diff --git a/cipher_test.go b/cipher_test.go
index b16e4a1..bd7458c 100644
--- a/cipher_test.go
+++ b/cipher_test.go
@@ -4,25 +4,55 @@ import (
 	"bytes"
 	"crypto/aes"
 	"crypto/cipher"
+	"crypto/rand"
 	"testing"
 )
 
+func TestCipherSize(t *testing.T) {
+	data := []struct {
+		t     int
+		bsize int
+		isize int
+	}{
+		{GNUTLS_CIPHER_AES_128_CBC, 16, 16},
+		{GNUTLS_CIPHER_AES_192_CBC, 24, 16},
+		{GNUTLS_CIPHER_AES_256_CBC, 32, 16},
+	}
+	for _, d := range data {
+		blocksize := GetCipherKeySize(d.t)
+		if blocksize != d.bsize {
+			t.Errorf("%d block size expect: %d, got: %d", d.t, d.bsize, blocksize)
+		}
+		ivsize := GetCipherIVSize(d.t)
+		if ivsize != d.isize {
+			t.Errorf("%d iv size expect: %d, got: %d", d.t, d.bsize, ivsize)
+		}
+	}
+}
 func TestEncryptDecrypt(t *testing.T) {
-	key := []byte("0123456789abcdef")
-	iv := []byte("abcdefg123456789")
-	c, err := NewCipher(GNUTLS_CIPHER_AES_128_CBC, key, iv)
+	cipherName := GNUTLS_CIPHER_AES_256_CBC
+	keysize := GetCipherKeySize(cipherName)
+	ivsize := GetCipherIVSize(cipherName)
+	blocksize := GetCipherBlockSize(cipherName)
+
+	key := make([]byte, keysize)
+	iv := make([]byte, ivsize)
+	rand.Reader.Read(key)
+	rand.Reader.Read(iv)
+
+	c, err := NewCipher(cipherName, key, iv)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer c.Close()
 
-	c1, err := NewCipher(GNUTLS_CIPHER_AES_128_CBC, key, iv)
+	c1, err := NewCipher(cipherName, key, iv)
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer c1.Close()
 
-	data := []byte("1234012121212121")
+	data := make([]byte, blocksize*10)
 	if c == nil {
 		t.Fatal("new ciphoer failed")
 	}
@@ -45,3 +75,50 @@ func TestEncryptDecrypt(t *testing.T) {
 		t.Fatal("cipher text not equal to cypto/aes")
 	}
 }
+
+func BenchmarkAESEncrypt(b *testing.B) {
+	cipherName := GNUTLS_CIPHER_AES_256_CBC
+	keysize := GetCipherKeySize(cipherName)
+	ivsize := GetCipherIVSize(cipherName)
+	blocksize := GetCipherBlockSize(cipherName)
+	datalen := blocksize * 500
+
+	key := make([]byte, keysize)
+	iv := make([]byte, ivsize)
+	rand.Reader.Read(key)
+	rand.Reader.Read(iv)
+	buf := make([]byte, datalen)
+
+	for i := 0; i < b.N; i++ {
+		c, err := NewCipher(cipherName, key, iv)
+		if err != nil {
+			b.Fatal(err)
+		}
+		c.Encrypt(buf)
+		c.Close()
+	}
+}
+
+func BenchmarkAESEncrypt2(b *testing.B) {
+	cipherName := GNUTLS_CIPHER_AES_256_CBC
+	keysize := GetCipherKeySize(cipherName)
+	ivsize := GetCipherIVSize(cipherName)
+	blocksize := GetCipherBlockSize(cipherName)
+	datalen := blocksize * 500
+
+	key := make([]byte, keysize)
+	iv := make([]byte, ivsize)
+	buf := make([]byte, datalen)
+
+	rand.Reader.Read(buf)
+	rand.Reader.Read(key)
+	rand.Reader.Read(iv)
+
+	dst := make([]byte, datalen)
+
+	for i := 0; i < b.N; i++ {
+		block, _ := aes.NewCipher(key)
+		mode := cipher.NewCBCEncrypter(block, iv)
+		mode.CryptBlocks(dst, buf)
+	}
+}
diff --git a/hash_test.go b/hash_test.go
index d44c889..50ebf0b 100644
--- a/hash_test.go
+++ b/hash_test.go
@@ -2,6 +2,7 @@ package gnutls
 
 import (
 	"bytes"
+	"crypto/rand"
 	"crypto/sha512"
 	"encoding/hex"
 	"log"
@@ -9,16 +10,40 @@ import (
 )
 
 func TestHashSHA(t *testing.T) {
-	h := NewHash(GNUTLS_SHA512)
+	h := NewHash(GNUTLS_HASH_SHA512)
 	defer h.Close()
 
 	data := []byte("1234")
 
 	h1 := h.Sum(data)
 
-	h3 := sha512.Sum512(data)
-	if !bytes.Equal(h3[:], h1) {
-		log.Printf("\n%s\n%s", hex.EncodeToString(h3[:]), hex.EncodeToString(h1))
+	h3 := sha512.New()
+	h3.Write(data)
+	h4 := h3.Sum(nil)
+	if !bytes.Equal(h4[:], h1) {
+		log.Printf("\n%s\n%s", hex.EncodeToString(h4[:]), hex.EncodeToString(h1))
 		t.Fatal("hash not equal")
 	}
 }
+
+func BenchmarkHashSHA512(b *testing.B) {
+	buf := make([]byte, 1000*1024)
+	rand.Reader.Read(buf)
+	for i := 0; i < b.N; i++ {
+		h := NewHash(GNUTLS_HASH_SHA512)
+		h.Write(buf)
+		h.Sum(nil)
+		h.Close()
+	}
+}
+
+func BenchmarkHashSHA512s(b *testing.B) {
+	buf := make([]byte, 1000*1024)
+	rand.Reader.Read(buf)
+	for i := 0; i < b.N; i++ {
+		h := sha512.New()
+		h.Write(buf)
+		h.Sum(nil)
+		//h.Close()
+	}
+}
diff --git a/tls_test.go b/tls_test.go
index 2c481b0..83e9043 100644
--- a/tls_test.go
+++ b/tls_test.go
@@ -45,7 +45,7 @@ func TestTLSClient(t *testing.T) {
 		}
 	}()
 
-	c, err := Dial("tcp", addr, &Config{})
+	c, err := Dial("tcp", addr, &Config{InsecureSkipVerify: true})
 	if err != nil {
 		t.Fatal("gnutls dial ", err)
 	}