WIN ZIP Password Recovery

Is there anybody who tell me how to recover WIN ZIP password using VB or any other mathod.

Waiting for your valueable reply.
Thanks in advance.

The only method to recover the zip password is with brute force ...

Supply a password like "aaaaaaaaaa" ... test it, if it fails sequentialy increment to "aaaaaaaaab" etc...

This method can take HOURS, but is the only way to retrive it..

The password is not stored in the ZIP file, but is used as an Encryption key, and is required to Decrypt....

Gremmy...

OMG that may take weeks or months also? if the system is slow. it means it have to try all the possible combination of keyboard and also it will try every name in the universe we have

Thanks GremlinSA and GremlinSA for your reply.

I tried that to find such a software to recover but all are trial versions and can find only 2,3 character password. all are required to purchase the software.

Is there any website or source code from where I can download free.

Depends on the length of the passwords you want to check for.

If checking for 3, 4, 5, 6, 7, 8 and 9 character passwords (assuming any ascii character can be used), your looking at

3^255 + 4^255 + 5^255 + 6^255 + 7^255 + 8^255 + 9^255

I make that 2.147e+243 which is a pretty big number :o

These functions might help get you started. Note that they are only for alphanumeric (and only uppercase letters), so you need to modify them if you are going to check all characters:

Code:

---

        Public Function IncrementMaxID(ByVal MaxID As String, ByVal MaxLength As Integer) As String
                ' This Function Gets the Next Alphanumeric ID i.e if 009 passed in next would be 00A, 19Z becomes 1A0
                While LTrim(MaxID).Length < MaxLength
                        MaxID = "0" + MaxID
                End While
                For iloop As Integer = MaxLength - 1 To 0 Step -1
                        Dim NewID As String = MaxID.Substring(0, iloop) + getNextChar(MaxID.Chars(iloop))
                        While NewID.Length < MaxLength
                                NewID += "0"
                        End While
                        'if its a zero returned must increment next char
                        If NewID.Chars(iloop) <> "0" Then
                                Return NewID
                        End If
                Next
                Dim returnValue As String = ""
                For iloop As Integer = 0 To MaxLength - 1
                        returnValue += "0"
                Next
                Return returnValue
        End Function
 
        Private Function getNextChar(ByVal Ch As Char) As String
                'next ascii character after next one
                For AsciiLoop As Integer = 48 To 90
                        If Ch = Chr(AsciiLoop) Then
                                'if its 9 jump to A as next
                                If AsciiLoop = 57 Then
                                        Return CStr(Chr(65))
                                        'If its Z return to 0 as next
                                ElseIf AsciiLoop = 90 Then
                                        Return CStr(Chr(48))
                                Else
                                        'just increment character
                                        Return CStr(Chr(AsciiLoop + 1))
                                End If
                        End If
                Next
                Return "0"
        End Function

---

Dear HairyMonkeyMan thanks a lot for ur help. Where i give the file name and how it reads file name ??

Factian,

This code takes a string and increments the characters.. As far as putting in the filename and having it try the password.. have a look into the sharp zip component. Sorry I don't have time to work on this for you.

ps... what I posted is .net code... it might need a little reworking.

Regards