RFR: 8354469: Keytool exposes the password in plain text when command is piped using | grep [v4]

[Weijun Wang]

> Add more description on password handling into the keytool man page. A link to the man page is now added to the keytool help screen.
> 
> When keytool output is redirected into a file or file, a warning is shown:
> 
> $ keytool -genkeypair | type
> 
> Warning: password will be echoed because output is redirected.
> Enter keystore password:  password
> Warning: password will be echoed because output is redirected.
> Re-enter new password:
> 
> 
> A new manual test is added.
> 
> Sorry we cannot suppress password echoing in this case at the moment because `System.console()` is not available.

Weijun Wang has updated the pull request incrementally with one additional commit since the last revision:

  no more wildcard imports

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/24805/files
  - new: https://git.openjdk.org/jdk/pull/24805/files/5e0ddfc1..8677312e

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24805&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24805&range=02-03

  Stats: 3 lines in 1 file changed: 1 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/24805.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24805/head:pull/24805

PR: https://git.openjdk.org/jdk/pull/24805