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   enum Perspective {
  28     SERVER,
  29     CLIENT,
  30   };
  31
  32   // Generates the connection nonce. The nonce is formed as:
  33   //   <4 bytes> current time
  34   //   <8 bytes> |orbit| (or random if |orbit| is empty)
  35   //   <20 bytes> random
  36   static void GenerateNonce(QuicWallTime now,
  37                             QuicRandom* random_generator,
  38                             base::StringPiece orbit,
  39                             std::string* nonce);
  40
  41   // Returns true if the sni is valid, false otherwise.
  42   //  (1) disallow IP addresses;
  43   //  (2) check that the hostname contains valid characters only; and
  44   //  (3) contains at least one dot.
  45   static bool IsValidSNI(base::StringPiece sni);
  46
  47   // Convert hostname to lowercase and remove the trailing '.'.
  48   // Returns |hostname|. NormalizeHostname() doesn't support IP address
  49   // literals. IsValidSNI() should be called before calling NormalizeHostname().
  50   static std::string NormalizeHostname(const char* hostname);
  51
  52   // DeriveKeys populates |crypters->encrypter|, |crypters->decrypter|, and
  53   // |subkey_secret| (optional -- may be null) given the contents of
  54   // |premaster_secret|, |client_nonce|, |server_nonce| and |hkdf_input|. |aead|
  55   // determines which cipher will be used. |perspective| controls whether the
  56   // server's keys are assigned to |encrypter| or |decrypter|. |server_nonce| is
  57   // optional and, if non-empty, is mixed into the key derivation.
  58   // |subkey_secret| will have the same length as |premaster_secret|.
  59   static bool DeriveKeys(base::StringPiece premaster_secret,
  60                          QuicTag aead,
  61                          base::StringPiece client_nonce,
  62                          base::StringPiece server_nonce,
  63                          const std::string& hkdf_input,
  64                          Perspective perspective,
  65                          CrypterPair* crypters,
  66                          std::string* subkey_secret);
  67
  68   // Performs key extraction to derive a new secret of |result_len| bytes
  69   // dependent on |subkey_secret|, |label|, and |context|. Returns false if the
  70   // parameters are invalid (e.g. |label| contains null bytes); returns true on
  71   // success.
  72   static bool ExportKeyingMaterial(base::StringPiece subkey_secret,
  73                                    base::StringPiece label,
  74                                    base::StringPiece context,
  75                                    size_t result_len,
  76                                    std::string* result);
  77
  78  private:
  79   DISALLOW_COPY_AND_ASSIGN(CryptoUtils);
  80 };
  81
  82 }  // namespace net
  83
  84 #endif  // NET_QUIC_CRYPTO_CRYPTO_UTILS_H_