2 files changed, 20 insertions, 5 deletions

diff --git a/src/core/crypto/key_manager.cpp b/src/core/crypto/key_manager.cpp
index 8997c7082..f87fe0abc 100644
--- a/src/core/crypto/key_manager.cpp
+++ b/src/core/crypto/key_manager.cpp
@@ -695,8 +695,9 @@ void KeyManager::WriteKeyToFile(KeyCategory category, std::string_view keyname,
 }
 
 void KeyManager::SetKey(S128KeyType id, Key128 key, u64 field1, u64 field2) {
-    if (s128_keys.find({id, field1, field2}) != s128_keys.end())
+    if (s128_keys.find({id, field1, field2}) != s128_keys.end() || key == Key128{}) {
         return;
+    }
     if (id == S128KeyType::Titlekey) {
         Key128 rights_id;
         std::memcpy(rights_id.data(), &field2, sizeof(u64));
@@ -716,8 +717,9 @@ void KeyManager::SetKey(S128KeyType id, Key128 key, u64 field1, u64 field2) {
             return std::tie(elem.second.type, elem.second.field1, elem.second.field2) ==
                    std::tie(id, field1, field2);
         });
-    if (iter2 != s128_file_id.end())
+    if (iter2 != s128_file_id.end()) {
         WriteKeyToFile(category, iter2->first, key);
+    }
 
     // Variable cases
     if (id == S128KeyType::KeyArea) {
@@ -745,16 +747,18 @@ void KeyManager::SetKey(S128KeyType id, Key128 key, u64 field1, u64 field2) {
 }
 
 void KeyManager::SetKey(S256KeyType id, Key256 key, u64 field1, u64 field2) {
-    if (s256_keys.find({id, field1, field2}) != s256_keys.end())
+    if (s256_keys.find({id, field1, field2}) != s256_keys.end() || key == Key256{}) {
         return;
+    }
     const auto iter = std::find_if(
         s256_file_id.begin(), s256_file_id.end(),
         [&id, &field1, &field2](const std::pair<std::string, KeyIndex<S256KeyType>> elem) {
             return std::tie(elem.second.type, elem.second.field1, elem.second.field2) ==
                    std::tie(id, field1, field2);
         });
-    if (iter != s256_file_id.end())
+    if (iter != s256_file_id.end()) {
         WriteKeyToFile(KeyCategory::Standard, iter->first, key);
+    }
     s256_keys[{id, field1, field2}] = key;
 }
 
diff --git a/src/core/crypto/key_manager.h b/src/core/crypto/key_manager.h
index 7265c4171..9269a73f2 100644
--- a/src/core/crypto/key_manager.h
+++ b/src/core/crypto/key_manager.h
@@ -223,7 +223,16 @@ bool operator<(const KeyIndex<KeyType>& lhs, const KeyIndex<KeyType>& rhs) {
 
 class KeyManager {
 public:
-    KeyManager();
+    static KeyManager& Instance() {
+        static KeyManager instance;
+        return instance;
+    }
+
+    KeyManager(const KeyManager&) = delete;
+    KeyManager& operator=(const KeyManager&) = delete;
+
+    KeyManager(KeyManager&&) = delete;
+    KeyManager& operator=(KeyManager&&) = delete;
 
     bool HasKey(S128KeyType id, u64 field1 = 0, u64 field2 = 0) const;
     bool HasKey(S256KeyType id, u64 field1 = 0, u64 field2 = 0) const;
@@ -257,6 +266,8 @@ public:
     bool AddTicketPersonalized(Ticket raw);
 
 private:
+    KeyManager();
+
     std::map<KeyIndex<S128KeyType>, Key128> s128_keys;
     std::map<KeyIndex<S256KeyType>, Key256> s256_keys;