SSL Configuration Generator(ssl-config.mozilla.org)
ssl-config.mozilla.org
SSL Configuration Generator
https://ssl-config.mozilla.org/
86 comments
Honestly, i disagree with the security headers one. Various security headers do different things and should not be applied blindly. While some are always appropriate there are also some that make sense to skip depending on what specificly your site is doing.
Not to mention, when i looked at the hall of fame entries, most had a CSP header, but it was a useless CSP header that was meaningless. It doesn't seem to distinguish between having the header and actually using it correctly.
Not to mention, when i looked at the hall of fame entries, most had a CSP header, but it was a useless CSP header that was meaningless. It doesn't seem to distinguish between having the header and actually using it correctly.
This was always my pet peeve when working as a penetration tester. We'd run simple tools like this to cover the basics, but so many coworkers would blindly copy paste the issues without considering the site's context and suitability. Not to knock their skills, they'd find real vulnerabilities too. It's just that this stuff was considered beneath them, while I felt that giving a client tailored advice on little details like this is what they were looking for and shows attention to detail.
[deleted]
As a security conscious dev that has worked in various highly regulated spaces I want to say we really appreciate people like you, because they’re super rare
It's seriously infuriating receiving these "Critical vulnerability reports" customers let other agencies do, and having to justify why you have no Referer-Policy header.
Nice to read that you are reasonable.
Also, they want a strict CSP while serving 10 different ad networks :)
Nice to read that you are reasonable.
Also, they want a strict CSP while serving 10 different ad networks :)
I needed to perform scans internally, and testssl.sh was too slow (minimum 20 seconds with parallelization and all optional scans disabled). So I made my own scanner, for a 60-100x speedup: https://github.com/boppreh/hello_tls . It doesn't do vulnerability assessment, but I was more interested in extracting the configuration.
Why is 20 s too slow? How often do you run it?
We also it at my work, where it's used both for mass scans of internal hosts, and scanning the same host many times during incidents/configuration changes.
And the 20s is extra annoying because it's completely unnecessary. The tool is so slow because it's thousands of lines of pure bash, manipulating individual bytes. And because it's bash, it also breaks in confusing ways when you look at it wrong[1].
[1] https://github.com/testssl/testssl.sh/pull/2429
And the 20s is extra annoying because it's completely unnecessary. The tool is so slow because it's thousands of lines of pure bash, manipulating individual bytes. And because it's bash, it also breaks in confusing ways when you look at it wrong[1].
[1] https://github.com/testssl/testssl.sh/pull/2429
Why are we still using the term "SSL" anywhere? It feels immediately like someone forgot the last 10 years of tech.
I'm one of the few using "TLS", but it's hard.
When doing this, you see that some people feel that you are being pedantic.
And the biggest issue is that it creates confusion. During calls with customers, when I tell that we're going to setup their TLS certs, they reply, worried: "no, we need SSL certs!".
I see it as another chicken & egg situation: regular people don't know about TLS, and business are afraid of communicating about TLS because they don't want their customer going elsewhere because they don't understand what TLS is and want SSL
I went on Cloudflare to try and illustrate this, and it's... complicated https://www.cloudflare.com/application-services/products/ssl...
The path says SSL but most of the page it about TLS, unless sometimes it's SSL...
When doing this, you see that some people feel that you are being pedantic.
And the biggest issue is that it creates confusion. During calls with customers, when I tell that we're going to setup their TLS certs, they reply, worried: "no, we need SSL certs!".
I see it as another chicken & egg situation: regular people don't know about TLS, and business are afraid of communicating about TLS because they don't want their customer going elsewhere because they don't understand what TLS is and want SSL
I went on Cloudflare to try and illustrate this, and it's... complicated https://www.cloudflare.com/application-services/products/ssl...
The path says SSL but most of the page it about TLS, unless sometimes it's SSL...
There are no TLS certs, it's x509 certs :) SSL certificate is still the name used by everybody though. For the protocol, TLS is correct (apart from SSLv3 which is very deprecated).
SSL was developed by Netscape in the 90s and evolved into TLS. Netscape Navigator essentially evolved into Mozilla.
"They've" been at it from the beginning, so it somehow seems understandable that Mozilla has a lot of "SSL" momentum or carryover.
"They've" been at it from the beginning, so it somehow seems understandable that Mozilla has a lot of "SSL" momentum or carryover.
actually we wrote this many years ago and left mozilla ans nobody is really updating it other than adding new configs. its not super useful anymore :)
at the time it made sense to us because you couldnt have good SSL configuration everywhere (it was not well supported) so we had trade-offs and created tiers of configs. We barely had TLS coming out, so SSL eas still the name of the game.
nowaday just use the latest TLS defaults and you're golden.
at the time it made sense to us because you couldnt have good SSL configuration everywhere (it was not well supported) so we had trade-offs and created tiers of configs. We barely had TLS coming out, so SSL eas still the name of the game.
nowaday just use the latest TLS defaults and you're golden.
Back in the day, SSL didn't exists. When it came into existence, it was quite an expensive novelty.
It became a generic name that everyone knew for encrypted HTTP connections. It still is a generic name for that, even though the underlying protocol changed name to TLS.
It became a generic name that everyone knew for encrypted HTTP connections. It still is a generic name for that, even though the underlying protocol changed name to TLS.
The main answer is a lot of the software on that page predates SSLs deprecation and people (sysadmins especially, because they wrote some bash script 20 years ago and want it to keep working) like backwards compatibility.
I think the bigger answer is certificate vendors won't stop using the term.
Maybe, but who is actually still buying tls certs from a vendor?
We do or will until Certificate lifespan changes. We have customers cert pinning our API cert at work (shitty Enterprise security practices) so constant 60 days rotation with LE or ZeroSSL caused endless support heartache because these enterprise customers demanded we tell them when and what new fingerprint was.
So, 1-year certs and renew 60 days out, send out new fingerprint and at 30 days, we would occasionally swap it in and out as brownout with replacement at 15 days.
We have already indicated when it drops to 100 days, we will swap to automation and no longer communicate when changes will occur. Account Managers are already getting push back from customers. It's possible we will continue using Digicert because they seem to promise that Intermediate certs won't rotate unlike Let's Encrypt which rotates them more frequently which is better security practice. So Enterprise customers will cert pin to Intermediate instead.
So, 1-year certs and renew 60 days out, send out new fingerprint and at 30 days, we would occasionally swap it in and out as brownout with replacement at 15 days.
We have already indicated when it drops to 100 days, we will swap to automation and no longer communicate when changes will occur. Account Managers are already getting push back from customers. It's possible we will continue using Digicert because they seem to promise that Intermediate certs won't rotate unlike Let's Encrypt which rotates them more frequently which is better security practice. So Enterprise customers will cert pin to Intermediate instead.
Lots of people, I certainly don't trust free providers, and I think it's a lot less likely that malware will use a non-free cert, so some people trust those more. Plus there are email, code-signing and other cert types that aren't provided for free.
> I certainly don't trust free providers
What does this mean in practice? Do you remove the free providers from your OS & browser trust stores? Does this mean you get warnings every time you visit a site that uses LetsEncrypt (and other free providers)?
What does this mean in practice? Do you remove the free providers from your OS & browser trust stores? Does this mean you get warnings every time you visit a site that uses LetsEncrypt (and other free providers)?
What does it mean not to trust Let's Encrypt in this case? What is it you are concerned they will do?
I worry that the CA is somehow compromised (state actor holding private keys, etc).
BTW, all the recent certificate shenanigans have invovled for-profit CAs [1].
[1]: https://sslmate.com/resources/certificate_authority_failures
[1]: https://sslmate.com/resources/certificate_authority_failures
I still believe in "if it's free, you are the product."
In what way is a non-profit such as Lets Encrypt attempting to monetize their customer relationships? They've issued more 700 million certificates at no cost.
While I don't get the cynicism in this case, you would agree supporting a secure web is in the public interest, right?
While I don't get the cynicism in this case, you would agree supporting a secure web is in the public interest, right?
I wasn't referring to monetization, but government surveillance.
How would they surveil? And also, have you disabled the certs you don't trust from these providers on your systems?
[deleted]
To each their own, but you do realize that you are using a free website running on free software secured by free TLS libraries transmitted via routers that often run free software and firmware? Also how much did you pay for the browser you used to make these comments?
There is a sea of difference between something like Google/Facebook/TikTok and Let’s Encrypt/the Linux Foundation/FSF/etc. I can only assume you can’t see that difference if you have spent no time reading about these things, but I would encourage you to. This stuff is important especially if you get to make security decisions for any kind of product.
There is a sea of difference between something like Google/Facebook/TikTok and Let’s Encrypt/the Linux Foundation/FSF/etc. I can only assume you can’t see that difference if you have spent no time reading about these things, but I would encourage you to. This stuff is important especially if you get to make security decisions for any kind of product.
> I worry that the CA is somehow compromised (state actor holding private keys, etc).
"Somehow" is doing a lot work in that sentence.
Operationally, there's no difference between the security procedures and requirements that a for-profit or a non-profit CA must adhere to.
"Somehow" is doing a lot work in that sentence.
Operationally, there's no difference between the security procedures and requirements that a for-profit or a non-profit CA must adhere to.
I would have that concern, at minimum 100x more with random shitty unreliable SSL providers, than those being run by literal huge nerds and non-profits. Your analysis here is thin and lazy and that's being generous to your analysis.
Thanks for explaining.
I think this concern is reflects a misunderstanding of how the security of the WebPKI works. Specifically, any CA can issue certificates for your domain whether you are their customer or not. What that means is that if CA #1 is compromised but you choose CA #2, CA #1 can still be used to attack connections to your domain.
The situation is slightly worse if the CA you actually use is compromised because the main defense we have against misissuance is Certificate Transparency, and it's easier to detect that a certificate was issued by a CA you don't use than that too many certificates were issued by a CA you do use, but it's just slightly easier.
The bottom line here is that if you are worried about some group of CAs being compromised, then using a different CA doesn't help you much.
I think this concern is reflects a misunderstanding of how the security of the WebPKI works. Specifically, any CA can issue certificates for your domain whether you are their customer or not. What that means is that if CA #1 is compromised but you choose CA #2, CA #1 can still be used to attack connections to your domain.
The situation is slightly worse if the CA you actually use is compromised because the main defense we have against misissuance is Certificate Transparency, and it's easier to detect that a certificate was issued by a CA you don't use than that too many certificates were issued by a CA you do use, but it's just slightly easier.
The bottom line here is that if you are worried about some group of CAs being compromised, then using a different CA doesn't help you much.
Yes I understand all of that, but I still choose to trust free services less.
Of course the (more secure?) alternative would be to generate self-signed certs, but for customer-facing sites that's a big UX problem.
Of course the (more secure?) alternative would be to generate self-signed certs, but for customer-facing sites that's a big UX problem.
> Yes I understand all of that, but I still choose to trust free services less.
Well, you can choose to do whatever you want, but given that you're posting to a public forum, it would be helpful if you actually explained your reasoning.
> Of course the (more secure?) alternative would be to generate self-signed certs, but for customer-facing sites that's a big UX problem.
It's not just a big UX problem, it's a big security problem, because the customers have no way of knowing if your certificate is actually valid.
Well, you can choose to do whatever you want, but given that you're posting to a public forum, it would be helpful if you actually explained your reasoning.
> Of course the (more secure?) alternative would be to generate self-signed certs, but for customer-facing sites that's a big UX problem.
It's not just a big UX problem, it's a big security problem, because the customers have no way of knowing if your certificate is actually valid.
> it would be helpful if you actually explained your reasoning.
It's exceedingly clear that's not going to happen, and I think we all know why. Good reminder to anyone that anyone can just post here. Including people that logic-lessly think that paying a shitty third party that probably has a bad track record is somehow better than using LE. Like, this isn't a serious conversation?
It's exceedingly clear that's not going to happen, and I think we all know why. Good reminder to anyone that anyone can just post here. Including people that logic-lessly think that paying a shitty third party that probably has a bad track record is somehow better than using LE. Like, this isn't a serious conversation?
TLS is basically SSL 4. They only changed the name to signal the backwards incompatibility.
Not quite.
The name was changed from SSL to TLS as part of the adoption in IETF. I imagine different people had different motivations, but in part it was a signal that it was going to be controlled by IETF rather than Netscape.
As far as compatibility goes, TLS is backward compatible with SSLv3 [0] in that the client can send a ClientHello that is acceptable to both SSLv3 and TLS servers and the server can select the version to use.
Re: the version number, we're now on TLS 1.3, so I guess that would be SSLv7.
[0] The situation is more complicated with SSLv2, which had a different ClientHello format.
The name was changed from SSL to TLS as part of the adoption in IETF. I imagine different people had different motivations, but in part it was a signal that it was going to be controlled by IETF rather than Netscape.
As far as compatibility goes, TLS is backward compatible with SSLv3 [0] in that the client can send a ClientHello that is acceptable to both SSLv3 and TLS servers and the server can select the version to use.
Re: the version number, we're now on TLS 1.3, so I guess that would be SSLv7.
[0] The situation is more complicated with SSLv2, which had a different ClientHello format.
You might as well decry "Hoover" for a vacuum cleaner. I haven't seen a Hoover for way longer than SSL -> TLS. OK I have but I blanked it!
I’m going to xerox this Kleenex.
I think xerox still exits but darn if I haven’t seen one in ages.
I think xerox still exits but darn if I haven’t seen one in ages.
I did this recently then put it in my Tupperware (which most people have never seen or used since it was only sold at those at home Tupperware parties and not at stores).
The printers still exist, but the branding is deprecated.
Xerox -> Fuji-Xerox -> FUJIFILM Business Innovation
Xerox -> Fuji-Xerox -> FUJIFILM Business Innovation
I tend to expand TLS thread-local storage, so SSL is less confusing for me.
I had to double check my nginx configuration and the variables use SSL in the names even though I define the protocol to be TLS. I have the certbot commands and their naming conventions use SSL. Perhaps you've never actually implemented SSL or TLS and just use the latest tech jargon to fake understanding?
SSL is not going away, might as well forget TLS instead.
https://www.fortinet.com/resources/cyberglossary/ssl-vpn
https://www.fortinet.com/resources/cyberglossary/ssl-vpn
TLS is a Microsoftie term. I use SSL out of stubbornness.
https://news.ycombinator.com/item?id=44282378
https://news.ycombinator.com/item?id=44282378
Because “OpenSSL” was too lazy to rename themselves to “OpenTLS”
That's good! I'll use TLS when OpenSSL gets renamed :-D (I own many SSL domains and projects)
ElGamal says he uses them interchangeably. He says TLS exists for historical reasons, but the essence of the technology is the same. I got into the habit of using SSL/TLS.
I use it all the time.
Good luck renaming OpenSSL...
Proper configuration of cryptography should not be abdicated to application developers or operators: https://go.dev/blog/tls-cipher-suites
> The Mozilla SSL Configuration Generator is great, and it should not exist.
> The Mozilla SSL Configuration Generator is great, and it should not exist.
Not only is it difficult to make an informed choice, it also incurs a maintenance cost. Cost which is often not paid, resulting in configuration that becomes increasingly sub-optimal as time passes and the SSL/TLS library is updated.
I'm fairly certain that when that generator was made (or article written), OpenSSL and similar already had ciphersuite presets one could use. So it is a bit odd that the generator is not enhancing those.
As an example, in the case of OpenSSL you can combine presets such as "HIGH" with your additional preferences. Such as avoiding non-PFS key exchanges, DoS risks, SHA1 phase out or less frequently used block ciphers. Result being something like "HIGH:!kRSA:!kEDH:!SHA1:!CAMELLIA:!ARIA". Optionally one can also bump up global "SECLEVEL" in OpenSSL's configuration.
Such a combination helps avoid issues like accidentally crippling operations when an ECC key(/cert) is used and someone forgot to allow ECDHE+ECDSA in addition to ECDHE+RSA. Nor does it accidentally disable strong ciphersuites using ChaCha20 that aren't as old.
Same goes for key exchange configuration. Quite a few servers don't have EdDSA available that don't run Windows, I suspect it's because they were set at some point and forgotten. Now such configuration also disables post-quantum hybrid key exchange algorithms.
I'm fairly certain that when that generator was made (or article written), OpenSSL and similar already had ciphersuite presets one could use. So it is a bit odd that the generator is not enhancing those.
As an example, in the case of OpenSSL you can combine presets such as "HIGH" with your additional preferences. Such as avoiding non-PFS key exchanges, DoS risks, SHA1 phase out or less frequently used block ciphers. Result being something like "HIGH:!kRSA:!kEDH:!SHA1:!CAMELLIA:!ARIA". Optionally one can also bump up global "SECLEVEL" in OpenSSL's configuration.
Such a combination helps avoid issues like accidentally crippling operations when an ECC key(/cert) is used and someone forgot to allow ECDHE+ECDSA in addition to ECDHE+RSA. Nor does it accidentally disable strong ciphersuites using ChaCha20 that aren't as old.
Same goes for key exchange configuration. Quite a few servers don't have EdDSA available that don't run Windows, I suspect it's because they were set at some point and forgotten. Now such configuration also disables post-quantum hybrid key exchange algorithms.
They also have configs for ssh, although without the cool generator.
https://infosec.mozilla.org/guidelines/openssh
https://infosec.mozilla.org/guidelines/openssh
It's sad-funny that they include OCSP stapling when ~browsers~^W Let's Encrypt have decided to eradicate OCSP (including stapled OCSP) :(.
How do these configs differ to server defaults? If some really bad settings are enabled by default (thus needing this custom config), shouldn't it be better just to have the server-software devs fix the defaults to be 'good enough' (for most)?
Great question. Servers should ship with secure defaults.
I don’t see any option in this config generator for mTLS (mutual TLS, where you use client certificates in addition to server certificates).
Perhaps it is too niche of a thing. Sadly. It really is quite useful in some situations.
Perhaps it is too niche of a thing. Sadly. It really is quite useful in some situations.
Why are they recommending SSLHonorCipherOrder Off ?
Same reason they recommend the similar directive for nginx:
> all the ciphers in Modern and Intermediate are secure. As such, we let the client choose the most performant cipher suite for their hardware configuration.
https://github.com/mozilla/server-side-tls/issues/260#issuec...
https://wiki.mozilla.org/Security/Server_Side_TLS
> all the ciphers in Modern and Intermediate are secure. As such, we let the client choose the most performant cipher suite for their hardware configuration.
https://github.com/mozilla/server-side-tls/issues/260#issuec...
https://wiki.mozilla.org/Security/Server_Side_TLS
There's no need for that.
The choice between ChaCha20 and AES can be left to the clients with the "PrioritizeChaCha" option. On both OpenSSL and BoringSSL, likely similar options are available with other libraries as well. Anything else such as not enforcing any preference is unnecessary.
The choice between ChaCha20 and AES can be left to the clients with the "PrioritizeChaCha" option. On both OpenSSL and BoringSSL, likely similar options are available with other libraries as well. Anything else such as not enforcing any preference is unnecessary.
This has been around for a long time. Kudos to the folks that built it. It served a need at the time and made a big impact on improving configurations for people that didn't understand the myriad of ways to setup ssl/tls.
This looks like something that's been around forever, but it's the first time I've seen it. xkcd://{{derive_from_context}}
It's a great idea. I've created (or copied) at least half of these output formats, a few of which I remember being annoyingly difficult to surface from the project docs.
But in the moment today, it's mostly interesting to see the different ways of saying the same things in various configuration languages. And thinking that this might be why so many people with different brains find the technology world so obtuse and off-putting.
The joke's on them, of course. We like it this way! (Never wrestle with a pig...)
It's a great idea. I've created (or copied) at least half of these output formats, a few of which I remember being annoyingly difficult to surface from the project docs.
But in the moment today, it's mostly interesting to see the different ways of saying the same things in various configuration languages. And thinking that this might be why so many people with different brains find the technology world so obtuse and off-putting.
The joke's on them, of course. We like it this way! (Never wrestle with a pig...)
Feels like server developers should include turnkey configurations where you just give maybe a year/quarter and compatibility target (secure, medium, loose).
Needing to cha-cha your salsas, 128 to the 256 to the 1305...picking SSL ciphers is the biggest cargo-cult thing ever. I have no clue what I am doing.
Needing to cha-cha your salsas, 128 to the 256 to the 1305...picking SSL ciphers is the biggest cargo-cult thing ever. I have no clue what I am doing.
This and their Server Side TLS page have been a staple in my playbook for the last decade!
https://wiki.mozilla.org/Security/Server_Side_TLS
Such useful resources.
https://wiki.mozilla.org/Security/Server_Side_TLS
Such useful resources.
it is amazing that Chrome 80 still hasn’t upgrade its OpenSSL to v1.1.1.
why the site's back button doesn't work?
It does, but every time you click on a new option it's a new URL. So if you poke around a bit, you may have generated dozens of entries in the history.
Thanks Mozilla, I don't know what I would do if I couldn't generate a config for Apache 420 with OpenSSL 69.
[1] - https://securityheaders.com/
[2] - https://www.ssllabs.com/ssltest/
[3] - https://github.com/testssl/testssl.sh