Anonymizer extractor idea

[jochen]

@eduardohki

I would like to discuss the idea to add a new extractor type used to anonymize any string field/regex result into some SHA256, SHA512 or so.

Graylog already supports quite a few hash functions:

• http://docs.graylog.org/en/2.4/pages/pipelines/functions.html#crc32
• http://docs.graylog.org/en/2.4/pages/pipelines/functions.html#crc32c
• http://docs.graylog.org/en/2.4/pages/pipelines/functions.html#md5
• http://docs.graylog.org/en/2.4/pages/pipelines/functions.html#murmur3-32
• http://docs.graylog.org/en/2.4/pages/pipelines/functions.html#murmur3-128
• http://docs.graylog.org/en/2.4/pages/pipelines/functions.html#sha1
• http://docs.graylog.org/en/2.4/pages/pipelines/functions.html#sha256
• http://docs.graylog.org/en/2.4/pages/pipelines/functions.html#sha512