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# ansible-googleauth
This role is to install google authenticator and integrate it into ssh so that TOTP tokens may be required for ssh connections.
https://www.digitalocean.com/community/tutorials/how-to-set-up-multi-factor-authentication-for-ssh-on-ubuntu-16-04
It will create a `~/.google_authenticator` if required, and will NOT alter or remove any existing version.
It will update `/etc/ssh/sshd_config.d` and `/etc/pam.d/sshd` to ensure that a token is required for any ssh connection _without_ an ssh key. Connections _with_ an ssh key will not require a token, though this may be enabled so that tokens are *always* required. Set the global **google_auth_force** variable to _true_ or an individual host entry (see below) to enable this.
## Configuration
### Forcing use of Google Authenticator
Edit `defaults/main.yml` or override on cmdline to set `google_auth_force: true`. This will ensure that TOTP code entry is required regardless of use of SSH key for login. This creates a `/etc/ssh/sshd_config.d/71-google_auth.conf` and modifies `/etc/pam.d/sshd` to comment out the **@include common-auth** line.
### Allowing no-token logins when ~/.google_authenticator does not exist
Edit `defaults/main.yml` or override on cmdline to set `google_auth_nullok: true`. This sets adds **nullok** parameter on the `/etc/pamd./sshd` line for **auth required pam_google_authenticator.so nullok**
With this set users can still login with password only and no TOTP request if their `~/.google_authenticator` file does not exist. If not enabled (no **nullok** param) then users can NOT login until that `~/.google_authenticator` secret file is created.
### Pre-populating Google Authenticator secrets
To pre-populate the TOTP secret there are two locations to place the information.
* Place them into `defaults/main.yml` under the **google_auth_config** variable
* *Much* more preferably place them into an ansible-vault encrypted file under the **vault_google_auth_config** variable. Typically this might be in `group_vars/all/vault`
The format is as follows
| Variable | Description | Required ? |
| :--- | :--- | :--- |
| name: | The inventory_hostname for this block | Required |
| label: | Label for the otpauth: url for the QR code | Optional |
| issuer: | Issuer for the otpauth: url for the QR code | Optional |
| secret: | Standard `.google_authenticator` secret info | Required |
The Optional keys have default values in `defaults/main.yml`
```yaml
# 1st line of secret can be 16 or 26 chars
vault_google_auth_config:
- name: host1.example.com
label: "Mailsys%20{{ inventory_hostname_short }}:{{ username }}"
issuer: "Example%20Corp%20Mailsys"
secret: |
6DRWZ2AWOAFAQMSI
"RATE_LIMIT 3 30
" WINDOW_SIZE 3
" DISALLOW_REUSE
" TOTP_AUTH
36011504
52878834
36710801
23387673
16670568
- name: hosty.somewhere.com
secret: |
MVXECANUVTIQ2647HK3S35FM3A
" RATE_LIMIT 3 30 1734051365
" DISALLOW_REUSE 57801712
" TOTP_AUTH
17029728
27355189
27432004
50794981
18624382
```
NOTE: There must be at least 5x scratch codes for each secret
## Manually generating a google authenticator secret
For pre-populating the host secrets in the config, one can generate them via the command-line. For an Ubuntu system, ensure the following packages are installed :
* libpam-google-authenticator
* python3-qrcode
* qrencode
Generate an authenticator secret, placed in `/tmp/google.txt`
```bash
google-authenticator --time-based --disallow-reuse --label=Test1 --qr-mode=UTF8 --rate-limit=3 --rate-time=30 --secret=/tmp/google.txt --window-size=3 --force
```
The contents of the resulting `/tmp/google.txt` may be placed directly into the `vault_google_auth_config` variable for a specific host.
## Methods of installation
There are several methods of creating the `~/.google_authenticator` file
* Existing `~/.google_authenticator`, no pre-config
Any existing configuration will not be touched
* Existing `~/.google_authenticator`, pre-config in **vault_google_auth_config**
Any existing configuration will not be touched. You must manually remove any existing `~/.google_authenticator`
* No existing `~/.google_authenticator`, no pre-config
In this case a new secret key and scratch codes will be created
* No existing`~/.google_authenticator`, pre-config in **vault_google_auth_config**
If an entry in **vault_google_auth_config** exists it will be used, otherwise a new secret key will be created
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