From 9da984b86692ae492a2d7876574b9731a6c9cf53 Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Tue, 20 Dec 2016 14:10:14 -0500
Subject: [PATCH] use ElGamalEncrypt

---
 Crypto.cpp     | 24 ++++++++----------------
 Crypto.h       | 16 +---------------
 Garlic.cpp     |  3 +--
 TunnelConfig.h |  3 +--
 4 files changed, 11 insertions(+), 35 deletions(-)

diff --git a/Crypto.cpp b/Crypto.cpp
index a4a794ac..cc138923 100644
--- a/Crypto.cpp
+++ b/Crypto.cpp
@@ -272,10 +272,9 @@ namespace crypto
 	}	
 	
 // ElGamal
-
-	ElGamalEncryption::ElGamalEncryption (const uint8_t * key)
+	void ElGamalEncrypt (const uint8_t * key, const uint8_t * data, uint8_t * encrypted, bool zeroPadding)
 	{
-		ctx = BN_CTX_new ();
+		BN_CTX * ctx = BN_CTX_new ();
 		// select random k
 		BIGNUM * k = BN_new ();
 #if defined(__x86_64__)
@@ -284,6 +283,7 @@ namespace crypto
 		BN_rand (k, ELGAMAL_SHORT_EXPONENT_NUM_BITS, -1, 1); // short exponent of 226 bits
 #endif		
 		// calculate a
+		BIGNUM * a;	
 		if (g_ElggTable)
 			a = ElggPow (k, g_ElggTable, ctx);
 		else
@@ -295,21 +295,10 @@ namespace crypto
 		BIGNUM * y = BN_new ();
 		BN_bin2bn (key, 256, y);
 		// calculate b1
-		b1 = BN_new ();
+		BIGNUM * b1 = BN_new ();
 		BN_mod_exp (b1, y, k, elgp, ctx);
 		BN_free (y);
 		BN_free (k);
-	}
-
-	ElGamalEncryption::~ElGamalEncryption ()
-	{
-		BN_CTX_free (ctx);
-		BN_free (a);
-		BN_free (b1);
-	}
-			
-	void ElGamalEncryption::Encrypt (const uint8_t * data, uint8_t * encrypted, bool zeroPadding) const
-	{
 		// create m
 		uint8_t m[255];
 		m[0] = 0xFF;
@@ -319,6 +308,7 @@ namespace crypto
 		BIGNUM * b = BN_new ();
 		BN_bin2bn (m, 255, b);
 		BN_mod_mul (b, b1, b, elgp, ctx);
+		BN_free (b1);
 		// copy a and b
 		if (zeroPadding)
 		{
@@ -333,8 +323,10 @@ namespace crypto
 			bn2buf (b, encrypted + 256, 256);
 		}		
 		BN_free (b);
+		BN_free (a);
+		BN_CTX_free (ctx);
 	}
-	
+
 	bool ElGamalDecrypt (const uint8_t * key, const uint8_t * encrypted, 
 		uint8_t * data, bool zeroPadding)
 	{
diff --git a/Crypto.h b/Crypto.h
index 9e35f073..00255a37 100644
--- a/Crypto.h
+++ b/Crypto.h
@@ -47,21 +47,7 @@ namespace crypto
 	};	
 	
 	// ElGamal
-	class ElGamalEncryption
-	{
-		public:
-
-			ElGamalEncryption (const uint8_t * key);
-			~ElGamalEncryption ();
-			
-			void Encrypt (const uint8_t * data, uint8_t * encrypted, bool zeroPadding = false) const;
-
-		private:
-
-			BN_CTX * ctx;
-			BIGNUM * a, * b1;
-	};
-
+	void ElGamalEncrypt (const uint8_t * key, const uint8_t * data, uint8_t * encrypted, bool zeroPadding = false);
 	bool ElGamalDecrypt (const uint8_t * key, const uint8_t * encrypted, uint8_t * data, bool zeroPadding = false);
 	void GenerateElGamalKeyPair (uint8_t * priv, uint8_t * pub);
 
diff --git a/Garlic.cpp b/Garlic.cpp
index 81941cfc..51fa6c3b 100644
--- a/Garlic.cpp
+++ b/Garlic.cpp
@@ -187,8 +187,7 @@ namespace garlic
 			RAND_bytes (elGamal.preIV, 32); // Pre-IV
 			uint8_t iv[32]; // IV is first 16 bytes
 			SHA256(elGamal.preIV, 32, iv); 
-			i2p::crypto::ElGamalEncryption elGamalEncryption (m_Destination->GetEncryptionPublicKey ());
-			elGamalEncryption.Encrypt ((uint8_t *)&elGamal, buf, true);			
+			i2p::crypto::ElGamalEncrypt (m_Destination->GetEncryptionPublicKey (), (uint8_t *)&elGamal, buf, true);			
 			m_Encryption.SetIV (iv);
 			buf += 514;
 			len += 514;	
diff --git a/TunnelConfig.h b/TunnelConfig.h
index cb31243f..c131059c 100644
--- a/TunnelConfig.h
+++ b/TunnelConfig.h
@@ -101,8 +101,7 @@ namespace tunnel
 			htobe32buf (clearText + BUILD_REQUEST_RECORD_REQUEST_TIME_OFFSET, i2p::util::GetHoursSinceEpoch ()); 
 			htobe32buf (clearText + BUILD_REQUEST_RECORD_SEND_MSG_ID_OFFSET, replyMsgID); 
 			RAND_bytes (clearText + BUILD_REQUEST_RECORD_PADDING_OFFSET, BUILD_REQUEST_RECORD_CLEAR_TEXT_SIZE - BUILD_REQUEST_RECORD_PADDING_OFFSET);
-			i2p::crypto::ElGamalEncryption elGamalEncryption (ident->GetEncryptionPublicKey ());
-			elGamalEncryption.Encrypt (clearText, record + BUILD_REQUEST_RECORD_ENCRYPTED_OFFSET);
+			i2p::crypto::ElGamalEncrypt (ident->GetEncryptionPublicKey (), clearText, record + BUILD_REQUEST_RECORD_ENCRYPTED_OFFSET);
 			memcpy (record + BUILD_REQUEST_RECORD_TO_PEER_OFFSET, (const uint8_t *)ident->GetIdentHash (), 16);
 		}	
 	};