cros: Cryptohome stubs needed for PIN sign-in.

Also extend fake_cryptohome_client to support multiple keys, checking keys, and
removing keys. The implementation is still not entirely correct, but good enough
for testing PIN.

Bug: 826773
Change-Id: I3f789c87095b663ca3ab6fb8becae5e924f02a5a
Reviewed-on: https://chromium-review.googlesource.com/1054247Reviewed-by: Ryo Hashimoto <hashimoto@chromium.org>
Commit-Queue: Jacob Dufault <jdufault@chromium.org>
Cr-Commit-Position: refs/heads/master@{#559228}

chromeos/cryptohome/cryptohome_parameters.cc

@@ -174,6 +174,15 @@ bool KeyDefinition::ProviderData::operator==(const ProviderData& other) const {
          (!has_bytes || (*bytes == *other.bytes));
 }
 
+bool KeyDefinition::Policy::operator==(const Policy& other) const {
+  return low_entropy_credential == other.low_entropy_credential &&
+         auth_locked == other.auth_locked;
+}
+
+bool KeyDefinition::Policy::operator!=(const Policy& other) const {
+  return !(*this == other);
+}
+
 KeyDefinition KeyDefinition::CreateForPassword(
     const std::string& secret,
     const std::string& label,
@@ -206,7 +215,8 @@ KeyDefinition::~KeyDefinition() = default;
 
 bool KeyDefinition::operator==(const KeyDefinition& other) const {
   if (type != other.type || label != other.label ||
-      privileges != other.privileges || revision != other.revision ||
+      privileges != other.privileges || policy != other.policy ||
+      revision != other.revision ||
       challenge_response_keys != other.challenge_response_keys ||
       authorization_data.size() != other.authorization_data.size() ||
       provider_data.size() != other.provider_data.size()) {

chromeos/cryptohome/cryptohome_parameters.h

@@ -126,6 +126,14 @@ struct CHROMEOS_EXPORT KeyDefinition {
     std::unique_ptr<std::string> bytes;
   };
 
+  struct Policy {
+    bool operator==(const Policy& other) const;
+    bool operator!=(const Policy& other) const;
+
+    bool low_entropy_credential = false;
+    bool auth_locked = false;
+  };
+
   // Creates an instance with the TYPE_PASSWORD type.
   static KeyDefinition CreateForPassword(const std::string& secret,
                                          const std::string& label,
@@ -147,6 +155,7 @@ struct CHROMEOS_EXPORT KeyDefinition {
   std::string label;
   // Privileges associated with key. Combination of |AuthKeyPrivileges| values.
   int privileges = 0;
+  Policy policy;
   int revision = 0;
   std::string secret;
   std::vector<chromeos::ChallengeResponseKey> challenge_response_keys;

chromeos/cryptohome/cryptohome_util.cc

@@ -170,6 +170,11 @@ std::vector<KeyDefinition> GetKeyDataReplyToKeyDefinitions(
     if (privileges.authorized_update())
       key_definition.privileges |= PRIV_AUTHORIZED_UPDATE;
 
+    // Extract |policy|.
+    key_definition.policy.low_entropy_credential =
+        it->policy().low_entropy_credential();
+    key_definition.policy.auth_locked = it->policy().auth_locked();
+
     // Extract |authorization_data|.
     for (RepeatedPtrField<KeyAuthorizationData>::const_iterator auth_it =
              it->authorization_data().begin();

chromeos/dbus/cryptohome_client.cc

@@ -910,6 +910,13 @@ class CryptohomeClientImpl : public CryptohomeClient {
                        weak_ptr_factory_.GetWeakPtr(), std::move(callback)));
   }
 
+  void GetSupportedKeyPolicies(
+      const cryptohome::GetSupportedKeyPoliciesRequest& request,
+      DBusMethodCallback<cryptohome::BaseReply> callback) override {
+    CallCryptohomeMethod(cryptohome::kCryptohomeGetSupportedKeyPolicies,
+                         request, std::move(callback));
+  }
+
  protected:
   void Init(dbus::Bus* bus) override {
     proxy_ = bus->GetObjectProxy(

chromeos/dbus/cryptohome_client.h

@@ -27,6 +27,7 @@ class CheckKeyRequest;
 class FlushAndSignBootAttributesRequest;
 class GetBootAttributeRequest;
 class GetKeyDataRequest;
+class GetSupportedKeyPoliciesRequest;
 class MigrateToDircryptoRequest;
 class MountRequest;
 class RemoveFirmwareManagementParametersRequest;
@@ -579,6 +580,11 @@ class CHROMEOS_EXPORT CryptohomeClient : public DBusClient {
       const cryptohome::Identification& cryptohome_id,
       DBusMethodCallback<bool> callback) = 0;
 
+  // Calls GetSupportedKeyPolicies to determine which type of keys can be added.
+  virtual void GetSupportedKeyPolicies(
+      const cryptohome::GetSupportedKeyPoliciesRequest& request,
+      DBusMethodCallback<cryptohome::BaseReply> callback) = 0;
+
  protected:
   // Create() should be used instead.
   CryptohomeClient();

chromeos/dbus/fake_cryptohome_client.cc

@@ -59,8 +59,7 @@ FakeCryptohomeClient::FakeCryptohomeClient()
 
 FakeCryptohomeClient::~FakeCryptohomeClient() = default;
 
-void FakeCryptohomeClient::Init(dbus::Bus* bus) {
-}
+void FakeCryptohomeClient::Init(dbus::Bus* bus) {}
 
 void FakeCryptohomeClient::AddObserver(Observer* observer) {
   observer_list_.AddObserver(observer);
@@ -511,10 +510,17 @@ void FakeCryptohomeClient::GetKeyDataEx(
   const auto it = key_data_map_.find(cryptohome_id);
   if (it == key_data_map_.end()) {
     reply.set_error(cryptohome::CRYPTOHOME_ERROR_ACCOUNT_NOT_FOUND);
+  } else if (it->second.empty()) {
+    reply.set_error(cryptohome::CRYPTOHOME_ERROR_KEY_NOT_FOUND);
   } else {
+    auto key = FindKey(it->second, auth.key().data().label());
+    if (key != it->second.end()) {
       cryptohome::GetKeyDataReply* key_data_reply =
           reply.MutableExtension(cryptohome::GetKeyDataReply::reply);
-    *key_data_reply->add_key_data() = it->second;
+      *key_data_reply->add_key_data() = key->second.data();
+    } else {
+      reply.set_error(cryptohome::CRYPTOHOME_ERROR_KEY_NOT_FOUND);
+    }
   }
   ReturnProtobufMethodCallback(reply, std::move(callback));
 }
@@ -524,7 +530,25 @@ void FakeCryptohomeClient::CheckKeyEx(
     const cryptohome::AuthorizationRequest& auth,
     const cryptohome::CheckKeyRequest& request,
     DBusMethodCallback<cryptohome::BaseReply> callback) {
-  ReturnProtobufMethodCallback(cryptohome::BaseReply(), std::move(callback));
+  cryptohome::BaseReply reply;
+
+  if (enable_auth_check_) {
+    const auto it = key_data_map_.find(cryptohome_id);
+    if (it == key_data_map_.end()) {
+      reply.set_error(cryptohome::CRYPTOHOME_ERROR_ACCOUNT_NOT_FOUND);
+    } else if (it->second.empty()) {
+      reply.set_error(cryptohome::CRYPTOHOME_ERROR_KEY_NOT_FOUND);
+    } else {
+      auto key = FindKey(it->second, auth.key().data().label());
+      if (key == it->second.end()) {
+        reply.set_error(cryptohome::CRYPTOHOME_ERROR_KEY_NOT_FOUND);
+      } else if (key->second.secret() != auth.key().secret()) {
+        reply.set_error(cryptohome::CRYPTOHOME_ERROR_AUTHORIZATION_KEY_FAILED);
+      }
+    }
+  }
+
+  ReturnProtobufMethodCallback(reply, std::move(callback));
 }
 
 void FakeCryptohomeClient::MountEx(
@@ -553,7 +577,7 @@ void FakeCryptohomeClient::AddKeyEx(
     const cryptohome::AuthorizationRequest& auth,
     const cryptohome::AddKeyRequest& request,
     DBusMethodCallback<cryptohome::BaseReply> callback) {
-  key_data_map_.insert(std::make_pair(cryptohome_id, request.key().data()));
+  key_data_map_[cryptohome_id][request.key().data().label()] = request.key();
   ReturnProtobufMethodCallback(cryptohome::BaseReply(), std::move(callback));
 }
 
@@ -562,6 +586,12 @@ void FakeCryptohomeClient::RemoveKeyEx(
     const cryptohome::AuthorizationRequest& auth,
     const cryptohome::RemoveKeyRequest& request,
     DBusMethodCallback<cryptohome::BaseReply> callback) {
+  const auto it = key_data_map_.find(cryptohome_id);
+  if (it != key_data_map_.end()) {
+    auto key = FindKey(it->second, request.key().data().label());
+    if (key != it->second.end())
+      it->second.erase(key);
+  }
   ReturnProtobufMethodCallback(cryptohome::BaseReply(), std::move(callback));
 }
 
@@ -630,6 +660,16 @@ void FakeCryptohomeClient::NeedsDircryptoMigration(
       base::BindOnce(std::move(callback), needs_dircrypto_migration_));
 }
 
+void FakeCryptohomeClient::GetSupportedKeyPolicies(
+    const cryptohome::GetSupportedKeyPoliciesRequest& request,
+    DBusMethodCallback<cryptohome::BaseReply> callback) {
+  cryptohome::BaseReply reply;
+  cryptohome::GetSupportedKeyPoliciesReply* attr_reply =
+      reply.MutableExtension(cryptohome::GetSupportedKeyPoliciesReply::reply);
+  attr_reply->set_low_entropy_credentials(supports_low_entropy_credentials_);
+  ReturnProtobufMethodCallback(reply, std::move(callback));
+}
+
 void FakeCryptohomeClient::SetServiceIsAvailable(bool is_available) {
   service_is_available_ = is_available;
   if (!is_available)
@@ -792,4 +832,16 @@ bool FakeCryptohomeClient::LoadInstallAttributes() {
   return true;
 }
 
+std::map<std::string, cryptohome::Key>::const_iterator
+FakeCryptohomeClient::FindKey(
+    const std::map<std::string, cryptohome::Key>& keys,
+    const std::string& label) {
+  // Wildcard label.
+  if (label.empty())
+    return keys.begin();
+
+  // Specific label
+  return keys.find(label);
+}
+
 }  // namespace chromeos

chromeos/dbus/fake_cryptohome_client.h

@@ -200,6 +200,9 @@ class CHROMEOS_EXPORT FakeCryptohomeClient : public CryptohomeClient {
       DBusMethodCallback<cryptohome::BaseReply> callback) override;
   void NeedsDircryptoMigration(const cryptohome::Identification& cryptohome_id,
                                DBusMethodCallback<bool> callback) override;
+  void GetSupportedKeyPolicies(
+      const cryptohome::GetSupportedKeyPoliciesRequest& request,
+      DBusMethodCallback<cryptohome::BaseReply> callback) override;
 
   /////////// Test helpers ////////////
 
@@ -245,6 +248,14 @@ class CHROMEOS_EXPORT FakeCryptohomeClient : public CryptohomeClient {
     tpm_attestation_does_key_exist_should_succeed_ = should_succeed;
   }
 
+  void set_supports_low_entropy_credentials(bool supports) {
+    supports_low_entropy_credentials_ = supports;
+  }
+
+  void set_enable_auth_check(bool enable_auth_check) {
+    enable_auth_check_ = enable_auth_check;
+  }
+
   void SetTpmAttestationUserCertificate(
       const cryptohome::Identification& cryptohome_id,
       const std::string& key_name,
@@ -321,6 +332,11 @@ class CHROMEOS_EXPORT FakeCryptohomeClient : public CryptohomeClient {
   // Loads install attributes from the stub file.
   bool LoadInstallAttributes();
 
+  // Finds a key matching the given label. Wildcard labels are supported.
+  std::map<std::string, cryptohome::Key>::const_iterator FindKey(
+      const std::map<std::string, cryptohome::Key>& keys,
+      const std::string& label);
+
   bool service_is_available_;
   base::ObserverList<Observer> observer_list_;
 
@@ -336,7 +352,8 @@ class CHROMEOS_EXPORT FakeCryptohomeClient : public CryptohomeClient {
   std::map<std::string, std::vector<uint8_t>> install_attrs_;
   bool locked_;
 
-  std::map<cryptohome::Identification, cryptohome::KeyData> key_data_map_;
+  std::map<cryptohome::Identification, std::map<std::string, cryptohome::Key>>
+      key_data_map_;
 
   // User attestation certificate mapped by cryptohome_id and key_name.
   std::map<std::pair<cryptohome::Identification, std::string>, std::string>
@@ -355,6 +372,9 @@ class CHROMEOS_EXPORT FakeCryptohomeClient : public CryptohomeClient {
   bool tpm_attestation_is_enrolled_ = true;
   bool tpm_attestation_is_prepared_ = true;
   bool tpm_attestation_does_key_exist_should_succeed_ = true;
+  bool supports_low_entropy_credentials_ = false;
+  // Controls if CheckKeyEx actually checks the key.
+  bool enable_auth_check_ = false;
 
   // MountEx fields.
   cryptohome::CryptohomeErrorCode cryptohome_error_ =