Hallo Michael,
ich weiss nicht was Du da alles einbauen willst, wichtig ist eigentlich nur das es möglichst zufällig ist.
Ich weiss nicht, was Du weiter verschlüsseln willst, unterschiedliche Verfahren bringen fürs Erzeugen wenig Mehrwehrt.
Unten mal etwas was ich zusammengebastelt hatte unter Zuhilfenahme des
RNGCryptoServiceProvider
siehe auch
http://stackoverflow.com/questions/418817/pros-and-cons-of-rngcryptoserviceprovider
Imports System.Security.Cryptography
Imports System.Text
Public Class PasswordGenerator
Private Shared __simplePasswordChars As String = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstvwxyz"
' Kleines Subset (je nach Umgebung können einige Zeichen problematisch sein)
Private Shared __specialPasswordChars As String = "!#%&()*,-./:;?[\]_{|}§"
Dim _rngProvider As RNGCryptoServiceProvider
Dim _passwordChars As Char()
Dim _passwordCharsLength As Integer
Dim _passwordLength As Integer
Dim _iv As Byte()
Dim _ivLength As Integer
Dim _ivIndex As Integer
Public Sub New(ByVal passwordLength As Integer, ByVal useSpecialChars As Boolean)
If passwordLength < 1 Or passwordLength > 128 Then
Throw New ArgumentOutOfRangeException("passwordLength")
End If
Me._passwordLength = passwordLength
If useSpecialChars Then
Me._passwordChars = (__specialPasswordChars & __simplePasswordChars).ToCharArray()
Else
Me._passwordChars = __simplePasswordChars.ToCharArray()
End If
Me._passwordCharsLength = _passwordChars.Length
Me._rngProvider = New RNGCryptoServiceProvider()
Me._ivLength = Me._passwordLength * 2
Me._iv = New Byte(Me._ivLength - 1) {}
End Sub
Public Function Generate() As String
InitializeIV()
Dim password As New StringBuilder(Me._passwordLength)
For index As Integer = 0 To Me._passwordLength - 1
password.Append(NextChar)
Next
Return password.ToString()
End Function
Private Sub InitializeIV()
Me._rngProvider.GetNonZeroBytes(Me._iv)
Me._ivIndex = 0
End Sub
Private Function NextByte() As Byte
' Liefert das nächste Byte
If Me._ivIndex >= Me._ivLength Then
InitializeIV()
End If
Dim value As Byte = Me._iv(Me._ivIndex)
Me._ivIndex += 1
Return value
End Function
Private Function NextChar() As Char
' Zwei Bytes für bessere Verteilung
Dim charIndex As Integer = CType(NextByte(), Integer) + CType(NextByte(), Integer)
charIndex = charIndex Mod Me._passwordCharsLength
Return Me._passwordChars(charIndex)
End Function
Friend Shared Sub Test()
Const PasswordLength As Integer = 6
Const MaxRuns As Integer = 100000
Dim generator As New PasswordGenerator(PasswordLength, False)
Dim passwords As New HashSet(Of String)
Dim watch As New Stopwatch()
watch.Start()
Dim duplicateCount As Integer = 0
For index As Integer = 0 To MaxRuns - 1
Dim password As String = generator.Generate()
If passwords.Contains(password) Then
Console.WriteLine("Duplicate at: {0} = {1}", index, password)
duplicateCount += 1
End If
passwords.Add(password)
'If (index Mod 1000) = 0 Then
' Console.WriteLine("Generated {0} passwords", index)
'End If
Next
watch.Stop()
Console.WriteLine("Generation Time: {0} for {1} ({2} Duplicates)", watch.ElapsedMilliseconds, MaxRuns, duplicateCount)
Using writer As New System.IO.StreamWriter("C:\passwords.txt", False, System.Text.Encoding.Default)
For Each password As String In passwords
writer.WriteLine(password)
Next
End Using
Dim totalCount As Long
Dim charUsage As New SortedDictionary(Of Char, Long)
For Each password As String In passwords
For Each ch In password
Dim value As Long
If charUsage.TryGetValue(ch, value) Then
value += 1
Else
value = 1
End If
charUsage(ch) = value
totalCount += 1
Next
Next
Using writer As New System.IO.StreamWriter("C:\passwordchars.txt", False, System.Text.Encoding.Default)
writer.WriteLine("Average: {0} Chars => {1} Count", charUsage.Count, totalCount \ charUsage.Count)
For Each value In charUsage
writer.WriteLine("Char: {0} = {1} ({2:p3})", value.Key, value.Value, 1.0 * value.Value / totalCount)
Next
End Using
End Sub
End Class
Der Zeichenvorrat wird dort nur nach Zeichen/Zahlen mit oder ohne Sonderzeichen festgelegt,
was sich aber einfach ändern lässt. Ebenso die eingebaute Grenze von 128 Zeichen.
Am Ende findest Du eine kleine Testmethode inkl. minimaler Auswertung.
Googeln nach Password Generator VB.NET liefert Dir weitere.
Gruß Elmar
