While investigating an issue where some customer requests are being unexpectedly rejected with HTTP 403, I noticed that the Windows event log contains a lot of these errors for source Schannel.
EventID 36887
The following fatal alert was received: 80.
The reference shows this code as SEC_E_INTERNAL_ERROR 0x80090304. Further searching this new code reveals this page but none of the cases apply:
- Our Server certificate is 2048 bits
- We are not using EAP.
- We are not using EAP, no VPN is involved in our scenario.
- We are not using ISA.
How can I figure out what is causing my schannel to fail internally?