Certificate Transparency: Add observer for Signed Certificate Timestamps

net/cert/ct_verifier.h

 // 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.
 
 #ifndef NET_CERT_CT_VERIFIER_H_
 #define NET_CERT_CT_VERIFIER_H_
 
+#include <string>
+
 #include "net/base/net_export.h"
 
 namespace net {
 
 namespace ct {
 struct CTVerifyResult;
+struct SignedCertificateTimestamp;
 }  // namespace ct
 
 class BoundNetLog;
+class CTLogVerifier;
 class X509Certificate;
 
 // Interface for verifying Signed Certificate Timestamps over a certificate.
 class NET_EXPORT CTVerifier {
  public:
+  class NET_EXPORT Observer {
+   public:
+    // Called for each Signed Certificate Timestamp from a known log that vas
+    // verified successfully (i.e. the signature verifies). |sct| is the
+    // Signed Certificate Timestamp, |cert| is the certificate it applies to.
+    // The certificate is needed to calculate the hash of the log entry,
+    // necessary for checking inclusion in the log.
+    virtual void OnSCTVerified(X509Certificate* cert,
+                               const ct::SignedCertificateTimestamp* sct) = 0;
+  };
+
   virtual ~CTVerifier() {}
 
   // Verifies SCTs embedded in the certificate itself, SCTs embedded in a
   // stapled OCSP response, and SCTs obtained via the
   // signed_certificate_timestamp TLS extension on the given |cert|.
   // A certificate is permitted but not required to use multiple sources for
   // SCTs. It is expected that most certificates will use only one source
   // (embedding, TLS extension or OCSP stapling). If no stapled OCSP response
   // is available, |stapled_ocsp_response| should be an empty string. If no SCT
   // TLS extension was negotiated, |sct_list_from_tls_extension| should be an
   // empty string. |result| will be filled with the SCTs present, divided into
   // categories based on the verification result.
   virtual int Verify(X509Certificate* cert,
                      const std::string& stapled_ocsp_response,
                      const std::string& sct_list_from_tls_extension,
                      ct::CTVerifyResult* result,
                      const BoundNetLog& net_log) = 0;
+
+  // Registers |observer| to receive notifications of validated SCTs. Does not
+  // take ownership of the observer as the observer may be performing
+  // URLRequests which have to be cancelled before this object is destroyed.
+  // Setting |observer| to nullptr has the effect of stopping all notifications.
+  virtual void SetObserver(Observer* observer) = 0;
 };
 
 }  // namespace net
 
 #endif  // NET_CERT_CT_VERIFIER_H_