owner

Tools to prove ownership of content

To install: pip install owner

Essentially

from owner import weave, unweave

assert unweave(weave(b'bob and alice')) == b'bob and alice'

What's happening?

Well, here's what's happening by default.

First, a weaver is made...

from owner import HeadWeaver

weaver = HeadWeaver()

weave

When we weave, we get the same original content, but with a bunch of "other junk"...

content = b'--this is where content goes--'
extra_info = b'**optional free-from "extra info goes here: It is meant for ownership and dating info.**'
w = weaver.weave(content, extra_info)
w

b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xb8\xe8gU\xcc\xc1\n)\xd1\xb0\x1dd\x07\xa4\x90\xbd\xfe\x0f7\xe9\xb5\xcd\xf8\xd7[z\xc5\xeao\xac\x03|8**optional free-from "extra info goes here: It is meant for ownership and dating info.**--this is where content goes--'

unweave

No fret though, we can unjunk the weave.

unwoven_content = weaver.unweave(w)
assert unwoven_content == content  # see that the unwoven content is the same as the original content
unwoven_content

b'--this is where content goes--'

What does weaving and unweaving do for you?

Well, that's up to you. It's just a means to add some information to some content, within the bytes of the content itself, and be able to still access the original content.

What you put in the extra_info depends on you and your use case. The use case we have in mind here is: I want to prove that some content is mine by posting a hash of it on a block-chain. But if I just hash the content, only the content is represented, not any other information (such as my name etc.). Simple solution to that: Just prepend my name (or any other information) to the raw content. That's what extra_info is. Ah... but then I need to know where the original content starts. That's what offset is. And then we added a content_hash to add extra error-correcting abilities.

Let's now have a look at how the woven bytes are parsed.

inspecting the parts of the woven

parts = weaver.unweave_parts(w)
parts

UnWovenBaseHeaderWeave(offset=b'\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\xb8', content_hash=b'\xe8gU\xcc\xc1\n)\xd1\xb0\x1dd\x07\xa4\x90\xbd\xfe\x0f7\xe9\xb5\xcd\xf8\xd7[z\xc5\xeao\xac\x03|8', extra_info=b'**optional free-from "extra info goes here: It is meant for ownership and dating info.**', content=b'--this is where content goes--')

parts._fields

('offset', 'content_hash', 'extra_info', 'content')

As you see in the print out above, the parts are all given in raw bytes format.

If you need them to be interpreted you can do so like this:

parts = weaver.unweave_parts(w, interpret_bytes=True)
parts

UnWovenBaseHeaderWeave(offset=184, content_hash='e86755ccc10a29d1b01d6407a490bdfe0f37e9b5cdf8d75b7ac5ea6fac037c38', extra_info=b'**optional free-from "extra info goes here: It is meant for ownership and dating info.**', content=b'--this is where content goes--')

The offset tells us where the content actually starts. Here, we know it starts at the 184th byte.

parts.offset

184

The content_hash is the sha256 of the original contents, here presented in hex form.

parts.content_hash

'e86755ccc10a29d1b01d6407a490bdfe0f37e9b5cdf8d75b7ac5ea6fac037c38'

parts.extra_info

b'**optional free-from "extra info goes here: It is meant for ownership and dating info.**'

parts.content

b'--this is where content goes--'

a bit more control on how you get your woven parts

import json

weaver = HeadWeaver()
content = 'This is some text'
extra_info = {"name": "Thor Whalen", 
              "date": "2013-12-11"}
w = weaver.weave(content.encode(), json.dumps(extra_info).encode())


parts = weaver.unweave_parts(w, interpret_bytes=True, decode_content=True, decode_extra_info=json.loads)
parts

UnWovenBaseHeaderWeave(offset=141, content_hash='2263d8dd95ccfe1ad45d732c6eaaf59b3345e6647331605cb15aae52002dff75', extra_info={'name': 'Thor Whalen', 'date': '2013-12-11'}, content='This is some text')

assert isinstance(parts.extra_info, dict)  # I'm now getting extra_info in the form of a dict
parts.extra_info

{'name': 'Thor Whalen', 'date': '2013-12-11'}

assert isinstance(parts.content, str)  # content is as a str
parts.content

'This is some text'