Foro de elhacker.net

Public Function Rand(ByVal Low As Long, _
                     ByVal High As Long) As Long
  Rand = Int((High - Low + 1) * Rnd) + Low
End Function

Text4.Text = Rand(10, 99)

'---------------------------------------------------------------------------------------
' Module    : mRand
' DateTime  : 06/07/2007 04:13
' Author    : Cobein
' Mail      : cobein27@yahoo.com
' Purpose   : Microsoft C v4.0 rand() + shuffle output
'---------------------------------------------------------------------------------------
Option Explicit

Private m_bvBox(255) As Byte
Private m_dSeed As Double

Public Function Rand() As Byte
    Dim lRet As Long
    '// Rand Function
    m_dSeed = CustomMod((214013 * m_dSeed + 2531011), 2 ^ 31)
    lRet = Int(m_dSeed / 2 ^ 16)
    '// Shuffle our box
    ShuffleBox lRet
    '// Return Value
    Rand = m_bvBox(0)
End Function

Public Sub Randomize(ByVal lVal As Long)
    Dim i As Long
    '// Initialize Box
    If m_dSeed = 0 Then '// Just to prevent from reorganizing the elements in the array once initialized.
        For i = 0 To 255
            m_bvBox(i) = i
        Next
    End If
    '// Set the seed
    m_dSeed = lVal
End Sub

'// Custom mod to prevent overflow
' This is not mine is from a RSA implementation I found on PSC
Private Function CustomMod(ByVal dVal1 As Double, ByVal dVal2 As Double) As Double
    CustomMod = dVal1 - (Int(dVal1 / dVal2) * dVal2)
End Function

Private Function ShuffleBox(ByVal lVal As Long)
    Dim lKeyLen As Long
    Dim bvKey() As Byte
    Dim i As Long
    Dim j As Long
    Dim bTemp As Byte
    
    bvKey() = StrConv(lVal, vbFromUnicode)
    lKeyLen = UBound(bvKey) + 1
    
    For i = 0 To 255
        '// Calculate the index
        j = (j + m_bvBox(i) + bvKey(i Mod lKeyLen)) Mod 256
        '// Swap values
        bTemp = m_bvBox(i): m_bvBox(i) = m_bvBox(j): m_bvBox(j) = bTemp
    Next
End Function