From 7c3414b0721dfafb7c71904dcbac2ee0fda359ef Mon Sep 17 00:00:00 2001
From: Jeffrey Walton <noloader@gmail.com>
Date: Mon, 28 Jan 2019 10:01:19 -0500
Subject: [PATCH] Fix ChaCha20Poly1305 IVSize() (GH #724)

---
 chachapoly.cpp | 2 +-
 chachapoly.h   | 6 +++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/chachapoly.cpp b/chachapoly.cpp
index 90b2864c..02a1f6b1 100644
--- a/chachapoly.cpp
+++ b/chachapoly.cpp
@@ -19,7 +19,7 @@ void ChaCha20Poly1305_Base::RekeyCipherAndMac(const byte *userKey, size_t keylen
 	AccessSymmetricCipher().ProcessString(derived, derived.size());
 
 	// Set the Poly1305 key
-	AccessMAC().SetKey(derived, 32, params);
+	AccessMAC().SetKey(derived, derived.size(), params);
 
 	// Key Cipher for bulk encryption
 	AlgorithmParameters block1 = MakeParameters("InitialBlock", (word64)1, true);
diff --git a/chachapoly.h b/chachapoly.h
index 31dc9659..0c03e392 100644
--- a/chachapoly.h
+++ b/chachapoly.h
@@ -53,7 +53,7 @@ public:
 	IV_Requirement IVRequirement() const
 		{return UNIQUE_IV;}
 	unsigned int IVSize() const
-		{return 16;}
+		{return 12;}
 	unsigned int MinIVLength() const
 		{return 12;}
 	unsigned int MaxIVLength() const
@@ -128,6 +128,10 @@ protected:
 /// \since Crypto++ 8.1
 class ChaCha20Poly1305_Final : public ChaCha20Poly1305_Base
 {
+public:
+	static std::string StaticAlgorithmName()
+		{return std::string("ChaCha20/Poly1305");}
+
 protected:
 	const SymmetricCipher & GetSymmetricCipher()
 		{return const_cast<ChaCha20Poly1305_Final *>(this)->AccessSymmetricCipher();}