Filename: ExtraRelayDescriptorFields.txt Title: Adding new X- fields to relay descriptor Author: Virgil Griffith, Nick Mathewson Created: 2014-06-03 Status: Open
1. Motivation We wish to allow developers to build new applications atop relays. Towards this end, we wish to add the ability for users to specify arbitrary new key-value entries under the "X-" namespace.
2. Proposal Allow optional key-value lines in the relay's torrc file. These lines will be mirrored in the relay's descriptor which is then published in the directory consensus.
For example: X-bitcoin 19mP9FKrXqL46Si58pHdhGKow88SUPy1V8 X-gravatar https://s.gravatar.com/avatar/d27fce46c9ac41a41bb52455ae75701d X-favoritequote Be excellent to each other. Party on dudes! X-foo bar
The value field must be printable ASCII (characters 32-126). The value must not under any condition contain a newline. The key may contain lowercase ASCII letters (a-z), digits, underscore, or dash. In regex, [-_0-9a-z].
There may need to be a maximum sum length of the X- entries. This is left to the developers. I propose a maximum sum length of 5 kilobytes.
To mitigate the chance of a malformed torrc file, I additionally propose there be a schema for the relay descriptor, and if the relay descriptor fails to match the schema it errors to the user to change her torrc file.
-V