(VB.NET) RSA Encrypt Randomly Generated AES Key

Demonstrates how to RSA encrypt a randomly generated AES key.

Chilkat .NET Downloads Chilkat .NET Framework Chilkat for .NET Core

' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

' First generate a 256-bit AES key (32 bytes).
Dim prng As New Chilkat.Prng
Dim bdAesKey As New Chilkat.BinData
Dim success As Boolean = prng.GenRandomBd(32,bdAesKey)

' Use a public key from a certificate for RSA encryption.
Dim cert As New Chilkat.Cert

success = cert.LoadFromFile("qa_data/pem/mf_public_rsa.pem")
If (success = False) Then
    Debug.WriteLine(cert.LastErrorText)
    Exit Sub
End If


Dim pubKey As Chilkat.PublicKey = cert.ExportPublicKey()
If (cert.LastMethodSuccess <> True) Then
    Debug.WriteLine(cert.LastErrorText)
    Exit Sub
End If


Dim rsa As New Chilkat.Rsa
success = rsa.ImportPublicKeyObj(pubKey)
If (success = False) Then
    Debug.WriteLine(rsa.LastErrorText)
    Exit Sub
End If




' RSA encrypt our 32-byte AES key.
' The contents of bdAesKey are replaced with result of the RSA encryption.
success = rsa.EncryptBd(bdAesKey,False)
If (success = False) Then
    Debug.WriteLine(rsa.LastErrorText)
    Exit Sub
End If


' Return the result as a base64 string
Dim encryptedAesKey As String = bdAesKey.GetEncoded("base64")

Debug.WriteLine("encrypted AES key = " & encryptedAesKey)