OK, so having just got the key to be accepted and have an encrypted string out which is 44 char long, I now am unable to decrypt (aarrgghh):
Length of the data to decrypt is invalid.
Having looked around and read various posts it looks as though the conversion to a Base64String may be the problem but I can’t see where it is wrong – many of the solutions I have seen appear to be identical to what I have. Again, I’d really appreciate any help – extracts below:
Encryption/Decryption Function
Private byteKey As Byte() = Encoding.UTF8.GetBytes("B499F4BF48242E05548D1E4C8BB26A2E")
Private byteIV As Byte() = Encoding.UTF8.GetBytes(",%u'm&'CXSy/T7x;4")
Private Function Rijndael(ByVal sInput As String, ByVal bEncrypt As Boolean) As String
' Create an instance of encyrption algorithm.
Dim _rijndael As New RijndaelManaged()
' Create an encryptor using key and IV - already available in byte() as byteKey and byteIV
Dim transform As ICryptoTransform
If bEncrypt Then
transform = _rijndael.CreateEncryptor(byteKey, byteIV)
Else
transform = _rijndael.CreateDecryptor(byteKey, byteIV)
End If
' Create streams for input and output
Dim msOutput As New System.IO.MemoryStream()
Dim msInput As New CryptoStream(msOutput, transform, CryptoStreamMode.Write)
' Feed data into the crypto stream.
msInput.Write(Encoding.UTF8.GetBytes(sInput), 0, Encoding.UTF8.GetBytes(sInput).Length)
' Flush crypto stream.
msInput.FlushFinalBlock()
Dim byteOutput As Byte() = msOutput.ToArray
Return Convert.ToBase64String(byteOutput)
End Function
Usage:
Dim sEncrypted As String = Rijndael("This is a test", True)
Dim sDecrypted As String = Rijndael(sEncrypted, False) **This is the line where it is crashing**
EDIT – Final, seemingly working pair of functions (see comment) for ref:
Private byteKey As Byte() = Encoding.UTF8.GetBytes("B499F4BF48242E05548D1E4C8BB26A2E")
Private byteIV As Byte() = Encoding.UTF8.GetBytes(",%u'm&'CXSy/T7x;4")
Public Function Encrypt(ByVal sInput As String) As String
' Create an instance of our encyrption algorithm.
Dim _rijndael As New RijndaelManaged()
' Create an encryptor using our key and IV
Dim transform As ICryptoTransform
transform = _rijndael.CreateEncryptor(byteKey, byteIV)
' Create the streams for input and output
Dim msOutput As New System.IO.MemoryStream()
Dim msInput As New CryptoStream(msOutput, transform, CryptoStreamMode.Write)
' Feed our data into the crypto stream
msInput.Write(Encoding.UTF8.GetBytes(sInput), 0, Encoding.UTF8.GetBytes(sInput).Length)
msInput.FlushFinalBlock()
Return Convert.ToBase64String(msOutput.ToArray)
End Function
Public Function Decrypt(ByVal sInput As String) As String
' Create an instance of our encyrption algorithm.
Dim _rijndael As New RijndaelManaged()
' Create an encryptor using our key and IV
Dim transform As ICryptoTransform
transform = _rijndael.CreateDecryptor(byteKey, byteIV)
' Create the streams for input and output
Dim msOutput As New System.IO.MemoryStream()
Dim msInput As New CryptoStream(msOutput, transform, CryptoStreamMode.Write)
' Feed our data into the crypto stream.
msInput.Write(Convert.FromBase64String(sInput), 0, Convert.FromBase64String(sInput).Length)
msInput.FlushFinalBlock()
Return Encoding.UTF8.GetString(msOutput.ToArray)
End Function
Usage
Dim sEncrypted As String = Encrypt("This is a test")
Dim sDecrypted As String = Decrypt(sEncrypted)
If you’re going to convert it to base64 you’re going to have to decode it using Base64. At the moment you’re taking the output Base64 byte array then using UTF8 to convert it back to bytes, which gives you a completely different value.
You should be using Convert.FromBase64String instead of UTF8 for changing the string to bytes when decoding, then using UTF8 instead of Base64 for interpreting the data.
EG: On the decode you’d want
And for the return when decoding: