net/quic/crypto/crypto_utils.h

   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 // Some helpers for quic crypto
   6
   7 #ifndef NET_QUIC_CRYPTO_CRYPTO_UTILS_H_
   8 #define NET_QUIC_CRYPTO_CRYPTO_UTILS_H_
   9
  10 #include <string>
  11
  12 #include "base/strings/string_piece.h"
  13 #include "net/base/net_export.h"
  14 #include "net/quic/crypto/crypto_handshake.h"
  15 #include "net/quic/crypto/crypto_protocol.h"
  16 #include "net/quic/quic_protocol.h"
  17 #include "net/quic/quic_time.h"
  18
  19 namespace net {
  20
  21 class QuicTime;
  22 class QuicRandom;
  23 struct QuicCryptoNegotiatedParameters;
  24
  25 class NET_EXPORT_PRIVATE CryptoUtils {
  26  public:
  27   // Generates the connection nonce. The nonce is formed as:
  28   //   <4 bytes> current time
  29   //   <8 bytes> |orbit| (or random if |orbit| is empty)
  30   //   <20 bytes> random
  31   static void GenerateNonce(QuicWallTime now,
  32                             QuicRandom* random_generator,
  33                             base::StringPiece orbit,
  34                             std::string* nonce);
  35
  36   // Returns true if the sni is valid, false otherwise.
  37   //  (1) disallow IP addresses;
  38   //  (2) check that the hostname contains valid characters only; and
  39   //  (3) contains at least one dot.
  40   static bool IsValidSNI(base::StringPiece sni);
  41
  42   // Convert hostname to lowercase and remove the trailing '.'.
  43   // Returns |hostname|. NormalizeHostname() doesn't support IP address
  44   // literals. IsValidSNI() should be called before calling NormalizeHostname().
  45   static std::string NormalizeHostname(const char* hostname);
  46
  47   // DeriveKeys populates |crypters->encrypter|, |crypters->decrypter|, and
  48   // |subkey_secret| (optional -- may be null) given the contents of
  49   // |premaster_secret|, |client_nonce|, |server_nonce| and |hkdf_input|. |aead|
  50   // determines which cipher will be used. |perspective| controls whether the
  51   // server's keys are assigned to |encrypter| or |decrypter|. |server_nonce| is
  52   // optional and, if non-empty, is mixed into the key derivation.
  53   // |subkey_secret| will have the same length as |premaster_secret|.
  54   static bool DeriveKeys(base::StringPiece premaster_secret,
  55                          QuicTag aead,
  56                          base::StringPiece client_nonce,
  57                          base::StringPiece server_nonce,
  58                          const std::string& hkdf_input,
  59                          Perspective perspective,
  60                          CrypterPair* crypters,
  61                          std::string* subkey_secret);
  62
  63   // Performs key extraction to derive a new secret of |result_len| bytes
  64   // dependent on |subkey_secret|, |label|, and |context|. Returns false if the
  65   // parameters are invalid (e.g. |label| contains null bytes); returns true on
  66   // success.
  67   static bool ExportKeyingMaterial(base::StringPiece subkey_secret,
  68                                    base::StringPiece label,
  69                                    base::StringPiece context,
  70                                    size_t result_len,
  71                                    std::string* result);
  72
  73  private:
  74   DISALLOW_COPY_AND_ASSIGN(CryptoUtils);
  75 };
  76
  77 }  // namespace net
  78
  79 #endif  // NET_QUIC_CRYPTO_CRYPTO_UTILS_H_