Forget your rewrite rules and try this :
rserver redirect HTTPS-REDIRECT
webhost-redirection https://www.abc.com 301
inservice
exit
serverfarm redirect HTTPS-REDIRECT-SF
rserver HTTPS-REDIRECT
inservice
exit
class-map type http loadbalance match-any HOST-CM
match http header Host header-value "www[.]abc[.]com"
exit
policy-map type loadbalance first-match HTTPS
class HOST-CM
serverfarm XXXX
class class-default
serverfarm HTTPS-REDIRECT-SF
exit
exit
Anyway SSL Offload is mandatory and your certificate's FQDN should be www.abc.com, if a user uses the IP address instead, the web browser will raise a warning popup. If using only HTTP, there is no problem.
