How to Use Self-Signed Certificates for TLS

Self-signed certificates should not be used for production deployments. Self-signed certificates are created and stored in the keystore specified during the key-generation process, and should be replaced by a signed certificate. Using self-signed certificates requires generating and distributing the certificates and establishing explicit trust for the certificate.

However, using self-signed certificates lets you easily obtain certificates for TLS/SSL configuration and may be appropriate for non-production or test setups. See Manually Configuring TLS Encryption for Cloudera Manager for more information.

Replace paths, file names, aliases, and other examples in the commands below for your system.

Create the directory for the certificates:
```
mkdir -p /opt/cloudera/security/x509/ /opt/cloudera/security/jks/
```
Give Cloudera Manager access to the directory, set the correct permissions, and then change to the directory:
```
sudo chown -R cloudera-scm:cloudera-scm /opt/cloudera/security/jks
sudo umask 0700
cd /opt/cloudera/security/jks
```
Generate the key pair and self-signed certificate, storing everything in the keystore with the same password for keystore and storepass, as shown below. Use the FQDN of the current host for the CN to avoid raising a java.io.IOException: HTTPS hostname wrong exception. Replace values for OU, O, L, ST, and C with entries appropriate for your environment:
```
keytool -genkeypair -alias cmhost -keyalg RSA -keysize 2048 -dname "cn=cm01.example.com, ou=Department,
o=Company, l=City, st=State, c=US" -keypass password -keystore example.jks -storepass password
```
Copy the default Java truststore (cacerts) to the alternate system truststore (jssecacerts):
```
sudo cp $JAVA_HOME/jre/lib/security/cacerts $JAVA_HOME/jre/lib/security/jssecacerts
```

Export the certificate from the keystore (example.jks).

keytool -export -alias cmhost -keystore example.jks -rfc -file selfsigned.cer

Copy the self-signed certificate (selfsigned.cer) to the /opt/cloudera/security/x509/ directory.
```
cp selfsigned.cer /opt/cloudera/security/x509/cmhost.pem
```
Import the public key into the alternate system truststore (jssecacerts), so that any process that runs with Java on this machine will trust the key. The default password for the Java truststore is changeit. Do not use the password created for the keystore in step 2.
```
$ keytool -import -alias cmhost -file /opt/cloudera/security/jks/selfsigned.cer
-keystore $JAVA_HOME/jre/lib/security/jssecacerts -storepass changeit
```
important
Repeat this process on each host in the cluster.
Rename the keystore:
```
mv /opt/cloudera/security/jks/example.jks /opt/cloudera/security/jks/cmhost-keystore.jks
```
You can also delete the certificate because it was copied to the appropriate path in step 5.
```
rm /opt/cloudera/security/jks/selfsigned.cer
```

The self-signed certificate set up is complete.