i Rule for extracting specific value from http payload and using it for UIE persistence

Hi, the "X-3GPP-Intended-Identity" is a request header, isn't?

when HTTP_REQUEST {
    if { [HTTP::header exists "X-3GPP-Intended-Identity"] } {
        regexp {sip:(.+@\w*\.[\w|-]*\.[\w|-]*)} [HTTP::header value "X-3GPP-Intended-Identity"] dummy key 
        if { [info exists key] } {
            persist uie $key
        }
        unset -nocomplain dummy key
    }
}

or this (without costly regex):

when HTTP_REQUEST {
    if { [HTTP::header exists "X-3GPP-Intended-Identity"] } {
        set values [split [lindex [split [HTTP::header value "X-3GPP-Intended-Identity"] :] 1] .]
        set key [concat [lindex $values 0].[lindex $values 1].[lindex $values 2]]
        if { $key ne "" } {
            persist uie $key
        }
        unset values key
    }
}

I hope it helps.