MB-38457: Support for pkey passphrases
MB-38457: Support for pkey passphrases

ns_server change: http://review.couchbase.org/c/ns_server/+/160907

Change-Id: I60ec76b279bcfe1f805026998b01a96edffd362c
Reviewed-on: http://review.couchbase.org/c/cbauth/+/160909
Well-Formed: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Artem Stemkovski <15a0730a27c69f62ab86f2b6c639fca202166c02@couchbase.com>
Tested-by: Timofey Barmin <f30bdb2be8598fcffd705a378b25da4842d6bd7b@couchbase.com>

couchbase/cbauth,couchbase/cbauth