From fd780e3eab87b1f656b704aa439c21ac5ec1db76 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sun, 3 Sep 2017 21:18:19 +0800
Subject: [PATCH] move the nonce generation to the AEAD implementations

The AES AEAD used by IETF QUIC uses a different nonce format.
---
 crypto/aesgcm_aead.go           | 12 ++++++++++--
 crypto/chacha20poly1305_aead.go | 12 ++++++++++--
 crypto/nonce.go                 | 14 --------------
 3 files changed, 20 insertions(+), 18 deletions(-)
 delete mode 100644 crypto/nonce.go

diff --git a/crypto/aesgcm_aead.go b/crypto/aesgcm_aead.go
index baaed5c82..0997c3186 100644
--- a/crypto/aesgcm_aead.go
+++ b/crypto/aesgcm_aead.go
@@ -2,6 +2,7 @@ package crypto
 
 import (
 	"crypto/cipher"
+	"encoding/binary"
 	"errors"
 
 	"github.com/lucas-clemente/aes12"
@@ -50,9 +51,16 @@ func NewAEADAESGCM(otherKey []byte, myKey []byte, otherIV []byte, myIV []byte) (
 }
 
 func (aead *aeadAESGCM) Open(dst, src []byte, packetNumber protocol.PacketNumber, associatedData []byte) ([]byte, error) {
-	return aead.decrypter.Open(dst, makeNonce(aead.otherIV, packetNumber), src, associatedData)
+	return aead.decrypter.Open(dst, aead.makeNonce(aead.otherIV, packetNumber), src, associatedData)
 }
 
 func (aead *aeadAESGCM) Seal(dst, src []byte, packetNumber protocol.PacketNumber, associatedData []byte) []byte {
-	return aead.encrypter.Seal(dst, makeNonce(aead.myIV, packetNumber), src, associatedData)
+	return aead.encrypter.Seal(dst, aead.makeNonce(aead.myIV, packetNumber), src, associatedData)
+}
+
+func (aead *aeadAESGCM) makeNonce(iv []byte, packetNumber protocol.PacketNumber) []byte {
+	res := make([]byte, 12)
+	copy(res[0:4], iv)
+	binary.LittleEndian.PutUint64(res[4:12], uint64(packetNumber))
+	return res
 }
diff --git a/crypto/chacha20poly1305_aead.go b/crypto/chacha20poly1305_aead.go
index 3e9c1deeb..5d2e36f9f 100644
--- a/crypto/chacha20poly1305_aead.go
+++ b/crypto/chacha20poly1305_aead.go
@@ -4,6 +4,7 @@ package crypto
 
 import (
 	"crypto/cipher"
+	"encoding/binary"
 	"errors"
 
 	"github.com/aead/chacha20"
@@ -45,9 +46,16 @@ func NewAEADChacha20Poly1305(otherKey []byte, myKey []byte, otherIV []byte, myIV
 }
 
 func (aead *aeadChacha20Poly1305) Open(dst, src []byte, packetNumber protocol.PacketNumber, associatedData []byte) ([]byte, error) {
-	return aead.decrypter.Open(dst, makeNonce(aead.otherIV, packetNumber), src, associatedData)
+	return aead.decrypter.Open(dst, aead.makeNonce(aead.otherIV, packetNumber), src, associatedData)
 }
 
 func (aead *aeadChacha20Poly1305) Seal(dst, src []byte, packetNumber protocol.PacketNumber, associatedData []byte) []byte {
-	return aead.encrypter.Seal(dst, makeNonce(aead.myIV, packetNumber), src, associatedData)
+	return aead.encrypter.Seal(dst, aead.makeNonce(aead.myIV, packetNumber), src, associatedData)
+}
+
+func (aead *aeadChacha20Poly1305) makeNonce(iv []byte, packetNumber protocol.PacketNumber) []byte {
+	res := make([]byte, 12)
+	copy(res[0:4], iv)
+	binary.LittleEndian.PutUint64(res[4:12], uint64(packetNumber))
+	return res
 }
diff --git a/crypto/nonce.go b/crypto/nonce.go
deleted file mode 100644
index f862f461d..000000000
--- a/crypto/nonce.go
+++ /dev/null
@@ -1,14 +0,0 @@
-package crypto
-
-import (
-	"encoding/binary"
-
-	"github.com/lucas-clemente/quic-go/internal/protocol"
-)
-
-func makeNonce(iv []byte, packetNumber protocol.PacketNumber) []byte {
-	res := make([]byte, 12)
-	copy(res[0:4], iv)
-	binary.LittleEndian.PutUint64(res[4:12], uint64(packetNumber))
-	return res
-}