vbscript xmlhttp A certificate is required to complete client authentication [duplicate] - paypal

Question

I am supporting a Classic ASP application that connects to a payment gateway via HTTPS. Up until recently there have been no issues. A few days ago the latest updates were installed on the server (Windows Server 2003) and caused the site to break. A code snippet is below.
Dim oHttp
Dim strResult
Set oHttp = CreateObject("MSXML2.ServerXMLHTTP")
oHttp.setOption(2) = 13056
oHttp.open "POST", SOAP_ENDPOINT, false
oHttp.setRequestHeader "Content-Type", "application/soap+xml; charset=utf-8"
oHttp.setRequestHeader "SOAPAction", SOAP_NS + "/" & SOAP_FUNCTION
oHttp.send SOAP_REQUEST
Below is a dump of the error object :-
Number: -2147012852
Description: A certificate is required to complete client authentication
Message: A certificate is required to complete client authentication
At first I thought it was because the Payment Gateway's SSL certificate was not being authenticated or they needed a client certificate. I tested the URL in a browser on the server and it displayed correctly without errors and confirmed that the Payment Gateway server did not require a client certificate.
I am at a loss. All the research I have done has lead me nowhere. I even tried the following found on Stackoverflow :-
Getting XMLHTTP to work with HTTPS
xmlHttp, XML request,asp
The last one stated that a client certificate is required by XMLHTTP even though the server does not need it and pointed to a KB article on how to install one, but that is outdated and does not work.

Answer 1

Try adding oHttp.setOption 2, 13056

Answer 2

Just found the solution to this which has passed testing on:
Windows 10 (IIS 10)
Windows 2012 R2 (IIS 8.5)
It's a client problem. MSXML2.ServerXMLHTTP does indeed require you to use a client certificate when calling an endpoint secured with SSL (even if the endpoint doesn't require it), as the OP noted.
On the webserver, you need to:
Create a client certificate
Assign permissions to the certificate
Set the certificate on the ServerXMLHTTP object
In detail:
1. Create a client certificate
Use the following PowerShell command to create a new self-signed certificate:
New-SelfSignedCertificate -DnsName "ServerXMLHTTP", "ServerXMLHTTP" -CertStoreLocation "cert:\LocalMachine\My"
Note that the certificate created by this command will only be valid for 1 year.
2. Assign permissions to the certificate
Using MMC, view the certificate store for the computer account:
How to: View Certificates with the MMC Snap-in
The certificate created above can be found in Certificates (Local Computer)\Personal\Certificates (the "Issued By" and "Issued To" columns display "ServerXMLHTTP").
Right click the ServerXMLHTTP certificate, select "All Tasks" -> "Manage Private Keys" and the permissions dialog will display.
Add the user that the ASP website app pool is running as. By default it will be running as "ApplicationPoolIdentity", but your setup may be using a specific user account. If the app pool is using ApplicationPoolIdentity, the username to add is "IIS AppPool\APP POOL NAME", e.g. IIS AppPool\DefaultAppPool
The user will be added with "Full Control" which can be deselected. Only "Read" permission seems to be required. Click "OK" to confirm the permissions.
3. Set the certificate on the ServerXMLHTTP object
In your ASP code, set the ServerXMLHTTP object to use the certificate created above. For example calling PayPal for an access token:
Dim strAuthToken: strAuthToken = "<Base64 encoded version of ClientId:Secret>"
Dim oHttp: Set oHttp = Server.CreateObject("MSXML2.ServerXMLHTTP")
With oHttp
Call .Open("POST", "https://api.sandbox.paypal.com/v1/oauth2/token", False)
Call .SetOption(3, "LOCAL_MACHINE\My\ServerXMLHTTP")
Call .SetRequestHeader("Content-Type", "application/x-www-form-urlencoded")
Call .SetRequestHeader("Authorization", "Basic " & strAuthToken)
Call .Send("grant_type=client_credentials")
End With
Hopefully this is still of assistance.

Answer 3

I know it is an old question. This issue could be because of unsupported cipher suites.
Try adding
- TLS_RSA_WITH_AES_128_CBC_SHA AES128-SHA
- TLS_RSA_WITH_AES_256_CBC_SHA AES256-SHA
That means you have to follow this kb: http://support.microsoft.com/kb/948963
This update is also interesting if you are still using windows 2003. Which will allow connecting to site using SHA2 - http://support.microsoft.com/kb/968730
Please note that Windows Server 2003 support is ending July 14, 2015

Answer 4

This is probably a ServerFault.com question really, after all if the code is working fine then its not a programmatic problem.
However I would try a couple of things. First try using a the ProgID "MSXML2.ServerXMLHTTP.3.0", in some circumstances MSXML3 will behave differently depending on which ProgID was used to instantiate the component. Also update from other sources like your anti-virus supplier (Sophos had this problem) can break MSXML installs.
Another ProgID to try is "MSXML2.ServerXMLHTTP.6.0" after having installed MSXML6. If the problem is with an update to the MSXML3 core then perhaps the MSXML6 core doesn't have the same problem.

Answer 5

Can you try with oHttp.setOption(3) = "certificate store name/friendlyname of certificate"
as below. I hope this will works.
Dim oHttp
Dim strResult
Set oHttp = CreateObject("MSXML2.ServerXMLHTTP")
oHttp.setOption(2) = 13056
oHttp.setOption(3) = "certificate store name/friendlyname of certificate"
oHttp.open "POST", SOAP_ENDPOINT, false
oHttp.setRequestHeader "Content-Type", "application/soap+xml; charset=utf-8"
oHttp.setRequestHeader "SOAPAction", SOAP_NS + "/" & SOAP_FUNCTION
oHttp.send SOAP_REQUEST