[2005] File I/o With Encryption Problem

[RyanB88]

I am attempting to save a file as encrypted and be able to open and decrypt is but their are some errors.

Errors:
Error 22 Value of type 'System.IO.StreamReader' cannot be converted to '1-dimensional array of Byte'. LincenseInfo.vb 90 30

at line: mem = crypto.Decrypt(sr), specifically the sr part is causing the error

the related code is:
Private mem As New MemoryStream
Dim sr As StreamReader
sr = File.OpenText(_licenseFileName)
Dim crypto As New CryptEngine
mem = crypto.Decrypt(sr)

Error 23 Value of type 'System.IO.MemoryStream' cannot be converted to 'String'. LincenseInfo.vb 161 29

at line: fs = crypto.Encrypt(mem), specifically the mem part is causing the error

the related code is:
Private mem As New MemoryStream
Dim fs As FileStream
fs = File.OpenWrite(_licenseFileName)
Dim crypto As New CryptEngine
fs = crypto.Encrypt(mem)

Please help me resolve this problem, thanks in advance.

If you need the full coding to the files involved, here it is:

LicenseInfo.vb

Imports System
Imports System.IO
Imports System.Security
Imports System.Security.Cryptography
Imports System.Runtime.InteropServices
Imports System.Text
 
Public Class LicenseInfo
    Private _licenseFileName As String 'local var to hold the license file name
    Private _licenseFileType As License 'local var to hold the license file type (private or shared)
    Private mem As New MemoryStream
 
    'license file options
    Public Enum License
        MainFile  'The primary File, all data read from it
        FileOne 'Secondary File, check to verify integrety of MainFile, only changed
        FileTwo 'Secondary File, check to verify integrety of MainFile, only changed
        FileThree 'Secondary File, check to verify integrety of MainFile, only changed
        FileFour 'Secondary File, check to verify integrety of MainFile, only changed
    End Enum
 
    'constructor
    Public Sub New(ByVal LicenseFileType As License)
        _licenseFileType = LicenseFileType 'remember this setting
 
        InitializeLicenseFile() 'setup the filename and location
    End Sub
 
    'initialize the apps license file, create it if it doesn't exist
    Private Sub InitializelicenseFile()
        Dim sb As New Text.StringBuilder
 
        'build the path\filename depending on the location of the license file
        Select Case _licenseFileType
            Case License.MainFile 'primary license file
                'where the file is located
                sb.Append(Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData))
                sb.Append("\MedInfo.lic")
            Case License.FileOne 'secondary license file
                'where the file is located
                sb.Append(Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData))
                sb.Append("\backup\MedInfo.lic")
            Case License.FileTwo 'secondary license file
                'where the file is located
                sb.Append(Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData))
                sb.Append("\Licenses\MedInfo.lic")
            Case License.FileThree 'secondary license file
                'where the file is located
                sb.Append(Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData))
                sb.Append("\RBS\MedInfo.lic")
            Case License.FileFour 'secondary license file
                'where the file is located
                sb.Append(Environment.GetFolderPath(Environment.SpecialFolder.CommonApplicationData))
                sb.Append("\MedInfo\License.lic")
        End Select
 
        'create the directory if it isn't there
        If Not IO.Directory.Exists(sb.ToString) Then
            IO.Directory.CreateDirectory(sb.ToString)
        End If
 
        _licenseFileName = sb.ToString 'completed license filename
 
        'if the file doesn't exist, ignore it, revert to trial mode, and alert the user
        If Not IO.File.Exists(_licenseFileName) Then
            Vtype = "trial"
            MsgBox("A license file cannot be located, Medical Info will revert to trail mode, please re-register Medical Info to resolve this problem, thanyou.", MsgBoxStyle.Information, "Licensing Error")
        End If
 
        Dim sr As StreamReader
        sr = File.OpenText(_licenseFileName)
        Dim crypto As New CryptEngine
        mem = crypto.Decrypt(sr)
    End Sub
 
    'get an application setting by key value
    Public Function GetSetting(ByVal key As String) As String
        'xml document object
        Dim xd As New Xml.XmlDocument
 
        'load the xml file
        xd.Load(mem)
 
        'query for a value
        Dim Node As Xml.XmlNode = xd.DocumentElement.SelectSingleNode( _
                                  "/MedInfo/License/add[@key=""" & key & """]")
 
        'return the value or nothing if it doesn't exist
        If Not Node Is Nothing Then
            Return Node.Attributes.GetNamedItem("value").Value
        Else
            Return Nothing
        End If
 
    End Function
 
    'save an application setting, takes a key and a value
    Public Sub SaveSetting(ByVal key As String, ByVal value As String)
        'xml document object
        Dim xd As New Xml.XmlDocument
 
        'load the xml file
        xd.Load(mem)
 
        'get the value
        Dim Node As Xml.XmlElement = CType(xd.DocumentElement.SelectSingleNode( _
                                           "/MedInfo/License/add[@key=""" & _
                                           key & """]"), Xml.XmlElement)
        If Not Node Is Nothing Then
            'key found, set the value
            Node.Attributes.GetNamedItem("value").Value = value
        Else
            'key not found, create it
            Node = xd.CreateElement("add")
            Node.SetAttribute("key", key)
            Node.SetAttribute("value", value)
 
            'look for the appsettings node
            Dim Root As Xml.XmlNode = xd.DocumentElement.SelectSingleNode("/MedInfo/License")
 
            'add the new child node (this key)
            If Not Root Is Nothing Then
                Root.AppendChild(Node)
            Else
                Try
                    'appsettings node didn't exist, add it before adding the new child
                    Root = xd.DocumentElement.SelectSingleNode("/MedInfo")
                    Root.AppendChild(xd.CreateElement("License"))
                    Root = xd.DocumentElement.SelectSingleNode("/MedInfo/License")
                    Root.AppendChild(Node)
                Catch ex As Exception
                    'failed adding node, throw an error
                    Throw New Exception("Could not set value", ex)
                End Try
            End If
        End If
 
        'finally, save the new version of the license file
        xd.Save(mem)
 
        Dim fs As FileStream
        fs = File.OpenWrite(_licenseFileName)
        Dim crypto As New CryptEngine
        fs = crypto.Encrypt(mem)
    End Sub
End Class

CryptEngine.vb

Imports System
Imports System.IO
Imports System.Text
Imports System.Security.Cryptography
Public Class CryptEngine
    Private key() As Byte = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24}
    Private iv() As Byte = {1, 2, 3, 4, 5, 6, 7, 8}
 
    Public Function Encrypt(ByVal plainText As String) As Byte()
        Dim utf8encoder As UTF8Encoding = New UTF8Encoding()
        Dim inputInBytes() As Byte = utf8encoder.GetBytes(plainText)
 
        Dim tdesProvider As TripleDESCryptoServiceProvider = New TripleDESCryptoServiceProvider()
 
        Dim cryptoTransform As ICryptoTransform = tdesProvider.CreateEncryptor(Me.key, Me.iv)
 
        Dim encryptedStream As MemoryStream = New MemoryStream()
        Dim cryptStream As CryptoStream = New CryptoStream(encryptedStream, cryptoTransform, CryptoStreamMode.Write)
 
        cryptStream.Write(inputInBytes, 0, inputInBytes.Length)
        cryptStream.FlushFinalBlock()
        encryptedStream.Position = 0
 
        Dim result(encryptedStream.Length - 1) As Byte
        encryptedStream.Read(result, 0, encryptedStream.Length)
        cryptStream.Close()
        Return result
    End Function
 
    Public Function Decrypt(ByVal inputInBytes() As Byte) As String
        Dim utf8encoder As UTF8Encoding = New UTF8Encoding()
        Dim tdesProvider As TripleDESCryptoServiceProvider = New TripleDESCryptoServiceProvider()
 
        Dim cryptoTransform As ICryptoTransform = tdesProvider.CreateDecryptor(Me.key, Me.iv)
 
        Dim decryptedStream As MemoryStream = New MemoryStream()
        Dim cryptStream As CryptoStream = New CryptoStream(decryptedStream, cryptoTransform, CryptoStreamMode.Write)
        cryptStream.Write(inputInBytes, 0, inputInBytes.Length)
        cryptStream.FlushFinalBlock()
        decryptedStream.Position = 0
 
        Dim result(decryptedStream.Length - 1) As Byte
        decryptedStream.Read(result, 0, decryptedStream.Length)
        cryptStream.Close()
        Dim myutf As UTF8Encoding = New UTF8Encoding()
        Return myutf.GetString(result)
    End Function
End Class