1  /*
  2  * Copyright (c) 2013-2026, The PurpleI2P Project
  3  *
  4  * This file is part of Purple i2pd project and licensed under BSD3
  5  *
  6  * See full license text in LICENSE file at top of project tree
  7  */
  8  
  9  #ifndef GARLIC_H__
 10  #define GARLIC_H__
 11  
 12  #include <inttypes.h>
 13  #include <unordered_map>
 14  #include <list>
 15  #include <string>
 16  #include <thread>
 17  #include <mutex>
 18  #include <memory>
 19  #include <random>
 20  #include "Crypto.h"
 21  #include "I2NPProtocol.h"
 22  #include "LeaseSet.h"
 23  #include "Queue.h"
 24  #include "Identity.h"
 25  
 26  namespace i2p
 27  {
 28  namespace tunnel
 29  {
 30  	class OutboundTunnel;
 31  }
 32  
 33  namespace garlic
 34  {
 35  
 36  	enum GarlicDeliveryType
 37  	{
 38  		eGarlicDeliveryTypeLocal = 0,
 39  		eGarlicDeliveryTypeDestination = 1,
 40  		eGarlicDeliveryTypeRouter = 2,
 41  		eGarlicDeliveryTypeTunnel = 3
 42  	};
 43  
 44  	struct ElGamalBlock
 45  	{
 46  		uint8_t sessionKey[32];
 47  		uint8_t preIV[32];
 48  		uint8_t padding[158];
 49  	};
 50  
 51  	const int INCOMING_TAGS_EXPIRATION_TIMEOUT = 960; // 16 minutes
 52  	const int OUTGOING_TAGS_EXPIRATION_TIMEOUT = 720; // 12 minutes
 53  	const int OUTGOING_TAGS_CONFIRMATION_TIMEOUT = 10; // 10 seconds
 54  	const int LEASESET_CONFIRMATION_TIMEOUT = 4000; // in milliseconds
 55  	const int ROUTING_PATH_EXPIRATION_TIMEOUT = 120; // in seconds
 56  	const int INCOMING_SESSIONS_MINIMAL_INTERVAL = 200; // in milliseconds
 57  
 58  	struct SessionTag: public i2p::data::Tag<32>
 59  	{
 60  		SessionTag (const uint8_t * buf, uint32_t ts = 0): Tag<32>(buf), creationTime (ts) {};
 61  		SessionTag () = default;
 62  		SessionTag (const SessionTag& ) = default;
 63  		SessionTag& operator= (const SessionTag& ) = default;
 64  #ifndef _WIN32
 65  		SessionTag (SessionTag&& ) = default;
 66  		SessionTag& operator= (SessionTag&& ) = default;
 67  #endif
 68  		uint32_t creationTime; // seconds since epoch
 69  	};
 70  
 71  	// AESDecryption is associated with session tags and store key
 72  	class AESDecryption: public i2p::crypto::CBCDecryption
 73  	{
 74  		public:
 75  
 76  			AESDecryption (const uint8_t * key): m_Key (key)
 77  			{
 78  				SetKey (key);
 79  			}
 80  			const i2p::crypto::AESKey& GetKey () const { return m_Key; };
 81  
 82  		private:
 83  
 84  			i2p::crypto::AESKey m_Key;
 85  	};
 86  
 87  	struct GarlicRoutingPath
 88  	{
 89  		std::shared_ptr<i2p::tunnel::OutboundTunnel> outboundTunnel;
 90  		std::shared_ptr<const i2p::data::Lease> remoteLease;
 91  		// for streaming only
 92  		int rtt; // RTT
 93  		uint32_t updateTime; // seconds since epoch
 94  	};
 95  
 96  	class GarlicDestination;
 97  	class GarlicRoutingSession
 98  	{
 99  		protected:
100  
101  			enum LeaseSetUpdateStatus
102  			{
103  				eLeaseSetUpToDate = 0,
104  				eLeaseSetUpdated,
105  				eLeaseSetSubmitted,
106  				eLeaseSetDoNotSend
107  			};
108  
109  		public:
110  
111  			GarlicRoutingSession (GarlicDestination * owner, bool attachLeaseSet);
112  			GarlicRoutingSession ();
113  			virtual ~GarlicRoutingSession ();
114  			virtual std::shared_ptr<I2NPMessage> WrapSingleMessage (std::shared_ptr<const I2NPMessage> msg) = 0;
115  			virtual bool CleanupUnconfirmedTags () { return false; }; // for I2CP, override in ElGamalAESSession and ECIESX25519AEADRatchetSession
116  			virtual bool MessageConfirmed (uint32_t msgID);
117  			virtual bool IsRatchets () const { return false; };
118  			virtual bool IsReadyToSend () const { return true; };
119  			virtual bool IsTerminated () const { return !GetOwner (); };
120  			virtual uint64_t GetLastActivityTimestamp () const { return 0; }; // non-zero for rathets only
121  			virtual void SetAckRequestInterval (int interval) {}; // in milliseconds, override in ECIESX25519AEADRatchetSession
122  			virtual std::vector<std::shared_ptr<I2NPMessage> > WrapMultipleMessages (const std::vector<std::shared_ptr<const I2NPMessage> >& msgs);
123  
124  			void SetLeaseSetUpdated ()
125  			{
126  				if (m_LeaseSetUpdateStatus != eLeaseSetDoNotSend) m_LeaseSetUpdateStatus = eLeaseSetUpdated;
127  			};
128  			bool IsLeaseSetNonConfirmed () const { return m_LeaseSetUpdateStatus == eLeaseSetSubmitted; };
129  			bool IsLeaseSetUpdated () const { return m_LeaseSetUpdateStatus == eLeaseSetUpdated; };
130  			uint64_t GetLeaseSetSubmissionTime () const { return m_LeaseSetSubmissionTime; }
131  			void CleanupUnconfirmedLeaseSet (uint64_t ts);
132  
133  			std::shared_ptr<GarlicRoutingPath> GetSharedRoutingPath ();
134  			void SetSharedRoutingPath (std::shared_ptr<GarlicRoutingPath> path);
135  
136  			bool IsWithJava () const { return m_IsWithJava; }
137  			void SetIsWithJava (bool isWithJava) { m_IsWithJava = isWithJava; }
138  
139  			int NumSentPackets () const { return m_NumSentPackets; }
140  			void SetNumSentPackets (int numSentPackets) { m_NumSentPackets = numSentPackets; }
141  
142  			GarlicDestination * GetOwner () const { return m_Owner; }
143  			void SetOwner (GarlicDestination * owner) { m_Owner = owner; }
144  
145  		protected:
146  
147  			LeaseSetUpdateStatus GetLeaseSetUpdateStatus () const { return m_LeaseSetUpdateStatus; }
148  			void SetLeaseSetUpdateStatus (LeaseSetUpdateStatus status) { m_LeaseSetUpdateStatus = status; }
149  			uint32_t GetLeaseSetUpdateMsgID () const { return m_LeaseSetUpdateMsgID; }
150  			void SetLeaseSetUpdateMsgID (uint32_t msgID) { m_LeaseSetUpdateMsgID = msgID; }
151  			void SetLeaseSetSubmissionTime (uint64_t ts) { m_LeaseSetSubmissionTime = ts; }
152  
153  			std::shared_ptr<I2NPMessage> CreateEncryptedDeliveryStatusMsg (uint32_t msgID);
154  
155  		private:
156  
157  			GarlicDestination * m_Owner;
158  
159  			LeaseSetUpdateStatus m_LeaseSetUpdateStatus;
160  			uint32_t m_LeaseSetUpdateMsgID;
161  			uint64_t m_LeaseSetSubmissionTime; // in milliseconds
162  
163  			std::shared_ptr<GarlicRoutingPath> m_SharedRoutingPath;
164  			bool m_IsWithJava; // based on choked value from streaming
165  			int m_NumSentPackets; // for limit number of sent messages in streaming
166  
167  		public:
168  
169  			// for HTTP only
170  			virtual size_t GetNumOutgoingTags () const { return 0; };
171  	};
172  	//using GarlicRoutingSessionPtr = std::shared_ptr<GarlicRoutingSession>;
173  	typedef std::shared_ptr<GarlicRoutingSession> GarlicRoutingSessionPtr; // TODO: replace to using after switch to 4.8
174  
175  	class ElGamalAESSession: public GarlicRoutingSession,  public std::enable_shared_from_this<ElGamalAESSession>
176  	{
177  		struct UnconfirmedTags
178  		{
179  			UnconfirmedTags (int n): numTags (n), tagsCreationTime (0) { sessionTags = new SessionTag[numTags]; };
180  			~UnconfirmedTags () { delete[] sessionTags; };
181  			uint32_t msgID;
182  			int numTags;
183  			SessionTag * sessionTags;
184  			uint32_t tagsCreationTime;
185  		};
186  
187  		public:
188  
189  			ElGamalAESSession (GarlicDestination * owner, std::shared_ptr<const i2p::data::RoutingDestination> destination,
190  				int numTags, bool attachLeaseSet);
191  			ElGamalAESSession (const uint8_t * sessionKey, const SessionTag& sessionTag); // one time encryption
192  			~ElGamalAESSession () {};
193  
194  			std::shared_ptr<I2NPMessage> WrapSingleMessage (std::shared_ptr<const I2NPMessage> msg);
195  
196  			bool MessageConfirmed (uint32_t msgID);
197  			bool CleanupExpiredTags (); // returns true if something left
198  			bool CleanupUnconfirmedTags (); // returns true if something has been deleted
199  
200  		private:
201  
202  			size_t CreateAESBlock (uint8_t * buf, std::shared_ptr<const I2NPMessage> msg);
203  			size_t CreateGarlicPayload (uint8_t * payload, std::shared_ptr<const I2NPMessage> msg, UnconfirmedTags * newTags);
204  			size_t CreateGarlicClove (uint8_t * buf, std::shared_ptr<const I2NPMessage> msg, bool isDestination);
205  			size_t CreateDeliveryStatusClove (uint8_t * buf, uint32_t msgID);
206  
207  			void TagsConfirmed (uint32_t msgID);
208  			UnconfirmedTags * GenerateSessionTags ();
209  
210  		private:
211  
212  			std::shared_ptr<const i2p::data::RoutingDestination> m_Destination;
213  
214  			i2p::crypto::AESKey m_SessionKey;
215  			std::list<SessionTag> m_SessionTags;
216  			int m_NumTags;
217  			std::map<uint32_t, std::unique_ptr<UnconfirmedTags> > m_UnconfirmedTagsMsgs; // msgID->tags
218  
219  			i2p::crypto::CBCEncryption m_Encryption;
220  			i2p::data::Tag<16> m_IV;
221  
222  		public:
223  
224  			// for HTTP only
225  			size_t GetNumOutgoingTags () const { return m_SessionTags.size (); };
226  	};
227  	typedef std::shared_ptr<ElGamalAESSession> ElGamalAESSessionPtr;
228  
229  	class ECIESX25519AEADRatchetSession;
230  	typedef std::shared_ptr<ECIESX25519AEADRatchetSession> ECIESX25519AEADRatchetSessionPtr;
231  	class ReceiveRatchetTagSet;
232  	typedef std::shared_ptr<ReceiveRatchetTagSet> ReceiveRatchetTagSetPtr;
233  	struct ECIESX25519AEADRatchetIndexTagset
234  	{
235  		int index;
236  		ReceiveRatchetTagSetPtr tagset; // null if used
237  	};
238  
239  	class GarlicDestination: public i2p::data::LocalDestination
240  	{
241  		public:
242  
243  			GarlicDestination ();
244  			~GarlicDestination ();
245  
246  			void CleanUp ();
247  			std::mt19937& GetRng () { return m_Rng; };
248  			void SetNumTags (int numTags) { m_NumTags = numTags; };
249  			int GetNumTags () const { return m_NumTags; };
250  			void SetNumRatchetInboundTags (int numTags) { m_NumRatchetInboundTags = numTags; };
251  			int GetNumRatchetInboundTags () const { return m_NumRatchetInboundTags; };
252  			std::shared_ptr<GarlicRoutingSession> GetRoutingSession (std::shared_ptr<const i2p::data::RoutingDestination> destination,
253  				bool attachLeaseSet, bool requestNewIfNotFound = true);
254  			void CleanupExpiredTags ();
255  			void RemoveDeliveryStatusSession (uint32_t msgID);
256  			std::shared_ptr<I2NPMessage> WrapMessageForRouter (std::shared_ptr<const i2p::data::RouterInfo> router,
257  				std::shared_ptr<I2NPMessage> msg);
258  
259  			bool AEADChaCha20Poly1305Encrypt (const uint8_t * msg, size_t msgLen, const uint8_t * ad, size_t adLen,
260  				const uint8_t * key, const uint8_t * nonce, uint8_t * buf, size_t len);
261  			bool AEADChaCha20Poly1305Decrypt (const uint8_t * msg, size_t msgLen, const uint8_t * ad, size_t adLen,
262  				const uint8_t * key, const uint8_t * nonce, uint8_t * buf, size_t len);
263  
264  			void AddSessionKey (const uint8_t * key, const uint8_t * tag); // one tag
265  			void AddECIESx25519Key (const uint8_t * key, uint64_t tag); // one tag
266  			virtual bool SubmitSessionKey (const uint8_t * key, const uint8_t * tag); // from different thread
267  			virtual void SubmitECIESx25519Key (const uint8_t * key, uint64_t tag); // from different thread
268  			void DeliveryStatusSent (GarlicRoutingSessionPtr session, uint32_t msgID);
269  			uint64_t AddECIESx25519SessionNextTag (ReceiveRatchetTagSetPtr tagset);
270  			void AddECIESx25519Session (const uint8_t * staticKey, ECIESX25519AEADRatchetSessionPtr session);
271  			void RemoveECIESx25519Session (const uint8_t * staticKey);
272  			void HandleECIESx25519GarlicClove (const uint8_t * buf, size_t len, ECIESX25519AEADRatchetSession * from);
273  			uint8_t * GetPayloadBuffer ();
274  
275  			virtual void ProcessGarlicMessage (std::shared_ptr<I2NPMessage> msg);
276  			virtual void ProcessDeliveryStatusMessage (std::shared_ptr<I2NPMessage> msg);
277  			virtual void SetLeaseSetUpdated (bool post = false);
278  
279  			virtual std::shared_ptr<const i2p::data::LocalLeaseSet> GetLeaseSet () = 0; // TODO
280  			virtual std::shared_ptr<i2p::tunnel::TunnelPool> GetTunnelPool () const = 0;
281  			virtual i2p::data::CryptoKeyType GetRatchetsHighestCryptoType () const
282  			{
283  				return GetIdentity ()->GetCryptoKeyType () >= i2p::data::CRYPTO_KEY_TYPE_ECIES_X25519_AEAD ? GetIdentity ()->GetCryptoKeyType () : 0;
284  			}
285  
286  			virtual void ScheduleSessionResponseTimer (std::shared_ptr<ECIESX25519AEADRatchetSession> session) {};
287  
288  		protected:
289  
290  			void AddECIESx25519Key (const uint8_t * key, const uint8_t * tag); // one tag
291  			bool HandleECIESx25519TagMessage (uint8_t * buf, size_t len); // return true if found
292  			virtual void HandleI2NPMessage (const uint8_t * buf, size_t len) = 0; // called from clove only
293  			virtual bool HandleCloveI2NPMessage (I2NPMessageType typeID, const uint8_t * payload,
294  				size_t len, uint32_t msgID, ECIESX25519AEADRatchetSession * from) = 0;
295  			void HandleGarlicMessage (std::shared_ptr<I2NPMessage> msg);
296  			void HandleDeliveryStatusMessage (uint32_t msgID);
297  
298  			void SaveTags ();
299  			void LoadTags ();
300  
301  		private:
302  
303  			bool SupportsRatchets () const { return GetRatchetsHighestCryptoType () > 0; }
304  			void HandleAESBlock (uint8_t * buf, size_t len, std::shared_ptr<AESDecryption> decryption,
305  				std::shared_ptr<i2p::tunnel::InboundTunnel> from);
306  			void HandleGarlicPayload (uint8_t * buf, size_t len, std::shared_ptr<i2p::tunnel::InboundTunnel> from);
307  
308  		private:
309  
310  			std::mt19937 m_Rng;
311  			// outgoing sessions
312  			int m_NumTags;
313  			std::mutex m_SessionsMutex;
314  			std::unordered_map<i2p::data::IdentHash, ElGamalAESSessionPtr> m_Sessions;
315  			std::unordered_map<i2p::data::Tag<32>, ECIESX25519AEADRatchetSessionPtr> m_ECIESx25519Sessions; // static key -> session
316  			uint8_t * m_PayloadBuffer; // for ECIESX25519AEADRatchet
317  			uint64_t m_LastIncomingSessionTimestamp; // in milliseconds
318  			// incoming
319  			int m_NumRatchetInboundTags;
320  			std::unordered_map<SessionTag, std::shared_ptr<AESDecryption>, std::hash<i2p::data::Tag<32> > > m_Tags;
321  			std::unordered_map<uint64_t, ECIESX25519AEADRatchetIndexTagset> m_ECIESx25519Tags; // session tag -> session
322  			// DeliveryStatus
323  			std::mutex m_DeliveryStatusSessionsMutex;
324  			std::unordered_map<uint32_t, GarlicRoutingSessionPtr> m_DeliveryStatusSessions; // msgID -> session
325  			// encryption
326  			i2p::crypto::AEADChaCha20Poly1305Encryptor m_Encryptor;
327  			i2p::crypto::AEADChaCha20Poly1305Decryptor m_Decryptor;
328  
329  		public:
330  
331  			// for HTTP only
332  			size_t GetNumIncomingTags () const { return m_Tags.size (); }
333  			size_t GetNumIncomingECIESx25519Tags () const { return m_ECIESx25519Tags.size (); }
334  			const decltype(m_Sessions)& GetSessions () const { return m_Sessions; };
335  			const decltype(m_ECIESx25519Sessions)& GetECIESx25519Sessions () const { return m_ECIESx25519Sessions; }
336  	};
337  
338  	void CleanUpTagsFiles ();
339  
340  }
341  }
342  
343  #endif