[tor-bugs] #33428 [Core Tor/Chutney]: Make chutney check for relay microdescriptors before verifying

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#33428: Make chutney check for relay microdescriptors before verifying
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 Reporter:  teor                           |          Owner:  (none)
     Type:  enhancement                    |         Status:  new
 Priority:  Medium                         |      Milestone:
Component:  Core Tor/Chutney               |        Version:
 Severity:  Normal                         |     Resolution:
 Keywords:  ipv6, prop311, outreachy-ipv6  |  Actual Points:
Parent ID:  #33232                         |         Points:  1
 Reviewer:                                 |        Sponsor:  Sponsor55-can
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Comment (by teor):

 Replying to [comment:5 anuradha1904]:
 > Hey teor, what do you think is appropriate issue for me to start from a
 beginner perspective, and I do know how to code in C but am more
 comfortable with python, so would like to start my work in python. Thank
 you.

 I have looked at all the current outreachy-ipv6 issues, and this is the
 best Python issue. Here are some hints to get you started:

 We don't want to wait for the new ed25519-identity file in #30642, so
 here's how you can read the binary data from the key file, and encode it
 in base64:
 {{{
 $ chutney/tools/test-network.sh
 # the last 32 bytes of the key file is the key data
 # we want to remove the newline and the trailing "=" from the base64
 output
 $ cat chutney/net/nodes/000a/keys/ed25519_master_id_public_key | tail -c
 32 | base64 | head -c -2
 Hqp2E6Pi0BAWmip+2XEowl/CgjGesgfC0jNipORQ37A
 $ grep "Hqp2E6Pi0BAWmip+2XEowl/CgjGesgfC0jNipORQ37A" chutney/net/nodes
 /*/cached-microdescs*
 net/nodes/000a/cached-microdescs.new:id ed25519
 Hqp2E6Pi0BAWmip+2XEowl/CgjGesgfC0jNipORQ37A
 net/nodes/001a/cached-microdescs.new:id ed25519
 Hqp2E6Pi0BAWmip+2XEowl/CgjGesgfC0jNipORQ37A
 ...
 }}}
 The key data is random, so the exact values will be different in every
 chutney network. You'll need to take the script `cat
 chutney/net/nodes/000a/keys/ed25519_master_id_public_key | tail -c 32 |
 base64 | head -c -2`, and translate it into Python.

 You can start by writing a function called _setEd25519Id(), which should
 be called at the end of _genRouterKey():
 https://github.com/torproject/chutney/blob/master/lib/chutney/TorNet.py#L741

 The function should:
 * read keys/ed25519_master_id_public_key from datadir, if that file exists
 * extract the key data
 * convert it to base64
 * discard the trailing "="
 * set `ed25519-id` in the Environ to that value

 You can check you have the right value, by printing it out, then searching
 for it in the cached-microdescs and cached-microdescs.new files in the
 datadir.

 After you've written _setEd25519Id(), we can move on to the rest of this
 task.

 I hope that's enough to get you started!

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/33428#comment:6>
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