Java Keystore Files

Application server like Jetty, Glassfish or Tomcat need a keystore (.jks) in order to properly handling the certificates. These three simple steps will create a valid keystore file for your application server using the Let's Encrypt service. Have fun, be encrypted!

Step 1 - Create keys

Skip if you already have a cert

./letsencrypt-auto certonly --standalone -d DOMAIN.TLD -d DOMAIN_2.TLD --email EMAIL@EMAIL.TLD

Change to the directory (probably /etc/letsencrypt/live/DOMAIN.tld) where the certificates were created.

Step 2 - Create a PKCS12 file containing full chain and private key

openssl pkcs12 -export -in fullchain.pem -inkey privkey.pem -out pkcs.p12 -name NAME

Step 3 - Convert PKCS12 to Keystore

The STORE_PASS is the password which was entered in step 2) as a password for the pkcs12 file.

keytool -importkeystore -deststorepass PASSWORD_STORE -destkeypass PASSWORD_KEYPASS -destkeystore keystore.jks -srckeystore pkcs.p12 -srcstoretype PKCS12 -srcstorepass STORE_PASS -alias NAME

If you happen to get a java.io.IOException: failed to decrypt safe contents entry: javax.crypto.BadPaddingException: Given final block not properly padded, you have probably forgotten to enter the correct password from step 2.

The commands

sudo openssl pkcs12 -export -in OUTPUT_FILE_HERE.pem -inkey KEYFILE_HERE -out pkcs.p12 -name NAME_HERE

sudo keytool -importkeystore -deststorepass PASSWORD -destkeystore keystore.jks -srckeystore pkcs.p12 -srcstoretype PKCS12 -srcstorepass PASSWORD -alias ALIAS_HERE