Description of problem:

When using a back-tick exec call in unlang, the trailing CR or whitespace are not trimmed from the call. This leads to issues with attributes. In FreeRADIUS 2.x this does not occur.

Version-Release number of selected component (if applicable): 3.0.1

How reproducible: Easy (all the time when using a back-tick)

Steps to Reproduce:
1. Insert the following into the post-auth section:

update control {
    Tmp-String-1 := `/bin/date -u +%%FT%%TZ`
}

2. Run radiusd -X
3. Examine the debug output and look at the Tmp-String-1 attribute that's been set after an authentication occurs.

Actual results: 

This is the FR 3.0 debug output for this statement

(20)   update control {
(20) Executing: "/bin/date -u +%%FT%%TZ"
(20)    expand: "+%%FT%%TZ" -> '+%FT%TZ'
(20)  Program returned code (0): 2014-01-27T17:20:42Z
(20)             Tmp-String-1 := '2014-01-27T17:20:42Z\n'
(20)    } # update control = noop

See the trailing '\n', it shouldn't be there

Expected results:

FR 2.2.0 output (which is still correct)

        expand: +%%FT%%TZ -> +%FT%TZ
Exec-Program output: 2014-01-27T17:35:00Z
Exec-Program-Wait: plaintext: 2014-01-27T17:35:00Z
Exec-Program: returned: 0
+++[control] returns noop

Additional info:

As a workaround, add the below after the 'offending' update statement to strip the whitespace

if ("%{control:Tmp-String-1}" =~ /^(([^ ]+)([ ]*)([^ ]+))([ ]*)$/) {
    update control {
        Tmp-String-1 := "%{1}"
    }
}

There is a commit in Github for this:

https://github.com/FreeRADIUS/freeradius-server/commit/023974a2829f3f260c38f7a85b31aa929636abcf