Mornin', I'm trying to just get basic encryption working using System.Security.Cryptography.RjindaelManaged. I have google for this error and cannot find the problem, or what I am doing wrong. All I am attempting to do is encrypt a string, and then decrypt a string.
Following is my code, and any help would be appreciated.
Imports System.Security.Cryptography
Imports System.Text
Public rj As New RijndaelManaged
Try
rj.Padding = PaddingMode.None
rj.GenerateKey()
rj.GenerateIV()
Dim curProvider As New AesCryptoServiceProvider
Dim curEncryptor As ICryptoTransform
Dim memEncStream As New MemoryStream
Dim cryptoEncStream As CryptoStream
curEncryptor = curProvider.CreateEncryptor(rj.Key, rj.IV)
cryptoEncStream = New CryptoStream(memEncStream, curEncryptor, CryptoStreamMode.Write)
Dim startingBytes() As Byte = Encoding.ASCII.GetBytes("This is a test")
Debug.Print("before length: " & startingBytes.Length)
Debug.Print("before text: " & Encoding.ASCII.GetString(startingBytes))
EcryptoEncStream.Write(startingBytes, 0, startingBytes.Length)
cryptoEncStream.FlushFinalBlock()
memEncStream.Position = 0
Dim theBytes(memEncStream.Length) As Byte
memEncStream.Read(theBytes, 0, memEncStream.Length)
memEncStream.Flush()
memEncStream.Close()
cryptoEncStream.Close()
Debug.Print("How long? " & theBytes.Length)
Debug.Print("Data: " & Encoding.ASCII.GetString(theBytes))
Dim curDecryptor As ICryptoTransform
curDecryptor = curProvider.CreateDecryptor(rj.Key, rj.IV)
Dim memDecStream As New MemoryStream
Dim cryptoDecStream As CryptoStream
curDecryptor = curProvider.CreateDecryptor(rj.Key, rj.IV)
cryptoDecStream = New CryptoStream(memDecStream, curDecryptor, CryptoStreamMode.Write)
Dim endingBytes() As Byte = theBytes
Debug.Print("before length: " & theBytes.Length)
Debug.Print("before text: " &am开发者_运维百科p; Encoding.ASCII.GetString(theBytes))
cryptoDecStream.Write(theBytes, 0, theBytes.Length)
cryptoDecStream.FlushFinalBlock()
memDecStream.Position = 0
Dim endBytes(memDecStream.Length) As Byte
memDecStream.Read(theBytes, 0, memDecStream.Length)
memDecStream.Flush()
memDecStream.Close()
cryptoEncStream.Close()
Debug.Print("How long? " & endBytes.Length)
Debug.Print("Data: " & Encoding.ASCII.GetString(endBytes))
Catch ex As Exception
Debug.Print(ex.ToString)
End Try
You have overridden the PaddingMode and set it None
. Why? Leave the PaddingMode to its default value of PaddingMode.PKCS7
unless you have a good reason to change it and you understand padding in a block cipher.
It appears that the problem is the length of the data that you are passing to the decryption stream. If you change the declaration of theBytes
from this:
Dim theBytes(memEncStream.Length) As Byte
To this:
Dim theBytes(memEncStream.Length - 1) As Byte
Then it runs fine (at least it did for me). I'm not a VB wizard at all, but I think the array declaration is one byte longer than the given size (I think it is 0 to N). With that extra byte passed to the decryption stream, it does not work.
And I'm sure you will see it soon enough, but your printing of the final decrypted text is not quite right. It is printing theBytes
instead of endBytes
.
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