How to add subject alernative name to ssl certs?

Although this question was more specifically about IP addresses in Subject Alt. Names, the commands are similar (using DNS entries for a host name and IP entries for IP addresses).

To quote myself:

If you're using keytool, as of Java 7, keytool has an option to include a Subject Alternative Name (see the table in the documentation for -ext): you could use -ext san=dns:www.example.com or -ext san=ip:10.0.0.1

Note that you only need Java 7's keytool to use this command. Once you've prepared your keystore, it should work with previous versions of Java.

(The rest of this answer also mentions how to do this with OpenSSL, but it doesn't seem to be what you're using.)

Both IP and DNS can be specified with the keytool additional argument -ext SAN=dns:abc.com,ip:1.1.1.1

Example:

keytool -genkeypair -keystore <keystore> -dname "CN=test, OU=Unknown, O=Unknown, L=Unknown, ST=Unknown, C=Unknown" -keypass <keypwd> -storepass <storepass> -keyalg RSA -alias unknown -ext SAN=dns:test.abc.com,ip:1.1.1.1

When generating CSR is possible to specify -ext attribute again to have it inserted in the CSR

keytool -certreq -file test.csr -keystore test.jks -alias testAlias -ext SAN=dns:test.example.com

complete example here: How to create CSR with SANs using keytool