Certificate Transparency: Fetching of Signed Tree Heads (DRAFT)

net/cert/ct_log_verifier.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/cert/ct_log_verifier.h"
 
 #include "base/logging.h"
 #include "net/cert/ct_serialization.h"
 #include "net/cert/signed_tree_head.h"
 
 namespace net {
 
 // static
 scoped_ptr<CTLogVerifier> CTLogVerifier::Create(
     const base::StringPiece& public_key,
-    const base::StringPiece& description) {
-  scoped_ptr<CTLogVerifier> result(new CTLogVerifier());
-  if (!result->Init(public_key, description))
+    const base::StringPiece& description,
+    const base::StringPiece& url) {
+  scoped_ptr<CTLogVerifier> result(new CTLogVerifier(description, url));
+  if (!result->Init(public_key))
     result.reset();
   return result.Pass();
 }
 
+CTLogVerifier::CTLogVerifier(const base::StringPiece& description,
+                             const base::StringPiece& url)
+    : description_(description.as_string()),
+      url_(url.as_string()),
+      hash_algorithm_(ct::DigitallySigned::HASH_ALGO_NONE),
+      signature_algorithm_(ct::DigitallySigned::SIG_ALGO_ANONYMOUS),
+      public_key_(NULL) {
+}
+
 bool CTLogVerifier::Verify(const ct::LogEntry& entry,
                            const ct::SignedCertificateTimestamp& sct) {
   if (sct.log_id != key_id()) {
     DVLOG(1) << "SCT is not signed by this log.";
     return false;
   }
 
   if (!SignatureParametersMatch(sct.signature))
     return false;
 
   std::string serialized_log_entry;
   if (!ct::EncodeLogEntry(entry, &serialized_log_entry)) {
     DVLOG(1) << "Unable to serialize entry.";
     return false;
   }
   std::string serialized_data;
   if (!ct::EncodeV1SCTSignedData(sct.timestamp, serialized_log_entry,
                                  sct.extensions, &serialized_data)) {
     DVLOG(1) << "Unable to create SCT to verify.";
     return false;
   }
 
   return VerifySignature(serialized_data, sct.signature.signature_data);
 }
 
-bool CTLogVerifier::SetSignedTreeHead(
-    scoped_ptr<ct::SignedTreeHead> signed_tree_head) {
+bool CTLogVerifier::VerifySignedTreeHead(
+    const ct::SignedTreeHead* signed_tree_head) {
   if (!SignatureParametersMatch(signed_tree_head->signature))
     return false;
 
   std::string serialized_data;
-  ct::EncodeTreeHeadSignature(*signed_tree_head.get(), &serialized_data);
+  ct::EncodeTreeHeadSignature(*signed_tree_head, &serialized_data);
   if (VerifySignature(serialized_data,
                       signed_tree_head->signature.signature_data)) {
-    signed_tree_head_.reset(signed_tree_head.release());
     return true;
   }
   return false;
 }
 
 bool CTLogVerifier::SignatureParametersMatch(
     const ct::DigitallySigned& signature) {
   if (!signature.SignatureParametersMatch(hash_algorithm_,
                                           signature_algorithm_)) {
     DVLOG(1) << "Mismatched hash or signature algorithm. Hash: "
              << hash_algorithm_ << " vs " << signature.hash_algorithm
              << " Signature: " << signature_algorithm_ << " vs "
              << signature.signature_algorithm << ".";
     return false;
   }
 
   return true;
 }
 
 }  // namespace net