Loading a Certificate from a Keystore

Question

I have a Base-64 encoded X.509 (.CER) certificate that is causing a NullPointerException on the below java code. The line causing it is PublicKey pubKey = pubCert.getPublicKey();

Is there a way to verify that myfile.keystore has the "xyz" certificate?

final FileInputStream keyFile = new FileInputStream(filePath
                    + "myfile.keystore");
final KeyStore keyStore = KeyStore.getInstance("JKS");
String storepass = "mypass";
keyStore.load(keyFile, storepass.toCharArray());
Certificate pubCert = keyStore.getCertificate("xyz");
PublicKey pubKey = pubCert.getPublicKey();

Answer 1

Try the keytool command that should be in your JRE or JDK bin directory, see output below:

@raspbmc:~$ /opt/jdk1.8.0/bin/keytool  -list -help
keytool -list [OPTION]...

Lists entries in a keystore

Options:

 -rfc                            output in RFC style
 -alias <alias>                  alias name of the entry to process
 -keystore <keystore>            keystore name
 -storepass <arg>                keystore password
 -storetype <storetype>          keystore type
 -providername <providername>    provider name
 -providerclass <providerclass>  provider class name
 -providerarg <arg>              provider argument
 -providerpath <pathlist>        provider classpath
 -v                              verbose output
 -protected                      password through protected mechanism

Use "keytool -help" for all available commands

Reference:

http://docs.oracle.com/javase/1.4.2/docs/tooldocs/windows/keytool.html