD (0, 0)
    call SetConsoleCursorPosition

    add rsp, 64
    pop rbp
    ret

; =============================================================================
; show_system_info
; =============================================================================
show_system_info:
    push rbp
    mov rbp, rsp
    sub rsp, 32

    lea rdx, [sys_header]
    call print_str

    ; Computer name
    mov dword [nameSize], 256
    lea rcx, [computerName]
    lea rdx, [nameSize]
    call GetComputerNameA

    lea rdx, [sys_comp]
    call print_str
    lea rdx, [computerName]
    call print_str
    lea rdx, [newline]
    call print_str

    ; User name
    mov dword [nameSize], 256
    lea rcx, [userName]
    lea rdx, [nameSize]
    call GetUserNameA

    lea rdx, [sys_user]
    call print_str
    lea rdx, [userName]
    call print_str
    lea rdx, [newline]
    call print_str

    ; Current directory
    mov rcx, MAX_PATH
    lea rdx, [currentDir]
    call GetCurrentDirectoryA

    lea rdx, [sys_dir]
    call print_str
    lea rdx, [currentDir]
    call print_str
    lea rdx, [newline]
    call print_str

    add rsp, 32
    pop rbp
    ret

; =============================================================================
; show_directory_tree
; =============================================================================
show_directory_tree:
    push rbp
    mov rbp, rsp
    sub rsp, 48

    lea rdx, [tree_header]
    call print_str

    lea rcx, [search_pattern]
    lea rdx, [findData]
    call FindFirstFileA
    mov [rsp+40], rax
    cmp rax, -1
    je .done

.loop:
    mov eax, [findData]
    test eax, 0x10
    jnz .is_dir

    lea rdx, [tree_file]
    call print_str
    lea rdx, [findData + 44]
    call print_str
    lea rdx, [newline]
    call print_str
    jmp .next

.is_dir:
    lea rsi, [findData + 44]
    cmp byte [rsi], '.'
    jne .print_dir
    cmp byte [rsi + 1], 0
    je .next
    cmp byte [rsi + 1], '.'
    je .next

.print_dir:
    lea rdx, [tree_dir]
    call print_str
    lea rdx, [findData + 44]
    call print_str
    lea rdx, [tree_slash]
    call print_str

.next:
    mov rcx, [rsp+40]
    lea rdx, [findData]
    call FindNextFileA
    test eax, eax
    jnz .loop

    mov rcx, [rsp+40]
    call FindClose

.done:
    add rsp, 48
    pop rbp
    ret

; =============================================================================
; do_http_request
; =============================================================================
do_http_request:
    push rbp
    mov rbp, rsp
    sub rsp, 64

    lea rdx, [http_header]
    call print_str
    
    ; Prompt for hostname
    lea rdx, [http_prompt]
    call print_str
    
    mov rcx, [hStdIn]
    lea rdx, [input_host]
    mov r8, 256
    lea r9, [bytesRead]
    call ReadConsoleA
    
    ; Strip \r\n
    lea rdi, [input_host]
    call strip_newline
    
    ; Build HTTP request: "GET / HTTP/1.1\r\nHost: HOSTNAME\r\nUser-Agent: ASM-Utils/1.0\r\nConnection: close\r\n\r\n"
    lea rdi, [http_full_req]
    
    ; GET line
    mov rsi, get_line
    call copy_string
    
    ; Host header
    mov rsi, host_header
    call copy_string
    lea rsi, [input_host]
    call copy_string
    mov rsi, crlf
    call copy_string
    
    ; User-Agent
    mov rsi, ua_header
    call copy_string
    
    ; Connection
    mov rsi, conn_header
    call copy_string
    
    ; Final CRLF
    mov rsi, crlf
    call copy_string
    
    mov byte [rdi], 0
    
    ; Calculate length
    lea rax, [http_full_req]
    sub rdi, rax
    mov r15, rdi
    
    ; Print connecting
    lea rdx, [http_connecting]
    call print_str
    lea rdx, [input_host]
    call print_str
    lea rdx, [http_port]
    call print_str

    ; Create socket
    mov rcx, AF_INET
    mov rdx, SOCK_STREAM
    mov r8, IPPROTO_TCP
    call socket
    mov [sockfd], rax
    cmp rax, -1
    je .error

    ; Setup sockaddr
    mov word [sockaddr], AF_INET
    mov rcx, 80
    call htons
    mov word [sockaddr + 2], ax
    
    ; Resolve hostname
    lea rcx, [input_host]
    call gethostbyname
    test rax, rax
    jz .error
    
    mov rax, [rax + 24]
    mov rax, [rax]
    mov eax, [rax]
    mov dword [sockaddr + 4], eax

    ; Connect
    mov rcx, [sockfd]
    lea rdx, [sockaddr]
    mov r8, 16
    call connect
    test eax, eax
    jnz .error_connect

    ; Send
    lea rdx, [http_sent]
    call print_str
    
    mov rcx, [sockfd]
    lea rdx, [http_full_req]
    mov r8, r15
    xor r9, r9
    call send

    ; Receive
    lea rdx, [http_response_header]
    call print_str

    mov rcx, [sockfd]
    lea rdx, [recvBuffer]
    mov r8, 4096
    xor r9, r9
    call recv
    
    test eax, eax
    jle .close
    
    mov rcx, [hStdOut]
    lea rdx, [recvBuffer]
    mov r8, 800
    lea r9, [bytesWritten]
    call WriteConsoleA
    
    lea rdx, [newline]
    call print_str

.close:
    mov rcx, [sockfd]
    call closesocket
    jmp .done

.error_connect:
    lea rdx, [error_connect]
    call print_str
    mov rcx, [sockfd]
    call closesocket
    jmp .done

.error:
    lea rdx, [error_socket]
    call print_str

.done:
    add rsp, 64
    pop rbp
    ret

; =============================================================================
; do_ping
; =============================================================================
do_ping:
    push rbp
    mov rbp, rsp
    sub rsp, 64

    lea rdx, [ping_header]
    call print_str
    
    lea rdx, [ping_prompt]
    call print_str
    
    mov rcx, [hStdIn]
    lea rdx, [input_ip]
    mov r8, 64
    lea r9, [bytesRead]
    call ReadConsoleA
    
    lea rdi, [input_ip]
    call strip_newline
    
    ; Resolve hostname/IP
    lea rcx, [input_ip]
    call resolve_host
    test eax, eax
    jz .resolve_error
    
    mov [resolved_ip], eax
    
    ; Print status
    lea rdx, [ping_sending]
    call print_str
    lea rdx, [input_ip]
    call print_str
    lea rdx, [ping_dots]
    call print_str

    ; Create ICMP handle
    call IcmpCreateFile
    mov [icmpHandle], rax
    test rax, rax
    jz .done

    ; Prepare data
    mov rcx, 32
    lea rdi, [pingData]
    mov al, 0x45
    rep stosb

    ; Get start time
    call GetTickCount64
    mov r11, rax

    ; Send ping
    mov rcx, [icmpHandle]
    mov edx, [resolved_ip]
    lea r8, [pingData]
    mov r9, 32
    push 0
    push 0
    push 256
    lea rax, [replyBuffer]
    push rax
    push 1000
    sub rsp, 32
    call IcmpSendEcho
    add rsp, 72

    test eax, eax
    jz .timeout

    ; Calculate RTT
    call GetTickCount64
    sub rax, r11

    lea rdx, [ping_reply]
    call print_str
    lea rdx, [input_ip]
    call print_str
    lea rdx, [ping_time]
    call print_str
    call print_number
    lea rdx, [ping_ms]
    call print_str
    jmp .close

.timeout:
    lea rdx, [ping_timeout]
    call print_str
    jmp .close

.resolve_error:
    lea rdx, [ping_resolve_error]
    call print_str
    jmp .done

.close:
    mov rcx, [icmpHandle]
    call IcmpCloseHandle

.done:
    add rsp, 64
    pop rbp
    ret

; =============================================================================
; do_port_scan
; =============================================================================
do_port_scan:
    push rbp
    mov rbp, rsp
    sub rsp, 64

    lea rdx, [scan_header]
    call print_str
    
    ; Get IP
    lea rdx, [scan_ip_prompt]
    call print_str
    mov rcx, [hStdIn]
    lea rdx, [input_ip]
    mov r8, 64
    lea r9, [bytesRead]
    call ReadConsoleA
    lea rdi, [input_ip]
    call strip_newline
    
    ; Resolve
    lea rcx, [input_ip]
    call resolve_host
    test eax, eax
    jz .error
    mov [resolved_ip], eax
    
    ; Get start port
    lea rdx, [scan_start_prompt]
    call print_str
    mov rcx, [hStdIn]
    lea rdx, [input_port_start]
    mov r8, 10
    lea r9, [bytesRead]
    call ReadConsoleA
    lea rdx, [input_port_start]
    call parse_number
    mov r12, rax
    
    ; Get end port
    lea rdx, [scan_end_prompt]
    call print_str
    mov rcx, [hStdIn]
    lea rdx, [input_port_end]
    mov r8, 10
    lea r9, [bytesRead]
    call ReadConsoleA
    lea rdx, [input_port_end]
    call parse_number
    mov r13, rax
    
    ; Print scanning
    lea rdx, [scan_scanning]
    call print_str
    lea rdx, [input_ip]
    call print_str
    lea rdx, [scan_ports]
    call print_str
    mov rax, r12
    call print_number
    lea rdx, [scan_to]
    call print_str
    mov rax, r13
    call print_number
    lea rdx, [scan_ellipsis]
    call print_str

.scan_loop:
    cmp r12, r13
    jg .done

    ; Create socket
    mov rcx, AF_INET
    mov rdx, SOCK_STREAM
    mov r8, IPPROTO_TCP
    call socket
    mov [sockfd], rax
    cmp rax, -1
    je .next_port

    ; Setup sockaddr
    mov word [sockaddr], AF_INET
    mov rcx, r12
    call htons
    mov word [sockaddr + 2], ax
    mov eax, [resolved_ip]
    mov dword [sockaddr + 4], eax

    ; Try connect
    mov rcx, [sockfd]
    lea rdx, [sockaddr]
    mov r8, 16
    call connect
    
    test eax, eax
    jnz .close_sock

    ; Port open
    lea rdx, [scan_open]
    call print_str
    mov rax, r12
    call print_number
    lea rdx, [scan_open_suffix]
    call print_str

.close_sock:
    mov rcx, [sockfd]
    call closesocket

.next_port:
    inc r12
    jmp .scan_loop

.error:
    lea rdx, [ping_resolve_error]
    call print_str
    jmp .done

.done:
    lea rdx, [scan_done]
    call print_str
    
    add rsp, 64
    pop rbp
    ret

; =============================================================================
; resolve_host - Using gethostbyname
; Input: rcx = hostname/IP string
; Output: eax = IP address (network byte order), 0 on error
; =============================================================================
resolve_host:
    push rbp
    mov rbp, rsp
    sub rsp, 32
    
    call gethostbyname
    test rax, rax
    jz .error
    
    mov rdx, [rax + 24]
    test rdx, rdx
    jz .error
    
    mov rdx, [rdx]
    test rdx, rdx
    jz .error
    
    mov eax, [rdx]
    jmp .done
    
.error:
    xor eax, eax
    
.done:
    add rsp, 32
    pop rbp
    ret

; =============================================================================
; print_hex - Print 32-bit value in hex
; Input: rdx = value
; =============================================================================
print_hex:
    push rbp
    mov rbp, rsp
    sub rsp, 32
    push rbx
    push r12
    
    mov r12, rdx
    lea rdi, [numBuffer]
    
    mov byte [rdi], '0'
    inc rdi
    mov byte [rdi], 'x'
    inc rdi
    
    mov ecx, 8
.loop:
    mov eax, r12d
    shr eax, 28
    and eax, 0xF
    cmp al, 10
    jb .digit
    add al, 'A' - 10
    jmp .store
.digit:
    add al, '0'
.store:
    mov [rdi], al
    inc rdi
    shl r12d, 4
    dec ecx
    jnz .loop
    
    mov byte [rdi], 0
    
    lea rdx, [numBuffer]
    call print_str
    
    pop r12
    pop rbx
    add rsp, 32
    pop rbp
    ret

; =============================================================================
; copy_string - Copy null-terminated string
; Input: rsi = source, rdi = dest (updated)
; =============================================================================
copy_string:
    push rax
.loop:
    lodsb
    test al, al
    jz .done
    stosb
    jmp .loop
.done:
    pop rax
    ret

; =============================================================================
; strip_newline
; =============================================================================
strip_newline:
    push rax
.loop:
    mov al, [rdi]
    test al, al
    jz .done
    cmp al, 0x0D
    je .null_it
    cmp al, 0x0A
    je .null_it
    inc rdi
    jmp .loop
.null_it:
    mov byte [rdi], 0
.done:
    pop rax
    ret

; =============================================================================
; parse_number
; =============================================================================
parse_number:
    push rbx
    push rcx
    
    xor rax, rax
    xor rbx, rbx
    mov rcx, 10
    
.loop:
    movzx ebx, byte [rdx]
    cmp bl, '0'
    jb .done
    cmp bl, '9'
    ja .done
    
    sub bl, '0'
    mul rcx
    add rax, rbx
    inc rdx
    jmp .loop
    
.done:
    pop rcx
    pop rbx
    ret

; =============================================================================
; print_str
; =============================================================================
print_str:
    push rbp
    mov rbp, rsp
    sub rsp, 32
    push rsi
    push rdi

    mov rdi, rdx
    mov rsi, rdx
    xor rcx, rcx

.len_loop:
    lodsb
    test al, al
    jz .print
    inc rcx
    jmp .len_loop

.print:
    push rcx
    mov rcx, [hStdOut]
    mov rdx, rdi
    pop r8
    lea r9, [bytesWritten]
    call WriteConsoleA

    pop rdi
    pop rsi
    add rsp, 32
    pop rbp
    ret

; =============================================================================
; print_number
; =============================================================================
print_number:
    push rbp
    mov rbp, rsp
    sub rsp, 32
    push rbx

    lea rdi, [numBuffer]
    mov rbx, 10
    xor rcx, rcx

.divide:
    xor rdx, rdx
    div rbx
    add dl, '0'
    push rdx
    inc rcx
    test rax, rax
    jnz .divide

.write:
    pop rax
    stosb
    loop .write
    
    mov byte [rdi], 0

    lea rdx, [numBuffer]
    call print_str

    pop rbx
    add rsp, 32
    pop rbp
    ret

; =============================================================================
; pause_screen
; =============================================================================
pause_screen:
    push rbp
    mov rbp, rsp
    sub rsp, 32

    lea rdx, [press_key]
    call print_str
    
    mov rcx, [hStdIn]
    lea rdx, [choice]
    mov r8, 10
    lea r9, [bytesRead]
    call ReadConsoleA

    add rsp, 32
    pop rbp
    ret

; HTTP request template strings
section .data
get_line    db "GET / HTTP/1.1", 0x0D, 0x0A, 0
host_header db "Host: ", 0
ua_header   db "User-Agent: ASM-Utils/1.0", 0x0D, 0x0A, 0
conn_header db "Connection: close", 0x0D, 0x0A, 0
crlf        db 0x0D, 0x0A, 0