Can we replace new server certificate from old server certificate? - ssl

My server certificate will expire at end of the next month. So I am planning to replace it with the new one before it expires. but I need to do some testing with the new certificate (My mobile applications) and if the testing fails Can I replace the old certificate again until I found a way to fix my issues.

I have experience with Windows / IIS and info is based on that background:
you can install multiple certs on a server
you can assign your new cert to the site while keeping old on the server
if new cert fails, reassign old cert to your site
This concept should work with other servers too, but I cannot confirm that for sure

Related

Authorization Failed to install new certificate on Windows server 2012

I'm trying to create a new certificate for my website which is hosted on Windows server 2012.
Currently, I have a self signed expired certificate. I would like to try Let's Encrypt SSL cert. So, I've downloaded latest version of Lets Encrypt from https://github.com/PKISharp/win-acme/releases and ran wacs.exe from unzipped folder.
When I select N=Create new certificate and entered my domain, I'm getting below error.
Expected: Certificate installed
Actual: Authorization failed error
It looks like the server is not reachable from the Internet. Your server must be accessible from Internet in order to allow Let's Encrypt systems to verify the ownership of the domain.
According to the error which appears (NXDOMAIN), it may be that the website is too new (DNS registers can take up to 48 hours to replicate), the DNS are not properly configured to point to your server, or maybe you have a firewall or filter which disallows external connections.
Make sure that you can reach your domain from Internet first and it points to your server, then try again to request a certificate.

How to force browser to fetch new SSL certificate instead of old one using server side configuration (Nginx)?

We have a website with SSL configured. 2 days back SSL certificate was expired so I purchased a new instead of renewing. I have configured the new one. Now some of users are still getting SSL certificate expired issue although the new one is configured.
I want to force the browser to recheck the new SSL certificate using some server side configuration since we can not go and update each user browser certificate manually. It have to be done using some server side configuration. We are using Nginx.
This is really critical to us.
Please help in this regard.
Thanks!
The certificate is validated by the client only when the server sends one. The server sends one with each full TLS handshake. The browser does not somehow cache an old certificate and ignore the one sent by the server when validating.
It is more likely that you've not fully rolled out the new certificate on the server side. For example if you have multiple servers make sure that all have the new certificate. If your server provides access for IPv4 and IPv6 make sure that in both cases the proper certificate is served. If you provide service on multiple ports make sure that they all use the new certificate.
It's also possible your affected users are behind a proxy that caches certificates. For example if they're behind a Smoothwall proxy that generates its own certificates after inspecting HTTPS traffic and caches them.
Either way, if you've updated the certificates on your server and restarted the necessary services, it's probably nothing you have control over and will most likely resolve itself in time.

Odd SSL certificate issue

So, I have a wildcard SSL cert from Go Daddy, and it has been installed on a few servers. However, on one particular server I cannot seem to get this thing done. Here's the process that has worked on all servers but this one:
1. Create CSR
2. Having gotten the certificate from the provider, I open the MMC certificates snap-in and import the intermediate cert to the intermediate authority store (or personal store, both have been tried). This is successful, in that I can view the certificate from the MMC
3. Go to the IIS server and under Server Certificates, I complete the CSR, point to the provided certificate and it imports into the web server successfully.
4. I go to an individual web site to assign the certificate to the web site under binding. When I select https and the IP address, the drop-down menu activates, but the certificate I just installed is not available for choosing.
5. I go back to the server Certificates, and the cert I just viewed is no longer there.
Go Daddy says to rekey, however, this makes no sense, since immediately prior to this, I installed that same wildcard cert to a different server, and it works fine. Obviously, this is something with IIS or Windows on this particular server.
Does anyone have any idea how to fix this without rekeying? Server platform is Windows 2008R2, IIS 7.5
If you have followed steps described in https://www.godaddy.com/help/iis-7-install-a-certificate-4801 then from your side it's done. And for more references, you can also check out this https://stackoverflow.com/a/43247419/7738413
Otherwise, rekeying is the last option.

Renew SSL certificates on huge number of machines

I'm using SSL certificates in a client-server application; both the client and the server are using 2 certificates that will expire soon. Normally, you'd just replace the certificates with new ones, but this cannot happen at once because of the huge numbers of clients.
So, if only the servers and a part of the clients are updated, the rest of the clients won't be able to authenticate anymore.
A quick fix is to replace the binaries with a version which simply disregards expiry date of the certificates; the update of the clients can be done sequentially, as long as it will finish before the certificates expire.
Long term solutions I thought about:
use Puppet to push new certificates on clients
unfortunately, not viable because not all clients are/will be managed via Puppet
use a second set of certificates
if first set has expired, use the second one
in this manner, server will have new certificates, a part of clients will have new certificates and the rest of the clients will have old certificates, but everything works
client requests a new certificate from the server, if the current one has expired.
Are there any other solutions?
I assume you use the SSL certificates for an online SSL connection, like HTTPS, or SFTP.
The big question is: Do you still trust and want to use your server-side key! If so you can just re-issue the server certificate with a new expiration date still using the old key and thus extending the lifetime. The question is, if you still trust the old key or if it should be replaced. Old clients may still connect to you at that point.. You are still using the same public / private key pair, just made a new 'lifetime version' of the certificate for it. (That is what most public servers do..)
Using two sets of active SSL certificates for different keys on the server side is not really viable and only possible if you have good control over the handshake process on the client side and your server application supports it. The issue is that during an SSL negotiation, the server has to send its certificate first and the only indication it might get from the client is a ServerName extension during the ClientHello. (Assuming the client actually sends one). Otherwise the server is 'at a loss' on what the other side will or will not support. (There are some other extensions that might help for in indicating supported CA certificates, but your clients should support those).
The first is the most practical for the clients that do support it. Just renew their certificates (and perhaps keys) and push them. And you are done with those.
For the others, updating the client software and making sure they generate a new key and request a new certificate from the server when they need it (or in advance) might be the best solution.

SSL certificate migration from one server to another

What's necessary to migrate valid SSL certificate from one server and service provider to another?
In some cases it may be simply a matter of copying the keys to and changing apache configuration on the new server.
For example:
http://www.digicert.com/ssl-support/apache-ssl-export.htm
Some certificate authorities may tie an SSL certificate to a specific server.
Essentially, you export SSL certificates from the server that they are currently installed on, move SSL certificates to the new server, and then import SSL certificates on the new server. But this only really only applies if you are sticking with the same certificate authority ("provider")... which it sounds by your question that you are not.
Keep in mind that even if you stick with the same provider, many require that you purchase a "server license" for each server that you install an SSL certificate to, even if it uses the same private key. And speaking of private keys, it is slightly less secure to copy the SSL certificate and use the same private key on a different server. If an attacker breaks into one server and gets the private key, he will be able to listen in on the connections that other servers are making.
So my advice to you since you want to switch providers is just purchase a new one all together with the new provider once you move to the new server... But maybe I'm misunderstanding your question.
First determine if the device installed with the certs are storing the private key in hardware/software. In most today's servers, they are in software *.key files (e.g. web server SSL).
To be found near the key files are the certificate and perhaps even CSR. Moving these files to another server is generally allowed (Considering the destination server will have the same hostname) and hence keeping the same CA. Most CAs have no concern to customers who does that.
But if you are just looking to switch the service provider from one to another, simply ask current CA to 'revoke' the cert. Then start with the new Cert buying process with the new CA.