They are pretty bad from a user perspective. Some of the browser UIs make it very scary looking to continue, if you can even figure out how.
If, as you say, just an information site, I would get rid of them immediately.
Ask HN: How bad is it to use a self-signed SSL certificate?
21–30 of 118 posts
Re: Ask HN: How bad is it to use a self-signed SSL certificate?
#22It's terrible, because Man-In-The-Middle attacks are trivial and automatable. namecheap.com sells PositiveSSL certs for $9/year -- that's pretty cheap and easy.
What could be achieved with a MitM attack on an information-only site?
Re: Ask HN: How bad is it to use a self-signed SSL certificate?
#23If you are careful when generating your certificate (that is, careful to generate a subject certificate, and not a CA certificate) and can reliably distribute your certificate to all clients you are interested in , then self-signed certificates are usually much better than the public CA system . But actually achieving the pre-distribution step is pretty hard, and basically impossible over the internet. You can achiev…
A site claiming to offer cryptographic security when it is in fact not is, in reality, worse than a site that simply doesn't offer cryptographic security. Both those sites --- the SSL site and the non-SSL site --- aren't offering security. But only one of them is also being deceptive about it.
However, you'll get no argument from me if you constrain your argument about dismal mis-design to browser UI/UX. The browser UX design for TLS security hasn't meaningfully changed since Netscape.
Re: Ask HN: How bad is it to use a self-signed SSL certificate?
#24Earlier quoted context omitted.
I agree with your answer, but I don't recall ever seeing a post mortem write-up of such an attack. Are people who have seen them in the wild all bound my NDAs or something?
I agree with your answer, but I don't recall ever seeing a post mortem write-up of such an attack. So, if you know how MITM operates, tell me: How would the server operator ever know?
Reports of user data being compromised could lead to a consultant being hired to figure out where the security problem is, for instance.
(I'm assuming the site requires a login or perhaps even takes CC information - the kind of stuff a user might notice a third-party using)
Re: Ask HN: How bad is it to use a self-signed SSL certificate?
#25It's terrible, because Man-In-The-Middle attacks are trivial and automatable. namecheap.com sells PositiveSSL certs for $9/year -- that's pretty cheap and easy.
Thanks. I needed some encouragement. I will buy two PositiveSSL certificates today.
It isn't terrible advice, but it isn't good advice either. X.509's entire trust model is based on MITM. There is nothing wrong with a self signed certificate if all you want to do is encrypt on the wire.
The visible UI of a self-signed is admittedly terrible. The invisible UI of the Certificate Authority system is an outright catastrophe.
Re: Ask HN: How bad is it to use a self-signed SSL certificate?
#26Earlier quoted context omitted.
I agree with your answer, but I don't recall ever seeing a post mortem write-up of such an attack. Are people who have seen them in the wild all bound my NDAs or something?
I agree with your answer, but I don't recall ever seeing a post mortem write-up of such an attack. So, if you know how MITM operates, tell me: How would the server operator ever know?
http://www.scmagazine.com/researchers-detect-ssl-mitm-attack...
About 0.2% for Facebook is MITM. And they are not using self signed certificates.
Re: Ask HN: How bad is it to use a self-signed SSL certificate?
#27Depends what you want, if you want trust that you can only grant yourself, then go for self signed, especially internal projects. If you want exposure of your certificates to common browsers and don't want to raise warnings in them, go for cert authorities. But remember Snowden, certificate authorities are less trustfull than you can trust yourself.
This is the right answer and it's too bad it was way down the page (I upvoted).
For your situation, mark_I_watson, probably get a cert from a CA, the cheap "domain only" variety where you can verify your site to the CA simply by putting a file in the web root directory.
I say this assuming the content is whatever you were already displaying to the world without encryption - therefore low-security. The cert allows you to put meaningful authentication on your site (otherwise passwords go in plaintext, for example).
For a medium security level, sufficient for online money transactions, you would have to get a higher-assurance type of cert - this requires more money, sending business and personal ID documents to verify your business to the CA, etc..
For really secret communications - getting into a degree of NSA-proofing - among other things you have to avoid involving a CA, and preferably make browser certificates for trusted clients, to spare them the warnings that browsers throw up on non-CA server certificates. This is unsuitable for (legal) commerce (commercial payment processors would reject your business), and still vulnerable to metadata collection (unless you put it on TOR or equivalent), and still vulnerable to state coercion of private keys or forced code-trojaning.
Note that the third solution requires that your clients have a means of verifying that the site is yours rather than an imposter - you avoid a CA having the power to enable some other site to impersonate yours, but trusted users must have a basis for trust by a "side channel" such as knowing you personally, you being their employer, or reputation of your digital signature over time.
Re: Ask HN: How bad is it to use a self-signed SSL certificate?
#28It's good, because you have control over the certificate creation, and never have to share your private key. The one catch is, as you noticed, the key has to be distributed. Depending on your goals, and your audience, this might be impractical, or within the realm of reason. Here's a link that goes into more detail. https://blogs.oracle.com/java-platform-group/entry/self_sign...
> It's good, because you have control over the certificate creation, and never have to share your private key. You will never have to share your private key when getting a certificate from a proper CA, either.
This is true, but you wouldn't believe the system-as-practiced by most large IT departments.
edit: small IT departments, too. nobody really pays attention as long as the lock icon is green.
Re: Ask HN: How bad is it to use a self-signed SSL certificate?
#29If you are careful when generating your certificate (that is, careful to generate a subject certificate, and not a CA certificate) and can reliably distribute your certificate to all clients you are interested in , then self-signed certificates are usually much better than the public CA system . But actually achieving the pre-distribution step is pretty hard, and basically impossible over the internet. You can achiev…
A site claiming to offer cryptographic security when it is in fact not is, in reality, worse than a site that simply doesn't offer cryptographic security. Both those sites --- the SSL site and the non-SSL site --- aren't offering security. But only one of them is also being deceptive about it. However, you'll get no argument from me if you constrain your argument about dismal mis-design to browser UI/UX. The browser…
[deleted]
Re: Ask HN: How bad is it to use a self-signed SSL certificate?
#30Earlier quoted context omitted.
Just keep in mind that Class 1 (free) certificates are for non-commercial sites only.
Also, StartSSL's certs don't work on android (you get cert not trusted error) for some reason.
I haven't checked any recent Android trust stores, but this might be due to a lack of an intermediate certificate.
The vast majority of modern browsers know how to find intermediate certificates online. Android's browser doesn't, for whatever reason. You have to bundle it on your web server.