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492

answers:

2

OK, I give up. I have been trying to figure this out for weeks now. I think I will leave it to the crowd-sourcing machine.

Can Somebody Please Make A PHP 5 Equivalent Of Anyone Of The 2 Classes Below? (I mean with that both encrypted

Silverlight Cryptography Class 1:

Public Class AES128Helper
    Public Password As String = Nothing
    Public PasswordSalt As String = Nothing
    Private DefaultIntSize As Integer = 4

    Public Function Encryptaes128(ByVal PlainText() As Byte) As Byte()
        Try
            Using MStream As New MemoryStream 'Memory stream to write encrypted data to.
                Using A128 As New AesManaged
                    'Key.
                    Dim DeriveBytes As New Rfc2898DeriveBytes(Password, Encoding.UTF8.GetBytes(PasswordSalt))
                    A128.Key = DeriveBytes.GetBytes(128 / 8)
                    'IV.
                    If Integer.MaxValue = Int64.MaxValue Then DefaultIntSize = 8
                    MStream.Write(BitConverter.GetBytes(A128.IV.Length), 0, DefaultIntSize)
                    MStream.Write(A128.IV, 0, A128.IV.Length)
                    'Create Crypto Stream that transforms memory stream using des encryption.
                    Using CryptoStream As New CryptoStream(MStream, A128.CreateEncryptor(), CryptoStreamMode.Write)
                        'Write out and flush TripleDES encrypted file to memory stream.
                        With CryptoStream
                            .Write(PlainText, 0, PlainText.Length)
                            .FlushFinalBlock()
                        End With
                        CryptoStream.Close()
                    End Using
                    'Return encrypted data.
                    Return MStream.ToArray
                End Using
                MStream.Close()
            End Using
        Catch ex As Exception
            Return Nothing
        End Try
    End Function

    Public Function Decryptaes128(ByVal EncryptedByteData() As Byte) As Byte()
        Try
            Using MStream As MemoryStream = New MemoryStream(EncryptedByteData) 'Memory stream to write decrypted data to.
                Using A128 As New AesManaged
                    'Key.
                    Dim DeriveBytes As New Rfc2898DeriveBytes(Password, Encoding.UTF8.GetBytes(PasswordSalt))
                    A128.Key = DeriveBytes.GetBytes(128 / 8)
                    'Get the IV from the encrypted stream.
                    A128.IV = ReadByteArray(MStream)
                    'Create crypto stream set to read and do a TripleDES decryption transform on incoming bytes.
                    Using CryptoStream As New CryptoStream(MStream, A128.CreateDecryptor(), CryptoStreamMode.Read)
                        'Get the decrypted bytes.
                        Dim DestArray() As Byte = New BinaryReader(CryptoStream).ReadBytes(MStream.Length * 2)
                        Return DestArray 'Return decrypted data.
                    End Using
                End Using
                MStream.Close()
            End Using
        Catch ex As Exception
            Return Nothing
        End Try
    End Function

    Private Function ReadByteArray(ByVal s As Stream) As Byte()
        If Integer.MaxValue = Int64.MaxValue Then DefaultIntSize = 8
        Dim rawLength(DefaultIntSize - 1) As Byte
        If s.Read(rawLength, 0, rawLength.Length) <> rawLength.Length Then
            Throw New SystemException("Stream did not contain properly formatted byte array.")
        End If
        Dim buffer(BitConverter.ToInt32(rawLength, 0) - 1) As Byte
        If s.Read(buffer, 0, buffer.Length) <> buffer.Length Then
            Throw New SystemException("Did not read byte array properly.")
        End If
        Return buffer
    End Function
End Class

Example Usage For The Above:

Dim g As New AES128Helper
g.Password = "Password"
g.PasswordSalt = "PasswordSalt"
Dim b As Byte() = System.Text.Encoding.UTF8.GetBytes("Sad day really.")
Dim b2 As Byte() = g.Encryptaes128(b)
Dim b64 As String = Convert.ToBase64String(b2)

OR For This Silverlight Class (if you think it's easier)

Public Class AES128Helper2
    Public Key As Byte() = Nothing
    Public IV As Byte() = Nothing

    Public Function Encryptaes128(ByVal PlainText() As Byte) As Byte()
        Dim CryptoStream As CryptoStream = Nothing
        Dim MStream As New System.IO.MemoryStream 'Memory stream to write encrypted data to.
        Dim A128 As New AesManaged
        Try
            'Create aes128 Encryptor from this instance.
            Dim A128Encrypt As ICryptoTransform = A128.CreateEncryptor(Key, IV)
            'Create Crypto Stream that transforms memory stream using des encryption.
            CryptoStream = New CryptoStream(MStream, A128Encrypt, CryptoStreamMode.Write)
            'Write out and flush TripleDES encrypted file to memory stream.
            With CryptoStream
                .Write(PlainText, 0, PlainText.Length)
                .FlushFinalBlock()
            End With
            'Return encrypted data.
            Return MStream.ToArray
        Catch ex As Exception
            Return Nothing
        Finally 'Close streams.
            If CryptoStream IsNot Nothing Then CryptoStream.Close()
            If MStream IsNot Nothing Then MStream.Close()
        End Try
        Return Nothing
    End Function

    Public Function Decryptaes128(ByVal EncryptedByteData() As Byte) As Byte()
        Dim MStream As System.IO.MemoryStream = Nothing 'Memory stream to write decrypted data to.
        Dim CryptoStreamDecr As CryptoStream
        Dim A128 As New AesManaged
        Try
            'Create aes128 instance and Decryptor.
            Dim A128Decrypt As ICryptoTransform = A128.CreateDecryptor(Key, IV)
            'Create crypto stream set to read and do a TripleDES decryption transform on incoming bytes.
            MStream = New MemoryStream(EncryptedByteData)
            CryptoStreamDecr = New CryptoStream(MStream, A128Decrypt, CryptoStreamMode.Read)
            'Get the decrypted bytes.
            Dim DestArray() As Byte = New BinaryReader(CryptoStreamDecr).ReadBytes(MStream.Length * 2)
            Return DestArray 'Return decrypted data.
        Catch ex As Exception
            Return Nothing
        Finally 'Close streams.
            If MStream IsNot Nothing Then MStream.Close()
            '-- Don't use the following. It gives error "Stream does not support writing
            'If Not (cryptostreamDecr Is Nothing) Then cryptostreamDecr.Close()
        End Try
        Return Nothing
    End Function

    Public Function Md5Hash(ByVal ByteData() As Byte) As Byte()
        Return New MD5CryptoServiceProvider().ComputeHash(ByteData)
    End Function

    Public Function Md5HashString(ByVal ByteData() As Byte) As String
        Return BitConverter.ToString(Md5Hash(ByteData)).Replace("-", "").ToLower()
    End Function
End Class

Example Usage For The Above:

Dim c As New Cryptography.AES128Helper
Dim md5 As String = c.Md5HashString(UTF8Encoding.UTF8.GetBytes("Password"))
Dim key As Byte() = System.Text.Encoding.UTF8.GetBytes(md5)
Dim iv As Byte() = System.Text.Encoding.UTF8.GetBytes("PasswordSalt")
Dim data As Byte() = System.Text.Encoding.UTF8.GetBytes("Sad day really.")
c.Key = key
c.IV = iv
Dim enc As Byte() = c.Encryptaes128(data)
Dim b64 As String = Convert.ToBase64String(enc)

AGAIN, What I would like is a PHP mcrypt function that takes a base 64 string, the Password and PasswordSalt variables and just spits out the decrypted "Sad day really."

(NOTE: The MD5 function on the second class is another custom class because SL does not support MD5. If anyone needs I would be glad to post it here.)

The below PHP does NOT work.

$cc = $_POST['VariableFromSilverlight'];
$key = 'Password';
$iv = 'PasswordSalt';
$length = strlen($cc);
$cipher = mcrypt_module_open("rijndael-128", '', 'cbc', '');
$ks = mcrypt_enc_get_key_size($cipher);
$key = substr(md5($key), 0, $ks);
mcrypt_generic_init($cipher, $key, $iv);
$decrypted = mdecrypt_generic($cipher, $cc);
mcrypt_generic_deinit($cipher);
echo "decrypted: " . substr($decrypted, 0, $length) . "\n";
A: 

Why don't you use the openssl PHP extension ? It works fine (I use it for DES and 3DES, it works like a charm).

FWH
A: 

I don't have the time nor really the inclination to "write this for you", but this article should be of some assistance.

Peter Bailey
Ohhhh, that's so sweat. You want to help but not appear all "worker-bee"...The cool thing is that it's now working! If you ditch the MD5 part and just put your Key and IV carefully it works. Not perfect but working.Great!(P.S. @Peter Bailey, beeeeeeeeeeeeeeeeeeeeeeeeep)
Glad it helped! Also, Top Gear is my favorite show!
Peter Bailey
@Peter Bailey, :D