Databases
StackOverflow2013
Postsdbo
POPython byte per byte XOR decryption
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POPython byte per byte XOR decryption
    primarykey
    data
    text
    <p>I have an XOR encypted file by a VB.net program using this function to scramble:</p> <pre><code>Public Class Crypter ... 'This Will convert String to bytes, then call the other function. Public Function Crypt(ByVal Data As String) As String Return Encoding.Default.GetString(Crypt(Encoding.Default.GetBytes(Data))) End Function 'This calls XorCrypt giving Key converted to bytes Public Function Crypt(ByVal Data() As Byte) As Byte() Return XorCrypt(Data, Encoding.Default.GetBytes(Me.Key)) End Function 'Xor Encryption. Private Function XorCrypt(ByVal Data() As Byte, ByVal Key() As Byte) As Byte() Dim i As Integer If Key.Length &lt;&gt; 0 Then For i = 0 To Data.Length - 1 Data(i) = Data(i) Xor Key(i Mod Key.Length) Next End If Return Data End Function End Class </code></pre> <p>and saved this way:</p> <pre><code>Dim Crypter As New Cryptic(Key) 'open destination file Dim objWriter As New StreamWriter(fileName) 'write crypted content objWriter.Write(Crypter.Crypt(data)) </code></pre> <p>Now I have to reopen the file with Python but I have troubles getting <b>single bytes</b>, this is the XOR function in python:</p> <pre><code>def crypto(self, data): 'crypto(self, data) -&gt; str' return ''.join(chr((ord(x) ^ ord(y)) % 256) \ for (x, y) in izip(data.decode('utf-8'), cycle(self.key)) </code></pre> <p>I had to add the % 256 since sometimes x is > 256 i.e. <b>not a single byte</b>.</p> <p>This thing of two bytes being passed <b>does not break the decryption</b> because the key keeps "paired" with the following data.</p> <p>The problem is some decrypted character in the conversion is wrong. These chars are all accented letters like à, è, ì but <b>just a few of the overall accented letters</b>. The others are all correctly restored.</p> <p>I guess it could be due to the 256 mod but without it I of course get a chr exception...</p> <p>Thanks for your support</p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. This table or related slice is empty.
    1. USneurino
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POPython byte per byte XOR decryption
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POPython byte per byte XOR decryption
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POPython byte per byte XOR decryption
      1. USGareth Davis
      1. VTFavorite
    1. COI hope you don't actually expect actual security from this.
      singulars
      1. POPython byte per byte XOR decryption
      1. USGlenn Maynard
    2. COAll I need is to get integral data back, I get files scrambled that way, security is not my duty.
      singulars
      1. POPython byte per byte XOR decryption
      1. USneurino
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload