1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
|
# Copyright (c) 2014, NORDUnet A/S.
# See LICENSE for licensing information.
import subprocess
import json
import base64
import urllib
import urllib2
import struct
import sys
import hashlib
import ecdsa
publickeys = {
"https://ct.googleapis.com/pilot/":
"MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEfahLEimAoz2t01p3uMziiLOl/fHTD"
"M0YDOhBRuiBARsV4UvxG2LdNgoIGLrtCzWE0J5APC2em4JlvR8EEEFMoA==",
"https://127.0.0.1:8080/":
"MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE4qWq6afhBUi0OdcWUYhyJLNXTkGqQ9"
"PMS5lqoCgkV2h1ZvpNjBH2u8UbgcOQwqDo66z6BWQJGolozZYmNHE2kQ==",
"https://flimsy.ct.nordu.net/":
"MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE4qWq6afhBUi0OdcWUYhyJLNXTkGqQ9"
"PMS5lqoCgkV2h1ZvpNjBH2u8UbgcOQwqDo66z6BWQJGolozZYmNHE2kQ==",
}
def get_cert_info(s):
p = subprocess.Popen(
["openssl", "x509", "-noout", "-subject", "-issuer", "-inform", "der"],
stdin=subprocess.PIPE, stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
parsed = p.communicate(s)
if parsed[1]:
print "ERROR:", parsed[1]
sys.exit(1)
result = {}
for line in parsed[0].split("\n"):
(key, sep, value) = line.partition("=")
if sep == "=":
result[key] = value
return result
def get_certs_from_file(certfile):
certs = []
cert = ""
incert = False
for line in open(certfile):
line = line.strip()
if line == "-----BEGIN CERTIFICATE-----":
cert = ""
incert = True
elif line == "-----END CERTIFICATE-----":
certs.append(base64.decodestring(cert))
incert = False
elif incert:
cert += line
return certs
def get_root_cert(issuer):
accepted_certs = \
json.loads(open("googlelog-accepted-certs.txt").read())["certificates"]
root_cert = None
for accepted_cert in accepted_certs:
subject = get_cert_info(base64.decodestring(accepted_cert))["subject"]
if subject == issuer:
root_cert = base64.decodestring(accepted_cert)
return root_cert
def get_sth(baseurl):
result = urllib2.urlopen(baseurl + "ct/v1/get-sth").read()
return json.loads(result)
def get_proof_by_hash(baseurl, hash, tree_size):
try:
params = urllib.urlencode({"hash":base64.b64encode(hash),
"tree_size":tree_size})
result = \
urllib2.urlopen(baseurl + "ct/v1/get-proof-by-hash?" + params).read()
return json.loads(result)
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
def unpack_tls_array(packed_data, length_len):
padded_length = ["\x00"] * 8
padded_length[-length_len:] = packed_data[:length_len]
(length,) = struct.unpack(">Q", "".join(padded_length))
unpacked_data = packed_data[length_len:length_len+length]
assert len(unpacked_data) == length, \
"data is only %d bytes long, but length is %d bytes" % \
(len(unpacked_data), length)
rest_data = packed_data[length_len+length:]
return (unpacked_data, rest_data)
def add_chain(baseurl, submission):
try:
result = urllib2.urlopen(baseurl + "ct/v1/add-chain",
json.dumps(submission)).read()
return json.loads(result)
except urllib2.HTTPError, e:
print "ERROR:", e.read()
sys.exit(1)
except ValueError, e:
print "==== FAILED REQUEST ===="
print submission
print "======= RESPONSE ======="
print result
print "========================"
raise e
def get_entries(baseurl, start, end):
try:
params = urllib.urlencode({"start":start, "end":end})
result = urllib2.urlopen(baseurl + "ct/v1/get-entries?" + params).read()
return json.loads(result)
except urllib2.HTTPError, e:
print "ERROR:", e.read()
sys.exit(1)
def decode_certificate_chain(packed_certchain):
(unpacked_certchain, rest) = unpack_tls_array(packed_certchain, 3)
assert len(rest) == 0
certs = []
while len(unpacked_certchain):
(cert, rest) = unpack_tls_array(unpacked_certchain, 3)
certs.append(cert)
unpacked_certchain = rest
return certs
def decode_signature(signature):
(hash_alg, signature_alg) = struct.unpack(">bb", signature[0:2])
(unpacked_signature, rest) = unpack_tls_array(signature[2:], 2)
assert rest == ""
return (hash_alg, signature_alg, unpacked_signature)
def check_signature(baseurl, signature, data):
publickey = base64.decodestring(publickeys[baseurl])
(hash_alg, signature_alg, unpacked_signature) = decode_signature(signature)
assert hash_alg == 4, \
"hash_alg is %d, expected 4" % (hash_alg,) # sha256
assert signature_alg == 3, \
"signature_alg is %d, expected 3" % (signature_alg,) # ecdsa
vk = ecdsa.VerifyingKey.from_der(publickey)
vk.verify(unpacked_signature, data, hashfunc=hashlib.sha256,
sigdecode=ecdsa.util.sigdecode_der)
def check_sth_signature(baseurl, sth):
signature = base64.decodestring(sth["tree_head_signature"])
version = struct.pack(">b", 0)
signature_type = struct.pack(">b", 1)
timestamp = struct.pack(">Q", sth["timestamp"])
tree_size = struct.pack(">Q", sth["tree_size"])
hash = base64.decodestring(sth["sha256_root_hash"])
tree_head = version + signature_type + timestamp + tree_size + hash
check_signature(baseurl, signature, tree_head)
def check_sct_signature(baseurl, leafcert, sct):
publickey = base64.decodestring(publickeys[baseurl])
calculated_logid = hashlib.sha256(publickey).digest()
received_logid = base64.decodestring(sct["id"])
assert calculated_logid == received_logid, \
"log id is incorrect:\n should be %s\n got %s" % \
(calculated_logid.encode("hex_codec"),
received_logid.encode("hex_codec"))
signature = base64.decodestring(sct["signature"])
version = struct.pack(">b", sct["sct_version"])
signature_type = struct.pack(">b", 0)
timestamp = struct.pack(">Q", sct["timestamp"])
entry_type = struct.pack(">H", 0)
signed_struct = version + signature_type + timestamp + \
entry_type + tls_array(leafcert, 3) + \
tls_array(base64.decodestring(sct["extensions"]), 2)
check_signature(baseurl, signature, signed_struct)
def pack_mtl(timestamp, leafcert):
entry_type = struct.pack(">H", 0)
extensions = ""
timestamped_entry = struct.pack(">Q", timestamp) + entry_type + \
tls_array(leafcert, 3) + tls_array(extensions, 2)
version = struct.pack(">b", 0)
leaf_type = struct.pack(">b", 0)
merkle_tree_leaf = version + leaf_type + timestamped_entry
return merkle_tree_leaf
def get_leaf_hash(merkle_tree_leaf):
leaf_hash = hashlib.sha256()
leaf_hash.update(struct.pack(">b", 0))
leaf_hash.update(merkle_tree_leaf)
return leaf_hash.digest()
|
