Adds function for generating MerkleTreeLeaf hash.

net/cert/merkle_tree_leaf.h

 // Copyright 2016 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_MERKLE_TREE_LEAF_H_
 #define NET_CERT_MERKLE_TREE_LEAF_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 12 matching lines @@
 // slightly differently.
 struct NET_EXPORT MerkleTreeLeaf {
   // Version enum in RFC 6962, Section 3.2.
   enum Version { VERSION_1 = 0, };
   // MerkleLeafType enum in RFC 6962, Section 3.4.
   enum Type { TYPE_TIMESTAMPED_ENTRY = 0, };
 
   MerkleTreeLeaf();
   ~MerkleTreeLeaf();
 
+  // Sets |*out| to the hash of this Merkle tree leaf, as defined in RFC6962.
+  // Returns true if the hash was generated, false if an error occurred.
+  bool Hash(std::string* out) const;
+
   // Version and Merkle leaf type fields are omitted, as there is only one
   // possible value for each of them in CTv1.
 
   // The log id this leaf belongs to.
   std::string log_id;
 
   // Certificate / Precertificate and indication of entry type.
   LogEntry log_entry;
 
   // Timestamp from the SCT.
   base::Time timestamp;
 
   // Extensions from the SCT.
   std::string extensions;
 };
 
 NET_EXPORT bool GetMerkleTreeLeaf(const X509Certificate* cert,
                                   const SignedCertificateTimestamp* sct,
                                   MerkleTreeLeaf* merkle_tree_leaf);
 
 }  // namespace ct
 
 }  // namespace net
 
 #endif  // NET_CERT_MERKLE_TREE_LEAF_H_