eddsa signer fallback

libi2pd/Signature.cpp

@@ -52,30 +52,7 @@ namespace crypto
 	}
 #endif
 
-#if OPENSSL_EDDSA	
-	EDDSA25519Signer::EDDSA25519Signer (const uint8_t * signingPrivateKey, const uint8_t * signingPublicKey)
-	{
-		m_Pkey = EVP_PKEY_new_raw_private_key (EVP_PKEY_ED25519, NULL, signingPrivateKey, 32);
-		// TODO: check public key 
-		m_MDCtx = EVP_MD_CTX_create ();	
-		EVP_DigestSignInit (m_MDCtx, NULL, NULL, NULL, m_Pkey);
-	}
-
-	EDDSA25519Signer::~EDDSA25519Signer ()
-	{
-		EVP_MD_CTX_destroy (m_MDCtx);
-		EVP_PKEY_free (m_Pkey);
-	}
-
-	void EDDSA25519Signer::Sign (const uint8_t * buf, int len, uint8_t * signature) const
-	{
-		size_t l = 64;	
-		EVP_DigestSignInit (m_MDCtx, NULL, NULL, NULL, NULL);
-		EVP_DigestSign (m_MDCtx, signature, &l, buf, len); 
-	}	
-	
-#else	
-	EDDSA25519Signer::EDDSA25519Signer (const uint8_t * signingPrivateKey, const uint8_t * signingPublicKey)
+	EDDSA25519SignerCompat::EDDSA25519SignerCompat (const uint8_t * signingPrivateKey, const uint8_t * signingPublicKey)
 	{
 		// expand key
 		Ed25519::ExpandPrivateKey (signingPrivateKey, m_ExpandedPrivateKey);
@@ -95,14 +72,56 @@ namespace crypto
 		BN_CTX_free (ctx);
 	}
 
-	EDDSA25519Signer::~EDDSA25519Signer ()
+	EDDSA25519SignerCompat::~EDDSA25519SignerCompat ()
 	{
 	}	
 	
-	void EDDSA25519Signer::Sign (const uint8_t * buf, int len, uint8_t * signature) const
+	void EDDSA25519SignerCompat::Sign (const uint8_t * buf, int len, uint8_t * signature) const
 	{
 		GetEd25519 ()->Sign (m_ExpandedPrivateKey, m_PublicKeyEncoded, buf, len, signature);
 	}
+	
+#if OPENSSL_EDDSA	
+	EDDSA25519Signer::EDDSA25519Signer (const uint8_t * signingPrivateKey, const uint8_t * signingPublicKey):
+		m_Fallback (nullptr)
+	{		
+		m_Pkey = EVP_PKEY_new_raw_private_key (EVP_PKEY_ED25519, NULL, signingPrivateKey, 32);
+		uint8_t publicKey[EDDSA25519_PUBLIC_KEY_LENGTH];	
+		size_t len = EDDSA25519_PUBLIC_KEY_LENGTH;
+		EVP_PKEY_get_raw_public_key (pkey, publicKey, &len);
+		if (memcmp (publicKey, signingPublicKey, EDDSA25519_PUBLIC_KEY_LENGTH))
+		{
+			LogPrint (eLogWarning, "EdDSA public key mismatch. Fallback");
+			EVP_PKEY_free (m_Pkey);
+			m_Fallback = new EDDSA25519SignerCompat (signingPrivateKey, signingPublicKey);
+		}
+		else
+		{		
+			m_MDCtx = EVP_MD_CTX_create ();	
+			EVP_DigestSignInit (m_MDCtx, NULL, NULL, NULL, m_Pkey);
+		}	
+	}
+
+	EDDSA25519Signer::~EDDSA25519Signer ()
+	{
+		if (m_Fallback) delete m_Fallback;
+		else
+		{
+			EVP_MD_CTX_destroy (m_MDCtx);
+			EVP_PKEY_free (m_Pkey);
+		}		
+	}
+
+	void EDDSA25519Signer::Sign (const uint8_t * buf, int len, uint8_t * signature) const
+	{
+		if (m_Fallback) return m_Fallback->Sign (buf, len, signature);
+		else
+		{	
+			size_t l = 64;	
+			EVP_DigestSignInit (m_MDCtx, NULL, NULL, NULL, NULL);
+			EVP_DigestSign (m_MDCtx, signature, &l, buf, len); 
+		}	
+	}		
 #endif	
 }
 }

libi2pd/Signature.h

@@ -385,6 +385,24 @@ namespace crypto
 #endif			
 	};
 
+	class EDDSA25519SignerCompat: public Signer
+	{
+		public:
+
+			EDDSA25519SignerCompat (const uint8_t * signingPrivateKey, const uint8_t * signingPublicKey = nullptr);
+			// we pass signingPublicKey to check if it matches private key
+			~EDDSA25519SignerCompat ();
+			
+			void Sign (const uint8_t * buf, int len, uint8_t * signature) const;
+			const uint8_t * GetPublicKey () const { return m_PublicKeyEncoded; }; // for keys creation
+
+		private:
+		
+			uint8_t m_ExpandedPrivateKey[64];
+			uint8_t m_PublicKeyEncoded[EDDSA25519_PUBLIC_KEY_LENGTH];
+	};
+
+#if OPENSSL_EDDSA	
 	class EDDSA25519Signer: public Signer
 	{
 		public:
@@ -394,20 +412,18 @@ namespace crypto
 			~EDDSA25519Signer ();
 			
 			void Sign (const uint8_t * buf, int len, uint8_t * signature) const;
-#if !OPENSSL_EDDSA
-			const uint8_t * GetPublicKey () const { return m_PublicKeyEncoded; }; // for keys creation
-#endif
 
 		private:
-#if OPENSSL_EDDSA
 			EVP_PKEY * m_Pkey;
-			EVP_MD_CTX * m_MDCtx;
-#else			
-			uint8_t m_ExpandedPrivateKey[64];
-			uint8_t m_PublicKeyEncoded[EDDSA25519_PUBLIC_KEY_LENGTH];
-#endif			
+			EVP_MD_CTX * m_MDCtx;	
+			EDDSA25519SignerCompat * m_Fallback;
 	};
+#else
 
+	typedef EDDSA25519SignerCompat EDDSA25519Signer;
+	
+#endif	
+	
 	inline void CreateEDDSA25519RandomKeys (uint8_t * signingPrivateKey, uint8_t * signingPublicKey)
 	{
 #if OPENSSL_EDDSA