crypto/hkdf.cc

   1 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "crypto/hkdf.h"
   6
   7 #include <stddef.h>
   8 #include <stdint.h>
   9
  10 #include <memory>
  11
  12 #include "base/logging.h"
  13 #include "crypto/hmac.h"
  14 #include "third_party/boringssl/src/include/openssl/digest.h"
  15 #include "third_party/boringssl/src/include/openssl/hkdf.h"
  16
  17 namespace crypto {
  18
  19 std::string HkdfSha256(base::StringPiece secret,
  20                        base::StringPiece salt,
  21                        base::StringPiece info,
  22                        size_t derived_key_size) {
  23   std::string key;
  24   key.resize(derived_key_size);
  25   int result = ::HKDF(
  26       reinterpret_cast<uint8_t*>(&key[0]), derived_key_size, EVP_sha256(),
  27       reinterpret_cast<const uint8_t*>(secret.data()), secret.size(),
  28       reinterpret_cast<const uint8_t*>(salt.data()), salt.size(),
  29       reinterpret_cast<const uint8_t*>(info.data()), info.size());
  30   DCHECK(result);
  31   return key;
  32 }
  33
  34 }  // namespace crypto