Introducing Amigo, a tool to manage Google Cloud Platform Security

cyberpunk

I wrote a tool called Amigo that uses the GCP API to fetch an organization's project data and, with a set of customizable rules, searches for security risks!

How Amigo Works

i) Amigo retrieves the GCP project list and their attributes (defined in a config.yaml file).

ii) For each attribute in a project, Amigo creates an updated report.

iii) Amigo checks the previous report for differences (verifying when the data was modified). If there is a diff, Amigo logs the report for this diff.

iv) Amigo saves the resources data in a database and then it checks the custom rules specified in rules.yaml, reporting everything that violates those rules.

v) The science generated by Amigo can be fed into ELK.

Setting up and Running Amigo

Setting a Virtual Environment

$ make venv
$ source venv/bin/activate

Installing Amigo

$ make install

Creating a Service Account

This should be done once, for the first time you run Amigo:

  1. Create a project and a service account at https://console.cloud.google.com/iam-admin/serviceaccounts.

  2. Add the IAM roles Security Reviewer and Viewer permissions to the service account.

  3. Download the Service Account JSON credential file to a safe directory (e.g. your home directory). If amigo runs in other machines (or other people in the same organization is running Amigo), this key can be shared (and step 1. and 2. do not need to be repeated).

Setting gcloud

Install gcloud SDK and authenticate with:

$ gcloud auth application-default login

You can also check whether env variable GOOGLE_APPLICATION_CREDENTIALS is pointing to the Service Account JSON credential file.

Setting the Config file

Copy config.yaml_example to config.yaml and customize it.

In the bottom of this file you are able to edit the attributes that you want to report on:

### Attributes to inspect
gcp_attributes:
    compute:
        - firewalls
        - networks
        - snapshots

Setting the Rules file

Inspect rules.yaml either removing or adding rules that should be searched in the reports.

Running Amigo

Run amigo with:

$ sudo amigo

This retrieves the data from GCP and generates JSON reports. These reports will be saved where is reports_dir in the config file.

It is advised to watch for STERR and STDOUT in the log_file file defined in config.yaml (default to amigo_log.txt):

$ tail -f amigo_log.txt

Alerting with Amigo

Relevant reports (e.g. diff reports) are generated inside the directory defined as results_dir, in the file results.log (e.g. /log/amigo.log). This is a JSON file that can be fed to ELK.


Creating Custom rules

Firewalls Resource

Firewall reports have this format:

{
  "kind": "compute#firewall",
  "network": "https://www.googleapis.com/compute/v1/projects/<name>/global/networks/default",
  "direction": "INGRESS",
  "sourceRanges": [
    "0.0.0.0/0"
  ],
  "name": "default-allow-icmp",
  "priority": 65534,
  "allowed": [
    {
      "IPProtocol": "icmp"
    }
  ],
  "creationTimestamp": <Time stamp>,
  "id": <ID>,
  "selfLink": "https://www.googleapis.com/compute/v1/projects/<name>/global/firewalls/default-allow-icmp",
  "description": "Allow ICMP from anywhere"
}

Networks Resource

Snapshot reports have this format:

{
  "kind": "compute#network",
  "description": "Default network for the project",
  "subnetworks": [
    "https://www.googleapis.com/compute/v1/projects/<name>/regions/<region>/subnetworks/default",
  ],
  "autoCreateSubnetworks": true,
  "routingConfig": {
    "routingMode": "REGIONAL"
  },
  "creationTimestamp": <Time stamp>,
  "id": <ID>,
  "selfLink": "https://www.googleapis.com/compute/v1/projects/<name>/global/networks/default",
  "name": "default"
}

Snapshots Resource

Snapshot reports have this format:

{
  "status": "READY",
  "kind": "compute#snapshot",
  "storageBytes": <number>,
  "name": <name>,
  "sourceDisk": "https://www.googleapis.com/compute/v1/projects/<name>/zones/us-central1-c/disks/deployhost",
  "storageBytesStatus": "UP_TO_DATE",
  "labelFingerprint": <code>,
  "sourceDiskId": <ID>,
  "diskSizeGb": <size>,
  "licenses": [
    "https://www.googleapis.com/compute/v1/projects/centos-cloud/global/licenses/centos-7"
  ],
  "creationTimestamp": <time stamp>,
  "id": <ID>,
  "selfLink": "https://www.googleapis.com/compute/v1/projects/<name>/global/snapshots/snapshot-1-deployhost"
}

Instance Template Resource

Instance Template reports have this format:

{
  "kind": "compute#instanceTemplate",
  "description": "",
  "properties": {
    "machineType": <type>,
    "tags": {
      "items": [
        <items>
      ]
    },
    "disks": [
      {
        "deviceName": "persistent-disk-0",
        "kind": "compute#attachedDisk",
        "initializeParams": {
          "sourceImage": "global/images/<name>",
          "diskType": "pd-standard"
        },
        "autoDelete": true,
        "index": 0,
        "boot": true,
        "mode": "READ_WRITE",
        "interface": "SCSI",
        "type": "PERSISTENT"
      }
    ],
    "scheduling": {
      "automaticRestart": true,
      "preemptible": false,
      "onHostMaintenance": "MIGRATE"
    },
    "serviceAccounts": [
      {
        "scopes": [
          "https://www.googleapis.com/auth/compute.readonly"
        ],
        "email": <service-account-email>
      }
    ],
    "metadata": {
      "items": [
        <metadata>
      "kind": "compute#metadata",
    }
  },
  "creationTimestamp": "2017-11-14T12:24:00.744-08:00",
  "id": <ID>
  "selfLink": "https://www.googleapis.com/compute/v1/projects/<project-name>/global/instanceTemplates/",
  "name": <name>
}

Aloha, bt3