CT: Adding SCT verification functionality: A CTLogVerifier instance can verify SCTs signed by a sin…

net/cert/ct_log_verifier.h

+// Copyright (c) 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_LOG_VERIFIER_H_
+#define NET_CERT_CT_LOG_VERIFIER_H_
+
+#include <string>
+
+#include "base/gtest_prod_util.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/strings/string_piece.h"
+#include "net/base/net_export.h"
+#include "net/cert/signed_certificate_timestamp.h"
+
+// Forward declare the crypto types to avoid having to include the full
+// headers.
+#if defined(USE_OPENSSL)
+typedef struct evp_pkey_st EVP_PKEY;
+#else
+typedef struct SECKEYPublicKeyStr SECKEYPublicKey;
+#endif
+
+namespace net {
+
+// Class for verifying Signed Certificate Timestamps (SCTs) provided by a
+// specific log (whose identity is provided during construction).
+class NET_EXPORT CTLogVerifier {
+ public:
+  // Creates a new CTLogVerifier that will verify SignedCertificateTimestamps
+  // using |public_key|, which is a DER-encoded SubjectPublicKeyInfo.
+  // If |public_key| refers to an unsupported public key, returns NULL.
+  // |description| is a textual description of the log.
+  static scoped_ptr<CTLogVerifier> Create(
+      const base::StringPiece& public_key,
+      const base::StringPiece& description);
+
+  ~CTLogVerifier();
+
+  // Returns the log's key ID (RFC6962, Section 3.2)
+  const std::string& key_id() const { return key_id_; }
+  // Returns the log's human-readable description.
+  const std::string& description() const { return description_; }
+
+  // Verifies that |sct| contains a valid signature for |entry|.
+  bool Verify(const ct::LogEntry& entry,
+              const ct::SignedCertificateTimestamp& sct);
+
+ private:
+  FRIEND_TEST_ALL_PREFIXES(CTLogVerifierTest, VerifySignature);
+
+  CTLogVerifier();
+
+  // Performs crypto-library specific initialization.
+  bool Init(const base::StringPiece& public_key,
+            const base::StringPiece& description);
+
+  // Performs the underlying verification using the selected public key. Note
+  // that |signature| contains the raw signature data (eg: without any
+  // DigitallySigned struct encoding).
+  bool VerifySignature(const base::StringPiece& data_to_sign,
+                       const base::StringPiece& signature);
+
+  std::string key_id_;
+  std::string description_;
+  ct::DigitallySigned::HashAlgorithm hash_algorithm_;
+  ct::DigitallySigned::SignatureAlgorithm signature_algorithm_;
+
+#if defined(USE_OPENSSL)
+  EVP_PKEY* public_key_;
+#else
+  SECKEYPublicKey* public_key_;
+#endif
+};
+
+}  // namespace net
+
+#endif  // NET_CERT_CT_LOG_VERIFIER_H_