4.2.6. Fingerprint Provider

FastAPI microservice that retrieves and forges browser fingerprints from SQL Server, with Arkose BDA decryption and user agent transformation

Fingerprint Provider

Internal microservice that serves browser fingerprints from a centralized database. It retrieves stored fingerprint data and, for supported antibot vendors, transforms it to match a desired user agent before returning it. For agent-side usage (configuration and script integration), see the Fingerprint Provider guide.

How It Works

Receives a fingerprint request with filters (antibot vendor, website, collection date)
Queries the SQL Server database for a random matching fingerprint
If the vendor is Arkose, decrypts the BDA payload, updates the user agent and timestamp, re-encrypts it, and returns the forged fingerprint. The Arkose vendor is dealt with the (now deprecated) Github repo Unfuncaptcha-bda - many thanks !
Otherwise, returns the raw fingerprint data

API

`GET /get-fingerprint`

Request body (JSON):

Field	Type	Description
`antibot_vendor`	string	Antibot vendor name (e.g. `"arkose"`)
`website`	string	Target website identifier
`collection_date_day`	int \| null	Day component of the minimum collection date
`collection_date_month`	int \| null	Month component of the minimum collection date
`collection_date_year`	int \| null	Year component of the minimum collection date

The three date fields together form a single date (YYYY-MM-DD). Only fingerprints collected on or after this date will be returned — older fingerprints are excluded. The date is split into separate fields to avoid format ambiguity. Setting all three to null removes the date filter, returning fingerprints from any date. | additional_data | object | Vendor-specific data (e.g. {"desired_ua": "..."} for Arkose) |

Response: The transformed fingerprint payload (format depends on the vendor).

Environment Variables

Variable	Description
`SQL_SERVER_NAME`	SQL Server hostname
`SQL_SERVER_USER`	Database user
`SQL_SERVER_PASSWORD`	Database password
`SQL_SERVER_DB`	Database name

Project Structure

fingerprint-provider/
├── main.py            # FastAPI application and endpoint
├── config.py          # Environment variable loading and DB config
├── db.py              # Database connection, query building, and fetching
├── Dockerfile
├── requirements.txt
└── src/
    ├── crypto.py                  # AES-CBC encryption/decryption (BDA)
    ├── fingerprint.py             # ArkoseBrowserFingerprint class
    └── forge_arkose_fingerprint.py # Arkose fingerprint transformation logic

Running Locally

pip install -r requirements.txt
python main.py

The service starts on port 5005.

Docker

docker build -t fingerprint-provider .
docker run -p 5005:5005 \
  -e SQL_SERVER_NAME=... \
  -e SQL_SERVER_USER=... \
  -e SQL_SERVER_PASSWORD=... \
  -e SQL_SERVER_DB=... \
  fingerprint-provider