Revert 184133

crypto/hkdf.cc

Index: crypto/hkdf.cc
===================================================================
--- crypto/hkdf.cc	(revision 184145)
+++ crypto/hkdf.cc	(working copy)
@@ -1,92 +0,0 @@
-// 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.
-
-#include "crypto/hkdf.h"
-
-#include "base/logging.h"
-#include "crypto/hmac.h"
-
-namespace crypto {
-
-const size_t kSHA256HashLength = 32;
-
-HKDF::HKDF(const base::StringPiece& secret,
-           const base::StringPiece& salt,
-           const base::StringPiece& info,
-           size_t key_bytes_to_generate,
-           size_t iv_bytes_to_generate) {
-  // https://tools.ietf.org/html/rfc5869#section-2.2
-  base::StringPiece actual_salt = salt;
-  char zeros[kSHA256HashLength];
-  if (actual_salt.empty()) {
-    // If salt is not given, HashLength zeros are used.
-    memset(zeros, 0, sizeof(zeros));
-    actual_salt.set(zeros, sizeof(zeros));
-  }
-
-  // Perform the Extract step to transform the input key and
-  // salt into the pseudorandom key (PRK) used for Expand.
-  HMAC prk_hmac(HMAC::SHA256);
-  bool result = prk_hmac.Init(actual_salt);
-  DCHECK(result);
-
-  // |prk| is a pseudorandom key (of kSHA256HashLength octets).
-  uint8 prk[kSHA256HashLength];
-  DCHECK_EQ(sizeof(prk), prk_hmac.DigestLength());
-  result = prk_hmac.Sign(secret, prk, sizeof(prk));
-  DCHECK(result);
-
-  // https://tools.ietf.org/html/rfc5869#section-2.3
-  // Perform the Expand phase to turn the pseudorandom key
-  // and info into the output keying material.
-  const size_t material_length =
-      2*key_bytes_to_generate + 2*iv_bytes_to_generate;
-  const size_t n = (material_length + kSHA256HashLength-1) /
-                   kSHA256HashLength;
-  DCHECK_LT(n, 256u);
-
-  output_.resize(n * kSHA256HashLength);
-  base::StringPiece previous;
-
-  char* buf = new char[kSHA256HashLength + info.size() + 1];
-  uint8 digest[kSHA256HashLength];
-
-  HMAC hmac(HMAC::SHA256);
-  result = hmac.Init(prk, sizeof(prk));
-  DCHECK(result);
-
-  for (size_t i = 0; i < n; i++) {
-    memcpy(buf, previous.data(), previous.size());
-    size_t j = previous.size();
-    memcpy(buf + j, info.data(), info.size());
-    j += info.size();
-    buf[j++] = static_cast<char>((i + 1) & 0xFF);
-
-    result = hmac.Sign(base::StringPiece(buf, j), digest, sizeof(digest));
-    DCHECK(result);
-
-    memcpy(&output_[i*sizeof(digest)], digest, sizeof(digest));
-    previous = base::StringPiece(reinterpret_cast<char*>(digest),
-                                 sizeof(digest));
-  }
-
-  size_t j = 0;
-  client_write_key_ = base::StringPiece(reinterpret_cast<char *>(&output_[j]),
-                                        key_bytes_to_generate);
-  j += key_bytes_to_generate;
-  server_write_key_ = base::StringPiece(reinterpret_cast<char *>(&output_[j]),
-                                        key_bytes_to_generate);
-  j += key_bytes_to_generate;
-  client_write_iv_ = base::StringPiece(reinterpret_cast<char *>(&output_[j]),
-                                       iv_bytes_to_generate);
-  j += iv_bytes_to_generate;
-  server_write_iv_ = base::StringPiece(reinterpret_cast<char *>(&output_[j]),
-                                       iv_bytes_to_generate);
-  delete[] buf;
-}
-
-HKDF::~HKDF() {
-}
-
-}  // namespace crypto