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author | Linus Nordberg <linus@nordu.net> | 2015-09-24 16:47:32 +0200 |
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committer | Linus Nordberg <linus@nordu.net> | 2015-09-27 13:38:30 +0200 |
commit | 38722592047855cedd4ef2701854638bd50e0467 (patch) | |
tree | 229a7e5718b0d4c9750918d654484dba354f5194 /tools/merge_sth.py | |
parent | 7fd70ad913ecdb2585d50d27763d00f30a1e5a6f (diff) |
Merge is now run by shell script tools/merge.
tools/merge run merge_fetch.py, merge_backup.py, merge_sth.py and
merge_dist.py sequentially.
TODO: test backupquorum != 0
Diffstat (limited to 'tools/merge_sth.py')
-rwxr-xr-x | tools/merge_sth.py | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/tools/merge_sth.py b/tools/merge_sth.py new file mode 100755 index 0000000..68b52a0 --- /dev/null +++ b/tools/merge_sth.py @@ -0,0 +1,123 @@ +#!/usr/bin/env python +# -*- coding: utf-8 -*- +# +# Copyright (c) 2014-2015, NORDUnet A/S. +# See LICENSE for licensing information. + +import sys +import json +import urllib2 +import time +from base64 import b64encode, b64decode +from mergetools import parse_args, get_nfetched, hexencode, hexdecode, \ + get_logorder, get_sth +from certtools import create_ssl_context, get_public_key_from_file, \ + timing_point, create_sth_signature, write_file, check_sth_signature, \ + build_merkle_tree + +def merge_sth(args, config, localconfig): + paths = localconfig["paths"] + own_key = (localconfig["nodename"], + "%s/%s-private.pem" % (paths["privatekeys"], + localconfig["nodename"])) + ctbaseurl = config["baseurl"] + signingnodes = config["signingnodes"] + mergenodes = config.get("mergenodes", []) + mergedb = paths["mergedb"] + sthfile = mergedb + "/sth" + logorderfile = mergedb + "/logorder" + logpublickey = get_public_key_from_file(paths["logpublickey"]) + backupquorum = localconfig.get("backupquorum", 0) + assert backupquorum <= len(mergenodes) - 1 + create_ssl_context(cafile=paths["https_cacertfile"]) + timing = timing_point() + + trees = [{'tree_size': 0, 'sha256_root_hash': ''}] + for mergenode in mergenodes: + if mergenode["name"] == config["primarymergenode"]: + continue + verifiedfile = mergedb + "/verified." + mergenode["name"] + try: + tree = json.loads(open(verifiedfile, "r").read()) + except (IOError, ValueError): + tree = {'tree_size': 0, "sha256_root_hash": ''} + trees.append(tree) + trees.sort(key=lambda e: e['tree_size'], reverse=True) + print >>sys.stderr, "DEBUG: trees:", trees + tree_size = trees[backupquorum]['tree_size'] + root_hash = hexdecode(trees[backupquorum]['sha256_root_hash']) + print >>sys.stderr, "DEBUG: tree size candidate at backupquorum", \ + backupquorum, ":", tree_size + + cur_sth = get_sth(sthfile) + if tree_size < cur_sth['tree_size']: + print >>sys.stderr, "candidate tree < current tree:", \ + tree_size, "<", cur_sth['tree_size'] + return + + assert tree_size >= 0 # Don't read logorder without limit. + logorder = get_logorder(logorderfile, tree_size) + timing_point(timing, "get logorder") + if tree_size == -1: + tree_size = len(logorder) + print >>sys.stderr, "new tree size will be", tree_size + + root_hash_calc = build_merkle_tree(logorder)[-1][0] + assert root_hash == '' or root_hash == root_hash_calc + root_hash = root_hash_calc + timestamp = int(time.time() * 1000) + + tree_head_signature = None + for signingnode in signingnodes: + try: + tree_head_signature = \ + create_sth_signature(tree_size, timestamp, + root_hash, + "https://%s/" % signingnode["address"], + key=own_key) + break + except urllib2.URLError, err: + print >>sys.stderr, err + sys.stderr.flush() + if tree_head_signature == None: + print >>sys.stderr, "Could not contact any signing nodes" + sys.exit(1) + + sth = {"tree_size": tree_size, "timestamp": timestamp, + "sha256_root_hash": b64encode(root_hash), + "tree_head_signature": b64encode(tree_head_signature)} + + check_sth_signature(ctbaseurl, sth, publickey=logpublickey) + timing_point(timing, "build sth") + + print hexencode(root_hash), timestamp, tree_size + sys.stdout.flush() + + write_file(sthfile, sth) + + if args.timing: + print >>sys.stderr, timing["deltatimes"] + sys.stderr.flush() + +def main(): + """ + Read file 'sth' to get current tree size, assuming zero if file not + found. + + Read tree sizes from the backup.<secondary> files, put them in a + list and sort it. Let new tree size equal list[backup-quorum]. Barf + on a new tree size smaller than the currently published tree size. + + Decide on a timestamp, build an STH and write it to file 'sth'. + """ + args, config, localconfig = parse_args() + + while True: + merge_sth(args, config, localconfig) + if args.interval is None: + break + print >>sys.stderr, "sleeping", args.interval, "seconds" + time.sleep(args.interval) + +if __name__ == '__main__': + sys.exit(main()) |