diff options
| -rwxr-xr-x | sigsum-witness.py | 17 |
1 files changed, 9 insertions, 8 deletions
diff --git a/sigsum-witness.py b/sigsum-witness.py index 2be3f3a..52005df 100755 --- a/sigsum-witness.py +++ b/sigsum-witness.py @@ -29,6 +29,7 @@ from hashlib import sha256 import time from math import floor from pathlib import PurePath +from tools.libsigntools import ssh_to_sign BASE_URL_DEFAULT = 'http://poc.sigsum.org:4780/' CONFIG_DIR_DEFAULT = os.path.expanduser('~/.config/sigsum-witness/') @@ -140,12 +141,12 @@ class TreeHead: text += 'signature={}\n'.format(self._text['signature']) return text.encode('ascii') - def serialise(self, pubkey): - data = struct.pack('!QQ', self.timestamp, self.tree_size) - data += unhexlify(self._text['root_hash']) - data += sha256(pubkey.encode()).digest() - assert(len(data) == 8 + 8 + 32 + 32) - return data + def to_signed_data(self, pubkey): + namespace = 'tree_head:v0:{}@sigsum.org'.format(hexlify(sha256(pubkey.encode()).digest()).decode()) + msg = struct.pack('!QQ', self.timestamp, self.tree_size) + msg += unhexlify(self._text['root_hash']) + assert(len(msg) == 8 + 8 + 32) + return ssh_to_sign(namespace, 'sha256', sha256(msg).digest()) def signature_valid(self, pubkey): # Guard against tree head with >1 signature -- don't try to @@ -153,7 +154,7 @@ class TreeHead: assert(type(self._text['signature']) is str) sig = unhexlify(self._text['signature']) assert(len(sig) == 64) - data = self.serialise(pubkey) + data = self.to_signed_data(pubkey) try: verified_data = pubkey.verify(sig + data) except nacl.exceptions.BadSignatureError: @@ -348,7 +349,7 @@ def consistency_proof_valid(first, second, proof): return sn == 0 and fr == first.root_hash and sr == second.root_hash def sign_send_store_tree_head(signing_key, log_key, tree_head): - signature = signing_key.sign(tree_head.serialise(log_key)).signature + signature = signing_key.sign(tree_head.to_signed_data(log_key)).signature hash = sha256(signing_key.verify_key.encode()) post_data = 'cosignature={}\n'.format(hexlify(signature).decode('ascii')) |