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

base/security/hmac.c

-// 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.
-// ========================================================================
-//
-// Optimized for minimal code size.
-
-#include "hmac.h"
-
-#include <memory.h>
-#include "sha.h"
-#include "md5.h"
-
-static void HMAC_init(HMAC_CTX* ctx, const void* key, int len) {
-  int i;
-  memset(&ctx->opad[0], 0, sizeof(ctx->opad));
-
-  if (len > sizeof(ctx->opad)) {
-    HASH_init(&ctx->hash);
-    HASH_update(&ctx->hash, key, len);
-    memcpy(&ctx->opad[0], HASH_final(&ctx->hash), HASH_size(&ctx->hash));
-  } else {
-    memcpy(&ctx->opad[0], key, len);
-  }
-
-  for (i = 0; i < sizeof(ctx->opad); ++i) {
-    ctx->opad[i] ^= 0x36;
-  }
-
-  HASH_init(&ctx->hash);
-  HASH_update(&ctx->hash, ctx->opad, sizeof(ctx->opad));  // hash ipad
-
-  for (i = 0; i < sizeof(ctx->opad); ++i) {
-    ctx->opad[i] ^= (0x36 ^ 0x5c);
-  }
-}
-
-void HMAC_MD5_init(HMAC_CTX* ctx, const void* key, int len) {
-  MD5_init(&ctx->hash);
-  HMAC_init(ctx, key, len);
-}
-
-void HMAC_SHA_init(HMAC_CTX* ctx, const void* key, int len) {
-  SHA_init(&ctx->hash);
-  HMAC_init(ctx, key, len);
-}
-
-const uint8_t* HMAC_final(HMAC_CTX* ctx) {
-  uint8_t digest[32];  // upto SHA2
-  memcpy(digest, HASH_final(&ctx->hash),
-         (HASH_size(&ctx->hash) <= sizeof(digest) ?
-             HASH_size(&ctx->hash) : sizeof(digest)));
-  HASH_init(&ctx->hash);
-  HASH_update(&ctx->hash, ctx->opad, sizeof(ctx->opad));
-  HASH_update(&ctx->hash, digest, HASH_size(&ctx->hash));
-  memset(&ctx->opad[0], 0, sizeof(ctx->opad));  // wipe key
-  return HASH_final(&ctx->hash);
-}