bitcoin/contrib/verify-commits
MeshCollider e946fc7eb1
Merge #14809: Tools: improve verify-commits.py script
45842c3d2 Improve documentation for running verify-commits.py script (Jameson Lopp)

Pull request description:

  I ran into 3 different issues while trying to run the verify-commits script for the first time and I think documenting them would help save time for future developers.

  1. I was trying to just run it with "python" and didn't realize I had multiple python versions installed and this script is only syntactically valid for python 3.x.
  2. I needed to import the trusted keys
  3. The script was hanging because it was triggering my yubikey for signature verification

Tree-SHA512: dfc7a62972ca3de528fae3c9d420c7d2d6658767a555ebbf5f4a27c04748c35ccf8bf63bfc9f264358346de0db49bfbaf2d1540793a609d81c2d9b622ee8182c
2018-12-10 17:18:38 +13:00
..
allow-incorrect-sha512-commits Use python instead of slow shell script on verify-commits 2018-06-12 14:48:02 +00:00
allow-revsig-commits Add Marco-expired-key-signed-commits to allow-revsig-commits 2018-03-28 14:55:50 -04:00
allow-unclean-merge-commits Use python instead of slow shell script on verify-commits 2018-06-12 14:48:02 +00:00
gpg.sh Merge #13454: Make sure LC_ALL=C is set in all shell scripts 2018-06-18 13:18:12 +02:00
pre-push-hook.sh Obsolete #!/bin/bash shebang 2018-06-20 11:12:41 +03:00
README.md Improve documentation for running verify-commits.py script 2018-12-06 10:41:08 -05:00
trusted-git-root Revert "test: Update trust git root". 2018-03-28 14:55:50 -04:00
trusted-keys scripts: Add trusted key for Samuel Dobson 2018-12-04 13:51:53 +01:00
trusted-sha512-root-commit Update trusted-sha512-root-commit for new bad tree hash 2017-03-09 09:53:19 -05:00
verify-commits.py Improve documentation for running verify-commits.py script 2018-12-06 10:41:08 -05:00

Tooling for verification of PGP signed commits

This is an incomplete work in progress, but currently includes a pre-push hook script (pre-push-hook.sh) for maintainers to ensure that their own commits are PGP signed (nearly always merge commits), as well as a Python 3 script to verify commits against a trusted keys list.

Using verify-commits.py safely

Remember that you can't use an untrusted script to verify itself. This means that checking out code, then running verify-commits.py against HEAD is not safe, because the version of verify-commits.py that you just ran could be backdoored. Instead, you need to use a trusted version of verify-commits prior to checkout to make sure you're checking out only code signed by trusted keys:

git fetch origin && \
./contrib/verify-commits/verify-commits.py origin/master && \
git checkout origin/master

Note that the above isn't a good UI/UX yet, and needs significant improvements to make it more convenient and reduce the chance of errors; pull-reqs improving this process would be much appreciated.

Configuration files

  • trusted-git-root: This file should contain a single git commit hash which is the first unsigned git commit (hence it is the "root of trust").
  • trusted-sha512-root-commit: This file should contain a single git commit hash which is the first commit without a SHA512 root commitment.
  • trusted-keys: This file should contain a \n-delimited list of all PGP fingerprints of authorized commit signers (primary, not subkeys).
  • allow-revsig-commits: This file should contain a \n-delimited list of git commit hashes. See next section for more info.

Import trusted keys

In order to check the commit signatures you must add the trusted PGP keys to your machine. This can be done in Linux by running

gpg --recv-keys $(<contrib/verify-commits/trusted-keys)

Key expiry/revocation

When a key (or subkey) which has signed old commits expires or is revoked, verify-commits will start failing to verify all commits which were signed by said key. In order to avoid bumping the root-of-trust trusted-git-root file, individual commits which were signed by such a key can be added to the allow-revsig-commits file. That way, the PGP signatures are still verified but no new commits can be signed by any expired/revoked key. To easily build a list of commits which need to be added, verify-commits.py can be edited to test each commit with BITCOIN_VERIFY_COMMITS_ALLOW_REVSIG set to both 1 and 0, and those which need it set to 1 printed.