[chef] restoring lost encrypted data bag item entries

likely due to not having a YAML engine config in my knife.rb on one of my
systems, i think i caused some contents to drop out of one of my encrypted
data bags.

missing in knife.rb: YAML::ENGINE.yamler = 'syck' if RUBY_VERSION > '1.9'

[ops:master chef-repo]$ knife data bag show secrets --secret-file 
~/.chef/encrypted_data_bag_secret -Fj db-item | grep X509
  "FOO_X509_PRIVATEKEY": "",
  "FOO_X509_SERVERCERT": "",


i do have the data bag item contents committed to git in encrypted form:

[ops:master chef-repo]$ grep FOO data_bags/secrets/db-item.json 
  "FOO_X509_SERVERCERT": "redacted\n",
  "FOO_X509_PRIVATEKEY": "redacted\n",

how could i use ~/.chef/encrypted_data_bag_secret to decrypt the contents of
the file in git to restore the full data bag contents to the chef server?
i suspect there's some openssl or gpg or library incantantion to do this.
i just don't know what.

if can get the decrypted contents into a json file, i'd then restore using:

knife data bag from file --secret-file ~/.chef/encrypted_data_bag_secret 
secrets decrypted.json

thanks!
kallen