Encryption libraries

[thinker]

Hi, I am attempting to use RSACryptoServiceProvider. In .Net the constructor takes a parameter of type CspParameters. I can not figure out how to initialize the object with using CspParameters.

Dim rsa As New RSACryptoServiceProvider
Dim cp As New CspParameters
cp.KeyContainerName = "RSAKEY" & CInt(Int((10000 * Rnd()) + 1))


Any help would be greatly appreciated.

[Kelly Ethridge]

Hello Thinker,

There is a constructor you can use that accepts a CspParameter object. You would utilize it like the following:

Public Sub Main()
   Dim csp As New CspParameters
   ' set parameters
   
   Dim rsa As RSACryptoServiceProvider
   Set rsa = Cor.NewRSACryptoServiceProvider(, csp)
   
   ' rest of the code
End Sub


When you type Cor. you will see a lot of additional constructors. This is how VBCorLib simulates having constructor parameters. So if you are attempting to create an object with parameters, this will be the first place to look.

I hope this helps get you going in the right direction!

Thanks,
kelly

[thinker]

Thanks a lot, Kelly.

Where would the documentation on "Cor" be located?

Darrell

[Kelly Ethridge]

You can navigate to the online documentation from the main page or the compile help file that is included with the downloads:

Here is a direct link for the online documentation:
www.kellyethridge.com/vbcorlib/doc/VBCorLib.html

All of the Cor. methods are located in the Constructors/b] link on that page.

Kelly

[thinker]

Thanks, again.

I am trying to implement a VB6 version of a component that I have working fine in VB 2005. The problem that I am currently experiencing occurs when I try to export the parameters into an RSAParameters object. There are several fields on the RSACryptoServiceProvider that are not populated (KeyExchangeAlgorithm, CSPKeyContainerInfo has invalid algorithm specified, etc.) The same code works fine in .Net. Any suggestions on what I am doing incorrectly?

Thanks


Dim i As Integer
Dim j As Integer
Dim encryptedData() As Byte
Dim decryptedData() As Byte
Dim ByteConverter As New UnicodeEncoding

Dim rsa As New RSACryptoServiceProvider
Dim cp As CspParameters
Dim rsaTypeIn As Long

rsaTypeIn = 1

Set cp = Cor.NewCspParameters(rsaTypeIn)
cp.KeyContainerName = "RSAKEY" & CInt(Int((10000 * Rnd()) + 1))

Set rsa = Cor.NewRSACryptoServiceProvider(1, cp)

Dim RSAParams As RSAParameters
RSAParams = rsa.ExportParameters(False)


Dim sendlength As Integer
Dim expLen As Integer
Dim modLen As Integer
expLen = UBound(RSAParams.Exponent) - LBound(RSAParams.Exponent) + 1
modLen = UBound(RSAParams.Modulus) - LBound(RSAParams.Modulus) + 1

sendlength = expLen + modLen

Dim sendPublicKey() As Byte
ReDim sendPublicKey(sendlength)

For i = 0 To expLen
sendPublicKey(j) = RSAParams.Exponent(i)
j = j + 1
Next
For i = 0 To modLen
' sendPublicKey(j) = RSAParams.Modulus(i)
j = j + 1
Next

[Kelly Ethridge]

Hello,

You're right that the algorithm is not correct in your case. What you can do is set the KeyNumber to 1 in your cp instance. Also, you need to change

Set rsa = Cor.NewRSACryptoServiceProvider(1, cp)

to

Set rsa = Cor.NewRSACryptoServiceProvider(, cp)
' or
Set rsa = Cor.NewRSACryptoServiceProvider(ValidKeySize, cp)


and you need to change

RSAParams = rsa.ExportParameters(False)

to

Set RSAParams = rsa.ExportParameters(False)


And don't forget that you can't directly access a returned byte array's elements like you have at the end. You'll need to assign them to a local variable first.


Kelly

[thinker]

Hi,

I made the changes that you mentioned, but I am still receiving an "Invalid Algorithm Specified" error on the CspKeyContainerInfo field. Is there a way to set the Algorithm?

Thanks in advance.

Dim i As Integer
Dim j As Integer
Dim encryptedData() As Byte
Dim decryptedData() As Byte
Dim ByteConverter As New UnicodeEncoding

Dim rsa As New RSACryptoServiceProvider
Dim cp As CspParameters
Dim rsaTypeIn As Long

rsaTypeIn = 1

Set cp = Cor.NewCspParameters(rsaTypeIn)
cp.KeyContainerName = "RSAKEY" & CInt(Int((10000 * Rnd()) + 1))

Set rsa = Cor.NewRSACryptoServiceProvider(1024, cp)

Dim RSAParams As RSAParameters
Set RSAParams = rsa.ExportParameters(False)


Dim sendlength As Integer
Dim expLen As Integer
Dim modLen As Integer
expLen = UBound(RSAParams.Exponent) - LBound(RSAParams.Exponent) + 1
modLen = UBound(RSAParams.Modulus) - LBound(RSAParams.Modulus) + 1

sendlength = expLen + modLen

Dim sendPublicKey() As Byte
ReDim sendPublicKey(sendlength)

Dim holdExp() As Byte
holdExp = RSAParams.Exponent

For i = 0 To expLen
sendPublicKey(j) = holdExp(i)
j = j + 1
Next

Dim holdMod() As Byte
holdMod = RSAParams.Modulus

For i = 0 To modLen
sendPublicKey(j) = holdMod(i)
j = j + 1
Next

[Kelly Ethridge]

You still aren't setting the KeyNumber property on your cp instance:

cp.KeyNumber = 1


Kelly