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authorMagnus Ahltorp <map@kth.se>2015-02-15 15:23:29 +0100
committerMagnus Ahltorp <map@kth.se>2015-02-19 13:42:11 +0100
commitf7dd4e73ae8829f71f51c8af2dcf45a904e42664 (patch)
treed99a49b8cca4fb8d9094bdaeb51e5d41e27c52cd
parent4ee7e18aa4a31d605bc751a514698641aa9fae4c (diff)
Implement function to fetch consistency proof
Implement function to calculate tree head from disk Implement function to calculate an intermediate node from disk
-rw-r--r--tools/certtools.py108
1 files changed, 99 insertions, 9 deletions
diff --git a/tools/certtools.py b/tools/certtools.py
index 6a144c9..31045b9 100644
--- a/tools/certtools.py
+++ b/tools/certtools.py
@@ -105,6 +105,17 @@ def get_proof_by_hash(baseurl, hash, tree_size):
print "ERROR:", e.read()
sys.exit(1)
+def get_consistency_proof(baseurl, tree_size1, tree_size2):
+ try:
+ params = urllib.urlencode({"first":tree_size1,
+ "second":tree_size2})
+ result = \
+ urllib2.urlopen(baseurl + "ct/v1/get-sth-consistency?" + params).read()
+ return json.loads(result)["consistency"]
+ except urllib2.HTTPError, e:
+ print "ERROR:", e.read()
+ sys.exit(1)
+
def tls_array(data, length_len):
length_bytes = struct.pack(">Q", len(data))[-length_len:]
return length_bytes + data
@@ -340,16 +351,24 @@ def get_certs_from_zipfiles(zipfiles, firstleaf, lastleaf):
except KeyError:
return
-def get_merkle_hash_64k(store, blocknumber, write_to_cache=False):
- hashfilename = "%s/%04x.64khash" % (store, blocknumber)
- try:
- hash = base64.b16decode(open(hashfilename).read())
- assert len(hash) == 32
- return ("hash", hash)
- except IOError:
- pass
+def get_merkle_hash_64k(store, blocknumber, write_to_cache=False, treesize=None):
firstleaf = blocknumber * 65536
lastleaf = firstleaf + 65535
+ if treesize != None:
+ assert firstleaf < treesize
+ usecache = lastleaf < treesize
+ lastleaf = min(lastleaf, treesize - 1)
+ else:
+ usecache = True
+
+ hashfilename = "%s/%04x.64khash" % (store, blocknumber)
+ if usecache:
+ try:
+ hash = base64.b16decode(open(hashfilename).read())
+ assert len(hash) == 32
+ return ("hash", hash)
+ except IOError:
+ pass
firstfile = firstleaf / 10000
lastfile = lastleaf / 10000
zipfiles = {}
@@ -364,10 +383,81 @@ def get_merkle_hash_64k(store, blocknumber, write_to_cache=False):
calculated_hash = tree[-1][0]
for zf in zipfiles.values():
zf.close()
- if len(layer0) != 65536:
+ if len(layer0) != lastleaf - firstleaf + 1:
return ("incomplete", (len(layer0), calculated_hash))
if write_to_cache:
f = open(hashfilename, "w")
f.write(base64.b16encode(calculated_hash))
f.close()
return ("hash", calculated_hash)
+
+def get_tree_head(store, treesize):
+ merkle_64klayer = []
+
+ for blocknumber in range(0, (treesize / 65536) + 1):
+ (resulttype, result) = get_merkle_hash_64k(store, blocknumber, treesize=treesize)
+ if resulttype == "incomplete":
+ print >>sys.stderr, "Couldn't read until tree size", treesize
+ (incompletelength, hash) = result
+ print >>sys.stderr, "Stopped at", blocknumber * 65536 + incompletelength
+ sys.exit(1)
+ assert resulttype == "hash"
+ hash = result
+ merkle_64klayer.append(hash)
+ #print >>sys.stderr, print blocknumber * 65536,
+ sys.stdout.flush()
+ tree = build_merkle_tree(merkle_64klayer)
+ calculated_root_hash = tree[-1][0]
+ return calculated_root_hash
+
+def get_intermediate_hash(store, treesize, level, index):
+ if level >= 16:
+ merkle_64klayer = []
+
+ levelsize = (2**(level-16))
+
+ for blocknumber in range(index * levelsize, (index + 1) * levelsize):
+ if blocknumber * (2 ** 16) >= treesize:
+ break
+ #print "looking at block", blocknumber
+ (resulttype, result) = get_merkle_hash_64k(store, blocknumber, treesize=treesize)
+ if resulttype == "incomplete":
+ print >>sys.stderr, "Couldn't read until tree size", treesize
+ (incompletelength, hash) = result
+ print >>sys.stderr, "Stopped at", blocknumber * 65536 + incompletelength
+ sys.exit(1)
+ assert resulttype == "hash"
+ hash = result
+ #print "block hash", base64.b16encode(hash)
+ merkle_64klayer.append(hash)
+ #print >>sys.stderr, print blocknumber * 65536,
+ sys.stdout.flush()
+ tree = build_merkle_tree(merkle_64klayer)
+ return tree[-1][0]
+ else:
+ levelsize = 2 ** level
+ firstleaf = index * levelsize
+ lastleaf = firstleaf + levelsize - 1
+ #print "firstleaf", firstleaf
+ #print "lastleaf", lastleaf
+ assert firstleaf < treesize
+ lastleaf = min(lastleaf, treesize - 1)
+ #print "modified lastleaf", lastleaf
+ firstfile = firstleaf / 10000
+ lastfile = lastleaf / 10000
+ #print "files", firstfile, lastfile
+ zipfiles = {}
+ for i in range(firstfile, lastfile + 1):
+ try:
+ zipfiles[i] = zipfile.ZipFile("%s/%04d.zip" % (store, i))
+ except IOError:
+ break
+ certs = get_certs_from_zipfiles(zipfiles, firstleaf, lastleaf)
+ layer0 = [get_hash_from_certfile(cert) for cert in certs]
+ #print "layer0", repr(layer0)
+ tree = build_merkle_tree(layer0)
+ calculated_hash = tree[-1][0]
+ for zf in zipfiles.values():
+ zf.close()
+ assert len(layer0) == lastleaf - firstleaf + 1
+ return calculated_hash