Certificate Transparency: Fetching consistency proofs.

components/certificate_transparency/log_proof_fetcher.h

Index: components/certificate_transparency/log_proof_fetcher.h
diff --git a/components/certificate_transparency/log_proof_fetcher.h b/components/certificate_transparency/log_proof_fetcher.h
index ba952e365d6f77177184a9c70648e2b9f6ef6b09..a7a5a57154f8c74c87332f0b129cbb59be42c253 100644
--- a/components/certificate_transparency/log_proof_fetcher.h
+++ b/components/certificate_transparency/log_proof_fetcher.h
@@ -7,12 +7,14 @@
 
 #include <map>
 #include <string>
+#include <vector>
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "net/url_request/url_request.h"
+#include "url/gurl.h"
 
 namespace base {
 class Value;
@@ -53,6 +55,14 @@ class LogProofFetcher : public net::URLRequest::Delegate {
   using FetchFailedCallback = base::Callback<
       void(const std::string& log_id, int net_error, int http_response_code)>;
 
+  // Callback for successful retrieval of consistency proofs between two
+  // STHs. Called with the log_id of the log the consistency belongs to (as
+  // supplied by the caller to FetchConsistencyProof) and the vector of
+  // proof nodes.
+  using ConsistencyProofFetchedCallback =
+      base::Callback<void(const std::string& log_id,
+                          const std::vector<std::string>& consistency_proof)>;
+
   explicit LogProofFetcher(net::URLRequestContext* request_context);
   ~LogProofFetcher() override;
 
@@ -73,6 +83,20 @@ class LogProofFetcher : public net::URLRequest::Delegate {
       const SignedTreeHeadFetchedCallback& fetched_callback,
       const FetchFailedCallback& failed_callback);
 
+  // Fetch a consistency proof between the Merkle trees identified by
+  // |old_tree_size| and |new_tree_size| of the log identified by |log_id|
+  // from |base_log_url|.
+  //
+  // See the documentation of FetchSignedTreeHead regarding request destruction
+  // and multiple requests to the same log.
+  void FetchConsistencyProof(
+      const GURL& base_log_url,
+      const std::string& log_id,
+      uint64_t old_tree_size,
+      uint64_t new_tree_size,
+      const ConsistencyProofFetchedCallback& fetched_callback,
+      const FetchFailedCallback& failed_callback);
+
   // net::URLRequest::Delegate
   void OnResponseStarted(net::URLRequest* request) override;
   void OnReadCompleted(net::URLRequest* request, int bytes_read) override;
@@ -103,9 +127,16 @@ class LogProofFetcher : public net::URLRequest::Delegate {
                              int http_response_code);
 
   // Callbacks for parsing the STH's JSON by the SafeJsonParser
-  void OnSTHJsonParseSuccess(net::URLRequest* request,
-                             scoped_ptr<base::Value> parsed_json);
-  void OnSTHJsonParseError(net::URLRequest* request, const std::string& error);
+  void OnJsonParseSuccess(net::URLRequest* request,
+                          scoped_ptr<base::Value> parsed_json);
+  void OnJsonParseError(net::URLRequest* request, const std::string& error);
+
+  // Creates and starts a URLRequest for actual fetching from the log.
+  // takes ownership of |fetch_state| and puts it (together with the
+  // URLRequest created) into |inflight_requests_|.
+  void FetchFromLog(const GURL& base_log_url,
+                    const std::string& log_id,
+                    FetchState* fetch_state);
 
   net::URLRequestContext* const request_context_;