Classic ASP

RSA Sign Binary Data and Verify (Recover the Original Data)

Demonstrates how to RSA sign binary data and then verify/recover the original data.

Note: This example uses methods introduced in Chilkat v9.5.0.77.

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Classic ASP

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

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

' Load an RSA private key for signing.
set privKey = Server.CreateObject("Chilkat.PrivateKey")
success = privKey.LoadEncryptedPemFile("qa_data/pem/rsa_passwd.pem","passwd")
If (success = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( privKey.LastErrorText) & "</pre>"
    Response.End
End If

set rsa = Server.CreateObject("Chilkat.Rsa")
success = rsa.UsePrivateKey(privKey)

' We have some binary data (in hex) to sign
originalData = "0102030405060708090A"
set bd = Server.CreateObject("Chilkat.BinData")
success = bd.AppendEncoded(originalData,"hex")

' If successful, the contents of bd are replaced with the RSA signature.
success = rsa.SignRawBd(bd)
If (success = 0) Then
    Response.Write "<pre>" & Server.HTMLEncode( rsa.LastErrorText) & "</pre>"
    Response.End
End If

' Show the RSA signature in base64
Response.Write "<pre>" & Server.HTMLEncode( bd.GetEncoded("base64")) & "</pre>"

' ------------------------------------------
' Get the public key from the private key
set pubKey = Server.CreateObject("Chilkat.PublicKey")
success = privKey.ToPublicKey(pubKey)

' Verify the signature and extract the original data.
set rsa2 = Server.CreateObject("Chilkat.Rsa")
success = rsa2.UsePublicKey(pubKey)

bVerified = rsa2.VerifyRawBd(bd)
Response.Write "<pre>" & Server.HTMLEncode( "signature verified: " & bVerified) & "</pre>"

' Show the original data:
Response.Write "<pre>" & Server.HTMLEncode( "original data: " & bd.GetEncoded("hex")) & "</pre>"

%>
</body>
</html>