Asp Certificate in ASP
In Classic ASP, handling Certificates (like SSL/TLS client certificates) is limited because ASP itself is server-side scripting with no direct built-in methods to manage certificates. However, you can access client SSL certificate info if your web server (IIS) is configured to require or accept client certificates.
How to Access Client Certificate Info in Classic ASP
If IIS is set up for SSL with client certificates, you can get info about the client certificate using the Request.ServerVariables collection.
Common Server Variables for Client Certificates:
| Server Variable | Description |
|---|---|
CERT_COOKIE | Unique identifier for the certificate |
CERT_FLAGS | Flags about the certificate |
CERT_ISSUER | Issuer of the certificate |
CERT_KEYSIZE | Key size in bits |
CERT_SECRETKEYSIZE | Secret key size |
CERT_SERIALNUMBER | Certificate serial number |
CERT_SERVER_ISSUER | Server issuer name |
CERT_SERVER_SUBJECT | Server subject name |
CERT_SUBJECT | Subject of the client certificate |
CERT_TYPE | Certificate type |
Example: Display client certificate info in ASP
<%Response.Write "Client Certificate Information:<br><br>"Response.Write "Certificate Subject: " & Request.ServerVariables("CERT_SUBJECT") & "<br>"Response.Write "Certificate Issuer: " & Request.ServerVariables("CERT_ISSUER") & "<br>"Response.Write "Certificate Serial Number: " & Request.ServerVariables("CERT_SERIALNUMBER") & "<br>"Response.Write "Certificate Key Size: " & Request.ServerVariables("CERT_KEYSIZE") & "<br>"Response.Write "Certificate Flags: " & Request.ServerVariables("CERT_FLAGS") & "<br>"%>Important Notes
IIS must be configured to Require or Accept client certificates on the web site or virtual directory.
Without client certificates enabled on IIS, these server variables will be empty.
Server certificates (for HTTPS) are handled by IIS and not directly accessible from ASP.
For signing or encrypting data with certificates, you’d use COM objects or external libraries (like CAPICOM), but that’s more complex.
If you want, I can show you how to configure IIS for client certificates or sample code for using CAPICOM in ASP for signing/encrypting. Would that help?
