Added precert handling for SCT calculation

1 files changed, 15 insertions, 5 deletions

diff --git a/tools/certtools.py b/tools/certtools.py
index 1436863..cc423af 100644
--- a/tools/certtools.py
+++ b/tools/certtools.py
@@ -257,7 +257,7 @@ def create_sth_signature(tree_size, timestamp, root_hash, baseurl, key=None):
 
     return create_signature(baseurl, tree_head, key=key)
 
-def check_sct_signature(baseurl, leafcert, sct):
+def check_sct_signature(baseurl, signed_entry, sct, precert=False):
     publickey = base64.decodestring(publickeys[baseurl])
     calculated_logid = hashlib.sha256(publickey).digest()
     received_logid = base64.decodestring(sct["id"])
@@ -271,9 +271,12 @@ def check_sct_signature(baseurl, leafcert, sct):
     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)
+    if precert:
+        entry_type = struct.pack(">H", 1)
+    else:
+        entry_type = struct.pack(">H", 0)
     signed_struct = version + signature_type + timestamp + \
-      entry_type + tls_array(leafcert, 3) + \
+      entry_type + signed_entry + \
       tls_array(base64.decodestring(sct["extensions"]), 2)
 
     check_signature(baseurl, signature, signed_struct)
@@ -292,15 +295,22 @@ def pack_mtl(timestamp, leafcert):
 def pack_mtl_precert(timestamp, cleanedcert, issuer_key_hash):
     entry_type = struct.pack(">H", 1)
     extensions = ""
-    assert len(issuer_key_hash) == 32
 
     timestamped_entry = struct.pack(">Q", timestamp) + entry_type + \
-      issuer_key_hash + tls_array(cleanedcert, 3) + tls_array(extensions, 2)
+      pack_precert(cleanedcert, issuer_key_hash) + 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 pack_precert(cleanedcert, issuer_key_hash):
+    assert len(issuer_key_hash) == 32
+
+    return issuer_key_hash + tls_array(cleanedcert, 3)
+
+def pack_cert(cert):
+    return tls_array(cert, 3)
+
 def unpack_mtl(merkle_tree_leaf):
     version = merkle_tree_leaf[0:1]
     leaf_type = merkle_tree_leaf[1:2]