From e5b2cd8e7564b9fc2ed4f63fe49efb0af60b4460 Mon Sep 17 00:00:00 2001 From: Chun Kuan Lee Date: Thu, 10 May 2018 16:22:58 +0000 Subject: Use python instead of slow shell script on verify-commits --- contrib/verify-commits/README.md | 10 +- .../verify-commits/allow-incorrect-sha512-commits | 2 + contrib/verify-commits/allow-unclean-merge-commits | 4 + contrib/verify-commits/pre-push-hook.sh | 4 +- contrib/verify-commits/verify-commits.py | 155 +++++++++++++++++++++ contrib/verify-commits/verify-commits.sh | 153 -------------------- 6 files changed, 168 insertions(+), 160 deletions(-) create mode 100644 contrib/verify-commits/allow-incorrect-sha512-commits create mode 100644 contrib/verify-commits/allow-unclean-merge-commits create mode 100755 contrib/verify-commits/verify-commits.py delete mode 100755 contrib/verify-commits/verify-commits.sh (limited to 'contrib') diff --git a/contrib/verify-commits/README.md b/contrib/verify-commits/README.md index fa492fdd27..aa805ad1b9 100644 --- a/contrib/verify-commits/README.md +++ b/contrib/verify-commits/README.md @@ -7,18 +7,18 @@ are PGP signed (nearly always merge commits), as well as a script to verify commits against a trusted keys list. -Using verify-commits.sh safely +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.sh` against `HEAD` is -_not_ safe, because the version of `verify-commits.sh` that you just ran could +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.sh origin/master && \ + ./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 @@ -42,6 +42,6 @@ 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.sh can be edited to test +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. diff --git a/contrib/verify-commits/allow-incorrect-sha512-commits b/contrib/verify-commits/allow-incorrect-sha512-commits new file mode 100644 index 0000000000..c572806f26 --- /dev/null +++ b/contrib/verify-commits/allow-incorrect-sha512-commits @@ -0,0 +1,2 @@ +f8feaa4636260b599294c7285bcf1c8b7737f74e +8040ae6fc576e9504186f2ae3ff2c8125de1095c diff --git a/contrib/verify-commits/allow-unclean-merge-commits b/contrib/verify-commits/allow-unclean-merge-commits new file mode 100644 index 0000000000..7aab274b9a --- /dev/null +++ b/contrib/verify-commits/allow-unclean-merge-commits @@ -0,0 +1,4 @@ +6052d509105790a26b3ad5df43dd61e7f1b24a12 +3798e5de334c3deb5f71302b782f6b8fbd5087f1 +326ffed09bfcc209a2efd6a2ebc69edf6bd200b5 +97d83739db0631be5d4ba86af3616014652c00ec diff --git a/contrib/verify-commits/pre-push-hook.sh b/contrib/verify-commits/pre-push-hook.sh index c21febb9e9..1f14635f61 100755 --- a/contrib/verify-commits/pre-push-hook.sh +++ b/contrib/verify-commits/pre-push-hook.sh @@ -12,9 +12,9 @@ while read LINE; do if [ "$4" != "refs/heads/master" ]; then continue fi - if ! ./contrib/verify-commits/verify-commits.sh $3 > /dev/null 2>&1; then + if ! ./contrib/verify-commits/verify-commits.py $3 > /dev/null 2>&1; then echo "ERROR: A commit is not signed, can't push" - ./contrib/verify-commits/verify-commits.sh + ./contrib/verify-commits/verify-commits.py exit 1 fi done < /dev/stdin diff --git a/contrib/verify-commits/verify-commits.py b/contrib/verify-commits/verify-commits.py new file mode 100755 index 0000000000..80f0aa0bf1 --- /dev/null +++ b/contrib/verify-commits/verify-commits.py @@ -0,0 +1,155 @@ +#!/usr/bin/env python3 +# Copyright (c) 2018 The Bitcoin Core developers +# Distributed under the MIT software license, see the accompanying +# file COPYING or http://www.opensource.org/licenses/mit-license.php. +"""Verify commits against a trusted keys list.""" +import argparse +import hashlib +import os +import subprocess +import sys +import time + +GIT = os.getenv('GIT', 'git') + +def tree_sha512sum(commit='HEAD'): + """Calculate the Tree-sha512 for the commit. + + This is copied from github-merge.py.""" + + # request metadata for entire tree, recursively + files = [] + blob_by_name = {} + for line in subprocess.check_output([GIT, 'ls-tree', '--full-tree', '-r', commit]).splitlines(): + name_sep = line.index(b'\t') + metadata = line[:name_sep].split() # perms, 'blob', blobid + assert metadata[1] == b'blob' + name = line[name_sep + 1:] + files.append(name) + blob_by_name[name] = metadata[2] + + files.sort() + # open connection to git-cat-file in batch mode to request data for all blobs + # this is much faster than launching it per file + p = subprocess.Popen([GIT, 'cat-file', '--batch'], stdout=subprocess.PIPE, stdin=subprocess.PIPE) + overall = hashlib.sha512() + for f in files: + blob = blob_by_name[f] + # request blob + p.stdin.write(blob + b'\n') + p.stdin.flush() + # read header: blob, "blob", size + reply = p.stdout.readline().split() + assert reply[0] == blob and reply[1] == b'blob' + size = int(reply[2]) + # hash the blob data + intern = hashlib.sha512() + ptr = 0 + while ptr < size: + bs = min(65536, size - ptr) + piece = p.stdout.read(bs) + if len(piece) == bs: + intern.update(piece) + else: + raise IOError('Premature EOF reading git cat-file output') + ptr += bs + dig = intern.hexdigest() + assert p.stdout.read(1) == b'\n' # ignore LF that follows blob data + # update overall hash with file hash + overall.update(dig.encode("utf-8")) + overall.update(" ".encode("utf-8")) + overall.update(f) + overall.update("\n".encode("utf-8")) + p.stdin.close() + if p.wait(): + raise IOError('Non-zero return value executing git cat-file') + return overall.hexdigest() + +def main(): + # Parse arguments + parser = argparse.ArgumentParser(usage='%(prog)s [options] [commit id]') + parser.add_argument('--disable-tree-check', action='store_false', dest='verify_tree', help='disable SHA-512 tree check') + parser.add_argument('--clean-merge', type=float, dest='clean_merge', default=float('inf'), help='Only check clean merge after days ago (default: %(default)s)', metavar='NUMBER') + parser.add_argument('commit', nargs='?', default='HEAD', help='Check clean merge up to commit ') + args = parser.parse_args() + + # get directory of this program and read data files + dirname = os.path.dirname(os.path.abspath(__file__)) + print("Using verify-commits data from " + dirname) + verified_root = open(dirname + "/trusted-git-root", "r").read().splitlines()[0] + verified_sha512_root = open(dirname + "/trusted-sha512-root-commit", "r").read().splitlines()[0] + revsig_allowed = open(dirname + "/allow-revsig-commits", "r").read().splitlines() + unclean_merge_allowed = open(dirname + "/allow-unclean-merge-commits", "r").read().splitlines() + incorrect_sha512_allowed = open(dirname + "/allow-incorrect-sha512-commits", "r").read().splitlines() + + # Set commit and branch and set variables + current_commit = args.commit + if ' ' in current_commit: + print("Commit must not contain spaces", file=sys.stderr) + sys.exit(1) + verify_tree = args.verify_tree + no_sha1 = True + prev_commit = "" + initial_commit = current_commit + branch = subprocess.check_output([GIT, 'show', '-s', '--format=%H', initial_commit], universal_newlines=True).splitlines()[0] + + # Iterate through commits + while True: + if current_commit == verified_root: + print('There is a valid path from "{}" to {} where all commits are signed!'.format(initial_commit, verified_root)) + sys.exit(0) + if current_commit == verified_sha512_root: + if verify_tree: + print("All Tree-SHA512s matched up to {}".format(verified_sha512_root), file=sys.stderr) + verify_tree = False + no_sha1 = False + + os.environ['BITCOIN_VERIFY_COMMITS_ALLOW_SHA1'] = "0" if no_sha1 else "1" + os.environ['BITCOIN_VERIFY_COMMITS_ALLOW_REVSIG'] = "1" if current_commit in revsig_allowed else "0" + + # Check that the commit (and parents) was signed with a trusted key + if subprocess.call([GIT, '-c', 'gpg.program={}/gpg.sh'.format(dirname), 'verify-commit', current_commit], stdout=subprocess.DEVNULL): + if prev_commit != "": + print("No parent of {} was signed with a trusted key!".format(prev_commit), file=sys.stderr) + print("Parents are:", file=sys.stderr) + parents = subprocess.check_output([GIT, 'show', '-s', '--format=format:%P', prev_commit], universal_newlines=True).splitlines()[0].split(' ') + for parent in parents: + subprocess.call([GIT, 'show', '-s', parent], stdout=sys.stderr) + else: + print("{} was not signed with a trusted key!".format(current_commit), file=sys.stderr) + sys.exit(1) + + # Check the Tree-SHA512 + if (verify_tree or prev_commit == "") and current_commit not in incorrect_sha512_allowed: + tree_hash = tree_sha512sum(current_commit) + if ("Tree-SHA512: {}".format(tree_hash)) not in subprocess.check_output([GIT, 'show', '-s', '--format=format:%B', current_commit], universal_newlines=True).splitlines(): + print("Tree-SHA512 did not match for commit " + current_commit, file=sys.stderr) + sys.exit(1) + + # Merge commits should only have two parents + parents = subprocess.check_output([GIT, 'show', '-s', '--format=format:%P', current_commit], universal_newlines=True).splitlines()[0].split(' ') + if len(parents) > 2: + print("Commit {} is an octopus merge".format(current_commit), file=sys.stderr) + sys.exit(1) + + # Check that the merge commit is clean + commit_time = int(subprocess.check_output([GIT, 'show', '-s', '--format=format:%ct', current_commit], universal_newlines=True).splitlines()[0]) + check_merge = commit_time > time.time() - args.clean_merge * 24 * 60 * 60 # Only check commits in clean_merge days + allow_unclean = current_commit in unclean_merge_allowed + if len(parents) == 2 and check_merge and not allow_unclean: + current_tree = subprocess.check_output([GIT, 'show', '--format=%T', current_commit], universal_newlines=True).splitlines()[0] + subprocess.call([GIT, 'checkout', '--force', '--quiet', parents[0]]) + subprocess.call([GIT, 'merge', '--no-ff', '--quiet', parents[1]], stdout=subprocess.DEVNULL) + recreated_tree = subprocess.check_output([GIT, 'show', '--format=format:%T', 'HEAD'], universal_newlines=True).splitlines()[0] + if current_tree != recreated_tree: + print("Merge commit {} is not clean".format(current_commit), file=sys.stderr) + subprocess.call([GIT, 'diff', current_commit]) + subprocess.call([GIT, 'checkout', '--force', '--quiet', branch]) + sys.exit(1) + subprocess.call([GIT, 'checkout', '--force', '--quiet', branch]) + + prev_commit = current_commit + current_commit = parents[0] + +if __name__ == '__main__': + main() diff --git a/contrib/verify-commits/verify-commits.sh b/contrib/verify-commits/verify-commits.sh deleted file mode 100755 index 6415eea4d5..0000000000 --- a/contrib/verify-commits/verify-commits.sh +++ /dev/null @@ -1,153 +0,0 @@ -#!/bin/sh -# Copyright (c) 2014-2016 The Bitcoin Core developers -# Distributed under the MIT software license, see the accompanying -# file COPYING or http://www.opensource.org/licenses/mit-license.php. - -DIR=$(dirname "$0") -[ "/${DIR#/}" != "$DIR" ] && DIR=$(dirname "$(pwd)/$0") - -echo "Using verify-commits data from ${DIR}" - -VERIFIED_ROOT=$(cat "${DIR}/trusted-git-root") -VERIFIED_SHA512_ROOT=$(cat "${DIR}/trusted-sha512-root-commit") -REVSIG_ALLOWED=$(cat "${DIR}/allow-revsig-commits") - -HAVE_GNU_SHA512=1 -[ ! -x "$(which sha512sum)" ] && HAVE_GNU_SHA512=0 - -if [ x"$1" = "x" ]; then - CURRENT_COMMIT="HEAD" -else - CURRENT_COMMIT="$1" -fi - -if [ "${CURRENT_COMMIT#* }" != "$CURRENT_COMMIT" ]; then - echo "Commit must not contain spaces?" > /dev/stderr - exit 1 -fi - -VERIFY_TREE=0 -if [ x"$2" = "x--tree-checks" ]; then - VERIFY_TREE=1 -fi - -NO_SHA1=1 -PREV_COMMIT="" -INITIAL_COMMIT="${CURRENT_COMMIT}" - -BRANCH="$(git rev-parse --abbrev-ref HEAD)" - -while true; do - if [ "$CURRENT_COMMIT" = $VERIFIED_ROOT ]; then - echo "There is a valid path from \"$INITIAL_COMMIT\" to $VERIFIED_ROOT where all commits are signed!" - exit 0 - fi - - if [ "$CURRENT_COMMIT" = $VERIFIED_SHA512_ROOT ]; then - if [ "$VERIFY_TREE" = "1" ]; then - echo "All Tree-SHA512s matched up to $VERIFIED_SHA512_ROOT" > /dev/stderr - fi - VERIFY_TREE=0 - NO_SHA1=0 - fi - - if [ "$NO_SHA1" = "1" ]; then - export BITCOIN_VERIFY_COMMITS_ALLOW_SHA1=0 - else - export BITCOIN_VERIFY_COMMITS_ALLOW_SHA1=1 - fi - - if [ "${REVSIG_ALLOWED#*$CURRENT_COMMIT}" != "$REVSIG_ALLOWED" ]; then - export BITCOIN_VERIFY_COMMITS_ALLOW_REVSIG=1 - else - export BITCOIN_VERIFY_COMMITS_ALLOW_REVSIG=0 - fi - - if ! git -c "gpg.program=${DIR}/gpg.sh" verify-commit "$CURRENT_COMMIT" > /dev/null; then - if [ "$PREV_COMMIT" != "" ]; then - echo "No parent of $PREV_COMMIT was signed with a trusted key!" > /dev/stderr - echo "Parents are:" > /dev/stderr - PARENTS=$(git show -s --format=format:%P $PREV_COMMIT) - for PARENT in $PARENTS; do - git show -s $PARENT > /dev/stderr - done - else - echo "$CURRENT_COMMIT was not signed with a trusted key!" > /dev/stderr - fi - exit 1 - fi - - # We always verify the top of the tree - if [ "$VERIFY_TREE" = 1 -o "$PREV_COMMIT" = "" ]; then - IFS_CACHE="$IFS" - IFS=' -' - for LINE in $(git ls-tree --full-tree -r "$CURRENT_COMMIT"); do - case "$LINE" in - "12"*) - echo "Repo contains symlinks" > /dev/stderr - IFS="$IFS_CACHE" - exit 1 - ;; - esac - done - IFS="$IFS_CACHE" - - FILE_HASHES="" - for FILE in $(git ls-tree --full-tree -r --name-only "$CURRENT_COMMIT" | LC_ALL=C sort); do - if [ "$HAVE_GNU_SHA512" = 1 ]; then - HASH=$(git cat-file blob "$CURRENT_COMMIT":"$FILE" | sha512sum | { read FIRST _; echo $FIRST; } ) - else - HASH=$(git cat-file blob "$CURRENT_COMMIT":"$FILE" | shasum -a 512 | { read FIRST _; echo $FIRST; } ) - fi - [ "$FILE_HASHES" != "" ] && FILE_HASHES="$FILE_HASHES"' -' - FILE_HASHES="$FILE_HASHES$HASH $FILE" - done - - if [ "$HAVE_GNU_SHA512" = 1 ]; then - TREE_HASH="$(echo "$FILE_HASHES" | sha512sum)" - else - TREE_HASH="$(echo "$FILE_HASHES" | shasum -a 512)" - fi - HASH_MATCHES=0 - MSG="$(git show -s --format=format:%B "$CURRENT_COMMIT" | tail -n1)" - - case "$MSG -" in - "Tree-SHA512: $TREE_HASH") - HASH_MATCHES=1;; - esac - - if [ "$HASH_MATCHES" = "0" ]; then - echo "Tree-SHA512 did not match for commit $CURRENT_COMMIT" > /dev/stderr - exit 1 - fi - fi - - PARENTS=$(git show -s --format=format:%P "$CURRENT_COMMIT") - PARENT1=${PARENTS%% *} - PARENT2="" - if [ "x$PARENT1" != "x$PARENTS" ]; then - PARENTX=${PARENTS#* } - PARENT2=${PARENTX%% *} - if [ "x$PARENT2" != "x$PARENTX" ]; then - echo "Commit $CURRENT_COMMIT is an octopus merge" > /dev/stderr - exit 1 - fi - fi - if [ "x$PARENT2" != "x" ]; then - CURRENT_TREE="$(git show --format="%T" "$CURRENT_COMMIT")" - git checkout --force --quiet "$PARENT1" - git merge --no-ff --quiet "$PARENT2" >/dev/null - RECREATED_TREE="$(git show --format="%T" HEAD)" - if [ "$CURRENT_TREE" != "$RECREATED_TREE" ]; then - echo "Merge commit $CURRENT_COMMIT is not clean" > /dev/stderr - git diff "$CURRENT_COMMIT" - git checkout --force --quiet "$BRANCH" - exit 1 - fi - git checkout --force --quiet "$BRANCH" - fi - PREV_COMMIT="$CURRENT_COMMIT" - CURRENT_COMMIT="$PARENT1" -done -- cgit v1.2.3