The goal is to have secret bits (passwords, private keys, and such) in your VCS repo but encrypted so that it is safe. On the puppet masters they sit on disk unencrypted but only readable by Puppet Master.

How does this work?

Private keys (and anything that is the entire file):

Files are kept in git/hg encrypted (foo.txt is stored as foo.txt.gpg).

After deploying an update to your Puppet Master, the master runs a script that decrypts them. The sit unencrypted on the master, which should already be locked down.

Passwords (and any short string): Passwords are kept in hieradata/blackbox.yaml.gpg, which is decrypted to become hieradata/blackbox.yaml. This data can be read by hiera. This file is encrypted/decrypted just like any other blackbox file.

Key management: The Puppet Masters have GPG keys with no passphrase so that they can decrypt the file unattended. That means having root access on a puppet master gives you the ability to find out all our secrets. That's ok because if you have root access to the puppet master, you own the world anyway.

The secret files are encrypted such that any one key on a list of keys can decrypt them. That is, when encrypting it is is "encrypted for multiple users". Each person that should have acecss to the secrets should have a key and be on the key list. There should also be a key for account that deploys new code to the Puppet master.

What does this look like to the typical sysadmin?

If you need to, start the GPG Agent:

eval $(gpg-agent --daemon)

Decrypt the file so it is editable:

bin/blackbox_edit_start.sh FILENAME

(You will need to enter your GPG passphrase.)

Edit FILENAME as you desire.

vim FILENAME

Re-encrypt the file:

bin/blackbox_edit_end.sh FILENAME

Commit the changes.

git commit -a
# or
hg commit

This content is released under the MIT License. See the LICENSE.txt file.

How to use the secrets with Puppet?

Small strings:

Small strings, such as passwords and API keys, are stored in a hiera yaml file. You can access them using the hiera() function.

Puppet example for a single password:

$the_password = hiera('module::test_password', 'fail')
file {'/tmp/debug-blackbox.txt':
    content => $the_password,
    owner   => 'root',
    group   => 'root',
    mode    => '0600',
}

Entire files:

Entire files, such as SSL certs and private keys, are treated just like files.

Puppet example for an encrypted file:

file { '/etc/my_little_secret.key':
    ensure  => 'file',
    owner   => 'root',
    group   => 'puppet',
    mode    => '0760',
    source  => "puppet:///modules/${module_name}/secret_file.key",
}

How to enroll a new file into the system?

If you need to, start the GPG Agent:

eval $(gpg-agent --daemon)

Add the file to the system:

bin/blackbox_register_new_file.sh path/to/file.name.key

How to indoctrinate a new user into the system?

keyrings/live/blackbox-admins.txt is a file that lists which users are able to decrypt files. (More pedantically, it is a list of the GnuPG key names that the file is encrypted for.)

To join the list of people that can edit the file requires three steps; You create a GPG key and add it to the key ring. Then, someone that already has access adds you to the system. Lastly, you should test your access.

Step 1: YOU create a GPG key pair on a secure machine and add to public keychain.

KEYNAME=$USER@$DOMAINNAME
# For example...
KEYNAME=myusername@example.com
gpg --gen-key

Pick defaults for encryption settings, 0 expiration. Pick a VERY GOOD passphrase.

When GPG is generating entropy, consider running this on the machine in another window:

dd if=/dev/sda of=/dev/null

Add your public key to the public key-ring.

gpg --export -a $KEYNAME >~/.gnupg/pubkey.txt
wc -l ~/.gnupg/pubkey.txt

The output of "wc" should be non-zero (usually it is 30 or more)

Add your keyname to the list of keys:

cd keyrings/live
gpg --homedir=. --import ~/.gnupg/pubkey.txt
cd ../..
blackbox_addadmin.sh $KEYNAME

Check all these updates into the VCS:

git add pubring.gpg trustdb.gpg blackbox-admins.txt
git commit -m"Adding my gpg key" pubring.gpg trustdb.gpg blackbox-admins.txt

or

hg commit -m"Adding my gpg key" pubring.gpg trustdb.gpg blackbox-admins.txt

Step 2: SOMEONE ELSE adds you to the system.

Ask someone that already has access to re-encrypt the data files. This gives you access. They simply decrypt and re-encrypt the data without making any changes:

gpg --import keyrings/live/pubring.gpg
bin/blackbox_update_all_files.sh

Push the re-encrypted files:

git push

or

hg push

Step 3: YOU test.

Make sure you can decrypt a file. (NOTE: It is a good idea to keep a dummy file in VCS just for new people to practice on.)

First Time Setup

Overview:

To add "blackbox" to a git repo, you'll need to do the following:

Create some directories
For each user, have them createa GPG key and add it to the key ring.
For any automated user (one that must be able to decrypt without a passphrase), create a GPG key and create a subkey with an empty passphrase.
Add

Create some directories

You'll want to include blackbox's binaries in your PATH:

export PATH=$PATH:/the/path/to/blackbox/bin

In the git repo you plan on using blackbox, add these two lines to .gitignore

pubring.gpg~
secring.gpg

Create this directory. It is where the pubkeys will be stored:

mkdir -p keyrings/live

And commit the change:

git add keyrings
git add .gitignore
git commit -m'Update .gitignore' .gitignore keyrings

For each user, have them create a GPG key and add it to the key ring.

Follow the instructions for "How to indoctrinate a new user into the system?". For the first user, you only have to do Step 1.

Once that is done, is a good idea to test the system by making sure a file can be added to the system (see "How to enroll a new file into the system?"), and a different user can decrypt the file.

Make a new file and register it:

rm -f foo.txt.gpg foo.txt
echo This is a test. >foo.txt
blackbox_register_new_file.sh foo.txt

Decrypt it:

blackbox_edit_start.sh foo.txt.gpg 
cat foo.txt
echo This is the new file contents. >foo.txt

Re-encrypt it:

blackbox_edit_end.sh foo.txt.gpg 
ls -l foo.txt*

Push these changes to the repo. Make sure another user can check out and change the contents of the file.

For any automated user create a key and subkey.

An automated user (a "role account") is one that that must be able to decrypt without a passphrase. In general you'll want to do this for the user that pulls the files from the repo to the master. This may be automated with Jenkins CI or other CI system.

GPG keys have to have a passphrase. However, passphrases are optional on subkeys. Therefore, we will create a key with a passphrase then create a subkey without a passphrase. Since the subkey is very powerful, it should be created on a very secure machine.

There's another catch. The role account probably can't check files into Git. It probably only has read-only access to the repo. That's a good security policy. This means that the role account can't be used to upload the subkey public bits into the repo.

Therefore, we will create the key/subkey on a secure machine as yourself. From there we can commit the public portions into the repo. Also from this account we will export the parts that the role account needs, copy them to where the role account can access them, and import them as the role account.

ProTip: If asked to generate entropy, consider running this on the same machine in another window:sudo dd if=/dev/sda of=/dev/null

For the rest of this doc, you'll need to make the following substittions:

ROLEUSER: svc_deployacct or whatever your role account's name is.
NEWMASTER: the machine this role account exists on.
SECUREHOST: The machine you use to create the keys.

NOTE: This should be more automated. Patches welcome.

On SECUREHOST, create thew puppet master's keys:

$ mkdir /tmp/NEWMASTER
$ cd /tmp/NEWMASTER
$ gpg --homedir . --gen-key
Your selection? 
   (1) RSA and RSA (default)
What keysize do you want? (2048) DEFAULT
Key is valid for? (0) DEFAULT

# Real name: Puppet CI Deploy Account
# Email address: svc_deployacct@hostname.domain.name

NOTE: Rather than a real email address, use the username@FQDN of the host the key will be used on. If you use this role account on many machines, each should have its own key. By using the FQDN of the host, you will be able to know which key is which. In this doc, we'll refer to username@FQDN as $KEYNAME

Save the passphrase somewhere safe!

ProTip: If asked to generate entropy, consider running this on the same machine in another window:sudo dd if=/dev/sda of=/dev/null

Create a sub-key that has no password:

$ gpg --homedir . --edit-key svc_deployacct
gpg> addkey
(enter passphrase)
  Please select what kind of key you want:
   (3) DSA (sign only)
   (4) RSA (sign only)
   (5) Elgamal (encrypt only)
   (6) RSA (encrypt only)
Your selection? 6
What keysize do you want? (2048) 
Key is valid for? (0) 
Command> key 2
(the new subkey has a "*" next to it)
Command> passwd
(enter the main key's passphrase)
(enter an empty passphrase for the subkey... confirm you want to do this)
Command> save

Now securely export this directory to NEWMASTER:

$ gpg --homedir . --export -a svc_sadeploy >/tmp/NEWMACHINE/pubkey.txt
$ tar cvf /tmp/keys.tar .
$ rsync -avP /tmp/keys.tar NEWMASTER:/tmp/.

On NEWMASTER, receive the new GnuPG config:

sudo -u svc_deployacct bash
mkdir -m 0700 -p ~/.gnupg
cd ~/.gnupg && tar xpvf /tmp/keys.tar

Back on SECUREHOST, add the new email address to keyrings/live/blackbox-admins.txt:

cd /path/to/the/repo
blackbox_addadmin.sh $KEYNAME

Verify that secring.gpg is a zero-length file. If it isn't, you have somehow added a private key to the keyring. Start over.

$ cd keyrings/live
$ ls -l secring.gpg

Commit the recent changes:

$ cd keyrings/live
git commit -m"Adding key for KEYNAME" pubring.gpg trustdb.gpg blackbox-admins.txt

Regenerate all encrypted files with the new key:

blackbox_update_all_files.sh
git status
git commit -m"updated encryption" -a
git push

On NEWMASTER, import the keys and decrypt the files:

sudo -u svc_sadeploy bash   # Become the role account.
gpg --import /etc/puppet/keyrings/live/pubring.gpg
export PATH=$PATH:/path/to/blackbox/bin
blackbox_postinstall.sh
sudo -u puppet cat /etc/puppet/hieradata/blackbox.yaml # or any encrypted file.

ProTip: If you get "gpg: decryption failed: No secret key" then you forgot to re-encrypt blackbox.yaml with the new key.

On SECUREHOST, securerly delete your files:

cd /tmp/NEWMASTER
# On machines with the "shred" command:
shred -u /tmp/keys.tar
find . -type f -print0 | xargs -0 shred -u
# All else:
rm -rf /tmp/NEWMASTER

Also shred any other temporary files you may have made.