Add a term feature extractor for client-side phishing detection.

base/sha2.h

 // Copyright (c) 2006-2008 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 BASE_SHA2_H_
 #define BASE_SHA2_H_
 #pragma once
 
 #include <string>
 
 namespace base {
 
 // These functions perform SHA-256 operations.
 //
 // Functions for SHA-384 and SHA-512 can be added when the need arises.
 
 enum {
   SHA256_LENGTH = 32  // length in bytes of a SHA-256 hash
 };
 
 // Computes the SHA-256 hash of the input string 'str' and stores the first
 // 'len' bytes of the hash in the output buffer 'output'.  If 'len' > 32,
 // only 32 bytes (the full hash) are stored in the 'output' buffer.
 void SHA256HashString(const std::string& str, void* output, size_t len);
 
+// Convenience version of the above that returns the result in a 32-byte
+// string.
+std::string SHA256HashString(const std::string& str);
+
 }  // namespace base
 
 #endif  // BASE_SHA2_H_