When I create an SSLServerSocket in Java 7 the server correctly uses my server certificate and key. The certificate was issued by a sub-ca of a ca. Therefore the complete chain from the root cert to the server cert has four certificates.
The complete chain is present in the keystore/truststore.
However when a client connects the server always sends only the server certificate itself.
This also applies to Java based web servers like Jetty.
Because most clients have only the root ca certificate installed and not the two sub-ca certificates this is a big problem.
How can I force Java to send the full certificate chain in the SSL/TLS handshake?
A key entry in a keystore isn't just for a single certificate, but for a certificate chain (see KeyStore.setKeyEntry, which takes a Certificate[] chain parameter).
If you want a specific chain to be used, it needs to be set up as a chain in the entry where you have the certificate and its private key. Whether the intermediate certificates are also in the same keystore, in different entries doesn't really matter.
This is a very similar problem to getting a client to send the full client-certificate chain. The same keystore configuration steps should also work from a server point of view, as described in this question.
Related
I am running the Java process (Microservice) and trustStore configured in the JVM parameter. If the Microservice needs to connect the external URL which required the cert to be imported in trustStore.
Example:
example.co.uk -> examplecouk as alias in trustStore
example.com -> examplecom as alias in trustStore
example.in -> examplein as alias in trustStore
How does Java know that which certs and alias to be picked from the trustStore for the particular endpoint as I don't pass/mention the alias in the JVM params? Is it pick randomly?
user207421 is nearly correct. To be more exact:
When you as client open an SSL/TLS connection to a server, as part of the handshake the server sends its certificate 'chain' containing its own cert, plus usually one or more linked CA (Certificate Authority) certificates ending with a 'root' CA that should be trusted. See the neighboring Stack https://security.stackexchange.com/questions/20803/how-does-ssl-work/ for an epically complete explanation. Public servers normally use a cert issued and signed by a public CA like Digicert, GoDaddy, LetsEncrypt/ISRG which are already in the standard default truststore (for Java in the file JRE/lib/security/cacerts) so no action is needed. If a server uses a cert from a off-brand or private CA, or a self-signed cert (from no CA at all), then (for Java) some cert in the chain must be added to the client truststore, or otherwise overridden; this is only required to be the server cert in the case where the server cert is self-signed (which is a chain by itself and has no relevant CA certs).
Java/JSSE implements this through an SSLContext which contains among other things a TrustManager, more specifically an X509ExtendedTrustManager, which is initialized from a truststore. You can create an SSLContext explicitly in code from any set of trusted certs (which doesn't even need to be from a file), or use the default context which uses the default truststore file, which defaults to the filename above unless overridden by a system property.
When the server cert chain is received it is passed to the context's TrustManager for validation; among (many!) other checks, at each level of a normal chain, or the single level of a self-signed cert, the JSSE TrustManager looks for an anchor cert with the same Subject and (Subject)PublicKey and if so uses it to validate the cert chain. Note that a normal (CA-issued) leaf cert can have Subject empty if Subject Alternative Name is used instead -- see rfc5280 and rfc2818 -- but a self-signed cert cannot, because it has Subject = Issuer and Issuer must not be empty. Certs for different entities (e.g. different servers) normally are expected to have different keys, although a single entity can have multiple certs with either the same key or different keys, and might correspond to multiple server names and/or addresses.
If the certificate is determined valid in general, for some TLS applications, notably HTTPS, the validator also checks it is for the correct server, specifically that the CommonName attribute in the Subject field, or an entry in the Subject Alternative Name extension if present -- which for public CAs for at least a decade it is, matches the host DNS name or IP adddress in the URL. In older versions of Java (through 6 IIRC) this was not done in JSSE but rather in the calling application(s) or library, such as HttpsURLConnection, which as a legacy still has the option to use its own HostnameVerifier instead.
All of this can be altered by using a custom TrustManager in place of the standard one, and some things like Apache HttpClient do so validly, but you will find (too many) answers here and some other Stacks recommending you 'solve' TLS errors by using a neutered TrustManager that just accepts any cert, regardless of whether it is actually valid and correct, and thus happily connects and sends sensitive data to, or accepts changes from, any attacker who manages to intercept the IP traffic, which is often pretty easy nowadays.
Alias is a way to directly access the certificate but your keystore has other information regarding the certificate as well. X.509 certificates have a field called SAN (Subject Alternative name) which contains the DNS information of the certificate. When you try to connect to a specific URL, the keystore is looked up for the corresponding DNS name in SAN and correct certificate is picked up.
I hope it clarifies your doubt about java not asking for the alias. Rest assured, there is nothing random in this process.
I want to setup mutual authentication on Tomcat 8.
I have done the setup of keys primarily keystore and truststore and the setup is working with Firefox tested.
When accessing the URL I am prompted for certificate and when appropriate certificate is provided I am allowed the access.
The piece of puzzle I am missing is, the truststore that I have which has CA cert and public keys of few clients. This CA should be a self signed CA, not from known authorities on the web, as.
I just do not want anybody to have access, people using my CA only should be able to access. Assuming say abc.com has certificate signed by authority godady or verisign, which are well known and trusted should not be able to call. I want strict access.
In my truststore I just want to keep CA no public keys, I do not want to keep adding certs as clients grow up. Clients would use my CA.
I think my self signed CA in truststore and clients using my CA only in chain for their certificates should be good enough for secure(only clients with my CA) scalable solution, where I do not have to keep adding clients in truststore.
Please advice my assumptions are correct for a production cloud based system.
Thanks for the time.
Yes, your assumption are correct. During SSL handshake server will ask client to provide any certificate issued by CA present in server trust-store. Also you need to consider that client trust-store should have issuing CA of server certificate otherwise it will show untrusted server certificate on client/browser.
I am writing a micro service which talks to another service through HTTPS. In java client implementation, reading root certificate from truststore and then validate incoming certificate through that.
Now, my question is - by default only 2nd level certificate will be validated using root Cert or all chained certificates in turn will also get validated?
I am Using okhttp; and my assumption is that all Java clients should behave in same way, please let me know if there is any subjectivity here? Thanks.
If you include the root certificate in the truststore, the entire chain will be validated
The SSL server during handshake sends to client the certification chain from leaf certificate to root. The root certificate may be included but usually it is not
The default Trust Manager of a Java client will validate the provided certification chain looking in the truststore until it find the issuer of the certificate or the certificate itself
I'm having an issue sending our certificate (client) to another server during a web service call.
We're expected to return the certificate with the CN:
b2b-test
however whenever we receive the servers certificate and attempt to send our own, we're getting:
Unable to find valid certificate path to requested target
From my understanding, if I put our certificate b2b-test inside of our keystore jre/lib/security/cacerts, then when receiving the server request, it should send the appropriate certificate.
How does the client know which key from the keystore it should send to the server? Should I be specifying the exact certificate to send during my request, or is it enough for it to be in the keystore?
Currently the server is sending back the certificate
b2b-a
The certificate chain shows:
*** Certificate chain
chain [0] = [
[
Version: V3
Subject: CN=b2b-a, OU=Web Technologies
The URL for the service is:
https://b2b-a/service
If I configure it like one way ssl, and put the servers certificate into our cacerts, then it picks up their cert and fails the handshake (I'm assuming because it's expecting our cert and not theirs back due to it being a two way setup).
I'm a little stumped here. Any clarification on what I've said is greatly appreciated.
The "Unable to find valid certificate path to requested target" error usually occurs when one side passes a certificate for which the other side doesn't trust any of the certs in the chain. You'll generally (always?) see the error message on the side that's receiving the cert (the side that's missing the truststore).
If you're the client and they're the server, one-way SSL would send their cert from them to you and you would validate it (making sure that the hostname matches the content in the cert), but it would not send any cert from you to them nor would they do any validation.
You'll want to make sure you're configuring a truststore that contains either the b2b-a certificate or a certificate that was used to sign it (but that cert doesn't appear to have any root CAs, so you're stuck with directly importing the cert itself). So yes, you want to do what you wrote in your post and put their certificate into your cacerts. And you'll also need to make sure that the b2b-a service trusts the cert you're sending (or a root CA that was used to sign your cert, if any), so you'll need to put your cert into their cacerts as well, or do something equivalent.
Note that putting a cert in cacerts (or in a truststore JKS) DOES NOT send any certs to anyone; any truststore is used only to allow you to validate that you trust the certificate someone else provides you, either because you trust the cert or because you trust a CA cert that was used to sign the cert. No certs are picked out of the cacerts directory to send to another machine.
If you're using a JKS rather than the JRE directory (which is generally a better idea, since you can specify a different set of trusted certs for your process without changing the default set for anyone running a Java project within your JRE), it's possible to use the same JKS as both a keystore and a truststore (you'll just provide the same filename and password for both the keystore and the truststore properties), or you can have two separate files; either approach will work.
From my understanding, if I put our certificate b2b-test inside of our keystore jre/lib/security/cacerts, then when receiving the server request, it should send the appropriate certificate.
Certainly not. That's a truststore. A source of trusted certificates. Don't mess with it. It isn't used for the purpose you require and in any case it is updated every Java dot release, which clobbers your changes.
Your own certificate and private/public key pair should go in a file of your own, a keystore, which is defined to JSSE by the javax.net.ssl.keyStore and javax.net.ssl.keyStorePassword system properties, or by more complex means described in the JSSE Reference Guide.
The keystore is a precious and confidential file containing your private key. Guard and protect it. Private key leakage would compromise your security and identity.
When I create an SSLServerSocket in Java 7 the server correctly uses my server certificate and key. The certificate was issued by a sub-ca of a ca. Therefore the complete chain from the root cert to the server cert has four certificates.
The complete chain is present in the keystore/truststore.
However when a client connects the server always sends only the server certificate itself.
This also applies to Java based web servers like Jetty.
Because most clients have only the root ca certificate installed and not the two sub-ca certificates this is a big problem.
How can I force Java to send the full certificate chain in the SSL/TLS handshake?
A key entry in a keystore isn't just for a single certificate, but for a certificate chain (see KeyStore.setKeyEntry, which takes a Certificate[] chain parameter).
If you want a specific chain to be used, it needs to be set up as a chain in the entry where you have the certificate and its private key. Whether the intermediate certificates are also in the same keystore, in different entries doesn't really matter.
This is a very similar problem to getting a client to send the full client-certificate chain. The same keystore configuration steps should also work from a server point of view, as described in this question.