separate X25519Keys

libi2pd/Crypto.cpp

@@ -12,9 +12,8 @@
 #if LEGACY_OPENSSL
 #include "ChaCha20.h"
 #include "Poly1305.h"
-#else
-#include <openssl/evp.h>
 #endif
+#include "Ed25519.h"
 #include "I2PEndian.h"
 #include "Log.h"
 
@@ -278,6 +277,58 @@ namespace crypto
 		BN_free (pk);
 	}
 
+// x25519
+	X25519Keys::X25519Keys ()
+	{
+#if OPENSSL_X25519
+		m_Ctx = EVP_PKEY_CTX_new_id (NID_X25519, NULL);
+#else		
+		m_Ctx = BN_CTX_new ();
+#endif		
+	}	
+	
+	X25519Keys::~X25519Keys ()
+	{
+#if OPENSSL_X25519
+		EVP_PKEY_CTX_free (m_Ctx);
+		if (m_Pkey)
+			EVP_PKEY_free (m_Pkey);	
+#else				
+		BN_CTX_free (m_Ctx);
+#endif		
+	}	
+
+	void X25519Keys::GenerateKeys ()
+	{
+#if OPENSSL_X25519
+		m_Pkey = nullptr;
+		EVP_PKEY_keygen_init (m_Ctx);
+		EVP_PKEY_keygen (m_Ctx, &m_Pkey);
+		size_t len = 32;
+		EVP_PKEY_get_raw_public_key (m_Pkey, m_PublicKey, &len);
+		// TODO: remove 
+		len = 32;
+		EVP_PKEY_get_raw_private_key (m_EphemeralPkey, m_PrivateKey, &len);
+#else		
+		RAND_bytes (m_PrivateKey, 32);
+		GetEd25519 ()->ScalarMulB (m_PrivateKey, m_PublicKey, m_Ctx);
+#endif		
+	}	
+
+	void X25519Keys::Agree (const uint8_t * pub, uint8_t * shared)
+	{
+#if OPENSSL_X25519		
+		EVP_PKEY_derive_init (m_Ctx);
+		auto pkey = EVP_PKEY_new_raw_public_key (EVP_PKEY_X25519, NULL, pub, 32);
+		EVP_PKEY_derive_set_peer (m_Ctx, pkey);
+		size_t len = 32;
+		EVP_PKEY_derive (m_Ctx, shared, &len);
+		EVP_PKEY_free (pkey);
+#else		
+		GetEd25519 ()->ScalarMul (pub, m_PrivateKey, shared, m_Ctx);
+#endif		
+	}		
+	
 // ElGamal
 	void ElGamalEncrypt (const uint8_t * key, const uint8_t * data, uint8_t * encrypted, BN_CTX * ctx, bool zeroPadding)
 	{

libi2pd/Crypto.h

@@ -13,11 +13,23 @@
 #include <openssl/evp.h>
 #include <openssl/rand.h>
 #include <openssl/engine.h>
+#include <openssl/opensslv.h>
 
 #include "Base.h"
 #include "Tag.h"
 #include "CPU.h"
 
+// recognize openssl version and features
+#if ((OPENSSL_VERSION_NUMBER < 0x010100000) || defined(LIBRESSL_VERSION_NUMBER)) // 1.0.2 and below or LibreSSL
+#   define LEGACY_OPENSSL 1
+#else
+#   define LEGACY_OPENSSL 0
+#   if (OPENSSL_VERSION_NUMBER >= 0x010101000) // 1.1.1
+#	   define OPENSSL_EDDSA 1
+#	   define OPENSSL_X25519 1
+#   endif
+#endif
+
 namespace i2p
 {
 namespace crypto
@@ -48,6 +60,31 @@ namespace crypto
 			uint8_t m_PublicKey[256];
 	};
 
+	// x25519
+	class X25519Keys
+	{
+		public:
+
+			X25519Keys ();
+			~X25519Keys ();
+
+			void GenerateKeys ();
+			const uint8_t * GetPublicKey () const { return m_PublicKey; };
+			const uint8_t * GetPrivateKey () const { return m_PrivateKey; }; // TODO: remove
+			void Agree (const uint8_t * pub, uint8_t * shared);			
+
+		private:
+
+			uint8_t m_PublicKey[32];	
+			uint8_t m_PrivateKey[32]; // TODO: move to #else
+#if OPENSSL_X25519
+			EVP_PKEY_CTX * m_Ctx;
+			EVP_PKEY * m_Pkey;
+#else			
+			BN_CTX * m_Ctx;
+#endif			
+	};
+	
 	// ElGamal
 	void ElGamalEncrypt (const uint8_t * key, const uint8_t * data, uint8_t * encrypted, BN_CTX * ctx, bool zeroPadding = false);
 	bool ElGamalDecrypt (const uint8_t * key, const uint8_t * encrypted, uint8_t * data, BN_CTX * ctx, bool zeroPadding = false);
@@ -260,18 +297,7 @@ namespace crypto
 }
 }
 
-// take care about openssl version
-#include <openssl/opensslv.h>
-#if ((OPENSSL_VERSION_NUMBER < 0x010100000) || defined(LIBRESSL_VERSION_NUMBER)) // 1.0.2 and below or LibreSSL
-#   define LEGACY_OPENSSL 1
-#else
-#   define LEGACY_OPENSSL 0
-#   if (OPENSSL_VERSION_NUMBER >= 0x010101000) // 1.1.1
-#	   define OPENSSL_EDDSA 1
-#	   define OPENSSL_X25519 1
-#   endif
-#endif
-
+// take care about openssl below 1.1.0
 #if LEGACY_OPENSSL
 // define getters and setters introduced in 1.1.0
 inline int DSA_set0_pqg(DSA *d, BIGNUM *p, BIGNUM *q, BIGNUM *g)

libi2pd/NTCP2.cpp

@@ -120,20 +120,10 @@ namespace transport
 		SHA256_Update (&ctx, epub, 32); 
 		SHA256_Final (m_H, &ctx);
 
-		// x25519 between remote pub and priv
+		// x25519 between remote pub and ephemaral priv
 		uint8_t inputKeyMaterial[32];
-#if OPENSSL_X25519
-		auto pctx = EVP_PKEY_CTX_new (m_EphemeralPkey, NULL);	
-		EVP_PKEY_derive_init (pctx);
-		auto pkey = EVP_PKEY_new_raw_public_key (EVP_PKEY_X25519, NULL, GetRemotePub (), 32);
-		EVP_PKEY_derive_set_peer (pctx, pkey);
-		size_t len = 32;
-		EVP_PKEY_derive (pctx, inputKeyMaterial, &len); 	
-		EVP_PKEY_free (pkey);
-		EVP_PKEY_CTX_free (pctx);
-#else
-		i2p::crypto::GetEd25519 ()->ScalarMul (GetRemotePub (), GetPriv (), inputKeyMaterial, m_Ctx);
-#endif 
+		m_EphemeralKeys.Agree (GetRemotePub (), inputKeyMaterial);
+		
 		MixKey (inputKeyMaterial, m_K);
 	}
 
@@ -157,27 +147,13 @@ namespace transport
 	void NTCP2Establisher::KDF3Bob ()
 	{
 		uint8_t inputKeyMaterial[32];
-		i2p::crypto::GetEd25519 ()->ScalarMul (m_RemoteStaticKey, m_EphemeralPrivateKey, inputKeyMaterial, m_Ctx); 
+		i2p::crypto::GetEd25519 ()->ScalarMul (m_RemoteStaticKey, GetPriv (), inputKeyMaterial, m_Ctx); 
 		MixKey (inputKeyMaterial, m_K);
 	}
 
 	void NTCP2Establisher::CreateEphemeralKey ()
 	{
-#if OPENSSL_X25519
-		m_EphemeralPkey = nullptr;
-		EVP_PKEY_CTX * pctx = EVP_PKEY_CTX_new_id (NID_X25519, NULL);
-		EVP_PKEY_keygen_init (pctx);
-		EVP_PKEY_keygen (pctx, &m_EphemeralPkey);
-		EVP_PKEY_CTX_free (pctx);
-		// TODO: remove, after switch to m_EphemeralPkey 
-		size_t len = 32;
-		EVP_PKEY_get_raw_public_key (m_EphemeralPkey, m_EphemeralPublicKey, &len);
-		len = 32;
-		EVP_PKEY_get_raw_private_key (m_EphemeralPkey, m_EphemeralPrivateKey, &len);
-#else
-		RAND_bytes (m_EphemeralPrivateKey, 32);
-		i2p::crypto::GetEd25519 ()->ScalarMulB (m_EphemeralPrivateKey, m_EphemeralPublicKey, m_Ctx);
-#endif
+		m_EphemeralKeys.GenerateKeys ();
 	}
 
 	void NTCP2Establisher::CreateSessionRequestMessage ()

libi2pd/NTCP2.h

@@ -20,6 +20,7 @@
 #include <openssl/bn.h>
 #include <openssl/evp.h>
 #include <boost/asio.hpp>
+#include "Crypto.h"
 #include "util.h"
 #include "RouterInfo.h"
 #include "TransportSession.h"
@@ -78,8 +79,8 @@ namespace transport
 		NTCP2Establisher ();
 		~NTCP2Establisher ();
 		
-		const uint8_t * GetPub () const { return m_EphemeralPublicKey; };
-		const uint8_t * GetPriv () const { return m_EphemeralPrivateKey; };
+		const uint8_t * GetPub () const { return m_EphemeralKeys.GetPublicKey (); };
+		const uint8_t * GetPriv () const { return m_EphemeralKeys.GetPrivateKey (); };
 		const uint8_t * GetRemotePub () const { return m_RemoteEphemeralPublicKey; }; // Y for Alice and X for Bob
 		uint8_t * GetRemotePub () { return m_RemoteEphemeralPublicKey; }; // to set
 
@@ -110,10 +111,8 @@ namespace transport
 		bool ProcessSessionConfirmedMessagePart2 (const uint8_t * nonce, uint8_t * m3p2Buf);
 
 		BN_CTX * m_Ctx;
-		uint8_t m_EphemeralPrivateKey[32], m_EphemeralPublicKey[32], m_RemoteEphemeralPublicKey[32]; // x25519
-#if OPENSSL_X25519
-		EVP_PKEY * m_EphemeralPkey;
-#endif
+		i2p::crypto::X25519Keys m_EphemeralKeys;
+		uint8_t m_RemoteEphemeralPublicKey[32]; // x25519
 		uint8_t m_RemoteStaticKey[32], m_IV[16], m_H[32] /*h*/, m_CK[33] /*ck*/, m_K[32] /*k*/;
 		i2p::data::IdentHash m_RemoteIdentHash;
 		uint16_t m3p2Len;