crypto/cipher: make AES-GCM benchmarks match ChaCha20Poly1305 ones

It's useful to compare TLS AEADs. Here are the numbers on my MacBook
with an Intel(R) Core(TM) i7-7920HQ CPU @ 3.10GHz.

name                            speed
AESGCM/Open-128-64-8             692MB/s ± 2%
AESGCM/Seal-128-64-8             568MB/s ± 1%
AESGCM/Open-128-1350-8          3.96GB/s ± 1%
AESGCM/Seal-128-1350-8          3.17GB/s ± 4%
AESGCM/Open-128-8192-8          5.46GB/s ± 2%
AESGCM/Seal-128-8192-8          4.40GB/s ± 3%

name                            speed
AESGCM/Open-256-64-8             602MB/s ± 2%
AESGCM/Seal-256-64-8             508MB/s ± 1%
AESGCM/Open-256-1350-8          3.06GB/s ± 1%
AESGCM/Seal-256-1350-8          2.65GB/s ± 2%
AESGCM/Open-256-8192-8          4.02GB/s ± 3%
AESGCM/Seal-256-8192-8          3.53GB/s ± 2%

name                            speed
Chacha20Poly1305/Open-64-8       385MB/s ± 3%
Chacha20Poly1305/Seal-64-8       396MB/s ± 3%
Chacha20Poly1305/Open-1350-8    1.67GB/s ± 2%
Chacha20Poly1305/Seal-1350-8    1.62GB/s ± 1%
Chacha20Poly1305/Open-8192-8    2.04GB/s ± 2%
Chacha20Poly1305/Seal-8192-8    2.04GB/s ± 3%

Change-Id: I9373ab85bf132b45b41078205259100fa2d46dda
Reviewed-on: https://go-review.googlesource.com/c/go/+/314610
Trust: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>

1 files changed, 26 insertions, 42 deletions

diff --git a/src/crypto/cipher/benchmark_test.go b/src/crypto/cipher/benchmark_test.go
index 90d0cd7138..eb02cd08c5 100644
--- a/src/crypto/cipher/benchmark_test.go
+++ b/src/crypto/cipher/benchmark_test.go
@@ -7,28 +7,15 @@ package cipher_test
 import (
 	"crypto/aes"
 	"crypto/cipher"
+	"strconv"
 	"testing"
 )
 
-func benchmarkAESGCMSign(b *testing.B, buf []byte) {
+func benchmarkAESGCMSeal(b *testing.B, buf []byte, keySize int) {
+	b.ReportAllocs()
 	b.SetBytes(int64(len(buf)))
 
-	var key [16]byte
-	var nonce [12]byte
-	aes, _ := aes.NewCipher(key[:])
-	aesgcm, _ := cipher.NewGCM(aes)
-	var out []byte
-
-	b.ResetTimer()
-	for i := 0; i < b.N; i++ {
-		out = aesgcm.Seal(out[:0], nonce[:], nil, buf)
-	}
-}
-
-func benchmarkAESGCMSeal(b *testing.B, buf []byte) {
-	b.SetBytes(int64(len(buf)))
-
-	var key [16]byte
+	var key = make([]byte, keySize)
 	var nonce [12]byte
 	var ad [13]byte
 	aes, _ := aes.NewCipher(key[:])
@@ -41,44 +28,41 @@ func benchmarkAESGCMSeal(b *testing.B, buf []byte) {
 	}
 }
 
-func benchmarkAESGCMOpen(b *testing.B, buf []byte) {
+func benchmarkAESGCMOpen(b *testing.B, buf []byte, keySize int) {
+	b.ReportAllocs()
 	b.SetBytes(int64(len(buf)))
 
-	var key [16]byte
+	var key = make([]byte, keySize)
 	var nonce [12]byte
 	var ad [13]byte
 	aes, _ := aes.NewCipher(key[:])
 	aesgcm, _ := cipher.NewGCM(aes)
 	var out []byte
-	out = aesgcm.Seal(out[:0], nonce[:], buf, ad[:])
+
+	ct := aesgcm.Seal(nil, nonce[:], buf[:], ad[:])
 
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		_, err := aesgcm.Open(buf[:0], nonce[:], out, ad[:])
-		if err != nil {
-			b.Errorf("Open: %v", err)
-		}
+		out, _ = aesgcm.Open(out[:0], nonce[:], ct, ad[:])
 	}
 }
 
-func BenchmarkAESGCMSeal1K(b *testing.B) {
-	benchmarkAESGCMSeal(b, make([]byte, 1024))
-}
-
-func BenchmarkAESGCMOpen1K(b *testing.B) {
-	benchmarkAESGCMOpen(b, make([]byte, 1024))
-}
-
-func BenchmarkAESGCMSign8K(b *testing.B) {
-	benchmarkAESGCMSign(b, make([]byte, 8*1024))
-}
-
-func BenchmarkAESGCMSeal8K(b *testing.B) {
-	benchmarkAESGCMSeal(b, make([]byte, 8*1024))
-}
-
-func BenchmarkAESGCMOpen8K(b *testing.B) {
-	benchmarkAESGCMOpen(b, make([]byte, 8*1024))
+func BenchmarkAESGCM(b *testing.B) {
+	for _, length := range []int{64, 1350, 8 * 1024} {
+		b.Run("Open-128-"+strconv.Itoa(length), func(b *testing.B) {
+			benchmarkAESGCMOpen(b, make([]byte, length), 128/8)
+		})
+		b.Run("Seal-128-"+strconv.Itoa(length), func(b *testing.B) {
+			benchmarkAESGCMSeal(b, make([]byte, length), 128/8)
+		})
+
+		b.Run("Open-256-"+strconv.Itoa(length), func(b *testing.B) {
+			benchmarkAESGCMOpen(b, make([]byte, length), 256/8)
+		})
+		b.Run("Seal-256-"+strconv.Itoa(length), func(b *testing.B) {
+			benchmarkAESGCMSeal(b, make([]byte, length), 256/8)
+		})
+	}
 }
 
 func benchmarkAESStream(b *testing.B, mode func(cipher.Block, []byte) cipher.Stream, buf []byte) {