AESFusion in Flash SWF

[turtle]

Sorry not sure if I should ask this here or at the extension... caus the extension post looks very clean.

Anyway, I am trying to use the AESFusion with Flash with it encrypting the string with a 16 char key. Then I use the Get Object to sent it over to a .aspx page.

I am trying to decrypt it at the .aspx but I have gone partially nuts trying to figure it out.

I know it's AES, I have used the Rijndael algo with the following assumption...

1. The key passed into the AES is converted to a byte array so using a "888888..." will give you a {56,56,56,56,56...}

2. I am using the cypher mode to ECB.

3. Pading mode to PKCS7.

4. I defaulted the IV by not doing anything to it.

5. The output of the encryption is Hex value.

6. Keysize of 128

7. Blocksize of 128

The closest I get when encrypting "hello" with the "8888888888888888" key using the AESFusion in MMF is

356F21A8FA105D5EE5B81A28906D44BC

while the .aspx I am making churns out

D3575367ED69EA6FDC11F7133A38EA7

I am sure there are something wrong somewhere but if someone got it right, please share the settings if possible. Thank you

[Christian_Wheel]

I also would like to know the inner workings of the algorithm for server-side script use. Jamie, could you shed some light? Pretty please?

[turtle]

Server side? I am using VB.NET for the server app ad it comes with the AES en/decrypt provider... adding the

Imports System.Security.Cryptography

makes calling to the AES functions.
Basically the encryption functon in VB.net looks like this

------------------------------------------------------------

Public Function EncryptAES(ByVal clearText As String, ByVal key As String) As String

Dim newarr = StrToByteArray(key)
Dim sourceBytes = Encoding.Unicode.GetBytes(clearText)


Dim aes = New AesCryptoServiceProvider

aes.BlockSize = 128
aes.FeedbackSize = 128

aes.Key = newarr

aes.Mode = CipherMode.ECB
aes.Padding = PaddingMode.PKCS7

Dim encryptor = aes.CreateEncryptor()

Dim ms = New MemoryStream
Dim cs = New CryptoStream(ms, encryptor, CryptoStreamMode.Write)
cs.Write(sourceBytes, 0, sourceBytes.Length)
cs.FlushFinalBlock()

Dim encrypted = ms.ToArray()

aes.Clear()
cs.Dispose()
ms.Dispose()

Return encrypted

End Function

------------------------------------------------------------

The StrToByteArray function simply converts the key string to bytearray

------------------------------------------------------------

Public Shared Function StrToByteArray(ByVal str As String) As Byte()
Dim encoding As New System.Text.UTF8Encoding()
Return encoding.GetBytes(str)
End Function 'StrToByteArray

------------------------------------------------------------

This is not the best way to do it I am sure there are other better methods