Collect Forcepoint ONE CASB logs

Supported in:

Google secops SIEM

This document explains how to ingest Forcepoint ONE CASB (formerly Forcepoint/Bitglass CASB) logs to Google Security Operations using Google Cloud Storage V2.

Forcepoint ONE CASB is a cloud access security broker that provides visibility, compliance, and threat protection for cloud applications. It monitors and controls access to SaaS applications, enforces data loss prevention policies, and detects anomalous user behavior across sanctioned and unsanctioned cloud services.

For more information, see Forcepoint CASB documentation.

Before you begin

Ensure that you have the following prerequisites:

A Google SecOps instance
A GCP project with Cloud Storage API enabled
Permissions to create and manage GCS buckets
Permissions to manage IAM policies on GCS buckets
Permissions to create Cloud Run services, Pub/Sub topics, and Cloud Scheduler jobs
Privileged access to the Forcepoint ONE portal (administrator role)
Forcepoint ONE API credentials (API access token or OAuth client credentials)

Create Google Cloud Storage bucket

Go to the Google Cloud Console.
Select your project or create a new one.
In the navigation menu, go to Cloud Storage > Buckets.
Click Create bucket.

Provide the following configuration details:

Setting	Value
Name your bucket	Enter a globally unique name (for example, `forcepoint-casb-logs`)
Location type	Choose based on your needs (Region, Dual-region, Multi-region)
Location	Select the location (for example, `us-central1`)
Storage class	Standard (recommended for frequently accessed logs)
Access control	Uniform (recommended)
Protection tools	Optional: Enable object versioning or retention policy

Click Create.

Collect Forcepoint ONE CASB API credentials

Get API access token

Sign in to the Forcepoint ONE portal at https://portal.bitglass.com (or your regional portal URL) with an administrator account.
Go to Settings > API Integration.
Click Generate API Token (or Create New Token if generating for the first time).
Provide the following configuration details:
- Token Name: Enter a descriptive name (for example, SecOps-GCS-Integration).
- Permissions: Select Read access for the following scopes:
  - Access Logs: User activity and access events.
  - Admin Audit Logs: Administrative changes and configuration events.
  - DLP Incidents: Data loss prevention events.
  - Threat Protection Logs: Malware and threat detection events.
Click Generate.
Copy and save the following values securely:
- API Access Token: The generated token value.
- API Base URL: Your Forcepoint ONE API endpoint (for example, https://portal.bitglass.com/api).
Note: The API token is displayed only once. If lost, you must generate a new token.

Verify permissions

To verify the account has the required permissions:

Sign in to the Forcepoint ONE portal.
Go to Settings > Administrators.
Verify that your account has the Administrator or Security Administrator role.
If you cannot see the API Integration option, contact your Forcepoint ONE administrator to grant the required role.

Test API access

Test your credentials before proceeding with the integration:

API_TOKEN="<your-api-token>"
API_BASE="https://portal.bitglass.com"

# Test API access - retrieve recent access logs
curl -v -H "Authorization: Bearer ${API_TOKEN}" \
    -H "Accept: application/json" \
    "${API_BASE}/api/v1/logs/access?limit=1"

A successful response returns HTTP 200 with a JSON object containing log entries. If you receive HTTP 401, verify the API token. If you receive HTTP 403, verify account permissions.

Create service account for Cloud Run function

The Cloud Run function needs a service account with permissions to write to the GCS bucket and be invoked by Pub/Sub.

Create service account

In the GCP Console, go to IAM & Admin > Service Accounts.
Click Create Service Account.
Provide the following configuration details:
- Service account name: Enter forcepoint-casb-collector-sa
- Service account description: Enter Service account for Cloud Run function to collect Forcepoint ONE CASB logs
Click Create and Continue.
In the Grant this service account access to project section, add the following roles:
1. Click Select a role.
2. Search for and select Storage Object Admin.
3. Click + Add another role.
4. Search for and select Cloud Run Invoker.
5. Click + Add another role.
6. Search for and select Cloud Functions Invoker.
Click Continue.
Click Done.

These roles are required for:

Storage Object Admin: Write logs to the GCS bucket and manage state files.
Cloud Run Invoker: Allow Pub/Sub to invoke the function.
Cloud Functions Invoker: Allow function invocation.

Grant IAM permissions on GCS bucket

Grant the service account write permissions on the GCS bucket:

Go to Cloud Storage > Buckets.
Click on your bucket name (for example, forcepoint-casb-logs).
Go to the Permissions tab.
Click Grant access.
Provide the following configuration details:
- Add principals: Enter the service account email (for example, forcepoint-casb-collector-sa@PROJECT_ID.iam.gserviceaccount.com)
- Assign roles: Select Storage Object Admin
Click Save.

Create Pub/Sub topic

Create a Pub/Sub topic that Cloud Scheduler will publish to and the Cloud Run function will subscribe to.

In the GCP Console, go to Pub/Sub > Topics.
Click Create topic.
Provide the following configuration details:
- Topic ID: Enter forcepoint-casb-trigger
- Leave other settings as default
Click Create.

Create Cloud Run function to collect logs

The Cloud Run function will be triggered by Pub/Sub messages from Cloud Scheduler to fetch logs from the Forcepoint ONE CASB API and write them to GCS.

In the GCP Console, go to Cloud Run.
Click Create service.
Select Function (use an inline editor to create a function).
In the Configure section, provide the following configuration details:

Setting Value

Service name forcepoint-casb-collector

Region Select region matching your GCS bucket (for example, us-central1)

Runtime Select Python 3.12 or later
In the Trigger (optional) section:
1. Click + Add trigger.
2. Select Cloud Pub/Sub.
3. In Select a Cloud Pub/Sub topic, choose forcepoint-casb-trigger.
4. Click Save.
In the Authentication section:
1. Select Require authentication.
2. Check Identity and Access Management (IAM).
Note: Pub/Sub will automatically handle authentication when invoking the function.
Scroll down and expand Containers, Networking, Security.
Go to the Security tab:
- Service account: Select forcepoint-casb-collector-sa

Setting	Value
Service name	`forcepoint-casb-collector`
Region	Select region matching your GCS bucket (for example, `us-central1`)
Runtime	Select Python 3.12 or later

Go to the Containers tab:

Click Variables & Secrets.
Click + Add variable for each environment variable:

Variable Name	Example Value	Description
`GCS_BUCKET`	`forcepoint-casb-logs`	GCS bucket name
`GCS_PREFIX`	`forcepoint-casb`	Prefix for log files
`STATE_KEY`	`forcepoint-casb/state.json`	State file path
`API_BASE`	`https://portal.bitglass.com`	Forcepoint ONE API base URL
`API_TOKEN`	`your-api-token`	Forcepoint ONE API token
`MAX_RECORDS`	`5000`	Max records per run
`PAGE_SIZE`	`500`	Records per page
`LOOKBACK_HOURS`	`24`	Initial lookback period

In the Variables & Secrets section, scroll down to Requests:
- Request timeout: Enter 600 seconds (10 minutes)
Go to the Settings tab:
- In the Resources section:
  - Memory: Select 512 MiB or higher
  - CPU: Select 1
In the Revision scaling section:
- Minimum number of instances: Enter 0
- Maximum number of instances: Enter 100 (or adjust based on expected load)
Click Create.
Wait for the service to be created (1-2 minutes).
After the service is created, the inline code editor will open automatically.

Add function code

Enter main in the Entry point field.

In the inline code editor, create two files:

main.py:

import functions_framework
from google.cloud import storage
import json
import os
import urllib3
from datetime import datetime, timezone, timedelta
import time

# Initialize HTTP client with timeouts
http = urllib3.PoolManager(
    timeout=urllib3.Timeout(connect=5.0, read=30.0),
    retries=False,
)

# Initialize Storage client
storage_client = storage.Client()

# Environment variables
GCS_BUCKET = os.environ.get('GCS_BUCKET')
GCS_PREFIX = os.environ.get('GCS_PREFIX', 'forcepoint-casb')
STATE_KEY = os.environ.get('STATE_KEY', 'forcepoint-casb/state.json')
API_BASE = os.environ.get('API_BASE')
API_TOKEN = os.environ.get('API_TOKEN')
MAX_RECORDS = int(os.environ.get('MAX_RECORDS', '5000'))
PAGE_SIZE = int(os.environ.get('PAGE_SIZE', '500'))
LOOKBACK_HOURS = int(os.environ.get('LOOKBACK_HOURS', '24'))

def parse_datetime(value: str) -> datetime:
    """Parse ISO datetime string to datetime object."""
    if value.endswith("Z"):
        value = value[:-1] + "+00:00"
    return datetime.fromisoformat(value)

@functions_framework.cloud_event
def main(cloud_event):
    """
    Cloud Run function triggered by Pub/Sub to fetch Forcepoint ONE CASB logs
    and write to GCS.

    Args:
        cloud_event: CloudEvent object containing Pub/Sub message
    """

    if not all([GCS_BUCKET, API_BASE, API_TOKEN]):
        print('Error: Missing required environment variables')
        return

    try:
        # Get GCS bucket
        bucket = storage_client.bucket(GCS_BUCKET)

        # Load state
        state = load_state(bucket, STATE_KEY)

        # Determine time window
        now = datetime.now(timezone.utc)
        last_time = None

        if isinstance(state, dict) and state.get("last_event_time"):
            try:
                last_time = parse_datetime(state["last_event_time"])
                # Overlap by 2 minutes to catch any delayed events
                last_time = last_time - timedelta(minutes=2)
            except Exception as e:
                print(f"Warning: Could not parse last_event_time: {e}")

        if last_time is None:
            last_time = now - timedelta(hours=LOOKBACK_HOURS)

        print(f"Fetching logs from {last_time.isoformat()} to {now.isoformat()}")

        # Fetch logs
        records, newest_event_time = fetch_logs(
            api_base=API_BASE,
            api_token=API_TOKEN,
            start_time=last_time,
            end_time=now,
            page_size=PAGE_SIZE,
            max_records=MAX_RECORDS,
        )

        if not records:
            print("No new log records found.")
            save_state(bucket, STATE_KEY, now.isoformat())
            return

        # Write to GCS as NDJSON
        timestamp = now.strftime('%Y%m%d_%H%M%S')
        object_key = f"{GCS_PREFIX}/logs_{timestamp}.ndjson"
        blob = bucket.blob(object_key)

        ndjson = '\n'.join([json.dumps(record, ensure_ascii=False) for record in records]) + '\n'
        blob.upload_from_string(ndjson, content_type='application/x-ndjson')

        print(f"Wrote {len(records)} records to gs://{GCS_BUCKET}/{object_key}")

        # Update state with newest event time
        if newest_event_time:
            save_state(bucket, STATE_KEY, newest_event_time)
        else:
            save_state(bucket, STATE_KEY, now.isoformat())

        print(f"Successfully processed {len(records)} records")

    except Exception as e:
        print(f'Error processing logs: {str(e)}')
        raise

def load_state(bucket, key):
    """Load state from GCS."""
    try:
        blob = bucket.blob(key)
        if blob.exists():
            state_data = blob.download_as_text()
            return json.loads(state_data)
    except Exception as e:
        print(f"Warning: Could not load state: {e}")

    return {}

def save_state(bucket, key, last_event_time_iso: str):
    """Save the last event timestamp to GCS state file."""
    try:
        state = {'last_event_time': last_event_time_iso}
        blob = bucket.blob(key)
        blob.upload_from_string(
            json.dumps(state, indent=2),
            content_type='application/json'
        )
        print(f"Saved state: last_event_time={last_event_time_iso}")
    except Exception as e:
        print(f"Warning: Could not save state: {e}")

def fetch_logs(api_base: str, api_token: str, start_time: datetime, end_time: datetime, page_size: int, max_records: int):
    """
    Fetch logs from Forcepoint ONE CASB API with pagination and rate limiting.

    Args:
        api_base: Forcepoint ONE API base URL
        api_token: API access token
        start_time: Start time for log query
        end_time: End time for log query
        page_size: Number of records per page
        max_records: Maximum total records to fetch

    Returns:
        Tuple of (records list, newest_event_time ISO string)
    """
    base_url = api_base.rstrip('/')
    endpoint = f"{base_url}/api/v1/logs/access"

    headers = {
        'Authorization': f'Bearer {api_token}',
        'Accept': 'application/json',
        'Content-Type': 'application/json',
        'User-Agent': 'GoogleSecOps-ForcepointCASBCollector/1.0'
    }

    records = []
    newest_time = None
    page_num = 0
    backoff = 1.0
    start_index = 0

    start_iso = start_time.strftime('%Y-%m-%dT%H:%M:%SZ')
    end_iso = end_time.strftime('%Y-%m-%dT%H:%M:%SZ')

    while True:
        page_num += 1

        if len(records) >= max_records:
            print(f"Reached max_records limit ({max_records})")
            break

        current_limit = min(page_size, max_records - len(records))
        url = f"{endpoint}?startDate={start_iso}&endDate={end_iso}&offset={start_index}&limit={current_limit}"

        try:
            response = http.request('GET', url, headers=headers)

            # Handle rate limiting with exponential backoff
            if response.status == 429:
                retry_after = int(response.headers.get('Retry-After', str(int(backoff))))
                print(f"Rate limited (429). Retrying after {retry_after}s...")
                time.sleep(retry_after)
                backoff = min(backoff * 2, 30.0)
                continue

            backoff = 1.0

            if response.status != 200:
                print(f"HTTP Error: {response.status}")
                response_text = response.data.decode('utf-8')
                print(f"Response body: {response_text}")
                return [], None

            data = json.loads(response.data.decode('utf-8'))

            page_results = data.get('data', [])

            if not page_results:
                print(f"No more results (empty page)")
                break

            print(f"Page {page_num}: Retrieved {len(page_results)} events")
            records.extend(page_results)

            # Track newest event time
            for event in page_results:
                try:
                    event_time = event.get('timestamp') or event.get('created_at')
                    if event_time:
                        if newest_time is None or parse_datetime(event_time) > parse_datetime(newest_time):
                            newest_time = event_time
                except Exception as e:
                    print(f"Warning: Could not parse event time: {e}")

            # Check for more results
            if len(page_results) < current_limit:
                print(f"Reached last page (size={len(page_results)} < limit={current_limit})")
                break

            start_index += len(page_results)

        except Exception as e:
            print(f"Error fetching logs: {e}")
            return [], None

    print(f"Retrieved {len(records)} total records from {page_num} pages")
    return records, newest_time

requirements.txt:

functions-framework==3.*
google-cloud-storage==2.*
urllib3>=2.0.0

Click Deploy to save and deploy the function.
Wait for deployment to complete (2-3 minutes).

Note: The Pub/Sub trigger configuration automatically creates the necessary subscriptions and permissions.

Create Cloud Scheduler job

Cloud Scheduler will publish messages to the Pub/Sub topic at regular intervals, triggering the Cloud Run function.

In the GCP Console, go to Cloud Scheduler.
Click Create Job.

Provide the following configuration details:

Setting	Value
Name	`forcepoint-casb-collector-hourly`
Region	Select same region as Cloud Run function
Frequency	`0 * * * *` (every hour, on the hour)
Timezone	Select timezone (UTC recommended)
Target type	Pub/Sub
Topic	Select `forcepoint-casb-trigger`
Message body	`{}` (empty JSON object)

Click Create.

Schedule frequency options

Choose frequency based on log volume and latency requirements:

Frequency	Cron Expression	Use Case
Every 5 minutes	`/5 * * *`	High-volume, low-latency
Every 15 minutes	`/15 * * *`	Medium volume
Every hour	`0 * * * *`	Standard (recommended)
Every 6 hours	`0 /6 * *`	Low volume, batch processing
Daily	`0 0 * * *`	Historical data collection

Test the integration

In the Cloud Scheduler console, find your job (forcepoint-casb-collector-hourly).
Click Force run to trigger the job manually.
Wait a few seconds.
Go to Cloud Run > Services.
Click on forcepoint-casb-collector.
Click the Logs tab.

Verify the function executed successfully. Look for:

Fetching logs from YYYY-MM-DDTHH:MM:SS+00:00 to YYYY-MM-DDTHH:MM:SS+00:00
Page 1: Retrieved X events
Wrote X records to gs://forcepoint-casb-logs/forcepoint-casb/logs_YYYYMMDD_HHMMSS.ndjson
Successfully processed X records

Go to Cloud Storage > Buckets.
Click on your bucket name (forcepoint-casb-logs).
Navigate to the forcepoint-casb/ folder.
Verify that a new .ndjson file was created with the current timestamp.

If you see errors in the logs:

HTTP 401: Check the API token in environment variables.
HTTP 403: Verify the account has required permissions in the Forcepoint ONE portal.
HTTP 429: Rate limiting - the function will automatically retry with backoff.
Missing environment variables: Check all required variables are set.

Retrieve the Google SecOps service account

Google SecOps uses a unique service account to read data from your GCS bucket. You must grant this service account access to your bucket.

Get the service account email

Go to SIEM Settings > Feeds.
Click Add New Feed.
Click Configure a single feed.
In the Feed name field, enter a name for the feed (for example, Forcepoint CASB Logs).
Select Google Cloud Storage V2 as the Source type.
Select Forcepoint CASB as the Log type.
Click Get Service Account. A unique service account email will be displayed, for example:
```
chronicle-12345678@chronicle-gcp-prod.iam.gserviceaccount.com
```
Copy this email address for use in the next step.

Note: Each Google SecOps instance has a unique service account. Do not use service accounts from other documentation or examples.
Click Next.
Specify values for the following input parameters:
- Storage bucket URL: Enter the GCS bucket URI with the prefix path:
```
gs://forcepoint-casb-logs/forcepoint-casb/
```
  Note: Always include the trailing slash (/) at the end of the URI.
- Source deletion option: Select the deletion option according to your preference:
  - Never: Never deletes any files after transfers (recommended for testing).
  - Delete transferred files: Deletes files after successful transfer.
  - Delete transferred files and empty directories: Deletes files and empty directories after successful transfer.
  Note: If you select a deletion option, the service account must have Storage Object Admin role instead of Storage Object Viewer. Update IAM permissions accordingly.
- Maximum File Age: Include files modified in the last number of days (default is 180 days).
- Asset namespace: The asset namespace.
- Ingestion labels: The label to be applied to the events from this feed.
Click Next.
Review your new feed configuration in the Finalize screen, and then click Submit.

Grant IAM permissions to the Google SecOps service account

The Google SecOps service account needs Storage Object Viewer role on your GCS bucket.

Go to Cloud Storage > Buckets.
Click on your bucket name (forcepoint-casb-logs).
Go to the Permissions tab.
Click Grant access.
Provide the following configuration details:
- Add principals: Paste the Google SecOps service account email.
- Assign roles: Select Storage Object Viewer.
Click Save.

Note: If you plan to use the deletion option "Delete transferred files" or "Delete transferred files and empty directories," grant Storage Object Admin role instead of Storage Object Viewer.

UDM mapping table

Log Field	UDM Mapping	Logic
`extensions`	`extensions`	Renamed/mapped
`request`	`extensions.auth.auth_details`	Directly mapped
`intermediary`	`intermediary`	Merged
`smb_host`	`intermediary.hostname`	Directly mapped
`smb_uid`	`intermediary.user.userid`	Directly mapped
`metadata`	`metadata`	Renamed/mapped
`msg`	`metadata.description`	Directly mapped
`event_name`	`metadata.product_event_type`	Directly mapped
`event_type`	`metadata.product_event_type`	Directly mapped
`value`	`metadata.product_name`	Directly mapped
`product`	`metadata.vendor_name`	Directly mapped
`network`	`network`	Renamed/mapped
`requestClientApplication`	`network.http.user_agent`	Directly mapped
`principal`	`principal`	Renamed/mapped
`ahost`	`principal.hostname`	Directly mapped
`agt`	`principal.ip`	Merged
`atz`	`principal.location.country_or_region`	Directly mapped
`amac`	`principal.mac`	Merged
`sourceServiceName`	`principal.platform_version`	Directly mapped
`av_label`	`principal.resource.attribute.labels`	Merged
`aid`	`principal.resource.id`	Directly mapped
`at`	`principal.resource.name`	Directly mapped
`agentZoneURI`	`principal.url`	Directly mapped
`cs1`	`principal.user.email_addresses`	Merged
`suid`	`principal.user.userid`	Directly mapped
`security_result`	`security_result`	Merged
`action`	`security_result.action`	Merged
`msg`	`security_result.summary`	Directly mapped
`src_label`	`src`	Renamed/mapped
`target`	`target`	Renamed/mapped
`dvchost`	`target.hostname`	Directly mapped
`dvc`	`target.ip`	Merged
`deviceProcessName`	`target.resource.name`	Directly mapped
`deviceZoneURI`	`target.url`	Directly mapped
N/A	`extensions.auth.type`	Constant: `SSO`
N/A	`intermediary`	Constant: `intermediary`
N/A	`metadata.event_type`	Constant: `USER_RESOURCE_ACCESS`
N/A	`principal.ip`	Constant: `agt`
N/A	`principal.mac`	Constant: `amac`
N/A	`principal.platform`	Constant: `WINDOWS`
N/A	`principal.resource.attribute.labels`	Constant: `av_label`
N/A	`principal.user.email_addresses`	Constant: `cs1`
N/A	`security_result`	Constant: `security_result`
N/A	`security_result.action`	Constant: `action`
N/A	`target.ip`	Constant: `dvc`

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