Classic ASP
Verfies an RSA Signature

Verifies an RSA signature against the original data.
Chilkat Classic ASP Downloads

Classic ASP
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body>
<%
success = 0

' The following data was signed by the following example:
' RSA Sign using a Private Key on a USB Token or Smartcard
set bd = Server.CreateObject("Chilkat.BinData")

For i = 0 To 100
    success = bd.AppendEncoded("000102030405060708090A0B0C0D0E0F","hex")
Next

' Load the signature
set bdSig = Server.CreateObject("Chilkat.BinData")
success = bdSig.LoadFile("rsaSignatures/test1.sig")
If (success = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( "Failed to load the RSA signature") & "</pre>"
    Response.End
End If

' Get the public key to be used for signature verification.
set pubKey = Server.CreateObject("Chilkat.PublicKey")
success = pubKey.LoadFromFile("rsaKeys/chilkat-rsa-2048.pem")
If (success = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( pubKey.LastErrorText) & "</pre>"
    Response.End
End If

set rsa = Server.CreateObject("Chilkat.Rsa")
success = rsa.UsePublicKey(pubKey)
If (success = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( rsa.LastErrorText) & "</pre>"
    Response.End
End If

' Verify the hash of the data against the signature.
' We pass in the original data.  Internally, the hash is generated
' and used to validate the signature.
' Validating the RSA signature means two things:  
' (1) the original data is exactly what was signed, and 
' (2) it was signed by the owner of the RSA private key.
success = rsa.VerifyBd(bd,"sha256",bdSig)

If (success = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( rsa.LastErrorText) & "</pre>"
    Response.Write "<pre>" & Server.HTMLEncode( "Signature invalid.") & "</pre>"
Else
    Response.Write "<pre>" & Server.HTMLEncode( "Signature valid.") & "</pre>"
End If


%>
</body>
</html>