For some of my site visitors, the SSL certificate is failing. Whatever tests I do on various browsers for me the SSL certificate is valid.
I can't think of how to test this on client side, and to identify the problem.
How would you do this?
One client gets: fatal certificate unknown
While RouMao's answer is mostly correct, he has missed what is (IME) the most common problem with SSL certificates - the certificate you are using requires an interim certificate from the CA which you have not included in your certificate chain. Most CAs provide an online tool for analysing the certificate - try the one located here.
Also, is there any correlation with which browser being used? Notably, Chrome does not handle SSL v2 by default
Most of the failing of SSL certificates were caused by visitors themselves. Somehow could not tests or verified by server implementation.
Here are some obvious examples:
Your cert is validated since April 1st 2012, but the client's local machine time is set to 2010 -- one year later than current time. In this case, the visitor should encounter problem all the times, until his machine time is later than April 1st 2012.
visitor is behind a restricted firewall. The firewall could terminate the SSL/TLS connection and re-crypt the link with a pseudo/self-sign certificate. Indeed this could be considered as a man-in-middle attach.
The Trusted Root Certification was removed by client himself
it is very hard to fix all these problem. Sometimes, you need to create a client side native application to detect or fix all the possible problems, and require client browser to execute the application each time before it enter the HTTPS mode.
P.S. most of the e-bank application do like this.
Related
I have godaddy ssl certificate for domain.There wasn't any problems with my SSL certificate and visiting my domain(Haven't receive any errors), but couple times(two weeks ago) when I visited site from other(mobile, tablet and desktop) devices(different internet) I received SSL warning. I tested my domain on sslshopper.com and in this system shows that everything is okay with our SSL(Expiry date in 200 days). But I tested my SSL in ssllabs.com and SSL got only C grade. Maybe you have any idea why such stuff happening? Is it possible that if we would change SSL to other one, there wouldn't be such error at all? Maybe you experienced something similar and you can help out. Because warning appears only sometimes and in different devices, but other than that everything is perfect
When some client devices show problems, and others don't, it must likely because some client's don't contain the necessary Intermediate or Root Certificate Authorities to establish a chain of trust.
This is not the fault of the client device.
Rather, it is up to the server-side (ie. the side sending its certificate) to supply enough of the chain (ie. its certificate, and its CA certificate(s)) so that the client can use those to fill in the steps in the chain until it gets to a certificate that is signed by another certificate that it has in its trusted CA keystore.
You're very likely only supplying the server certificate.
Also possible, but generally less likely, is that the certificates are being offered by the server in the incorrect order.
To help you further, we would need to have some details as to what software is implementing the SSL server end-point.
Cheers,
Cameron
I have a web service which is secured through HTTPS. I also have client software which talks to this web service, using libcurl (which may be linked to OpenSSL, or linked to GnuTLS; I don't know which one, it depends on how the user installed libcurl). Because the web service is only ever accessed through the client software and never through the browser, the web service utilizes a self-signed certificate. The client software, in turn, has a copy of this self-signed certificate and explicitly checks the connection against that certificate.
Because of Heartbleed, I want to change the private key and certificate. However I want my users to experience as little service disruption as possible.
For this reason, I cannot change the key/certificate on a fixed date and time. If I do this then all users must upgrade their client software at that exact date and time. Otherwise, the upgraded client software won't work before the server change, while old versions of the client software won't work after the server change.
Ideally, I want to tell my users that I'm going to change the certificate in 1 month, and that they have 1 month time to upgrade the client software. The client software should be compatible with both the old and the new certificate. Then, after 1 month, I can issue another client software update which removes support for the old certificate.
So now we've come to my question: can I append the old certificate and the new certificate into a single .crt file? Will this cause libcurl to accept both certificates? If not, what should I do instead? Does the behavior depend on the SSL library or version?
Tests on OS X seem to indicate that appending both certificates into a single file works, but I don't know whether this is OS X-specific behavior, or whether it works everywhere. My client software has to support a wide range of Unix systems, including Linux (multiple distros) and FreeBSD.
Short answer: You can't.
Long answer:
Yes you can put multiple certificates in a single .crt file, regardless of platforms.
However HTTPS can only serve one certificate, instead of a crt file. So it's not the file that is limiting you, it's the protocol.
You could have a look at SNI https://en.wikipedia.org/wiki/Server_Name_Indication
to be able to serve another certificate based on the SNI information sent by the client at the beginning of the SSL Handshake
Alternatively, you could use a separate TCP port (or IP, or both) that will serve the new certificate.
But you say
The client software, in turn, has a copy of this self-signed certificate and explicitly checks the connection against that certificate.
This then requires you to release a version of your software for your clients to run, to at least have the copy of the new certificate you are going to use.
I guess you should better use a certificate signed by well-known CA, to decouple your server certificate from its validation chain, but that indeed means paying.
Yes a cert file should be able to hold multiple certificates. I would expect this to be broadly supported.
Background:
I am updating an internal application to a two-step authentication process. I want to add a client certificate authentication process (via a smart card) on top of a traditional username/password form. The application is written in C#, hosted on IIS7, and targeting Chrome and IE8.
Problem:
I am having issues with getting the application to prompt the user for a client certificate. I have been debugging the application with the help of Fiddler. When I have a test client certificate saved in Fiddler's user's directory (C:\Documents and Settings\USER\My Documents\Fiddler2), the application works as expected. I am prompted for a PIN number protecting the smart card, and, when entered correctly, takes me to the login form. When I close Fiddler, the application throws a 403 Forbidden error instead (since Fiddler is no longer running and pointing to its certificate). What I haven't been able to figure out is why the application won't prompt for a certificate normally.
Current Server Setup:
Self Signed Certificate was created
443 Binding is pointing at Self Signed Certificate
Anonymous Authentication is Enabled
The Self Signed Certificate was added to both the Trusted Root CA and Intermediate CA (I read that another person had it in both rather than just the Trusted Root CA and that solved their issue, though neither set up has worked for us).
I cleared out the rest of the certificates in the Trusted Root CA that I didn't need (I read elsewhere that having too many certificates would cause SSL to choke).
I am out of ideas to try other than starting from scratch on another server. Does anyone know what the issue might be? This seems like it should be fairly straight forward and that I'm missing something minor. Any ideas are welcomed.
Update:
After spending more time with this issue today, I strongly believe it has to do with IIS7 not being configured correctly (I did not set up it originally). I think this because I enabled Failed Request Tracing, looked at the subsequent .xml files being generated, and saw that a 500 error was being thrown.
Chrome is throwing a "Access to the webpage was denied" message rather than a "403 - Forbidden: Access is denied". I don't know if this helps. I do know that when I do not make certificates required, the site will work as intended. Requiring a certificate is where it fails.
The Application Pool is set to .Net 4.0 | Classic | Network Service.
Your problem is that the browser doesn't either get the request to provide client certificate or there is a security related option to block it from happening. IE offers certificate only if the web site is in correct zone (intranet or trusted sites). Please check this before everything.
If that doesn't help then see this answer for next step. The netsh documentation says:
clientcertnegotiation
Optional. Specifies whether the negotiation of certificate is enabled or disabled. Default is disabled.
Enable that and even the dumbest browser should notice that it is supposed to offer certificate for authentication. To diagnose your problem further you can use WireShark to see the negotiation in action.
In every browser I've seen, the browser will not prompt you to select a certificate if it does not have any certificates signed by a CA the server trusts. So make sure your server is configured with the correct CAs. As Boklucius suggested, you can use openssl to examine the list of trusted CAs your server is sending to clients and see whether the CA you have signed your client certificates with is among them.
Try openssl s_client -connect yourip:443 -prexit
And see if the CA (your self signed cert) is send to the client in the Acceptable client certificate CA names.
you need to install openssl first if you don't have it
I'll throw in a "try restarting the browser" suggestion, particularly if you installed the certificate while the browser was running.
To add a rather painful lesson to the mix: Make sure you quit Skype (or any other application) that eats port 443.
So the idea here is if you are running a dev environment on the same machine (both client and IIS), and your team uses Skype or some other app to communicate.
Watch the hours go by as you try and debug this problem, seemingly doing everything "right", netsh http sslcerts and such, even rebooting but to no avail. Well, turns out Skype will eat 443 so turn it off and "poof" there goes your certificate prompt.
Then feel free to throw things at the wall, shout obscenities or just "Rage, rage against the dying of the light".
Also, make sure Fiddler isn't getting in the way. If you have it decrypting the SSL, it'll corrupt the message back to IE, and it doesn't have the certificate installed, so it can't offer it. Turn off fiddler, and voila, the certificate prompt appears.
In Firefox, if you press 'Cancel' the first time you're prompted for a certificate, and you left the sneaky 'Remember this decision' box checked, then Firefox will remember that and never offer it again.
You can view and delete your previous remembered decisions in Firefox Preferences -> Privacy & Security (about:preferences#privacy), View Certificates, and check the Authentication Decisions tab.
Just connecting to my VPN and trying showed me the certificate prompt. Needs to be done only the first time.
We're having an issue with securing an intranet / internet website with SSL where
we can't know the qualified domain name in advance.
Basically, I'm trying to make a program that will be installed on a webserver
outside my direct control, to be accessable over intra- or internet. In either case
I want it to be secure via SSL (https). To do this, I would like to include and
install a SSL certificate on the target machine. My installer is fully prepackaged
and should not require any particular during- or postinstall intervention from my
end. Problem is, I can't know ahead of time the target machine's name or domain
name, so as far as I can tell the SSL connection will be returning warnings (or
worse?) when accessed, since the certificate I include will (must) have a different
name on it.
I really want to avoid those warnings, but I still want to keep it secure. Is there
any way to install a SSL connection without certificate warnings without the domain
name known ahead of time?
Thanks for any help you folks can give.
What you want to do is not possible. Here's why.
A certificate will include a set of names (Common Name, possibly along with Subject Alternative Names, possibly including wildcard names).
The client's web browser will do the following:
The user wanted to visit "https://myapp.mydomain.com/blog/posts/1".
The request is via SSL and the domain name in the request is "myapp.mydomain.com".
Get the certificate from the Web server.
Ensure that at least one of the names in the certificate is exactly equal to, or wildcard-matches, the domain name in the request.
Display the page.
Therefore, you need a certificate with the exact domain name (or a wildcard matching the exact domain name) by which the application will be used. And the certificate needs to be available at the same time as, or later than, the time when the exact domain name of the website becomes known, and cannot be made available any earlier.
You seem to be under the misapprehension that somehow a certificate can "create" or "install" an SSL connection. That is false. The Web server - Apache, IIS, Nginx, LigHTTPD, or whichever one you happen to use - is the program that knows how to every aspect of SSL connectivity. The certificate is just a file that the Web server sends to the client, without even opening or using in any way.
Additionally, the author of a webapp to be distributed is not responsible for creating or distributing certificates, and should not be under the misapprehension that he is responsible. Only the website maintainer should be responsible for obtaining a certificate for his website. As another person remarked, in your installation process or perhaps in a post-installation process, you may ask the person installing the webapp for a certificate. But that is the best you can do.
The best you can do is to buy a wildcard SSL certificate - but wait, it's not what you think. You still need to know the second-level domain (the TLD being ".com") ahead of time. You can effectively ask for a cert that covers *.foo.com - then any site, a.foo.com, b.foo.com will be covered. Of course, these certs are more expensive that FQDN certs because you are doing the buggers out of some extra coin.
-Oisin
Each of those sites should have their own SSL certificate. Why not prompt the user to provide the cert file during installation?
In most (if not all) cases, the SSL certificate is associated with the webserver (apache, IIS, etc.) and is not part of your application. It's up to the admin of the web server to install the certificate and not you as the author of the program.
If your installation program does have the ability to modify the web server configuration, and you are willing to have it use a self-signed certificate, you can script the creation of the certificate to allow the domain name to be input. However, I sense this is not really available to you. Also, a self-signed certificate will generally cause certificate warnings.
If I understand you correctly there might be a solution to your problem now. This solution won't help you, however, if you have no control over specifying what SSL certificates are served from the web server where your program is installed (as mentioned by someone else). If your program itself contains a web server you won't have this issue.
If you start with a trusted https website, you can make cross-domain TLS (SSL) XmlHttpRequests to the web servers that are running your application. This is made possible using the opensource Forge project. The project uses a TLS implementation written in JavaScript and a small Flash swf to handle the cross-domain requests. Your program will need to serve an XML Flash policy file that grants the trusted website access to the web server running the application.
Your program will also need to generate a self-signed SSL certificate and upload it to the trusted website. From there, each program's certificate can be included as trusted via the JavaScript TLS implementation. Alternatively, you can have your program upload its certificate to be signed by a CA you create, using a common or subject alternative name that is appropriate for your use (it doesn't have to be the domain name). Then you can use JavaScript to trust the CA certificate and look for the correct name on each certificate.
For more details check out the Forge project at github:
http://github.com/digitalbazaar/forge/blob/master/README
The links to the blog posts at the end provide more in-depth information about how it works.
Here's a possible scenario.
Let's say I have a website "https://www.mywebsite.com" and there is a valid SSL certificate purchased for this domain.
I want to "mimick" this website on my LOCAL machine for a testing purpose.
So let's say I set up a locally-configured "https://www.mywebsite.com" (which is in essence https://localhost/mywebsite or something similar).
Would I be able to re-use the SSL certificate on my local testing website?
You can re-use your SSL certificate if you configure your DNS so that your test machine is the same domain name as server, which is probably a bad idea.
You can also re-use it on your test machine if you don't mind clicking the box "accept this whacked out ssl cert"... So I suppose that the answer is technically yes, although I wouldn't personally do it.
It depends what you are trying to test and why you need a certificate for testing.
If you use the certificate, it will correctly encrypt connections using SSL, but any client will get a certificate mis-match error. If you use a self-signed certificate instead, most clients will give you a warning about that, so it might be just as annoying or not.
If you are testing, for instance, a deployment script to make sure everything gets installed in the right place, it will work. If you are testing to make sure your code correctly redirects a non-secure connection to a secure one, it will work.
If you want to test the your website for functionality, usability, bugs, etc. then your testers will likely complain about the certificate warnings or errors, and you're probably better off doing something else.
I am not sure since the SSL certificate is bound by the domain name that was registered with the certificate. But you may be able to dupe the certificate by editing your hosts file to change localhost 127.0.0.1 to be mysite.com 127.0.0.1, ...in theory at least...if not this is a question for serverfault.com.
Hope this helps,
Best regards,
Tom.
You can't use it since the SSL cert is tied to the domain www.mywebsite.com unless you do a bit of trickery.
You can put an entry in your hosts file saying that domain is at 127.0.0.1, but that's not ideal as you could no longer reach the website.
If you just need a valid cert to test with, then a better alternative is to self-sign using the IIS Resource Kit.
I'm no expert on DNS, but this would introduce a pretty major vulnerability.
Basically if this was allowed, DNS poisoning could be used defeat the whole purpose of third party trust.
Think about it:
I infect your computer so that when you go to www.amazon.com it resolves www.amazon.com to a different domain. That domain uses amazon's ssl cert to fool you into thinking it's legit, so you send me your credit card information.
So, the answer to your question is, no you can't do this. You will still get errors, My guess is that somewhere on the verfication chain, it compares the domain that initiated the request with what its internal dns resolves the domain, to verify there is a match.
As others have said, you can test SSL with a Self Signed Cert, you just have to instruct your testers to import the cert, or go through the trouble of building your own trusted CA, and have testers add that CA as a trusted CA.
There is no point in stealing another sites SSL Cert.
Of course you could use the vulnerability in MD5 to create your own valid SSL cert.
http://www.digicert.com/news/2009-01-05-md5-ssl.htm