From 7692332f0e9df279e7e87822327aefbbea3f47a2 Mon Sep 17 00:00:00 2001
From: orignal <i2porignal@yandex.ru>
Date: Fri, 30 Nov 2018 21:31:06 -0500
Subject: [PATCH] don't inialize Chacha20 state twice

---
 libi2pd/ChaCha20.cpp | 32 +++++++++++++++++---------------
 libi2pd/ChaCha20.h   | 24 ++++++++++++------------
 libi2pd/Crypto.cpp   | 17 ++++++++++-------
 3 files changed, 39 insertions(+), 34 deletions(-)

diff --git a/libi2pd/ChaCha20.cpp b/libi2pd/ChaCha20.cpp
index 0ee7cf75..30e02f42 100644
--- a/libi2pd/ChaCha20.cpp
+++ b/libi2pd/ChaCha20.cpp
@@ -1,12 +1,15 @@
-#include "ChaCha20.h"
-
-/**
-   This code is licensed under the MCGSI Public License
-   Copyright 2018 Jeff Becker
-
-   Kovri go write your own code
+/*
+* Copyright (c) 2013-2018, The PurpleI2P Project
+*
+* This file is part of Purple i2pd project and licensed under BSD3
+*
+* See full license text in LICENSE file at top of project tree
+*
+* Kovri go write your own code
+*
+*/
 
- */
+#include "ChaCha20.h"
 
 #if LEGACY_OPENSSL
 namespace i2p
@@ -91,6 +94,12 @@ void Chacha20Init (Chacha20State& state, const uint8_t * nonce, const uint8_t *
 	    state.data[13 + i] = chacha::u8t32le(nonce + i * 4);
 }
 
+void Chacha20SetCounter (Chacha20State& state, uint32_t counter)
+{
+	state.data[12] = counter;
+	state.offset = 0;
+}	
+
 void Chacha20Encrypt (Chacha20State& state, uint8_t * buf, size_t sz)
 {	
 	if (state.offset > 0)
@@ -121,13 +130,6 @@ void Chacha20Encrypt (Chacha20State& state, uint8_t * buf, size_t sz)
 }
 } // namespace chacha
 
-
-	void chacha20(uint8_t * buf, size_t sz, const uint8_t * nonce, const uint8_t * key, uint32_t counter)
-	{
-		chacha::Chacha20State state;
-		chacha::Chacha20Init (state, nonce, key, counter);
-		chacha::Chacha20Encrypt (state, buf, sz);		
-	}
 }
 }
 #endif
diff --git a/libi2pd/ChaCha20.h b/libi2pd/ChaCha20.h
index 0a2f3be0..a5a8aafc 100644
--- a/libi2pd/ChaCha20.h
+++ b/libi2pd/ChaCha20.h
@@ -1,10 +1,13 @@
-/**
-   This code is licensed under the MCGSI Public License
-   Copyright 2018 Jeff Becker
-
-   Kovri go write your own code
-
- */
+/*
+* Copyright (c) 2013-2018, The PurpleI2P Project
+*
+* This file is part of Purple i2pd project and licensed under BSD3
+*
+* See full license text in LICENSE file at top of project tree
+*
+* Kovri go write your own code
+*
+*/
 #ifndef LIBI2PD_CHACHA20_H
 #define LIBI2PD_CHACHA20_H
 #include <cstdint>
@@ -59,12 +62,9 @@ namespace chacha
 	};
 
 	void Chacha20Init (Chacha20State& state, const uint8_t * nonce, const uint8_t * key, uint32_t counter);
-	void Chacha20Encrypt (Chacha20State& state, uint8_t * buf, size_t sz);		
+	void Chacha20SetCounter (Chacha20State& state, uint32_t counter);
+	void Chacha20Encrypt (Chacha20State& state, uint8_t * buf, size_t sz); // encrypt buf in place	
 }
-
-  /** encrypt buf in place with chacha20 */
-  void chacha20(uint8_t * buf, size_t sz, const uint8_t * nonce, const uint8_t * key, uint32_t counter=1);
-
 } 
 }
 #endif
diff --git a/libi2pd/Crypto.cpp b/libi2pd/Crypto.cpp
index 659fddcc..28df1399 100644
--- a/libi2pd/Crypto.cpp
+++ b/libi2pd/Crypto.cpp
@@ -1087,11 +1087,12 @@ namespace crypto
 		if (encrypt && len < msgLen + 16) return false;
 		bool ret = true;
 #if LEGACY_OPENSSL
+		chacha::Chacha20State state;
 		// generate one time poly key
+		chacha::Chacha20Init (state, nonce, key, 0);	
 		uint64_t polyKey[8];
 		memset(polyKey, 0, sizeof(polyKey));
-		chacha20 ((uint8_t *)polyKey, 64, nonce, key, 0);
-		
+		chacha::Chacha20Encrypt (state, (uint8_t *)polyKey, 64);
 		// create Poly1305 hash
 		Poly1305 polyHash (polyKey);
 		if (!ad) adLen = 0;
@@ -1108,17 +1109,18 @@ namespace crypto
 			}
 		}
 		// encrypt/decrypt data and add to hash
+		Chacha20SetCounter (state, 1);
 		if (buf != msg)
 			memcpy (buf, msg, msgLen);
 		if (encrypt)
 		{
-			chacha20 (buf, msgLen, nonce, key, 1); // encrypt
+			chacha::Chacha20Encrypt (state, buf, msgLen); // encrypt
 			polyHash.Update (buf, msgLen); // after encryption
 		}
 		else
 		{
 			polyHash.Update (buf, msgLen); // before decryption
-			chacha20 (buf, msgLen, nonce, key, 1); // decrypt
+			chacha::Chacha20Encrypt (state, buf, msgLen); // decrypt
 		}	
 
 		auto rem = msgLen & 0x0F; // %16
@@ -1176,14 +1178,15 @@ namespace crypto
 	{
 		if (bufs.empty ()) return;
 #if LEGACY_OPENSSL
+		chacha::Chacha20State state;
 		// generate one time poly key
+		chacha::Chacha20Init (state, nonce, key, 0);	
 		uint64_t polyKey[8];
 		memset(polyKey, 0, sizeof(polyKey));
-		chacha20 ((uint8_t *)polyKey, 64, nonce, key, 0);
+		chacha::Chacha20Encrypt (state, (uint8_t *)polyKey, 64);
 		Poly1305 polyHash (polyKey);
 		// encrypt buffers	
-		chacha::Chacha20State state;
-		chacha::Chacha20Init (state, nonce, key, 1);	
+		Chacha20SetCounter (state, 1);
 		size_t size = 0;
 		for (auto& it: bufs)
 		{