diff options
Diffstat (limited to 'tools/josef_auditor.py')
| -rwxr-xr-x | tools/josef_auditor.py | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/tools/josef_auditor.py b/tools/josef_auditor.py new file mode 100755 index 0000000..710e3da --- /dev/null +++ b/tools/josef_auditor.py @@ -0,0 +1,398 @@ +#!/usr/bin/python +# -*- coding: utf-8 -*- + +import time +import datetime +import base64 +import argparse +import errno +from certtools import * + +NAGIOS_OK = 0 +NAGIOS_WARN = 1 +NAGIOS_CRIT = 2 +NAGIOS_UNKNOWN = 3 + +DEFAULT_CUR_FILE = 'all-sth.json' + +base_urls = ["https://plausible.ct.nordu.net/", + "https://ct1.digicert-ct.com/log/", + "https://ct.izenpe.com/", + "https://log.certly.io/", + "https://ct.googleapis.com/aviator/", + "https://ct.googleapis.com/pilot/", + "https://ct.googleapis.com/rocketeer/", + "https://ct.ws.symantec.com/", + "https://ctlog.api.venafi.com/", + ] + +logkeys = {} +logkeys["https://plausible.ct.nordu.net/"] = get_public_key_from_file("../../plausible-logkey.pem") +logkeys["https://ct.googleapis.com/rocketeer/"] = get_public_key_from_file("../../rocketeer-logkey.pem") +logkeys["https://ct.googleapis.com/aviator/"] = get_public_key_from_file("../../aviator-logkey.pem") +logkeys["https://ct.googleapis.com/pilot/"] = get_public_key_from_file("../../pilot-logkey.pem") +logkeys["https://log.certly.io/"] = get_public_key_from_file("../../certly-logkey.pem") +logkeys["https://ct.izenpe.com/"] = get_public_key_from_file("../../izenpe-logkey.pem") +logkeys["https://ct.ws.symantec.com/"] = get_public_key_from_file("../../symantec-logkey.pem") +logkeys["https://ctlog.api.venafi.com/"] = get_public_key_from_file("../../venafi-logkey.pem") +logkeys["https://ct1.digicert-ct.com/log/"] = get_public_key_from_file("../../digicert-logkey.pem") + +parser = argparse.ArgumentParser(description="") +parser.add_argument('--audit', action='store_true', help="run lightweight auditor verifying consistency in STH") +parser.add_argument('--audit2', action='store_true', help="run medium-weight auditor verifying consistency in STH and inclusion proofs of new entries") +parser.add_argument('--audit3', action='store_true', help="continously run medium-weight auditor verifying consistency in STH and inclusion proofs of new entries") +parser.add_argument('--build-sth', action='store_true', help="get all entries and construct STH") +parser.add_argument('--verify-index', default=None, help="Verify a specific index in all logs" ) +# parser.add_argument('--verify-hash', action='store_true', help="Verify an entry hash in all logs" ) +parser.add_argument('--roots', action='store_true', help="Check accepted root certificates for all logs" ) +parser.add_argument('--cur-sth', + metavar='file', + default=DEFAULT_CUR_FILE, + help="File containing current STH (default=%s)" % DEFAULT_CUR_FILE) + +timings = {} +errors = [] + +class UTC(datetime.tzinfo): + def utcoffset(self, dt): + return datetime.timedelta(hours=0) + def dst(self, dt): + return datetime.timedelta(0) + +def reduce_layer(layer): + new_layer = [] + while len(layer) > 1: + e1 = layer.pop(0) + e2 = layer.pop(0) + new_layer.append(internal_hash((e1,e2))) + return new_layer + +def reduce_tree(entries, layers): + if len(entries) == 0 and layers is []: + return [[hashlib.sha256().digest()]] + + layer_idx = 0 + layers[layer_idx] += entries + + while len(layers[layer_idx]) > 1: + if len(layers) == layer_idx + 1: + layers.append([]) + + layers[layer_idx + 1] += reduce_layer(layers[layer_idx]) + layer_idx += 1 + return layers + +def reduce_subtree_to_root(layers): + while len(layers) > 1: + if len(layers[1]) == 0: + layers[1] = layers[0] + else: + layers[1] += next_merkle_layer(layers[0]) + del layers[0] + + if len(layers[0]) > 1: + return next_merkle_layer(layers[0]) + return layers[0] + +def fetch_all_sth(): + sths = {} + for base_url in base_urls: + # Fetch STH + try: + sths[base_url] = get_sth(base_url) + except: + sths[base_url] = None + error_str = time.strftime('%H:%M:%S') + " ERROR: Failed to retrieve STH from " + base_url + print error_str + errors.append(error_str) + continue + + # Check signature on the STH + try: + check_sth_signature(base_url, sths[base_url], logkeys[base_url]) + except: + error_str = time.strftime('%H:%M:%S') + " ERROR: Could not verify signature from " + base_url + print error_str + errors.append(error_str) + continue + + return sths + +def verify_progress(old, new): + print "Verifying progress" + for url in new: + if new and old and new[url] and old[url]: + if new[url]["tree_size"] == old[url]["tree_size"]: + if old[url]["sha256_root_hash"] != new[url]["sha256_root_hash"]: + errors.append(time.strftime('%H:%M:%S') + " CRITICAL: root hash is different for same tree size in " + url) + # print "tree size:", newsth["tree_size"], + # print "old hash:", b64_to_b16(oldsth["sha256_root_hash"]) + # print "new hash:", b64_to_b16(newsth["sha256_root_hash"]) + # sys.exit(NAGIOS_CRIT) + # TODO + elif new[url]["tree_size"] < old[url]["tree_size"]: + # if not args.allow_lag: + errors.append(time.strftime('%H:%M:%S') + " CRITICAL: new tree smaller than previous tree (%d < %d)" % \ + (new[url]["tree_size"], old[url]["tree_size"])) + # sys.exit(NAGIOS_CRIT) + if new[url]: + age = time.time() - new[url]["timestamp"]/1000 + sth_time = datetime.datetime.fromtimestamp(new[url]['timestamp'] / 1000, UTC()).strftime("%Y-%m-%d %H:%M:%S") + # roothash = b64_to_b16(sth['sha256_root_hash']) + roothash = new[url]['sha256_root_hash'] + if age > 24 * 3600: + errors.append(time.strftime('%H:%M:%S') + " CRITICAL: %s is older than 24h: %s UTC" % (url, sth_time)) + elif age > 12 * 3600: + errors.append(time.strftime('%H:%M:%S') + " WARNING: %s is older than 12h: %s UTC" % (url, sth_time)) + elif age > 6 * 3600: + errors.append(time.strftime('%H:%M:%S') + " WARNING: %s is older than 6h: %s UTC" % (url, sth_time)) + # elif age > 2 * 3600: + # errors.append(time.strftime('%H:%M:%S') + " WARNING: %s is older than 2h: %s UTC" % (url, sth_time)) + +def verify_consistency(old, new): + for url in old: + # try: + if old[url] and new[url] and old[url]["tree_size"]!= new[url]["tree_size"]: + consistency_proof = get_consistency_proof(url, old[url]["tree_size"], new[url]["tree_size"]) + decoded_consistency_proof = [] + for item in consistency_proof: + decoded_consistency_proof.append(base64.b64decode(item)) + res = verify_consistency_proof(decoded_consistency_proof, old[url]["tree_size"], new[url]["tree_size"], old[url]["sha256_root_hash"]) + + if old[url]["sha256_root_hash"] != str(base64.b64encode(res[0])): + print time.strftime('%H:%M:%S') + " Verification of old hash failed! " + old[url]["sha256_root_hash"], str(base64.b64encode(res[0])) + errors.append(time.strftime('%H:%M:%S') + " ERROR: Failed to verify consistency for " + url + ", tree size " + old[url]["tree_size"]) + elif new[url]["sha256_root_hash"] != str(base64.b64encode(res[1])): + print time.strftime('%H:%M:%S') + " Verification of new hash failed! " + new[url]["sha256_root_hash"], str(base64.b64encode(res[1])) + errors.append(time.strftime('%H:%M:%S') + " ERROR: Failed to verify consistency for " + url + ", tree size " + new[url]["tree_size"]) + else: + print time.strftime("%H:%M:%S") + " New STH from " + url + ", timestamp: " + \ + str(new[url]["timestamp"]) + ", size: " + str(new[url]["tree_size"]) + "...OK." + + # except: + # print "ERROR: Could not verify consistency for " + url + +def verify_inclusion_all(old, new): + for url in old: + try: + if old[url] and new[url]: + if old[url]["tree_size"]!= new[url]["tree_size"]: + entries = get_entries(url, old[url]["tree_size"], new[url]["tree_size"] -1)["entries"] + success = True + for i in entries: + h = get_leaf_hash(base64.b64decode(i["leaf_input"])) + if not verify_inclusion_by_hash(url, h): + success = False + + if success: + print time.strftime("%H:%M:%S") + " Verifying inclusion for " + str(len(entries)) + " new entries in " + url + " ...OK" + else: + print time.strftime('%H:%M:%S') + " ERROR: Failed to prove inclusion of all new entries in " + url + errors.append(time.strftime('%H:%M:%S') + " ERROR: Failed to prove inclusion of all new entries in " + url) + except: + print time.strftime('%H:%M:%S') + " ERROR: Failed to prove inclusion of all new entries in " + url + errors.append(time.strftime('%H:%M:%S') + " ERROR: Failed to prove inclusion of all new entries in " + url) + +def fetch_and_build_tree(old_sth, base_url): + sth = old_sth[base_url] + subtree = [[]] + idx = 0 + + res_strings = [""] + + print time.strftime('%H:%M:%S') + " Getting all entries from " + base_url + while idx < sth["tree_size"]: + pre_size = idx + entries = get_entries(base_url, idx, sth["tree_size"]-1)["entries"] + + new_leafs = [] + for item in entries: + new_leafs.append(get_leaf_hash(base64.b64decode(item["leaf_input"]))) + idx += len(new_leafs) + print time.strftime('%H:%M:%S') + " Got entries " + str(pre_size) + " to " + str(idx) + " from " + base_url + subtree = reduce_tree(new_leafs, subtree) + + root = base64.b64encode(reduce_subtree_to_root(subtree)[0]) + + if root == sth["sha256_root_hash"]: + print time.strftime('%H:%M:%S') + " Verifying root hashes for " + base_url + "...OK." + res_strings.append("STH for " + base_url + " built successfully.") + else: + print time.strftime('%H:%M:%S') + " ERROR: Failed to verify root hashes! STH root: " + sth["sha256_root_hash"] + ", Tree root: " + root + res_strings.append(time.strftime('%H:%M:%S') + " " + base_url + " Failed! STH root: " + sth["sha256_root_hash"] + " Calculated root: " + root) + errors.append(time.strftime('%H:%M:%S') + " ERROR: Failed to verify root hash for " + base_url + ", tre size " + sth["tree_size"]) + + for item in res_strings: + print item + "\n" + +def verify_inclusion_by_hash(base_url, leaf_hash): + try: + tmp_sth = get_sth(base_url) + proof = get_proof_by_hash(base_url, leaf_hash, tmp_sth["tree_size"]) + + decoded_inclusion_proof = [] + for item in proof["audit_path"]: + decoded_inclusion_proof.append(base64.b64decode(item)) + + root = base64.b64encode(verify_inclusion_proof(decoded_inclusion_proof, proof["leaf_index"], tmp_sth["tree_size"], leaf_hash)) + + if tmp_sth["sha256_root_hash"] == root: + # print "Verifying inclusion for entry " + str(proof["leaf_index"]) + " in " + base_url + "...OK." + return True + else: + print time.strftime('%H:%M:%S') + " ERROR: Could not prove inclusion for entry " + str(proof["leaf_index"]) + " in " + base_url + errors.append(time.strftime('%H:%M:%S') + " ERROR: Could not prove inclusion for entry " + str(proof["leaf_index"]) + " in " + base_url) + return False + except: + print time.strftime('%H:%M:%S') + " ERROR: Could not prove inclusion for hashed entry in " + base_url + errors.append(time.strftime('%H:%M:%S') + " ERROR: Could not prove inclusion for hashed entry in " + base_url) + return False + +def verify_inclusion_by_index(base_url, index): + try: + tmp_sth = get_sth(base_url) + proof = get_proof_by_index(base_url, index, tmp_sth["tree_size"]) + + decoded_inclusion_proof = [] + for item in proof["audit_path"]: + decoded_inclusion_proof.append(base64.b64decode(item)) + + root = base64.b64encode(verify_inclusion_proof(decoded_inclusion_proof, index, tmp_sth["tree_size"], get_leaf_hash(base64.b64decode(proof["leaf_input"])))) + + if tmp_sth["sha256_root_hash"] == root: + print time.strftime('%H:%M:%S') + " Verifying inclusion for entry " + str(index) + " in " + base_url + "...OK." + else: + print time.strftime('%H:%M:%S') + " ERROR: Could not prove inclusion for entry " + str(index) + " in " + base_url + errors.append(time.strftime('%H:%M:%S') + " ERROR: Could not prove inclusion for entry " + str(index) + " in " + base_url) + except: + print time.strftime('%H:%M:%S') + " ERROR: Could not prove inclusion for entry " + str(index) + " in " + base_url + errors.append(time.strftime('%H:%M:%S') + " ERROR: Could not prove inclusion for entry " + str(index) + " in " + base_url) + +def get_proof_by_index(baseurl, index, tree_size): + try: + params = urllib.urlencode({"leaf_index":index, + "tree_size":tree_size}) + result = \ + urlopen(baseurl + "ct/v1/get-entry-and-proof?" + params).read() + return json.loads(result) + except urllib2.HTTPError, e: + print "ERROR:", e.read() + sys.exit(0) + +def get_all_roots(base_url): + # print "Fetching roots from " + base_url + result = urlopen(base_url + "ct/v1/get-roots").read() + certs = json.loads(result)["certificates"] + print time.strftime('%H:%M:%S') + " Received " + str(len(certs)) + " certs from " + base_url + + for accepted_cert in certs: + subject = get_cert_info(base64.decodestring(accepted_cert))["subject"] + issuer = get_cert_info(base64.decodestring(accepted_cert))["issuer"] + if subject == issuer: + root_cert = base64.decodestring(accepted_cert) + print get_cert_info(root_cert)["subject"] + +def print_errors(errors): + print "Encountered " + str(len(errors)) + " errors:" + for item in errors: + print item + +def print_timings(timings): + for item in timings: + m,s = divmod(timings[item]["longest"], 60) + h,m = divmod(m, 60) + print item + " last seen " + datetime.datetime.fromtimestamp(int(timings[item]["last"])/1000).strftime('%Y-%m-%d %H:%M:%S') \ + + " longest between two STH: " + str(int(h)) + "h " + str(int(m)) + "m "# + str(int(s)) + "s." + + +def read_sth(fn): + try: + f = open(fn) + except IOError, e: + if e.errno == errno.ENOENT: + return None + raise e + return json.loads(f.read()) + + +def write_file(fn, sth): + tempname = fn + ".new" + open(tempname, 'w').write(json.dumps(sth)) + mv_file(tempname, fn) + + +def main(args): + + # print time.strftime("%H:%M:%S") + " Starting..." + if args.verify_index is None and not args.build_sth and not args.audit and not args.audit2 \ + and not args.audit3 and not args.verify_hash and not args.roots: + + print time.strftime('%H:%M:%S') + " Nothing to do." + return + else: + sth = fetch_all_sth() + + if args.verify_index is not None: + for url in base_urls: + verify_inclusion_by_index(url, int(args.verify_index)) + + + if args.roots: + print time.strftime('%H:%M:%S') + " Getting accepted Root Certs from all logs..." + for url in base_urls: + get_all_roots(url) + + + if args.build_sth: + print time.strftime('%H:%M:%S') + " Building trees from entries. This may take a while, go get coffee or something..." + for base_url in base_urls: + fetch_and_build_tree(sth, base_url) + # fetch_and_build_tree(sth, base_urls[2]) + + if args.audit: + print time.strftime('%H:%M:%S') + " Running auditor1 for " +str(len(base_urls)) + " logs..." + old_sth = read_sth(args.cur_sth) + if old_sth: + verify_consistency(old_sth, sth) + else: + print "No old sth found..." + write_file(args.cur_sth, sth) + + + if args.audit3: + print time.strftime('%H:%M:%S') + " Running auditor3 for " +str(len(base_urls)) + " logs..." + while True: + time.sleep(30) + new_sth = fetch_all_sth() + verify_consistency(sth, new_sth) + verify_inclusion_all(sth, new_sth) + sth = new_sth + + if args.audit2: + print time.strftime('%H:%M:%S') + " Running auditor2 for " +str(len(base_urls)) + " logs..." + old_sth = read_sth(args.cur_sth) + verify_progress(old_sth, sth) + if old_sth: + verify_consistency(old_sth, sth) + verify_inclusion_all(old_sth, sth) + write_file(args.cur_sth, sth) + + + +if __name__ == '__main__': + main(parser.parse_args()) + if len(errors) == 0: + print time.strftime('%H:%M:%S') + " Everything OK." + sys.exit(NAGIOS_OK) + else: + print_errors(errors) + sys.exit(NAGIOS_WARN) + + + + + + + + + |