Re: Bug#499774: starttls is a joke

[arno@natisbad.org (Arnaud Ebalard)]

Hi,

Matthias Andree <matthias.andree@gmx.de> writes:

> Comments:
> - the command line (l. 3) does not define trust anchors.
>   Particularly, there is no "--x509cafile /path/to/file.pem" option.
> - gnutls-cli v2.4.1 figures that it doesn't trust the issuer, ll. 8 & 9.
> - at that point in time, gnutls-cli should drop the connection. Instead, it
> continues.
>
> Desired behaviour/Goals:
> - gnutls-cli should drop the connect somewhen between lines 9 and 16, and
> should NOT enter forwarding/simple client state.
> - if clients want unsafe behaviour, they should be made to specify that in
> some way, and the program defaults should be "safest possible" mode
> - it may make sense that gnutls-cli doesn't even try to connect/handshake
> if it has
>   * neither "trust anchors" such as the --x509cafile
>   * nor some --unsafely-skip-cert-validation command line option.
> - man page, help output and manual should be consistent, example (2.4.1
> manpage of gnutls-cli):
>
>        --x509cafile FILE
>               Certificate file to use.
>
>        --x509certfile FILE
>               X.509 Certificate file to use.
>
>        --x509fmtder
>               Use DER format for certificates
>
>        --x509keyfile FILE
>               X.509 key file to use.
>
> This is pure crap^W^Wutterly unintelligible. What's the difference between
> --x509cafile and --x509certfile? It should read something like
> "--x509cafile: file that lists all Certification Authority (CA)
> certificates that gnutls-cli is allowed to trust. If this option is
> omitted, gnutls-cli will accept unsafe connections and trust any CA
> certificate. For secure operation, be sure to specify this option."

It would be better to have it fail when someone does not provide a
set of trust anchors. Then adding something --verify-peer (is there
something like that already?) with a default to "yes" that can be set to
"no" or something else when someone _*explicitly*_ asks for an insecure
behavior. I know for sure that GnuTLS internally support such a knob.

> Further consideration:
> - if the defaults are changed to "safe" mode, it may be sensible to rename
> the tool to gnutls-safe-client or something better.

Worst case scenario would that things would be safer.

Cheers,

a+