Decrypt Ansible AWX or Tower Data

README.md

Let's say you're having a bad day and while trying to upgrade your AWX instance you instead unrecoverably brick it, and then you realize that you made a point of storing a very important SSH key in AWX and nowhere else. Why? REASONS.

What do I need?

1. The secret key from your AWX config file.
2. A dump of your postgres database in plaintext.
   • If you're lucky yours is still functional and you can just query it.
3. Gumption.

What do I do?

1. Find the data you want to rescue, in example_dump this is out of the main_credential table.
2. Check the definition of the table to find the primary key. In this case it is the id column, which is the first one.
3. Plug in the relevant values to decrypt.py.

It's not super clear it the field_name is always going to be the key in the dict or a column name, or under what circumstances the pk is omitted, but this is what worked for me.

decrypt.py

# This is lifted with very minor modification from the AWX source:
# https://github.com/ansible/awx/blob/bfea00f6dc6af0fb01057ce38e9d0337e6c589aa/awx/main/utils/encryption.py
import base64, hashlib, json
from cryptography.fernet import Fernet, InvalidToken
from cryptography.hazmat.backends import default_backend

class Fernet256(Fernet):
    '''Not techincally Fernet, but uses the base of the Fernet spec and uses AES-256-CBC
    instead of AES-128-CBC. All other functionality remain identical.
    '''
    def __init__(self, key, backend=None):
        if backend is None:
            backend = default_backend()

        key = base64.urlsafe_b64decode(key)
        if len(key) != 64:
            raise ValueError(
                "Fernet key must be 64 url-safe base64-encoded bytes."
            )

        self._signing_key = key[:32]
        self._encryption_key = key[32:]
        self._backend = backend

# this function has been modified to take the secret as a parameter, rather than config
def get_encryption_key(field_name, secret, pk=None):
    '''
    Generate key for encrypted password based on field name,
    ``settings.SECRET_KEY``, and instance pk (if available).
    :param pk: (optional) the primary key of the model object;
               can be omitted in situations where you're encrypting a setting
               that is not database-persistent (like a read-only setting)
    '''
    h = hashlib.sha512()
    h.update(secret)
    if pk is not None:
        h.update(str(pk))
    h.update(field_name)
    return base64.urlsafe_b64encode(h.digest())

def decrypt_value(encryption_key, value):
    raw_data = value[len('$encrypted$'):]
    # If the encrypted string contains a UTF8 marker, discard it
    utf8 = raw_data.startswith('UTF8$')
    if utf8:
        raw_data = raw_data[len('UTF8$'):]
    algo, b64data = raw_data.split('$', 1)
    if algo != 'AESCBC':
        raise ValueError('unsupported algorithm: %s' % algo)
    encrypted = base64.b64decode(b64data)
    f = Fernet256(encryption_key)
    value = f.decrypt(encrypted)
    # If the encrypted string contained a UTF8 marker, decode the data
    if utf8:
        value = value.decode('utf-8')
    return value

secret = 'hunter2'
data = json.loads('{"username": "foobar", "ssh_key_data": "$encrypted$UTF8$AESCBC$..."}');
index_name = 'ssh_key_data'
pk = 6
key = get_encryption_key(index_name secret, pk)
print decrypt_value(data[index_name], key)

example_dump

6       2018-01-02 03:04:05.678901+00   2018-01-02 03:04:05.678901+00           Ansible SSH     3       3       4       88      90      89      {"username": "foobar", "ssh_key_data": "$encrypted$UTF8$AESCBC$..."} 1

First of all: a thanks to wrossman for publishing this, saved my bacon today.

If anyone finds this in the future I've put an updated version of this script that fixes the typos that prevents the script from working here:
https://gist.github.com/oalmlov-lst/2bd058a450a896e0462f3db832748039