verify blinding key for encrypted LS2

libi2pd/Identity.cpp

@@ -1,8 +1,7 @@
-#include <time.h>
-#include <stdio.h>
 #include "Crypto.h"
 #include "I2PEndian.h"
 #include "Log.h"
+#include "Timestamp.h"
 #include "Identity.h"
 
 namespace i2p
@@ -774,15 +773,7 @@ namespace data
 	{
 		uint8_t buf[41]; // ident + yyyymmdd
 		memcpy (buf, (const uint8_t *)ident, 32);
-		time_t t = time (nullptr);
-		struct tm tm;
-#ifdef _WIN32
-		gmtime_s(&tm, &t);
-		sprintf_s((char *)(buf + 32), 9, "%04i%02i%02i", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
-#else
-		gmtime_r(&t, &tm);
-		sprintf((char *)(buf + 32), "%04i%02i%02i", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
-#endif
+		i2p::util::GetCurrentDate ((char *)(buf + 32));
 		IdentHash key;
 		SHA256(buf, 40, key);
 		return key;

libi2pd/LeaseSet.cpp

@@ -466,6 +466,19 @@ namespace data
 		if (verified && identity && lenOuterCiphertext >= 32)
 		{
 			SetIsValid (false); // we must verify it again in Layer 2 
+			if (blindedKeyType == i2p::data::SIGNING_KEY_TYPE_REDDSA_SHA512_ED25519)
+			{
+				// verify blinding
+				char date[9];
+				i2p::util::GetCurrentDate (date);
+				uint8_t blinded[32];
+				BlindPublicKey (identity, date, blindedKeyType, blinded);
+				if (memcmp (blindedPublicKey, blinded, 32))
+				{
+					LogPrint (eLogError, "LeaseSet2: blinded public key doesn't match");
+					return;
+				}	
+			}	
 			// credentials
 			uint8_t credential[32], subcredential[36];
 			// A = destination's signing public key 
@@ -543,8 +556,16 @@ namespace data
 		i2p::crypto::GetEd25519 ()->BlindPublicKey (identity->GetSigningPublicKeyBuffer (), seed, blindedKey);
 	}
 
-	void LeaseSet2::CalculateStoreHash (std::shared_ptr<const IdentityEx> identity, const char * date, SigningKeyType blindedKeyType, i2p::data::IdentHash& hash)
+	void LeaseSet2::CalculateStoreHash (std::shared_ptr<const IdentityEx> identity, SigningKeyType blindedKeyType, i2p::data::IdentHash& hash)
 	{
+		if (blindedKeyType != i2p::data::SIGNING_KEY_TYPE_REDDSA_SHA512_ED25519 &&
+			blindedKeyType != SIGNING_KEY_TYPE_EDDSA_SHA512_ED25519)
+		{
+			LogPrint (eLogError, "LeaseSet2: blinded key type ", (int)blindedKeyType, " is not supported");			
+			return;
+		}
+		char date[9];
+		i2p::util::GetCurrentDate (date);
 		uint8_t blinded[32];
 		BlindPublicKey (identity, date, blindedKeyType, blinded);		
 		auto stA1 = htobe16 (blindedKeyType);

libi2pd/LeaseSet.h

@@ -139,7 +139,7 @@ namespace data
 			std::shared_ptr<const i2p::crypto::Verifier> GetTransientVerifier () const { return m_TransientVerifier; };
 			void Update (const uint8_t * buf, size_t len, bool verifySignature);
 
-			static void CalculateStoreHash (std::shared_ptr<const IdentityEx> identity, const char * date, SigningKeyType blindedKeyType, i2p::data::IdentHash& hash);
+			static void CalculateStoreHash (std::shared_ptr<const IdentityEx> identity, SigningKeyType blindedKeyType, i2p::data::IdentHash& hash);
 
 			// implements RoutingDestination
 			void Encrypt (const uint8_t * data, uint8_t * encrypted, BN_CTX * ctx) const;

libi2pd/Timestamp.cpp

@@ -1,3 +1,5 @@
+#include <time.h>
+#include <stdio.h>
 #include <inttypes.h>
 #include <string.h>
 #include <chrono>
@@ -37,7 +39,6 @@ namespace util
 				 std::chrono::system_clock::now().time_since_epoch()).count ();
 	}
 
-
 	static int64_t g_TimeOffset = 0; // in seconds
 
 	static void SyncTimeWithNTP (const std::string& address)
@@ -178,6 +179,19 @@ namespace util
 	{
 		return GetLocalSecondsSinceEpoch () + g_TimeOffset;
 	}
+
+	void GetCurrentDate (char * date)
+	{
+		time_t t = time (nullptr);
+		struct tm tm;
+#ifdef _WIN32
+		gmtime_s(&tm, &t);
+		sprintf_s(date, 9, "%04i%02i%02i", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
+#else
+		gmtime_r(&t, &tm);
+		sprintf(date, "%04i%02i%02i", tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
+#endif
+	}
 }
 }
 

libi2pd/Timestamp.h

@@ -15,6 +15,8 @@ namespace util
 	uint32_t GetHoursSinceEpoch ();
 	uint64_t GetSecondsSinceEpoch ();
 
+	void GetCurrentDate (char * date); // returns date as YYYYMMDD string, 9 bytes	
+
 	class NTPTimeSync
 	{
 		public: