fixed Elligator tests

libi2pd/Elligator.cpp

@@ -40,7 +40,7 @@ namespace crypto
 		BN_free (u); BN_free (iu); 
 	}
 
-	bool Elligator2::Encode (const uint8_t * key, uint8_t * encoded) const
+	bool Elligator2::Encode (const uint8_t * key, uint8_t * encoded, bool highY, bool random) const
     {
 		bool ret = true;
 		BN_CTX * ctx = BN_CTX_new ();
@@ -63,9 +63,12 @@ namespace crypto
 		
 		if (Legendre (uxxA, ctx) != -1)
 		{	
-            uint8_t randByte; // random highest bits and high y
-            RAND_bytes (&randByte, 1);
-            bool highY = randByte & 0x01;
+            uint8_t randByte = 0; // random highest bits and high y
+			if (random)
+			{	
+            	RAND_bytes (&randByte, 1);
+            	highY = randByte & 0x01;
+			}
 			
 			BIGNUM * r = BN_CTX_get (ctx);
 			if (highY)
@@ -83,7 +86,8 @@ namespace crypto
 			SquareRoot (r, r, ctx);
 			bn2buf (r, encoded, 32);
 
-            encoded[0] |= (randByte & 0xC0); // copy two highest bits from randByte
+			if (random)
+            	encoded[0] |= (randByte & 0xC0); // copy two highest bits from randByte
 			for (size_t i = 0; i < 16; i++) // To Little Endian
 			{
 				uint8_t tmp = encoded[i];

libi2pd/Elligator.h

@@ -17,7 +17,7 @@ namespace crypto
 			Elligator2 ();
 			~Elligator2 ();
 
-			bool Encode (const uint8_t * key, uint8_t * encoded) const;
+			bool Encode (const uint8_t * key, uint8_t * encoded, bool highY = false, bool random = true) const;
 			bool Decode (const uint8_t * encoded, uint8_t * key) const;
 
 		private:	

tests/test-elligator.cpp

@@ -69,9 +69,9 @@ int main ()
 	uint8_t buf[32];
 	i2p::crypto::Elligator2 el;
 	// encoding tests
-	el.Encode (key, buf);
+	el.Encode (key, buf, false, false);
 	assert(memcmp (buf, encoded_key, 32) == 0);
-	el.Encode (key, buf, true); // with highY
+	el.Encode (key, buf, true, false); // with highY
 	assert(memcmp (buf, encoded_key_high_y, 32) == 0);
 	// decoding tests
 	el.Decode (encoded1, buf);