; ==============================================================================
; DynamicPassword.ahk
; Deterministic Password Generator
; ==============================================================================
; This script generates a unique, complex password based on a service name 
; and a personal salt. The password is never stored and is generated on-the-fly.
; ==============================================================================

#NoEnv
#SingleInstance force
#Persistent

; --- Hotkeys ---

; WIN + F1: Generate a 32-character password
#F1::
    Password(32)
return

; WIN + F2: Generate a 16-character password
#F2::
    Password(16)
return

; --- Core Logic ---

Password(Length) { 
    ; Prompt for the website or service name (e.g., "gmail")
    InputBox, Service, Website/Service, Enter the name of the site:, , 200, 130
    if (ErrorLevel) ; User cancelled
        return

    ; Prompt for the personal salt (a simple password only you know)
    InputBox, Salt, Password Salt, Enter a salt password:, hide , 200, 130
    if (ErrorLevel) ; User cancelled
        return

    ; Generate a complex hash by combining MD5 of Service and Salt in a cross-pattern
    ; This creates a unique signature for the site/salt combination.
    Hash := MD5(MD5(Service) . Salt) . MD5(MD5(Salt) . Service)

    ; Map the hash characters to a wider range of ASCII symbols
    ; to create a complex password.
    Pwd := ""
    Loop, %Length% {
        ; Extract 2 characters from the hash
        Char := SubStr(Hash, A_Index * 2 - 1, 2)
        Char2Hex := "0x" . Char
        
        ; Transform the hex value into a printable ASCII character (Range: 33-126)
        ; Logic: (HexValue / 2.74) + 33 maps 0-255 to roughly 33-126 range.
        Hex := Chr(Round((Char2Hex + 0) / 2.74) + 33)
        Pwd .= Hex
    }

    ; Copy to clipboard and notify the user
    Clipboard := Pwd 
    MouseGetPos, x1, y1
    ToolTip, Password copied to clipboard, %x1%, %y1%
    
    ; Auto-hide the tooltip after 1 second
    SetTimer, RemoveToolTip, 1000
    Sleep, 1000
    
    ; Reload the script to clear variables from memory for extra security
    Reload
}

; MD5 Hashing Function using Windows Crypto API (advapi32)
MD5(ByRef V, L = 0) {
    VarSetCapacity(MD5_CTX, 104, 0)
    DllCall("advapi32\MD5Init", "Ptr", &MD5_CTX)
    DllCall("advapi32\MD5Update", "Ptr", &MD5_CTX, "Str", V, "UInt", L ? L : VarSetCapacity(V))
    DllCall("advapi32\MD5Final", "Ptr", &MD5_CTX)
    
    Hex := "123456789ABCDEF0"
    Loop 16 {
        N := NumGet(MD5_CTX, 87 + A_Index, "UChar")
        MD5 .= SubStr(Hex, N >> 4, 1) . SubStr(Hex, N & 15, 1)
    }
    Return MD5
}

; ToolTip Cleanup
RemoveToolTip:
    SetTimer, RemoveToolTip, Off
    ToolTip
return