Encrypt My.Settings setting?

[Tom]

Is it possible to encrypt a value in the my.settings area in VB.NET
2005? I.E. Can I add a settings value (via My Project / Settings) and
have it encrypt that value so that if anyone looks at the resulting
app.config file the value is encrypted? If so, (1) How do you specify
the value to be encrypted? And (2) How do you access it now from VB?
Can you still go through My.Settings??

Tom

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[iwdu15]

well theres no built in function to say, for example

Dim str as string = "password"

my.Settings.Pas sword1 = str
my.settings.Pas sword1.Encrypt( )

theres nothing built in to do that. you have to encrypt the string yourself,
be it by your own algorithm or by the Crytography namaespace (ive never used
it, so if you use it let me know how it goes). the easiest way ive found,
unless you need things heavily encrypted, is to just create a simple letter
bump. anyone looking at it wont make sense of it unless theyre seriously
trying to hack it.
--
-iwdu15

[Tom]

iwdu15: Well, one of the things I thought that was 'trumpted' as new
and great with VS 2005 was the ability to encrypt values in your
settings file, especially connection strings. I see that in ASP.NET,
things can be encrypted in the web.config file, but I don't see
anything about this for Windows Forms applications.
--

iwdu15 wrote:

>well theres no built in function to say, for example

Dim str as string = "password"

my.Settings.Pa ssword1 = str
my.settings.Pa ssword1.Encrypt ()

theres nothing built in to do that. you have to encrypt the string
yourself, be it by your own algorithm or by the Crytography
namaespace (ive never used it, so if you use it let me know how it
goes). the easiest way ive found, unless you need things heavily
encrypted, is to just create a simple letter bump. anyone looking at
it wont make sense of it unless theyre seriously trying to hack it.

[Izzy]

You can use this code to encrypt and decrypt a stored value.

Imports System.Security .Cryptography
Imports System.Text

Module mod_Globals

Public EncryptionKey As String =
"justsomewordst obeusedasacrypt ionkey"

Public Function EncryptString12 8Bit(ByVal vstrTextToBeEnc rypted As
String, ByVal vstrEncryptionK ey As String) As String

Dim bytValue() As Byte
Dim bytKey() As Byte
Dim bytEncoded() As Byte
Dim bytIV() As Byte = {121, 241, 10, 1, 132, 74, 11, 39, 255,
91, 45, 78, 14, 211, 22, 62}
Dim intLength As Integer
Dim intRemaining As Integer
Dim objMemoryStream As New MemoryStream
Dim objCryptoStream As CryptoStream
Dim objRijndaelMana ged As RijndaelManaged

vstrTextToBeEnc rypted =
StripNullCharac ters(vstrTextTo BeEncrypted)

bytValue =
Encoding.ASCII. GetBytes(vstrTe xtToBeEncrypted .ToCharArray)

intLength = Len(vstrEncrypt ionKey)

If intLength >= 32 Then
vstrEncryptionK ey = Strings.Left(vs trEncryptionKey , 32)
Else
intLength = Len(vstrEncrypt ionKey)
intRemaining = 32 - intLength
vstrEncryptionK ey = vstrEncryptionK ey &
Strings.StrDup( intRemaining, "X")
End If

bytKey = Encoding.ASCII. GetBytes(vstrEn cryptionKey.ToC harArray)

objRijndaelMana ged = New RijndaelManaged

Try
objCryptoStream = New CryptoStream(ob jMemoryStream,
objRijndaelMana ged.CreateEncry ptor(bytKey, bytIV),
CryptoStreamMod e.Write)
objCryptoStream .Write(bytValue , 0, bytValue.Length )
objCryptoStream .FlushFinalBloc k()
bytEncoded = objMemoryStream .ToArray
objMemoryStream .Close()
objCryptoStream .Close()
Catch

End Try

Return Convert.ToBase6 4String(bytEnco ded)

End Function

Public Function DecryptString12 8Bit(ByVal vstrStringToBeD ecrypted
As String, ByVal vstrDecryptionK ey As String) As String

Dim bytDataToBeDecr ypted() As Byte
Dim bytTemp() As Byte
Dim bytIV() As Byte = {121, 241, 10, 1, 132, 74, 11, 39, 255,
91, 45, 78, 14, 211, 22, 62}
Dim objRijndaelMana ged As New RijndaelManaged
Dim objMemoryStream As MemoryStream
Dim objCryptoStream As CryptoStream
Dim bytDecryptionKe y() As Byte
Dim intLength As Integer
Dim intRemaining As Integer
Dim intCtr As Integer
Dim strReturnString As String = String.Empty
Dim achrCharacterAr ray() As Char
Dim intIndex As Integer

bytDataToBeDecr ypted =
Convert.FromBas e64String(vstrS tringToBeDecryp ted)

intLength = Len(vstrDecrypt ionKey)

If intLength >= 32 Then
vstrDecryptionK ey = Strings.Left(vs trDecryptionKey , 32)
Else
intLength = Len(vstrDecrypt ionKey)
intRemaining = 32 - intLength
vstrDecryptionK ey = vstrDecryptionK ey &
Strings.StrDup( intRemaining, "X")
End If

bytDecryptionKe y =
Encoding.ASCII. GetBytes(vstrDe cryptionKey.ToC harArray)

ReDim bytTemp(bytData ToBeDecrypted.L ength)

objMemoryStream = New MemoryStream(by tDataToBeDecryp ted)

Try

objCryptoStream = New CryptoStream(ob jMemoryStream,
objRijndaelMana ged.CreateDecry ptor(bytDecrypt ionKey, bytIV),
CryptoStreamMod e.Read)
objCryptoStream .Read(bytTemp, 0, bytTemp.Length)
objCryptoStream .FlushFinalBloc k()
objMemoryStream .Close()
objCryptoStream .Close()

Catch

End Try

Return StripNullCharac ters(Encoding.A SCII.GetString( bytTemp))

End Function
Public Function StripNullCharac ters(ByVal vstrStringWithN ulls As
String) As String

Dim intPosition As Integer
Dim strStringWithOu tNulls As String

intPosition = 1
strStringWithOu tNulls = vstrStringWithN ulls

Do While intPosition 0
intPosition = InStr(intPositi on, vstrStringWithN ulls,
vbNullChar)

If intPosition 0 Then
strStringWithOu tNulls = Left$(strString WithOutNulls,
intPosition - 1) & _
Right$(strStrin gWithOutNulls,
Len(strStringWi thOutNulls) - intPosition)
End If

If intPosition strStringWithOu tNulls.Length Then
Exit Do
End If
Loop

Return strStringWithOu tNulls

End Function
End Module
Then to call this code do the following:

'Get Password
Dim strPassword as string = DecryptString12 8Bit(My.Setting s.Password,
EncryptionKey)

'Save Password
My.Settings.Pas sword = EncryptString12 8Bit(txt_Passwo rd1.Text.Trim,
EncryptionKey)

Hope this helps!

I didn't write this and I can't remember who did, otherwise I would
reference them.

Israel

Tom wrote:

Is it possible to encrypt a value in the my.settings area in VB.NET
2005? I.E. Can I add a settings value (via My Project / Settings) and
have it encrypt that value so that if anyone looks at the resulting
app.config file the value is encrypted? If so, (1) How do you specify
the value to be encrypted? And (2) How do you access it now from VB?
Can you still go through My.Settings??

Tom

--

[Sy]

I found this Class somehwere... can't remember where now... just include it
in your project.

Then somewhere in your main code just do something like the following...

dim EncClass as new Encryption
dim txtPlainTextPas sword as string = "ThisIsMyNewPas swordSoThere!"
dim txtEncryptedPas sword as string =
EncClass.Encryp tData(txtPlainT extPassword)
dim txtDecryptedPas sword as string =
EncClass.Decryp tData(txtEncryp tedPassword)

debug.print(txt PlainTextPasswo rd)
debug.print(txt EncryptedPasswo rd)
debug.print(txt DecryptedPasswo rd)

Cheers, Sy

PS. Here's the Encryption Class... As I said I liked to give credit where I
found this...

Imports System.Security .Cryptography

Public NotInheritable Class Encryption

Private TripleDes As New TripleDESCrypto ServiceProvider

Private svKey As String = "justsomewordst obeusedasacrypt ionkey"

Sub New(ByVal key As String)

' Initialize the crypto provider.

TripleDes.Key = TruncateHash(ke y, TripleDes.KeySi ze \ 8)

TripleDes.IV = TruncateHash("" , TripleDes.Block Size \ 8)

End Sub

Sub New()

TripleDes.Key = TruncateHash(sv Key, TripleDes.KeySi ze \ 8)

TripleDes.IV = TruncateHash("" , TripleDes.Block Size \ 8)

End Sub

Private Function TruncateHash( _

ByVal key As String, _

ByVal length As Integer) _

As Byte()

Dim sha1 As New SHA1CryptoServi ceProvider

' Hash the key.

Dim keyBytes() As Byte = _

System.Text.Enc oding.Unicode.G etBytes(key)

Dim hash() As Byte = sha1.ComputeHas h(keyBytes)

' Truncate or pad the hash.

ReDim Preserve hash(length - 1)

Return hash

End Function

Public Function EncryptData( _

ByVal plaintext As String) _

As String

' Convert the plaintext string to a byte array.

Dim plaintextBytes( ) As Byte = _

System.Text.Enc oding.Unicode.G etBytes(plainte xt)

' Create the stream.

Dim ms As New System.IO.Memor yStream

' Create the encoder to write to the stream.

Dim encStream As New CryptoStream(ms , _

TripleDes.Creat eEncryptor(), _

System.Security .Cryptography.C ryptoStreamMode .Write)

' Use the crypto stream to write the byte array to the stream.

encStream.Write (plaintextBytes , 0, plaintextBytes. Length)

encStream.Flush FinalBlock()

' Convert the encrypted stream to a printable string.

Return Convert.ToBase6 4String(ms.ToAr ray)

End Function

Public Function DecryptData( _

ByVal encryptedtext As String) _

As String

' Convert the encrypted text string to a byte array.

Dim encryptedBytes( ) As Byte = Convert.FromBas e64String(encry ptedtext)

' Create the stream.

Dim ms As New System.IO.Memor yStream

' Create the decoder to write to the stream.

Dim decStream As New CryptoStream(ms , _

TripleDes.Creat eDecryptor(), _

System.Security .Cryptography.C ryptoStreamMode .Write)

' Use the crypto stream to write the byte array to the stream.

decStream.Write (encryptedBytes , 0, encryptedBytes. Length)

decStream.Flush FinalBlock()

' Convert the plaintext stream to a string.

Return System.Text.Enc oding.Unicode.G etString(ms.ToA rray)

End Function

End Class

"Tom" <to*@nospam.com wrote in message
news:eF******** ******@TK2MSFTN GP04.phx.gbl...

Is it possible to encrypt a value in the my.settings area in VB.NET
2005? I.E. Can I add a settings value (via My Project / Settings) and
have it encrypt that value so that if anyone looks at the resulting
app.config file the value is encrypted? If so, (1) How do you specify
the value to be encrypted? And (2) How do you access it now from VB?
Can you still go through My.Settings??

Tom

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