I have a root ca, A that issues an intermediate cert B that in turn issues a specific cert C
A -> B -> C
I start up a server which has these certs in it's p12 as the keychain
If I then have a java client which has all three certs in its trustStore it can access the cert over https successfully.
If cert C expires but I still have A & B in the trustStore, HTTPs is still successful.
If I remove A & C from the trustStore and just have B HTTPs is still successful.
My question is, if I only have A in the trustStore, the original Root CA, will HTTPs access still be successful?
Thanks,
Mark.
Yes. Just adding the root certificate to your client trust store suffice to create the HTTPs successful connection. During the handshake, the certificate is validated from bottom-up way. It means that your Intermediate certificate must be signed by the root CA, and your leaf certificate must be signed by your intermediate CA. As long as your root CA is valid and present in your client's trust store, the connection will be successful.
Related
Is there a way to use just keytool to diagnose if a certificate in a .cer file is trusted by clients running on that particular JVM without importing it?
I figure for a certificate to be trusted by a client it must:
A) be present in trusted certificate store, the default being the JAVA_HOME/jre/lib/security/cacert
B) be valid. Not expired, Not revoked, etc
C) Have all issuing certificates up the chain fulfill the same conditions.
How to check for A, B, and C with just the built in keytool and the .cer file?
I figure for A, maybe there is a way I can query the cert store for a particular cert fingerprint?
Note: by 'Java Clients' I mean any JVM SSL clients. e.g Java 11's java.net.http.HTTPClient or any clients that respects JSSE trusted stores.
I have a Java SSL server application and I am able to communicate with its client counterpart using a self-signed certificate and key pair. This is done on my development machine.
Now, the time has come to launch the application on a live server and I have obtained my SSL certificate from an authority (LE).
I can export the signed certificate and import it into a Bouncy Castle keystore for my Android client. However, one thing got me thinking. If the certificate expires it means I'd have to update the application each time. I do not want to do this and it feels like too much work.
I was reading this page and they mentioned (Section Keys for SSL, item number 3) that simply having the CA certificate is enough to establish a connection.
[Optionally] Export the public key certificate of your private key and
distribute it to the SSL parties that will interact with you. (see
section "Export public key certificate from a keystore") If you are
using a certificate from a Certificate Authority then it will be
enough for others to have only the certificate of the Certificate
Authority itself.
I wanted to know how secure this is and what implications are there (if any).
The idea is to avoid recompiling the client application each time the certificate is renewed.
Thanks.
From what I gather, only your client is authenticating your server and not the other way around. This is one way authentication since only one of the two parties is authenticating the other. I could be wrong and you might be doing mutual authentication, but we'll get to that. First let's just consider the simpler case.
In order for your client to authenticate your server, the server needs an SSL certificate with a private key which it seems like you have. This certificate was signed by a CA certificate, which was probably signed by a Root certificate. In order for your client to trust your server, it needs a list of CA certificates which the client trusts to sign an ssl certificate. This list of certificates is your trust store. Your trust store should have the root and the CA certificate for the trusted CA.
If your server's SSL certificate expires, you will need to get a new certificate for your server. If your new certificate was signed by the same CA which signed your old certificate, the client will continue to trust your server without any updates. However, if your new certificate was signed by a CA which is unknown to your client (i.e. the CA certificate is not in the trust store), you will need to update the client's trust store with the CA and root certificates of the new certificate.
This describes one way authentication. However if your application requires mutual authentication, in addition to your client authenticating your server, your server will also need to authenticate your client. The process is exactly the same but in reverse. The client will also need an ssl certificate and the server will also need a trust store with the Root/CA certificates which signed the client's certificate. The same rules apply as when the server authenticates the client. So, if the client's ssl certificate expires and the new certificate is not known to the server's trust store, the trust store must be updated with the new CA's certificate.
One way to get around having to manually update your trust store is to automatically get new trust stores with CAs you trust. This is what your browser does. However, you will still need to update your application if a new certificate is needed.
What I need: A secure TLS/SSL communication between a server an a client over a LAN Network. The authentication must be a one way-authentication :
What I have already done: I have created a server and a client which are able to communicate over a Wi-Fi network. I have implemented the SSL sockets but the authentication is missing ... so it won't work :)
Where I need help: I'm a beginner at TLS/SSL, and at network security as well.
Is a CA mandatory or can I "emulate" it ? (It gives the server its certificate, right ?)
Should the server create its own certificate or should I gave one (hardcoded)?
How the client can verify this certificate ?
A CA is not mandatory per se. The alternative to CA-signed certificate is a self-signed certificate, but unless a particular self-signed certificate is explicitly trusted by a client program, authentication (verification) of the peer will fail.
You should create or request a server certificate, and configure the server to use that certificate. The details of how to configure the certificate and other TLS settings depend on what server software or TLS library you are using.
Typically, a client has a collection of trusted root CA certificates. An end-entity certificate is signed either by a root CA, or an intermediate CA which is signed by some superior certificate, all the way up to a root. Servers present a certificate chain of end-entity certificates and any intermediate certificates, up to but (usually) not including a root certificate.
During verification, the client validates that there is a valid chain of signatures down from any of the root CAs it trusts. If so, and provided none of the certificate in the chain are expired or revoked, the server certificate will be accepted and the session will proceed.
Root certificates of public CAs are usually installed and trusted by default in most browsers and operating systems. But you needn't use a public CA; you can create private CA for signing certificates. If you do this, clients will need to be configured to trust its root certificate (details differ by software).
Whether you use a public or private CA, as long as the clients trust the root CA and you have configured the server to present the (chained) server certificate, everything should work!
I've a task to write a communicator with PKI. I think about implementation (in Java)of X.509 certificate - I mean SSL/TLS to allow for data/message confidentiality, and message authentication codes for message integrity. All about these I've read in some literature and it's all theoretical. I'm not sure if I think properly. Could anyone, who good understand idea of PKI, give me any advice (for example website where it's good explanation of implementation PKI)?
As ntoskrnl commented, this is hard to do exactly right, even by the experts.
Here is a basic high-level look at the PKI you will need for an SSL connection:
A CA root key and corresponding self-signed certificate.
An intermediate CA key and certificate signed by the CA root key (this
is optional).
A server identity key and certificate signed by either
the intermediate CA or the CA root.
A client identity key and certificate signed by some CA that the server trusts. For your
academic work, you may want this CA to be the same as the one you created. The client identity is only needed if you want to have 2-way (mutual) SSL, where the server authenticates the client.
A web service that is running on something like Tomcat that can be configured for SSL. On the server side, the identity would point to the server key certificate. For 2-way SSL, there would also be a list or keystore of trusted CA certs on the server. Unless a client's certificate was signed by one of those trusted CAs, the server would not allow the client to connect.
On the client side, you would also need a list or keystore of trusted CA certs, and the server's certificate would have to be signed by one of those CAs. The client ID key and certificate and trust keystore would be used by Java when establishing an SSL connection. If you search Stack Overflow, you should find plenty of Java SSL connection examples.
To create the PKI, OpenSSL is a good tool to use. Here is one helpful website:
https://pki-tutorial.readthedocs.org/en/latest/simple/index.html
For a key and its corresponding certificate, you first create a private key, then create a certificate signing request (CSR). The CSR is then signed by a CA key, and becomes a certificate. The certificate contains the public key that corresponds to the private key used to create the CSR.
For MAC, there's a Java example of HMAC here: HMAC-SHA1: How to do it properly in Java?
I'm trying to set up a test environment for our application that uses X.509 client authentication over HTTPS in Tomcat 6.0. The servlet code is expecting to get a certificate chain as an array of X509Certificate objects using the javax.servlet.request.X509Certificate of the servlet request. However, this array only contains a single item (the client certificate), where I'm expecting it to have two (the client certificate and the root CA certificate that signed it).
Here's what I've done so far:
Generate a self-signed CA certificate using openssl.
Import the CA certificate as a trusted root certificate into a newly create Java keystore.
Configure the Tomcat HTTPS connector to require client authentication using the keystore created in step 2 as the truststore:
clientAuth="true"
truststoreFile="<path_to_truststore>"
Generate a new client certificate using openssl and sign it with the CA certificate.
Start Tomcat.
Install the client certificate in Chrome and navigate to my server's homepage. Stepping through the code in debug, I can see that the array returned as the javax.servlet.request.X509Certificate attribute only has the client certificate.
I know that Tomcat is picking up the root CA certificate from the truststore because when I delete it from the truststore, I get an SSL connection error. It's just not making it into the servlet request like the documentation says it should. Am I missing any additional configuration here? Perhaps Tomcat (or Java or JSSE) is expecting some additional X509 V3 extensions or something?
Any help is appreciated!
EDIT
Looks like my setup is legit, and this falls into the category of unusual but expected behavior due to a simplified test environment. In an enterprise scenario it's unlikely that the root certificate authority is going to be directly signing client certificates for individual users. Clearly when this code was written and tested, there was at least one intermediate CA involved in the trust chain.
What your are seeing is what is expected: Chrome is not sending the CA.
During the TSL Handshake when authenticating the client, the server will send a list of acceptable CAs as part of its CertificateRequest Message (RFC), the browser will then present a Certificate signed by one of these CAs.
ADD
btw, a great way of debugging an SSL connection client side is to use the fantastic openssl tools
openssl s_client -connect ssl.server.com:443
or for SSLV3 only servers
openssl s_client -connect ssl.server.com:443 -ssl3
This will print (among other things) the list of acceptable CAs.
To debug the server side add this to the JVM command line -Djavax.net.debug=ssl
The identity keystore should contain the cert signed by the CA ; not the self-signed cert. The CA root should be in the truststore.
Also, what is the purpose of step 4 ?