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authorLinus Nordberg <linus@nordu.net>2015-09-24 16:47:32 +0200
committerLinus Nordberg <linus@nordu.net>2015-09-27 13:38:30 +0200
commit38722592047855cedd4ef2701854638bd50e0467 (patch)
tree229a7e5718b0d4c9750918d654484dba354f5194 /tools/merge_sth.py
parent7fd70ad913ecdb2585d50d27763d00f30a1e5a6f (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-xtools/merge_sth.py123
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())