Keep only base/extractor.[cc|h].

base/security/hmac.h

-// Copyright 2007-2009 Google Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//      http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-// ========================================================================
-
-#ifndef OMAHA_COMMON_SECURITY_HMAC_H__
-#define OMAHA_COMMON_SECURITY_HMAC_H__
-
-#include <inttypes.h>
-#include "hash-internal.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-typedef struct HMAC_CTX {
-  HASH_CTX hash;
-  uint8_t opad[64];
-} HMAC_CTX;
-
-void HMAC_MD5_init(HMAC_CTX* ctx, const void* key, int len);
-void HMAC_SHA_init(HMAC_CTX* ctx, const void* key, int len);
-const uint8_t* HMAC_final(HMAC_CTX* ctx);
-
-#define HMAC_update(ctx, data, len) HASH_update(&(ctx)->hash, data, len)
-#define HMAC_size(ctx) HASH_size(&(ctx)->hash)
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif  // OMAHA_COMMON_SECURITY_HMAC_H__