RFR: 8313367: SunMSCAPI cannot read Local Computer certs w/o Windows elevation [v4]

[rebarbora-mckvak]

> This fixes the defect described at https://bugs.openjdk.org/browse/JDK-8313367
> 
> If the process does not have write permissions, the store is opened as read-only (instead of failing).
> 
> Please note that permissions to use a certificate in a local machine store must be granted - in a management console, select a certificate, right-click -> All tasks... -> Manage Private Keys... -> add Full control to user.

rebarbora-mckvak has updated the pull request incrementally with one additional commit since the last revision:

  8313367: signHash looks for a key in either user or machine store

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/16687/files
  - new: https://git.openjdk.org/jdk/pull/16687/files/7f5c04fe..ab60267b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16687&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16687&range=02-03

  Stats: 15 lines in 1 file changed: 4 ins; 8 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/16687.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16687/head:pull/16687

PR: https://git.openjdk.org/jdk/pull/16687