Use python instead of slow shell script on verify-commits

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 <NUMBER> days ago (default: %(default)s)', metavar='NUMBER')
+    parser.add_argument('commit', nargs='?', default='HEAD', help='Check clean merge up to commit <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()