Anonymiser

A command line tool to read a sql backup (created with pg_dump) and anonymise it based on a strategy file

Installing

There are a few options:

1. The binary can be downloded from the releases page.
2. An asdf plugin is available at Multiverse-io/asdf-anonymiser.
3. This repository is a Nix flake and can be used as input to your own flakes.

Running

1. Ensure you have a strategy.json file (you can generate a blank one using anonymiser generate-strategies --db-url postgres://postgres:postgres@localhost/DB_NAME
2. Choose a category / transformer for the fields (details below)
3. Create a clear text backup with pg_dump -x --no-owner > clear_text_dump.sql
4. Run the anonymiser with anonymiser anonymise -i clear_text_dump.sql -o anonymised.sql -s strategy.json

For further command line options you can use --help

Development

If you have Nix installed you can run nix develop inside the repository to open a subshell with the requisite development tools made available to you. If you also have direnv installed you can run direnv allow to automatically open the subshell upon entering the repository directory.

Otherwise you just need to ensure a Rust toolchain is available, as provided by rustup for example.

Creating releases

1. Checkout the lastest main branch on your machine
2. Create a git tag with the new version number git tag v1.2.3
3. Push the tag git push origin v1.2.3
4. Wait for CircleCI to create a draft release
5. Review the draft release and publish

Data Categories

The following data categories are supported

• CommerciallySensitive - Client names, addresses, anything that we might want to obfuscate for commercial reasons
• General - Normal data, not sensitive
• PotentialPii - Pretty much anything free text! Shouldn't contain PII but we can't guarantee that a user hasn't put their bank details and mothers maiden name in
• Pii - Personally Identifiable Information (e.g. phone number, email, name etc)
• Security - Related to the security of the system (e.g password hashes, magic links etc)
• Unknown - Unclassified, If any fields have this anonymisation will fail until it is replaced with a valid type

Data transformation

Table data can be transformed in one of two ways,

1. Truncating the table To use this option the table should be defined in the strategy file with the truncate key set to true and the columns key set to an empty array. e.g.

 {
  "table_name": "public.trunctable_table",
  "description": "",
  "truncate": true,
  "columns": []
},

2. Transform the data in the table Transforming table data requires a list of all table columns with a transformer defined for each and every column. (Note that for non PII or sensitive data, you can use the Identity transformer to not transform the data.

• EmptyJson - Literally {}
• Error - Not set. If any fields have this anonymisation will fail until it is replaced with a valid transformer
• FakeBase16String - Random Base16 string
• FakeBase32String - Random Base32 string
• FakeCity - Random city from faker
• FakeCompanyName * - Random Company Name from faker
• FakeEmail * - Random email address from faker
• FakeEmailOrPhone * - Either a random phone number OR a random email depending on whether the existing data starts with a + and doesn't contain an @ symbol or not!
• FakeFirstName - Random first name from faker
• FakeFullAddress - Random address made up of segments from faker
• FakeFullName - Random first plus last name from faker
• FakeIPv4 - Random IPV4 address from faker
• FakeLastName - Random last name from faker
• FakeNationalIdentityNumber - Random National Insurance number from list of dummy numbers
• FakePhoneNumber - Random phone number (looks at existing numbers country code, supports GB + US)
• FakePostCode - Truncates postcode to the first 3 chars e.g. NW5
• FakeState - Random US state from faker
• FakeStreetAddress - Random building number + street name from faker
• FakeUsername * - Random username from faker
• FakeUUID - Random UUIDv4
• Fixed - Returns a fixed value (requires a value arg with the value to use)
• Identity - Does not transform the original value
• ObfuscateDay - Takes a date and sets the day to the first of the month e.g. 12-12-2000 becomes 01-12-2000
• Scramble - Replaces text with random alphanumeric characters of the same length. Preserves spaces so word count is unchanged

Some transformers support option args. e.g. Fixed

  {
    "data_category": "Pii",
    "description": "",
    "name": "naughty_field",
    "transformer": {
      "name": "Fixed",
      "args": {
        "value": "new-value"
      }
    }
  },

All instances of this field with be replaced with new-value

Transformers with a * support the arg unique which will append an incrementing number to the random data to guarantee no duplicates will occur e.g.

  {
    "data_category": "Pii",
    "description": "user email address",
    "name": "email",
    "transformer": {
      "name": "FakeEmail",
      "args": {
        "unique": "true"
      }
    }
  },