[java] Trust Store vs Key Store - creating with keytool

I understand that the keystore would usually hold private/public keys and the trust store only public keys (and represents the list of trusted parties you intend to communicate with). Well, that's my first assumption, so if that's not correct, I probably haven't started very well...

I was interested though in understanding how / when you distinguish the stores when using keytool.

So, far I've created a keystore using

keytool -import -alias bob -file bob.crt -keystore keystore.ks

which creates my keystore.ks file. I answer yes to the question do I trust bob but it is unclear to me if this has created a keystore file or a truststore file? I can set up my application to use the file as either.

-Djavax.net.ssl.keyStore=keystore.ks -Djavax.net.ssl.keyStorePassword=x
-Djavax.net.ssl.trustStore=keystore.ks -Djavax.net.ssl.trustStorePassword=x

and with System.setProperty( "javax.net.debug", "ssl") set, I can see the certificate under trusted certifications (but not under the keystore section). The particular certificate I'm importing has only a public key and I intend to use it to send stuff over an SSL connection to Bob (but perhaps that's best left for another question!).

Any pointers or clarifications would be much appreciated. Is the output of keytool the same whatever you import and its just convention that says one is a keystore and the other a trust store? What's the relationship when using SSL etc?

This question is related to java ssl keytool jce

The answer is

There is no difference between keystore and truststore files. Both are files in the proprietary JKS file format. The distinction is in the use: To the best of my knowledge, Java will only use the store that is referenced by the -Djavax.net.ssl.trustStore system property to look for certificates to trust when creating SSL connections. Same for keys and -Djavax.net.ssl.keyStore. But in theory it's fine to use one and the same file for trust- and keystores.

These are the steps to create a Truststore in your local machine using Keytool. Steps to create truststore for a URL in your local machine.

1) Hit the url in the browser using chrome

2) Check for the "i" icon to the left of the url in the chrome and click it

3) Check for certificate option and click it and a Dialog box will open

4) check the "certificate path" tab for the number of certificates available to create the truststore

5) Go the "details" tab -> click"Copy to File" -> Give the path and the name for the certificate you want to create.

6) Check if it has parent certificates and follow the point "5".

7) After all the certificates are being create open Command Prompt and navigate to the path where you created the certificates.

8) provide the below Keytool command to add the certificates and create a truststore.

   keytool -import -alias abcdefg -file abcdefg.cer -keystore cacerts
        where "abcdefg" is the alias name and "abcdefg.cer" is the actual certificate name and "cacerts" is the truststore name

9) Provide the keytool command for all the certificates and add them to the trust store.

    keytool -list -v -keystore cacerts

To explain in common usecase/purpose or layman way:

TrustStore : As the name indicates, its normally used to store the certificates of trusted entities. A process can maintain a store of certificates of all its trusted parties which it trusts.

keyStore : Used to store the server keys (both public and private) along with signed cert.

During the SSL handshake,

  1. A client tries to access https://

  2. And thus, Server responds by providing a SSL certificate (which is stored in its keyStore)

  3. Now, the client receives the SSL certificate and verifies it via trustStore (i.e the client's trustStore already has pre-defined set of certificates which it trusts.). Its like : Can I trust this server ? Is this the same server whom I am trying to talk to ? No middle man attacks ?

  4. Once, the client verifies that it is talking to server which it trusts, then SSL communication can happen over a shared secret key.

Note : I am not talking here anything about client authentication on server side. If a server wants to do a client authentication too, then the server also maintains a trustStore to verify client. Then it becomes mutual TLS

In simplest terms :

Keystore is used to store your credential (server or client) while truststore is used to store others credential (Certificates from CA).

Keystore is needed when you are setting up server side on SSL, it is used to store server's identity certificate, which server will present to a client on the connection while trust store setup on client side must contain to make the connection work. If you browser to connect to any website over SSL it verifies certificate presented by server against its truststore.

keystore simply stores private keys, wheras truststore stores public keys. You will want to generate a java certificate for SSL communication. You can use a keygen command in windows, this will probably be the most easy solution.

Keystore is used by a server to store private keys, and Truststore is used by third party client to store public keys provided by server to access. I have done that in my production application. Below are the steps for generating java certificates for SSL communication:

  1. Generate a certificate using keygen command in windows:

keytool -genkey -keystore server.keystore -alias mycert -keyalg RSA -keysize 2048 -validity 3950

  1. Self certify the certificate:

keytool -selfcert -alias mycert -keystore server.keystore -validity 3950

  1. Export certificate to folder:

keytool -export -alias mycert -keystore server.keystore -rfc -file mycert.cer

  1. Import Certificate into client Truststore:

keytool -importcert -alias mycert -file mycert.cer -keystore truststore

Examples related to java

Under what circumstances can I call findViewById with an Options Menu / Action Bar item? How much should a function trust another function How to implement a simple scenario the OO way Two constructors How do I get some variable from another class in Java? this in equals method How to split a string in two and store it in a field How to do perspective fixing? String index out of range: 4 My eclipse won't open, i download the bundle pack it keeps saying error log

Examples related to ssl

Requests (Caused by SSLError("Can't connect to HTTPS URL because the SSL module is not available.") Error in PyCharm requesting website A fatal error occurred while creating a TLS client credential. The internal error state is 10013 curl: (35) error:1408F10B:SSL routines:ssl3_get_record:wrong version number How to install OpenSSL in windows 10? ssl.SSLError: tlsv1 alert protocol version Invalid self signed SSL cert - "Subject Alternative Name Missing" "SSL certificate verify failed" using pip to install packages ssl.SSLError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:749) Powershell Invoke-WebRequest Fails with SSL/TLS Secure Channel "ssl module in Python is not available" when installing package with pip3

Examples related to keytool

Keytool is not recognized as an internal or external command I have never set any passwords to my keystore and alias, so how are they created? Importing the private-key/public-certificate pair in the Java KeyStore keytool error bash: keytool: command not found How to add certificate chain to keystore? Change keystore password from no password to a non blank password How can I create keystore from an existing certificate (abc.crt) and abc.key files? Openssl is not recognized as an internal or external command How to properly import a selfsigned certificate into Java keystore that is available to all Java applications by default? Java Keytool error after importing certificate , "keytool error: java.io.FileNotFoundException & Access Denied"

Examples related to jce

How to create a secure random AES key in Java? Trust Store vs Key Store - creating with keytool Why java.security.NoSuchProviderException No such provider: BC? Hash String via SHA-256 in Java How to avoid installing "Unlimited Strength" JCE policy files when deploying an application?