From df2e6e32ebebe4c6f4337c23571b6a08d09bddb3 Mon Sep 17 00:00:00 2001
From: Lucas Clemente <lucas@clemente.io>
Date: Wed, 4 May 2016 17:26:44 +0200
Subject: [PATCH] move fnv128a implementation to separate package

---
 crypto/fnv.go       | 88 ---------------------------------------------
 crypto/fnv_test.go  | 24 -------------
 crypto/null_aead.go |  5 +--
 3 files changed, 3 insertions(+), 114 deletions(-)
 delete mode 100644 crypto/fnv.go
 delete mode 100644 crypto/fnv_test.go

diff --git a/crypto/fnv.go b/crypto/fnv.go
deleted file mode 100644
index 932f2fd5..00000000
--- a/crypto/fnv.go
+++ /dev/null
@@ -1,88 +0,0 @@
-package crypto
-
-// Implements FNV-1 and FNV-1a, non-cryptographic hash functions
-// created by Glenn Fowler, Landon Curt Noll, and Phong Vo.
-// See https://en.wikipedia.org/wiki/Fowler-Noll-Vo_hash_function.
-
-// Write() algorithm taken and modified from github.com/romain-jacotin/quic
-
-import "hash"
-
-// Hash128 is the common interface implemented by all 128-bit hash functions.
-type Hash128 interface {
-	hash.Hash
-	Sum128() (uint64, uint64)
-}
-
-type sum128a struct {
-	v0, v1, v2, v3 uint64
-}
-
-var _ Hash128 = &sum128a{}
-
-// New128a returns a new 128-bit FNV-1a hash.Hash.
-func New128a() Hash128 {
-	s := &sum128a{}
-	s.Reset()
-	return s
-}
-
-func (s *sum128a) Reset() {
-	s.v0 = 0x6295C58D
-	s.v1 = 0x62B82175
-	s.v2 = 0x07BB0142
-	s.v3 = 0x6C62272E
-}
-
-func (s *sum128a) Sum128() (uint64, uint64) {
-	return s.v3<<32 | s.v2, s.v1<<32 | s.v0
-}
-
-func (s *sum128a) Write(data []byte) (int, error) {
-	var t0, t1, t2, t3 uint64
-	const fnv128PrimeLow = 0x0000013B
-	const fnv128PrimeShift = 24
-
-	for _, v := range data {
-		// xor the bottom with the current octet
-		s.v0 ^= uint64(v)
-
-		// multiply by the 128 bit FNV magic prime mod 2^128
-		// fnv_prime	= 309485009821345068724781371 (decimal)
-		// 				= 0x0000000001000000000000000000013B (hexadecimal)
-		// 				= 0x00000000 	0x01000000 				0x00000000	0x0000013B (in 4*32 words)
-		//				= 0x0			1<<fnv128PrimeShift	0x0			fnv128PrimeLow
-		//
-		// fnv128PrimeLow = 0x0000013B
-		// fnv128PrimeShift = 24
-
-		// multiply by the lowest order digit base 2^32 and by the other non-zero digit
-		t0 = s.v0 * fnv128PrimeLow
-		t1 = s.v1 * fnv128PrimeLow
-		t2 = s.v2*fnv128PrimeLow + s.v0<<fnv128PrimeShift
-		t3 = s.v3*fnv128PrimeLow + s.v1<<fnv128PrimeShift
-
-		// propagate carries
-		t1 += (t0 >> 32)
-		t2 += (t1 >> 32)
-		t3 += (t2 >> 32)
-
-		s.v0 = t0 & 0xffffffff
-		s.v1 = t1 & 0xffffffff
-		s.v2 = t2 & 0xffffffff
-		s.v3 = t3 // & 0xffffffff
-		// Doing a s.v3 &= 0xffffffff is not really needed since it simply
-		// removes multiples of 2^128.  We can discard these excess bits
-		// outside of the loop when writing the hash in Little Endian.
-	}
-
-	return len(data), nil
-}
-
-func (s *sum128a) Size() int { return 16 }
-
-func (s *sum128a) BlockSize() int { return 1 }
-
-func (s *sum128a) Sum(in []byte) []byte {
-	panic("FNV: not supported")
-}
diff --git a/crypto/fnv_test.go b/crypto/fnv_test.go
deleted file mode 100644
index dcd68e16..00000000
--- a/crypto/fnv_test.go
+++ /dev/null
@@ -1,24 +0,0 @@
-package crypto
-
-import (
-	. "github.com/onsi/ginkgo"
-	. "github.com/onsi/gomega"
-)
-
-var _ = Describe("FNV", func() {
-	It("gives proper null hash", func() {
-		hash := New128a()
-		h, l := hash.Sum128()
-		Expect(l).To(Equal(uint64(0x62b821756295c58d)))
-		Expect(h).To(Equal(uint64(0x6c62272e07bb0142)))
-	})
-
-	It("calculates hash", func() {
-		hash := New128a()
-		_, err := hash.Write([]byte("foobar"))
-		Expect(err).ToNot(HaveOccurred())
-		h, l := hash.Sum128()
-		Expect(l).To(Equal(uint64(0x6f0d3597ba446f18)))
-		Expect(h).To(Equal(uint64(0x343e1662793c64bf)))
-	})
-})
diff --git a/crypto/null_aead.go b/crypto/null_aead.go
index 34babfda..ecd44f65 100644
--- a/crypto/null_aead.go
+++ b/crypto/null_aead.go
@@ -4,6 +4,7 @@ import (
 	"encoding/binary"
 	"errors"
 
+	"github.com/lucas-clemente/fnv128a"
 	"github.com/lucas-clemente/quic-go/protocol"
 )
 
@@ -18,7 +19,7 @@ func (*NullAEAD) Open(packetNumber protocol.PacketNumber, associatedData []byte,
 		return nil, errors.New("NullAEAD: ciphertext cannot be less than 12 bytes long")
 	}
 
-	hash := New128a()
+	hash := fnv128a.New()
 	hash.Write(associatedData)
 	hash.Write(ciphertext[12:])
 	testHigh, testLow := hash.Sum128()
@@ -36,7 +37,7 @@ func (*NullAEAD) Open(packetNumber protocol.PacketNumber, associatedData []byte,
 func (*NullAEAD) Seal(packetNumber protocol.PacketNumber, associatedData []byte, plaintext []byte) []byte {
 	res := make([]byte, 12+len(plaintext))
 
-	hash := New128a()
+	hash := fnv128a.New()
 	hash.Write(associatedData)
 	hash.Write(plaintext)
 	high, low := hash.Sum128()