BouncyCastle supports reading GPG keys without passphrase since 1.62.
Handle this in JGit, too, and don't prompt for a passphrase unless
it's necessary.
Make two passes over the private key files, a first pass without
passphrase provider. If that succeeds it has managed to read a
matching key without passphrase. Otherwise, ask the user for
the passphrase and make a second pass over the key files.
BouncyCastle 1.65 still has no method to get the GPG "key grip" from
a given public key, so JGit still cannot determine the correct file
to read up front. (The file name is the key grip as 40 hex digits,
upper case, with extension ".key").
Bug: 548763
Change-Id: I448181276548c08716d913c7ba1b4bc64c62f952
Signed-off-by: Thomas Wolf <thomas.wolf@paranor.ch>
e3f7a06764