Subject: [TLS] HTTPS Phishing sites

From: Sankalp Bagaria <[email-masked]>
Date: Fri, 26 May 2017 10:46:05 +0530

Hello,

http://securityaffairs.co/wordpress/59238/cyber-crime/
https-phishing-sites.html claims
that phishing websites using HTTPS are increasing in number. If malicious
sites can
get certificates, it defeats the purpose of TLS. In my opinion, tougher
measures are
required to prevent malicious sites getting legitimate certificates. What
can we do
about it ?

Regards,
Sankalp.

---

From: David Woodhouse <[email-masked]>
Date: Fri, 26 May 2017 06:24:03 +0100

On Fri, 2017-05-26 at 10:46 +0530, Sankalp Bagaria wrote:
> Hello,
> 
> http://securityaffairs.co/wordpress/59238/cyber-crime/https-phishing-sites.html claims
> that phishing websites using HTTPS are increasing in number. If malicious sites can
> get certificates, it defeats the purpose of TLS. In my opinion, tougher measures are
> required to prevent malicious sites getting legitimate certificates. What can we do
> about it ?

I wouldn't say that it defeats the purpose of TLS.

If https://hackerssite.co.ua/ has a TLS certificate validating that it
really is hackerssite.co.ua, and I go there for my online banking...
well that's kind of my fault. That domain *isn't* my bank's clearly
owned domain name, and I should be looking for an EV certificate with
my bank's name in it.

So that would be *my* fault.... unless I suppose my bank have ACTIVELY
TRAINED me to succumb to fraud, by doing something insanely
incompetently negligent.... like Nat West running their online banking
on 'nwolb.com', with a certificate that says 'Royal Bank of Scotland'.
Neither of which match the brand "Nat West" by which I know my bank.

Those morons should probably be prosecuted for aiding and abetting the
fraud that they are enabling. Because *their* behaviour defeats the
purpose of TLS.

cf. http://david.woodhou.se/re-registration.html

---

From: Eric Rescorla <[email-masked]>
Date: Fri, 26 May 2017 14:32:43 +0800

> required to prevent malicious sites getting legitimate certificates. What
This issue is out of scope for the TLS WG. You might try the IETF general
mailing list.

-Ekr

> Regards,
> Sankalp.
>
> _______________________________________________
> TLS mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/tls
>
>

---

From: "Yngve N. Pettersen" <[email-masked]>
Date: Fri, 26 May 2017 12:07:14 +0200

> required to prevent malicious sites getting legitimate certificates. What

As EKR says separately, this is out of scope for the TLS WG.

It might be in scope for the CA/Browser Forum <https://cabforum.org>,  
though.

However, you should not get your hopes up too high.

This is a very big problemspace, and I suspect that it is very difficult  
to get anything beyond checks for lookalike names to work properly (which  
could conceivably cause issues for legitimate sites, such as  
"sucks"-sites), without causing problems for the overriding goal of  
getting all internet traffic encrypted at an affordable cost.

Beyond this and the whack-a-mole system of lookup up lists of fraudulent  
sites, I suspect the difficult task of educating people is the only  
practical way of dealing with this issue; as mandating Extended Validation  
certficates would create trouble for the affordable encrypted internet  
goal.

-- 
Sincerely,
Yngve N. Pettersen

---

From: Ilari Liusvaara <[email-masked]>
Date: Fri, 26 May 2017 22:20:04 +0300

On Fri, May 26, 2017 at 10:46:05AM +0530, Sankalp Bagaria wrote:
> sites can get certificates, it defeats the purpose of TLS. In my opinion,
> tougher measures are required to prevent malicious sites getting legitimate
> certificates. What can we do about it ?

As EKR said, this isn't within scope of TLS Working Group. And I don't
think it is even in the scope of the entiere IETF as whole (considering
the scope of work IETF does).

My opinion is that the problem isn't maliscous sites getting security
certificates (so what if paypal.com.foobar.za gets certificate saying
it is paypal.com.foobar.za? That is completely true claim). The issue
is the completely screwed up handling of security indications in
browsers. That is certainly not the sort of work the IETF is doing.

Judging by resonable interpretation of browser indications:

- Unencrypted http:// is safe (apart from passwords/CC numbers).
- DV certificates are extra trustworthy.

Neither of these interpretations is correct. But both are still
in my opinion reasonable.

TLS with DV certificates is not above expected security, it is the
closest to expected security, so it in my opinion should get the
neutral indicators (so no lock). And http:// certainly is much below
expected, so it should get negative indications. EV is above expected,
so it could get positive indications.

-Ilari