Hash

Generate a hash of the text value using the Scrypt hash function under the hood. NULL values are kept.

Parameters

Name	Description	Default	Required	Supported DB types
column	The name of the column to be affected		Yes	text, varchar
salt	Hex encoded salt string. This value may be provided via environment variable GREENMASK_GLOBAL_SALT		Yes	text, varchar
function	Hash algorithm to anonymize data. Can be any of md5, sha1, sha256, sha512, sha3-224, sha3-254, sha3-384, sha3-512.	sha1	No	-
max_length	Indicates whether to truncate the hash tail and specifies at what length. Can be any integer number, where 0 means "no truncation".	0	No	-

Example: Generate hash from job title

The following example generates a hash from the jobtitle into sha1 and truncates the results after the 10th character.

We can set the salt via the environment variable GREENMASK_GLOBAL_SALT:

export GREENMASK_GLOBAL_SALT="12343567baaa"

Hash transformer example

- schema: "humanresources"
  name: "employee"
  transformers:
    - name: "Hash"
      params:
        column: "jobtitle"
        function: "sha1"
        max_length: 10

Expected result

| column name | original value                   | transformed |
|-------------|----------------------------------|-------------|
| jobtitle    | Research and Development Manager | 3a456da5c5  |