diff --git a/CMakeLists.txt b/CMakeLists.txt
index ca4d16314..4603576ec 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -482,6 +482,7 @@ set(TDLIB_SOURCE
   td/telegram/files/FileBitmask.h
   td/telegram/files/FileDb.h
   td/telegram/files/FileDownloader.h
+  td/telegram/files/FileEncryptionKey.h
   td/telegram/files/FileFromBytes.h
   td/telegram/files/FileGcParameters.h
   td/telegram/files/FileGcWorker.h
diff --git a/td/telegram/files/FileEncryptionKey.h b/td/telegram/files/FileEncryptionKey.h
new file mode 100644
index 000000000..4e83d1235
--- /dev/null
+++ b/td/telegram/files/FileEncryptionKey.h
@@ -0,0 +1,155 @@
+//
+// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2018
+//
+// Distributed under the Boost Software License, Version 1.0. (See accompanying
+// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
+//
+#pragma once
+
+#include "td/telegram/SecureStorage.h"
+
+#include "td/utils/as.h"
+#include "td/utils/common.h"
+#include "td/utils/crypto.h"
+#include "td/utils/logging.h"
+#include "td/utils/Random.h"
+#include "td/utils/Slice.h"
+#include "td/utils/StringBuilder.h"
+#include "td/utils/tl_helpers.h"
+#include "td/utils/UInt.h"
+
+namespace td {
+
+struct FileEncryptionKey {
+  enum class Type : int32 { None, Secret, Secure };
+  FileEncryptionKey() = default;
+  FileEncryptionKey(Slice key, Slice iv) : key_iv_(key.size() + iv.size(), '\0'), type_(Type::Secret) {
+    if (key.size() != 32 || iv.size() != 32) {
+      LOG(ERROR) << "Wrong key/iv sizes: " << key.size() << " " << iv.size();
+      type_ = Type::None;
+      return;
+    }
+    CHECK(key_iv_.size() == 64);
+    MutableSlice(key_iv_).copy_from(key);
+    MutableSlice(key_iv_).substr(key.size()).copy_from(iv);
+  }
+
+  explicit FileEncryptionKey(const secure_storage::Secret &secret) : type_(Type::Secure) {
+    key_iv_ = secret.as_slice().str();
+  }
+
+  bool is_secret() const {
+    return type_ == Type::Secret;
+  }
+  bool is_secure() const {
+    return type_ == Type::Secure;
+  }
+
+  static FileEncryptionKey create() {
+    FileEncryptionKey res;
+    res.key_iv_.resize(64);
+    Random::secure_bytes(res.key_iv_);
+    res.type_ = Type::Secret;
+    return res;
+  }
+  static FileEncryptionKey create_secure_key() {
+    return FileEncryptionKey(secure_storage::Secret::create_new());
+  }
+
+  const UInt256 &key() const {
+    CHECK(is_secret());
+    CHECK(key_iv_.size() == 64);
+    return *reinterpret_cast<const UInt256 *>(key_iv_.data());
+  }
+  Slice key_slice() const {
+    CHECK(is_secret());
+    CHECK(key_iv_.size() == 64);
+    return Slice(key_iv_.data(), 32);
+  }
+  secure_storage::Secret secret() const {
+    CHECK(is_secure());
+    return secure_storage::Secret::create(Slice(key_iv_).truncate(32)).move_as_ok();
+  }
+
+  bool has_value_hash() const {
+    CHECK(is_secure());
+    return key_iv_.size() > secure_storage::Secret::size();
+  }
+
+  void set_value_hash(const secure_storage::ValueHash &value_hash) {
+    key_iv_.resize(secure_storage::Secret::size() + value_hash.as_slice().size());
+    MutableSlice(key_iv_).remove_prefix(secure_storage::Secret::size()).copy_from(value_hash.as_slice());
+  }
+
+  secure_storage::ValueHash value_hash() const {
+    CHECK(has_value_hash());
+    return secure_storage::ValueHash::create(Slice(key_iv_).remove_prefix(secure_storage::Secret::size())).move_as_ok();
+  }
+
+  UInt256 &mutable_iv() {
+    CHECK(is_secret());
+    CHECK(key_iv_.size() == 64);
+    return *reinterpret_cast<UInt256 *>(&key_iv_[0] + 32);
+  }
+  Slice iv_slice() const {
+    CHECK(is_secret());
+    CHECK(key_iv_.size() == 64);
+    return Slice(key_iv_.data() + 32, 32);
+  }
+
+  int32 calc_fingerprint() const {
+    CHECK(is_secret());
+    char buf[16];
+    md5(key_iv_, {buf, sizeof(buf)});
+    return as<int32>(buf) ^ as<int32>(buf + 4);
+  }
+
+  bool empty() const {
+    return key_iv_.empty();
+  }
+  size_t size() const {
+    return key_iv_.size();
+  }
+
+  template <class StorerT>
+  void store(StorerT &storer) const {
+    td::store(key_iv_, storer);
+  }
+  template <class ParserT>
+  void parse(Type type, ParserT &parser) {
+    td::parse(key_iv_, parser);
+    if (key_iv_.empty()) {
+      type_ = Type::None;
+    } else {
+      if (type_ == Type::Secure) {
+        if (key_iv_.size() != 64) {
+          LOG(ERROR) << "Have wrong key size " << key_iv_.size();
+        }
+      }
+      type_ = type;
+    }
+  }
+
+  string key_iv_;  // TODO wrong alignment is possible
+  Type type_ = Type::None;
+};
+
+inline bool operator==(const FileEncryptionKey &lhs, const FileEncryptionKey &rhs) {
+  return lhs.key_iv_ == rhs.key_iv_;
+}
+
+inline bool operator!=(const FileEncryptionKey &lhs, const FileEncryptionKey &rhs) {
+  return !(lhs == rhs);
+}
+
+inline StringBuilder &operator<<(StringBuilder &string_builder, const FileEncryptionKey &key) {
+  if (key.is_secret()) {
+    return string_builder << "SecretKey{" << key.size() << "}";
+  }
+  if (key.is_secret()) {
+    return string_builder << "SecureKey{" << key.size() << "}";
+  }
+  return string_builder << "NoKey{}";
+}
+
+}  // namespace td
diff --git a/td/telegram/files/FileHashUploader.cpp b/td/telegram/files/FileHashUploader.cpp
index 7aae6b2ae..a66d2f44d 100644
--- a/td/telegram/files/FileHashUploader.cpp
+++ b/td/telegram/files/FileHashUploader.cpp
@@ -23,6 +23,7 @@
 #include "td/utils/Status.h"
 
 namespace td {
+
 void FileHashUploader::start_up() {
   auto status = init();
   if (status.is_error()) {
@@ -31,6 +32,7 @@ void FileHashUploader::start_up() {
     return;
   }
 }
+
 Status FileHashUploader::init() {
   TRY_RESULT(fd, FileFd::open(local_.path_, FileFd::Read));
   if (fd.get_size() != size_) {
@@ -43,6 +45,7 @@ Status FileHashUploader::init() {
   resource_state_.update_estimated_limit(size_);
   return Status::OK();
 }
+
 void FileHashUploader::loop() {
   if (stop_flag_) {
     return;
@@ -140,4 +143,5 @@ Status FileHashUploader::on_result_impl(NetQueryPtr net_query) {
       return Status::Error("UNREACHABLE");
   }
 }
+
 }  // namespace td
diff --git a/td/telegram/files/FileHashUploader.h b/td/telegram/files/FileHashUploader.h
index 81d0f0d8c..922965da2 100644
--- a/td/telegram/files/FileHashUploader.h
+++ b/td/telegram/files/FileHashUploader.h
@@ -79,4 +79,5 @@ class FileHashUploader : public FileLoaderActor {
 
   Status on_result_impl(NetQueryPtr net_query);
 };
+
 }  // namespace td
diff --git a/td/telegram/files/FileLocation.h b/td/telegram/files/FileLocation.h
index 67bd63199..ed71e54d1 100644
--- a/td/telegram/files/FileLocation.h
+++ b/td/telegram/files/FileLocation.h
@@ -11,22 +11,17 @@
 
 #include "td/telegram/DialogId.h"
 #include "td/telegram/files/FileBitmask.h"
+#include "td/telegram/files/FileEncryptionKey.h"
 #include "td/telegram/net/DcId.h"
-#include "td/telegram/SecureStorage.h"
 
-#include "td/utils/as.h"
 #include "td/utils/buffer.h"
 #include "td/utils/common.h"
-#include "td/utils/crypto.h"
 #include "td/utils/format.h"
-#include "td/utils/int_types.h"
 #include "td/utils/logging.h"
-#include "td/utils/Random.h"
 #include "td/utils/Slice.h"
 #include "td/utils/StringBuilder.h"
 #include "td/utils/tl_helpers.h"
 #include "td/utils/tl_storers.h"
-#include "td/utils/UInt.h"
 #include "td/utils/Variant.h"
 
 #include <tuple>
@@ -178,138 +173,6 @@ inline bool is_file_big(FileType file_type, int64 expected_size) {
   return expected_size > SMALL_FILE_MAX_SIZE;
 }
 
-struct FileEncryptionKey {
-  enum class Type : int32 { None, Secret, Secure };
-  FileEncryptionKey() = default;
-  FileEncryptionKey(Slice key, Slice iv) : key_iv_(key.size() + iv.size(), '\0'), type_(Type::Secret) {
-    if (key.size() != 32 || iv.size() != 32) {
-      LOG(ERROR) << "Wrong key/iv sizes: " << key.size() << " " << iv.size();
-      type_ = Type::None;
-      return;
-    }
-    CHECK(key_iv_.size() == 64);
-    MutableSlice(key_iv_).copy_from(key);
-    MutableSlice(key_iv_).substr(key.size()).copy_from(iv);
-  }
-
-  explicit FileEncryptionKey(const secure_storage::Secret &secret) : type_(Type::Secure) {
-    key_iv_ = secret.as_slice().str();
-  }
-
-  bool is_secret() const {
-    return type_ == Type::Secret;
-  }
-  bool is_secure() const {
-    return type_ == Type::Secure;
-  }
-
-  static FileEncryptionKey create() {
-    FileEncryptionKey res;
-    res.key_iv_.resize(64);
-    Random::secure_bytes(res.key_iv_);
-    res.type_ = Type::Secret;
-    return res;
-  }
-  static FileEncryptionKey create_secure_key() {
-    return FileEncryptionKey(secure_storage::Secret::create_new());
-  }
-
-  const UInt256 &key() const {
-    CHECK(is_secret());
-    CHECK(key_iv_.size() == 64);
-    return *reinterpret_cast<const UInt256 *>(key_iv_.data());
-  }
-  Slice key_slice() const {
-    CHECK(is_secret());
-    CHECK(key_iv_.size() == 64);
-    return Slice(key_iv_.data(), 32);
-  }
-  secure_storage::Secret secret() const {
-    CHECK(is_secure());
-    return secure_storage::Secret::create(Slice(key_iv_).truncate(32)).move_as_ok();
-  }
-
-  bool has_value_hash() const {
-    CHECK(is_secure());
-    return key_iv_.size() > secure_storage::Secret::size();
-  }
-
-  void set_value_hash(const secure_storage::ValueHash &value_hash) {
-    key_iv_.resize(secure_storage::Secret::size() + value_hash.as_slice().size());
-    MutableSlice(key_iv_).remove_prefix(secure_storage::Secret::size()).copy_from(value_hash.as_slice());
-  }
-
-  secure_storage::ValueHash value_hash() const {
-    CHECK(has_value_hash());
-    return secure_storage::ValueHash::create(Slice(key_iv_).remove_prefix(secure_storage::Secret::size())).move_as_ok();
-  }
-
-  UInt256 &mutable_iv() {
-    CHECK(is_secret());
-    CHECK(key_iv_.size() == 64);
-    return *reinterpret_cast<UInt256 *>(&key_iv_[0] + 32);
-  }
-  Slice iv_slice() const {
-    CHECK(is_secret());
-    CHECK(key_iv_.size() == 64);
-    return Slice(key_iv_.data() + 32, 32);
-  }
-
-  int32 calc_fingerprint() const {
-    CHECK(is_secret());
-    char buf[16];
-    md5(key_iv_, {buf, sizeof(buf)});
-    return as<int32>(buf) ^ as<int32>(buf + 4);
-  }
-
-  bool empty() const {
-    return key_iv_.empty();
-  }
-  size_t size() const {
-    return key_iv_.size();
-  }
-
-  template <class StorerT>
-  void store(StorerT &storer) const {
-    td::store(key_iv_, storer);
-  }
-  template <class ParserT>
-  void parse(Type type, ParserT &parser) {
-    td::parse(key_iv_, parser);
-    if (key_iv_.empty()) {
-      type_ = Type::None;
-    } else {
-      if (type_ == Type::Secure) {
-        if (key_iv_.size() != 64) {
-          LOG(ERROR) << "Have wrong key size " << key_iv_.size();
-        }
-      }
-      type_ = type;
-    }
-  }
-
-  string key_iv_;  // TODO wrong alignment is possible
-  Type type_ = Type::None;
-};
-
-inline bool operator==(const FileEncryptionKey &lhs, const FileEncryptionKey &rhs) {
-  return lhs.key_iv_ == rhs.key_iv_;
-}
-
-inline bool operator!=(const FileEncryptionKey &lhs, const FileEncryptionKey &rhs) {
-  return !(lhs == rhs);
-}
-
-inline StringBuilder &operator<<(StringBuilder &string_builder, const FileEncryptionKey &key) {
-  if (key.is_secret()) {
-    return string_builder << "SecretKey{" << key.size() << "}";
-  }
-  if (key.is_secret()) {
-    return string_builder << "SecureKey{" << key.size() << "}";
-  }
-  return string_builder << "NoKey{}";
-}
-
 struct EmptyRemoteFileLocation {
   template <class StorerT>
   void store(StorerT &storer) const {