Re: [Qemu-devel] [PATCH v4 09/24] ui/vnc: Use gcrypto_random_bytes for start_auth_vnc

[Laurent Vivier <lvivier@redhat.com>]

On 08/05/2019 02:32, Richard Henderson wrote:
> On 5/7/19 3:49 AM, Laurent Vivier wrote:
>>>      void start_auth_vnc(VncState *vs)
>>>    {
>>> -    make_challenge(vs);
>>> +    Error *err = NULL;
>>> +
>>> +    if (qcrypto_random_bytes(vs->challenge, sizeof(vs->challenge), &err)) {
>>> +        trace_vnc_auth_fail(vs, vs->auth, "cannot get random bytes",
>>> +                            error_get_pretty(err));
>>> +        error_free(err);
>>> +        authentication_failed(vs);
>>> +        return;
>>> +    }
>>> +
>>
>> This part is weird for me: if auth fails we send "vnc_write_u32(vs, 1)" but if
>> it succeeds we send the challenge. There is no success value to send (like
>> "vnc_write_u32(vs, 0)") ?
> 
> There is, but this code is a mess of callbacks.  In this case it happens toward
> the end of protocol_client_auth_vnc:
> 
>     2604         trace_vnc_auth_pass(vs, vs->auth);
>     2605         vnc_write_u32(vs, 0); /* Accept auth */
>     2606         vnc_flush(vs);
> 

ok, thanks.

Reviewed-by: Laurent Vivier <lvivier@redhat.com>