chromeos/dbus/fake_easy_unlock_client.cc

   1 // Copyright 2014 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 "base/json/json_string_value_serializer.h"
   6 #include "base/strings/stringprintf.h"
   7 #include "chromeos/dbus/fake_easy_unlock_client.h"
   8
   9 namespace {
  10
  11 // Keys generated using |GenerateEcP256KeyPair| are in the following format:
  12 // "{<key_type>: <key_pair_index>}".
  13 // <key_pair_index> is an integer identifying
  14 // the key pair.
  15 // <key_type> specifies whether the key is public or private. It can have one
  16 // of the following valies:
  17 const char kEc256PrivateKeyKey[] = "ec_p256_private_key";
  18 const char kEc256PublicKeyKey[] = "ec_p256_public_key";
  19
  20 // Extracts key pair index from a key in format "<key_type>: <key_pair_index>}".
  21 int ExtractKeyPairIndexFromKey(const std::string& key,
  22                                const std::string& key_type) {
  23   JSONStringValueSerializer serializer(key);
  24   scoped_ptr<base::Value> json_value(serializer.Deserialize(NULL, NULL));
  25   if (!json_value)
  26     return -1;
  27
  28   base::DictionaryValue* json_dictionary = NULL;
  29   if (!json_value->GetAsDictionary(&json_dictionary))
  30     return -1;
  31
  32   int key_pair_index = -1;
  33   if (!json_dictionary->GetInteger(key_type, &key_pair_index))
  34     return -1;
  35   return key_pair_index;
  36 }
  37
  38 }  // namespace
  39
  40 namespace chromeos {
  41
  42 // static
  43 bool FakeEasyUnlockClient::IsEcP256KeyPair(const std::string& private_key,
  44                                            const std::string& public_key) {
  45   int private_key_index =
  46       ExtractKeyPairIndexFromKey(private_key, kEc256PrivateKeyKey);
  47   int public_key_index =
  48       ExtractKeyPairIndexFromKey(public_key, kEc256PublicKeyKey);
  49
  50   return private_key_index > 0  && public_key_index == private_key_index;
  51 }
  52
  53 FakeEasyUnlockClient::FakeEasyUnlockClient() : generated_keys_count_(0) {}
  54
  55 FakeEasyUnlockClient::~FakeEasyUnlockClient() {}
  56
  57 void FakeEasyUnlockClient::Init(dbus::Bus* bus) {}
  58
  59 void FakeEasyUnlockClient::GenerateEcP256KeyPair(
  60     const KeyPairCallback& callback) {
  61   ++generated_keys_count_;
  62
  63   callback.Run(
  64       base::StringPrintf("{\"%s\": %d}",
  65                          kEc256PrivateKeyKey,
  66                          generated_keys_count_),
  67       base::StringPrintf("{\"%s\": %d}",
  68                          kEc256PublicKeyKey,
  69                          generated_keys_count_));
  70 }
  71
  72 void FakeEasyUnlockClient::WrapPublicKey(const std::string& key_algorithm,
  73                                          const std::string& public_key,
  74                                          const DataCallback& callback) {
  75   callback.Run(base::StringPrintf(
  76       "{\"wrapped_key\": {\"algorithm\":\"%s\", \"key\":\"%s\"}}",
  77       key_algorithm.c_str(),
  78       public_key.c_str()));
  79 }
  80
  81 void FakeEasyUnlockClient::PerformECDHKeyAgreement(
  82     const std::string& private_key,
  83     const std::string& public_key,
  84     const DataCallback& callback) {
  85   int private_key_index =
  86       ExtractKeyPairIndexFromKey(private_key, kEc256PrivateKeyKey);
  87   int public_key_index =
  88       ExtractKeyPairIndexFromKey(public_key, kEc256PublicKeyKey);
  89   if (private_key_index < 0 || public_key_index < 0) {
  90     callback.Run("");
  91     return;
  92   }
  93
  94   // ECDH key agreement should be commutative in respect to key pairs to which
  95   // used keys belong, i.e. (key_pair[1].private_key, key_pair[2].public_key)
  96   // and (key_pair[2].private_key, key_pair[1].public_key) should produce the
  97   // same shared key. To achieve this, identify the created key by sum and
  98   // product of the used key pairs.
  99   callback.Run(base::StringPrintf(
 100       "{\"secret_key\": [%d, %d]}",
 101       private_key_index + public_key_index,
 102       private_key_index * public_key_index));
 103 }
 104
 105 void FakeEasyUnlockClient::CreateSecureMessage(
 106     const std::string& payload,
 107     const CreateSecureMessageOptions& options,
 108     const DataCallback& callback) {
 109   callback.Run(base::StringPrintf(
 110       "{\"securemessage\": {"
 111           "\"payload\": \"%s\","
 112           "\"key\": \"%s\","
 113           "\"associated_data\": \"%s\","
 114           "\"public_metadata\": \"%s\","
 115           "\"verification_key_id\": \"%s\","
 116           "\"decryption_key_id\": \"%s\","
 117           "\"encryption_type\": \"%s\","
 118           "\"signature_type\": \"%s\""
 119       "}}",
 120       payload.c_str(),
 121       options.key.c_str(),
 122       options.associated_data.c_str(),
 123       options.public_metadata.c_str(),
 124       options.verification_key_id.c_str(),
 125       options.decryption_key_id.c_str(),
 126       options.encryption_type.c_str(),
 127       options.signature_type.c_str()));
 128 }
 129
 130 void FakeEasyUnlockClient::UnwrapSecureMessage(
 131     const std::string& message,
 132     const UnwrapSecureMessageOptions& options,
 133     const DataCallback& callback) {
 134   // TODO(tbarzic): Verify that |message| is in the format returned by
 135   // |CreateSecureMessage| and extract payload, metadata and
 136   // verification_key_id from there.
 137   callback.Run(base::StringPrintf(
 138       "{\"unwrapped_securemessage\": {"
 139           "\"message\": \"%s\","
 140           "\"key\": \"%s\","
 141           "\"associated_data\": \"%s\","
 142           "\"encryption_type\": \"%s\","
 143           "\"signature_type\": \"%s\""
 144       "}}",
 145       message.c_str(),
 146       options.key.c_str(),
 147       options.associated_data.c_str(),
 148       options.encryption_type.c_str(),
 149       options.signature_type.c_str()));
 150 }
 151
 152 }  // namespace chromeos