JAVA: how to obtain keystore file for a certification (crt) file

Question

HI All,

I have a .crt file and I need to get the associated keystore file. How to do so?

Is keytool is helpful in that?

Thanks.

Tybi

Answer 1

In JDK8 or higher:

Command below creates empty store and imports your certificate into the keystore:

keytool -import -alias alias -file cert_file.crt -keypass keypass -keystore yourkeystore.jks -storepass Hello1

In JDK7:

Older versions of JDK7 create non-empty keystore which then needs to be cleared. Below is how you do that.

Create store with temporary key inside:

keytool -genkey -alias temp -keystore yourkeystore.jks -storepass Hello1

Then delete existing entry:

keytool -delete -alias temp -keystore yourkeystore.jks -storepass Hello1 

Now you've got empty store. You can check that it's empty:

keytool -list -keystore yourkeystore.jks -storepass Hello1

Then import your certificate to the store:

keytool -import -alias alias -file cert_file.crt -keypass keypass -keystore yourkeystore.jks -storepass Hello1

And off you go!

Appall

why are trying to make it empty? I have keystore already which is not empty, will it make a difference to add another certificate rather than emptying it?? – Sewel

@Appall Hi, I find that you generate a .jks file. Is it possible to generate .keystore file? – Fireworm

@Fireworm .jks and .keystore are essentially same thing, you can rename to .keystore if you want. – Appall

Actually, you do not need to create an empty keystore first. If you use the last command only, it will create a keystore with just one trust entry for the imported certificate, given that the keystore does not yet exist. – Trapani

Well, keytool has been changed in one of 1.7.0_1xx updates. So if you have one of those older versions of jdk7, you need all 4 commands. In jdk8 or higher you only need last line, agree. – Appall

@Appall -keypass keyword is used for what purpose? – Lockwood

Answer 2

Yes, for eg.
keytool -genkey -alias duke -keypass dukekeypasswd from (http://download.oracle.com/javase/1.4.2/docs/tooldocs/windows/keytool.html)

Sirloin