How is TLS certificate problems supposed to be handled

[John Allberg]

Hi!

I'm currently implementing a TLS client for some custom certificate validation but don't understand how certificate validation errors is supposed to propagate.

I've created a class, BcTlsClient, that inherits from DefaultTlsClient. In the GetAuthentication method I supply another class, BcTlsAuthentication, that implements the TlsAuthentication interface.

I get the server certificate in the NotifyServerCertificate method and I'm able to verify the certificate. For an untrusted CA it seems I should throw new TlsFatalAlert(AlertDescription.bad_certificate), but that is being caught in TlsProtocolHandler->SafeReadData and propagated as IOException with message "Internal TLS error, this could be an attack", which might not be the most informative message when the certificate isn't trusted. :)

How am I supposed to handle those problems, not trusted, expired and so on?

Best regards,

John

[Peter Dettman]

Yes, you should be throwing
TlsFatalAlert(AlertDescription.bad_certificate), but it does seem the
propagation of that to the caller could stand some improvement. The
error handling wasn't originally exception-based, so there are these
loose ends still. We're open to suggestions...

If you are looking for a short-term escape hatch, there is a UserObject
property on TlsClientContext (passed to the TlsClient via Init), so you
might be able to work with that?

Regards,
Pete Dettman

Post by John Allberg
Hi!
I'm currently implementing a TLS client for some custom certificate
validation but don't understand how certificate validation errors is
supposed to propagate.
I've created a class, BcTlsClient, that inherits from
DefaultTlsClient. In the GetAuthentication method I supply another
class, BcTlsAuthentication, that implements the TlsAuthentication
interface.
I get the server certificate in the NotifyServerCertificate method and
I'm able to verify the certificate. For an untrusted CA it seems I
should throw new TlsFatalAlert(AlertDescription.bad_certificate), but
that is being caught in TlsProtocolHandler->SafeReadData and
propagated as IOException with message "/Internal TLS error, this
could be an attack/", which might not be the most informative message
when the certificate isn't trusted. J
How am I supposed to handle those problems, not trusted, expired and so on?
Best regards,
John