When FIPS Mode is enabled OAC ensures that all certificate based authentications are handled with the use of a FIPS compliant Cryptographic Service Provider (CSP). OAC does this by checking the CSP being used against a list of FIPS compliant providers. If the CSP in use is not in OAC's list of compliant providers, OAC will fail the authentication and insert an error similar to the one below into the debug log.
Example from a level 5 OAC debug log:
Cryptographic Provider "accsp.dll" version "v3, 0, 0, 0" was not specified as FIPS compliant.
Note: Log level 5 is required to see the error message.