mloda-anonymizer-binary

The license-gated binary behind mloda's anonymizer FeatureGroup: keyed HMAC-SHA256 pseudonyms of a utf8 column, as 64 lowercase hex characters. Nulls stay null. The binary sends no data anywhere.

Install

pip install "mloda-enterprise[anonymizer]"

This brings the FeatureGroup, this wheel and pyarrow.

Wheels exist for Linux x86_64 and aarch64 (manylinux2014), macOS x86_64 (10.12+) and arm64 (11.0+), and Windows x86_64, Python 3.10 or newer. There is no source distribution.

License

Every run needs a license entitling anonymizer_binary, read from the first of these that is set:

• MLODA_LICENSE_FILE: path to the license file
• MLODA_LICENSE_KEY: the license token itself

Without one the binary exits with a license error before reading any data. A license that names an unknown key id may need a newer release of this wheel.

Key

The pseudonymization key is 32 bytes, given as 64 hex characters in the environment variable that the FeatureGroup's pii_key_env option names. Keep it secret and stable: another key gives unrelated pseudonyms, so changing it re-tokenizes everything.

To get the same tokens as the anonymizer-rs tool for its master key file, use the key it derives (HKDF-SHA256, no salt, info anonymizer-rs-anon) from the file's raw bytes. Hex-encoding the master key file itself also passes the format check but gives tokens that never match.

import hashlib, hmac, pathlib

master = pathlib.Path("master.key").read_bytes()
assert len(master) >= 32, "the anonymizer-rs tool rejects master keys under 32 bytes"
prk = hmac.new(bytes(32), master, hashlib.sha256).digest()
print(hmac.new(prk, b"anonymizer-rs-anon\x01", hashlib.sha256).hexdigest())

A master key of 32 bytes 0x11 gives 14dd3905a43d3e02b42887fea94185e3881af0b62c8d5f6a7ccf470df9446477.