allow the SessionIdManager to use only two keys

winixd/core/sessionidmanager.cpp

@@ -5,7 +5,7 @@
  */
 
 /*
- * Copyright (c) 2014-2021, Tomasz Sowa
+ * Copyright (c) 2014-2022, Tomasz Sowa
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -40,6 +40,7 @@
 #include "utf8/utf8.h"
 #include "date/date.h"
 #include "misc.h"
+#include "convert/text.h"
 
 
 namespace Winix
@@ -48,8 +49,8 @@ namespace Winix
 
 SessionIdManager::SessionIdManager()
 {
-	algorithm_type		= 'a';
-	key_tab_size		= 256;
+	algorithm_type		= ALGORITHM_MULTIPLE_KEYS;
+	key_tab_size		= 0;
 	key_index			= 0;
 	last_key_generated	= 0;
 	key_renew_time		= 60;
@@ -57,9 +58,12 @@ SessionIdManager::SessionIdManager()
 }
 
 
-void SessionIdManager::Init(const std::wstring & keys_file)
+
+void SessionIdManager::InitMultipleKeys(const std::wstring & keys_file)
 {
+	algorithm_type = ALGORITHM_MULTIPLE_KEYS;
 	was_inited = true;
+	key_tab_size = 256;
 
 	key_tab1.resize(key_tab_size);
 	key_tab2.resize(key_tab_size);
@@ -72,6 +76,57 @@ void SessionIdManager::Init(const std::wstring & keys_file)
 }
 
 
+bool SessionIdManager::InitSingleKeys(const std::wstring & key1, const std::wstring & key2)
+{
+	algorithm_type = ALGORITHM_SINGLE_KEYS;
+	key_tab_size = 1;
+
+	key_tab1.resize(key_tab_size);
+	key_tab2.resize(key_tab_size);
+
+	aes1.resize(key_tab_size);
+	aes2.resize(key_tab_size);
+
+	was_inited = true;
+	was_inited = was_inited && InitializeKey(key1, key_tab1);
+	was_inited = was_inited && InitializeKey(key2, key_tab2);
+
+	if( was_inited )
+	{
+		InitializeAesKeys();
+	}
+
+	return was_inited;
+}
+
+
+bool SessionIdManager::IsInitialized()
+{
+	return was_inited;
+}
+
+
+bool SessionIdManager::InitializeKey(const std::wstring & key, std::vector<std::string> & key_tab)
+{
+	if( key.size() == 16 * 2 || key.size() == 24 * 2 || key.size() == 32 * 2 )
+	{
+		if( !pt::hex_string_to_bytes(key, key_tab[0]) )
+		{
+			log << log1 << "SIM: an incorrect character in a key, expected a hex digits in the range 0-9 or a-f" << logend;
+		}
+	}
+	else
+	{
+		log << log1 << "SIM: provided key has size: " << key.size()
+			<< ", expected size is 16, 24 or 32 bytes (written as two hex digits each)" << logend;
+		return false;
+	}
+
+	return true;
+}
+
+
+
 void SessionIdManager::SetKeyRenewTime(time_t renew_time)
 {
 	key_renew_time = renew_time;
@@ -400,6 +455,7 @@ return true;
 }
 
 
+
 bool SessionIdManager::EncodeToken(size_t id, unsigned int index, time_t cur_utc_time, std::wstring & token)
 {
 size_t pad_top_size;
@@ -413,10 +469,14 @@ char pad_bottom_value;
 	if( !was_inited )
 		return false;
 
-	CheckKeys(cur_utc_time);
+	if( algorithm_type == ALGORITHM_MULTIPLE_KEYS )
+	{
+		CheckKeys(cur_utc_time);
+	}
+
 	RandPadding(pad_top_size, pad_top_value, pad_bottom_size, pad_bottom_value);
 
-	string_token += algorithm_type;
+	string_token += GetAlgoritmTypeAsString();
 	string_token += (unsigned char)key_index;
 	string_token += pad_top_value;
 	string_token += pad_bottom_value;
@@ -553,6 +613,17 @@ return false;
 }
 
 
+char SessionIdManager::GetAlgoritmTypeAsString()
+{
+	if( algorithm_type == ALGORITHM_MULTIPLE_KEYS )
+		return 'a';
+
+	if( algorithm_type == ALGORITHM_SINGLE_KEYS )
+		return 'b';
+
+	return 'a';
+}
+
 
 } // namespace Winix
 

winixd/core/sessionidmanager.h

@@ -5,7 +5,7 @@
  */
 
 /*
- * Copyright (c) 2014-2018, Tomasz Sowa
+ * Copyright (c) 2014-2022, Tomasz Sowa
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -83,21 +83,54 @@ public:
 	SessionIdManager();
 
 	/*
-	 * initialization
+	 * we are using keys stored in a file
+	 * those keys are automatically generated
+	 * this is the default algorithm
+	 */
+	static const int ALGORITHM_MULTIPLE_KEYS = 1;
+
+	/*
+	 * we use only two keys
+	 * those keys you have to provide
+	 */
+	static const int ALGORITHM_SINGLE_KEYS = 2;
+
+	/*
+	 * initialization for ALGORITHM_MULTIPLE_KEYS algorithm
 	 * this method takes about 1MB memory more (for AES key expansions)
 	 * if you do not need the session cookie to be enrypted then don't call this method
 	 *
 	 */
-	void Init(const std::wstring & keys_file);
+	void InitMultipleKeys(const std::wstring & keys_file);
+
+
+	/*
+	 * initialization for ALGORITHM_SINGLE_KEYS algorithm
+	 * keys should be provided as 16*2 or 24*2 or 32*2 hexadecimal characters
+	 *
+	 */
+	bool InitSingleKeys(const std::wstring & key1, const std::wstring & key2);
+
+
+	/*
+	 * true if the object is correctly initialized
+	 *
+	 */
+	bool IsInitialized();
+
 
 	/*
 	 * how often a new AES key pairs should be generated
+	 * used with ALGORITHM_MULTIPLE_KEYS algorithm
 	 */
 	void SetKeyRenewTime(time_t renew_time);
 
 	/*
 	 * encode/decode the session cookie
-	 * make sure the Init() method is called first
+	 * make sure InitMultipleKeys() or InitSingleKeys() method is called first
+	 *
+	 * for ALGORITHM_SINGLE_KEYS algorithm the cur_utc_time parameter is ignored
+	 *
 	 */
 	bool EncodeToken(size_t id, unsigned int index, time_t cur_utc_time, std::wstring & token);
 	bool DecodeToken(const std::wstring & token, size_t & id, unsigned int & index);
@@ -106,7 +139,7 @@ public:
 private:
 
 	bool was_inited;
-	char algorithm_type;
+	int algorithm_type;
 	std::string string_token, string_token_base64;
 	std::vector<std::string> key_tab1, key_tab2;
 	size_t key_index;
@@ -120,6 +153,7 @@ private:
 	std::string file_name_ascii;
 	std::vector<Tito::AES> aes1, aes2;
 
+	bool InitializeKey(const std::wstring & key, std::vector<std::string> & key_tab);
 	bool ReadKeysFromFile(const wchar_t * file);
 	bool ReadKeysFromFile(const std::wstring & file);
 	bool SaveKeysToFile(const wchar_t * file);
@@ -142,6 +176,7 @@ private:
 	bool CheckControlSums(const char * str);
 	void InitializeAesKeys(size_t index);
 	bool DecodeAES(const char * str, size_t key);
+	char GetAlgoritmTypeAsString();
 
 	template<typename Value>
 	void Append(std::string & str, Value val);

winixd/core/sessionmanager.cpp

@@ -108,7 +108,7 @@ void SessionManager::InitBanList()
 void SessionManager::InitCookieEncoding()
 {
 	if( config->session_cookie_encode && !config->session_keys_file.empty() )
-		session_id_manager.Init(config->session_keys_file);
+		session_id_manager.InitMultipleKeys(config->session_keys_file);
 
 	session_id_manager.SetKeyRenewTime(config->session_key_renew_time);
 }