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Mozilla SSL policy bad for the Web

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Re: Mozilla SSL policy bad for the Web

#61

Post by tptacek »

jodrellblank wrote: post #55
tptacek wrote: post #31

Unbelievable. I've been poking about here for like 6 months now. You are all very smart people. Why is this so hard to understand? If you do not have a valid certificate signed by a CA, SSL is not providing any security . Yes, the warning you get when you visit a site with an invalid cert is much scarier than what you see if you visit an unencrypted site. But it's the sites that use encryption that users care about,…

To borrow from Eliezer, if you really can't believe something that is happening can happen, then your mental model is wrong. I originally posted: Every time I have hit this message, it has been mostly irrelevant to me and disrupted what I was doing [I'm no longer so certain - I can't be sure my router configs haven't been stolen by a MITM attack. I suppose I really ought to find out how to generate and install SSL ce…

The security of the DNS and the security of SSL are unrelated. This is one of those Reddit memes that won't die. You can claim to be bankofamerica.com all you want, but you cannot complete an SSL exchange with a signed certificate that says so.

Re: Mozilla SSL policy bad for the Web

#62

Post by tptacek »

fendale wrote: post #53
tptacek wrote: post #31

Unbelievable. I've been poking about here for like 6 months now. You are all very smart people. Why is this so hard to understand? If you do not have a valid certificate signed by a CA, SSL is not providing any security . Yes, the warning you get when you visit a site with an invalid cert is much scarier than what you see if you visit an unencrypted site. But it's the sites that use encryption that users care about,…

I don't fully agree with what you are saying. A self signed certificate DOES provide 100% cryptographic security, in that nobody sniffing on the the wire, or whatever open wi-fi I happen to be using can see my data. Securing the connection from 'spies' is only one part of an general SSL certificates function - the other is proving the identity of the site you are connecting to. A self signed cert provides zero use he…

Would you like to bet your social security on that statement? I'll win that bet. If I can watch your packets on the wire, I can inject my own packets, or redirect you to the middleman of my choosing. If I can inject my own packets, I can sub in my own certificate. You won't know, because you're using self-signed certificates --- meaning, meaningless certificates.

Re: Mozilla SSL policy bad for the Web

#63

Post by tptacek »

45454564654 wrote: post #50
huhtenberg wrote: post #27

Earlier quoted context omitted.

I'd like to know where I can buy a cert this way. Pretty please.

All that's require are scanned documents. And these documents can easily be tampered with or photoshopped. You may think your company details are checked before the cert is issued, but that's crap. We email our docs to a US company, and all the docs are issued by Irish government departments. There's no way in hell that some guy in what amounts to a call centre in the US has access to any Irish database to prove or d…

Give me a break. This is like saying all online security is a sham because I can always physically break into your office. You know how many times a real CA has fucked up and accidentally issued a Bank of America certificate to organized criminals in Estonia? ZERO.

Re: Mozilla SSL policy bad for the Web

#64

Post by tptacek »

plusbryan wrote: post #56

One possible solution: use two icons Since SSL covers two cases of security, both encryption and identity, maybe it's time to invent a new icon - i.e. this web site is secure (a lock) but its identity could not be verified (an id card). Self-signed certs wouldn't show warnings, but wouldn't show the ID-verified icon. CA certs would show both. If they're worried about user education, the first time firefox encounters…

You can't have one without the other. The first icon doesn't mean anything. You might as well add a third icon for "this connection is compressed". Attackers can't read your credit card number out of a compressed stream either.

Re: Mozilla SSL policy bad for the Web

#65

Post by tlrobinson »

aristus wrote: post #19
grhino wrote: post #8

What's encryption without authentication? Encryption ensures that only the entity you are sending the message to can read it. If you can't be sure of the entity you are sending the message to, then what's the point of encrypting it in the first place? Why does the article pick out Mozilla in particular? Are they suggesting that FireFox makes it overly complex to ignore the warning and continue on?

Encryption without authentication is just that: encryption. The point of encryption is to make sure no one else is listening OR modifying the data in transit. Like, say, your cash-starved ISP, or the government.

No, it's not. If a man-in-the-middle attack is possible (certainly the ISP could), then encryption without authentication is as insecure as no encryption at all. And in fact worse if the user has a false sense of security.

The MITM pretends to be the bank's server (or whatever) when talking to you, and pretends to be you when talking to the bank's server. Both channels can be encrypted, but the attacker still sees (and can modify) everything that you think you're sending directly to the bank's server.

This is the key point that most people seem to be missing here. If browsers didn't warn about self-signed certificate, the entire system would break down because an attacker could just use a self-signed cert in a MITM attack, and the user would have no idea.

Re: Mozilla SSL policy bad for the Web

#66

Post by Dobbs »

iigs wrote: post #40
axod wrote: post #3

SSL certificates for HTTPS are a big fat scam. Why do I need to pay money to get a certificate, just to provide encryption. Encryption should be separate from identity verification. Of course identity verification should be properly vetted and you should have to pay a fee, and have documents checked etc. If however, you just want to provide security for your users by encrypting http, you should not have to jump throu…

Commercial certificates are not a scam. You're paying for a company (the CA) to certify (via the SSL cert signature) that an identity belongs to someone that has provided proof that they're who they say they are. You can absolutely do what you're requesting by creating your own CA and signing certs for your sites and distributing your CA cert to your users somehow. If you can figure out how to reliably provide this s…

What about a public key ssl server?

Webmaster Bob wants to add his key to the server. Bob goes to the server page and hits add key button, puts in an email address for the webmaster, his public key and submits. Then the public key server sometime in the next couple hours goes outs and checks the website itself. If the two match it adds it to the database.

You can have the server require a reverse DNS lookup and also have it use something along the lines of OpenDNS to help secure against fraud. Also if the server itself uses a CA cert to secure data on transit that would also help secure it. Require a revocation key to invalidate self signed keys on the database would also further security.

Then user Joe can add "Self-sign Pub key extension" to Firefox to automate the checking of public keys.

This allows for a relatively cheap self-signing check. Does a minimal amount of is this the real website I'm using but still not quite the level of a paid CA cert that say a bank should have.

(Apologies about the ramblyness of this post)

Re: Mozilla SSL policy bad for the Web

#67

Post by tlrobinson »

nailer wrote: post #59
tptacek wrote: post #31

Unbelievable. I've been poking about here for like 6 months now. You are all very smart people. Why is this so hard to understand? If you do not have a valid certificate signed by a CA, SSL is not providing any security . Yes, the warning you get when you visit a site with an invalid cert is much scarier than what you see if you visit an unencrypted site. But it's the sites that use encryption that users care about,…

You might be overestimating the intelligence of your audience. Reddit, one of the ycombinator startups, famously kept all its users passwords in clear text, as 'using hashes was too hard' - until they were hacked.

I've noticed that a lot of really smart people are just complete idiots when it comes to security.

Re: Mozilla SSL policy bad for the Web

#68

Post by stcredzero »

I once bought a broadband router that was marked down ridiculously cheap. It had all the features I wanted, and it was half the price of any of the others. When I got it home, everything was running slowly. After poking around, I discovered that my machines' DNS servers had changed from Time Warner Cable's to IP addresses in China!

If self signed certificates were indistinguishable, I may have been making connections through man in the middle machine located there without any way of knowing.

Re: Mozilla SSL policy bad for the Web

#69

Post by DougBTX »

ajross wrote: post #49
tptacek wrote: post #33

Earlier quoted context omitted.

The warning says, "Here is a site that claims to be secure. Maybe you thought it was secure, maybe you didn't. Either way, the site is not secure. DO NOT ENTER YOUR PASSWORDS AND CREDIT CARD NUMBERS HERE." The warning is vibrant because the condition it reports on can be created by an attacker on any SSL connection. That stupid warning might be among the top five security mechanisms on the Internet.

Why is a self-signed site insecure? Why isn't an HTTP site with a credit card prompt equally insecure (please, don't try to tell me that users look at the yellow bar -- we all know from direct experience that they don't)? Why is a properly certed site known to be secure for password use and credit card transactions? You're assuming all kinds of facts not in evidence. My point was simply that the FireFox tradition (no…

Imagine your bank's certificate says that they run their web site. If one day the certificate changes to a self-signed one, you have clear evidence of a man in the middle attack.

What should the browser do in this situation? Someone pointed out that an HTTPS connection with an unknown self-signed certificate identifies the site just as well as a plain HTTP connection, suggesting that we should treat both connections as equally insecure: so simply hide the yellow bar.

    please, don't try to tell me that users look at the yellow bar
Lets imagine a user who never expects the yellow bar. In the example above, when there is strong evidence of a man in the middle attack, the only warning the user gets is that a UI element which they don't notice is unexpectedly hidden.

You really want to warn the user in this situation, so Firefox gives them a big error message and makes them take positive action (adding the unverified, possibly malicious, certificate to their list of fully trusted root certificates) before they can get past it. That is fair enough.

But then there is the kicker. The browser can only tell that a certificate has changed if it has already recorded the old one. It can't distinguish between a site which has always had a self-signed certificate and one which just happens to have one today, unless it recorded the certificate yesterday. So it treats both as man in the middle attacks, which explains why Firefox will always give you a warning about unverified certificates until you verify them yourself.

Re: Mozilla SSL policy bad for the Web

#70

Post by invisible »

In my opinion, self-signed SSL certificates shouldn't cause this. If I want to use an SSL connection for my users to sign in with, I shouldn't have to pay tons of money for a wildcard certificate for my domain (they charge a large amount more just to add *. to your certificate). SSL is to SECURE THE TRANSMISSION, but these companies have turned it into a certificate war, where you must have one signed by a "distinguished" CA or the browser will tell you that you're visiting a "bad" site (Mozilla has a stopping guard, IE has attention images).

So don't even show the user that it's SSL. I don't care if my site seems more secure to the end-user, it just should be SECURE without regard to the mindset of the individual operating on it. Heck, even hide the https! Banks and online stores, sure, they should buy SSL certificates so they ease the end-user's mind. That is a relevant operating cost to incur for those individuals.

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