This is the correct way to do it. The certificate must be replaced because DSA certificates are no longer supported.
Please, don't use the workarounds further above (e.g. tampering with the "Minimum SSL/TLS version supported" flag in Chrome) because they don't really solve the problem and they will stop working in the future when such workarounds get disabled in the browsers.
So, to create a Virgo server certificate similar to the original one, but using an RSA algorithm, do this:
keytool -genkey -alias s2dmk -dname "CN=SpringSource dm Kernel, OU=dm Server Team, O=SpringSource" -keyalg RSA -keystore keystore -keypass changeit -storepass changeit
Then replace file [VIRGO_ROOT]/configuration/keystore with the file you generated above. If you wish, you may back up the original 'keystore' file before overwriting it with the new one.
If necessary, you can also modify the HTTPS connector in file [VIRGO_ROOT]/configuration/tomcat-server.xml. Replace attribute:
sslProtocol="TLS"
with
sslEnabledProtocols="TLSv1,TLSv1.1,TLSv1.2"
Also, replace the 'ciphers' attribute with:
ciphers="TLS_RSA_WITH_AES_128_CBC_SHA, TLS_RSA_WITH_AES_256_CBC_SHA"