diff --git a/cipher/ctr_sm4_test.go b/cipher/ctr_sm4_test.go
index 0050329..69134ed 100644
--- a/cipher/ctr_sm4_test.go
+++ b/cipher/ctr_sm4_test.go
@@ -3,13 +3,17 @@ package cipher_test
 import (
 	"bytes"
 	"crypto/cipher"
+	"crypto/rand"
+	"encoding/hex"
+	"fmt"
+	"io"
 	"testing"
 
-	"github.com/emmansun/gmsm/internal/cryptotest"
+	"github.com/emmansun/gmsm/padding"
 	"github.com/emmansun/gmsm/sm4"
 )
 
-var ctrSM4Tests = []struct {
+var cbcSM4Tests = []struct {
 	name string
 	key  []byte
 	iv   []byte
@@ -17,170 +21,337 @@ var ctrSM4Tests = []struct {
 	out  []byte
 }{
 	{
-		"2 blocks",
-		[]byte{0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c},
-		[]byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f},
-		[]byte{
-			0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
-			0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51},
-		[]byte{
-			0xbc, 0x71, 0x0d, 0x76, 0x2d, 0x07, 0x0b, 0x26, 0x36, 0x1d, 0xa8, 0x2b, 0x54, 0x56, 0x5e, 0x46,
-			0xb0, 0x2b, 0x3d, 0xbd, 0xdd, 0x50, 0xd5, 0xb4, 0x58, 0xae, 0xcc, 0xb2, 0x5d, 0xa1, 0x05, 0xe1},
+		"from internet",
+		[]byte("0123456789ABCDEF"),
+		[]byte("0123456789ABCDEF"),
+		[]byte("Hello World"),
+		[]byte{0x0a, 0x67, 0x06, 0x2f, 0x0c, 0xd2, 0xdc, 0xe2, 0x6a, 0x7b, 0x97, 0x8e, 0xbf, 0x21, 0x34, 0xf9},
 	},
 	{
-		"4 blocks",
-		[]byte{0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c},
-		[]byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f},
+		"Three blocks",
+		[]byte("0123456789ABCDEF"),
+		[]byte("0123456789ABCDEF"),
+		[]byte("Hello World Hello World Hello World Hello Worldd"),
 		[]byte{
-			0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
-			0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
-			0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
-			0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10,
-		},
-		[]byte{
-			0xbc, 0x71, 0x0d, 0x76, 0x2d, 0x07, 0x0b, 0x26, 0x36, 0x1d, 0xa8, 0x2b, 0x54, 0x56, 0x5e, 0x46,
-			0xb0, 0x2b, 0x3d, 0xbd, 0xdd, 0x50, 0xd5, 0xb4, 0x58, 0xae, 0xcc, 0xb2, 0x5d, 0xa1, 0x05, 0xe1,
-			0x6a, 0xd7, 0x0b, 0xc0, 0x11, 0x75, 0xad, 0x43, 0xb0, 0x80, 0x6a, 0x2e, 0x7b, 0x9c, 0xa5, 0x45,
-			0x60, 0x24, 0x59, 0xa0, 0x6b, 0x7d, 0x13, 0x0d, 0xde, 0x42, 0xa3, 0xe0, 0x47, 0x68, 0x18, 0xd2,
+			0xd3, 0x1e, 0x36, 0x83, 0xe4, 0xfc, 0x9b, 0x51, 0x6a, 0x2c, 0x0f, 0x98, 0x36, 0x76, 0xa9, 0xeb,
+			0x1f, 0xdc, 0xc3, 0x2a, 0xf3, 0x84, 0x08, 0x97, 0x81, 0x57, 0xa2, 0x06, 0x5d, 0xe3, 0x4c, 0x6a,
+			0x06, 0x8d, 0x0f, 0xef, 0x4e, 0x2b, 0xfa, 0xb4, 0xbc, 0xab, 0xa6, 0x64, 0x41, 0xfd, 0xe0, 0xfe,
+			0x92, 0xc1, 0x64, 0xec, 0xa1, 0x70, 0x24, 0x75, 0x72, 0xde, 0x12, 0x02, 0x95, 0x2e, 0xc7, 0x27,
 		},
 	},
 	{
-		"6 blocks",
-		[]byte{0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c},
-		[]byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f},
+		"Four blocks",
+		[]byte("0123456789ABCDEF"),
+		[]byte("0123456789ABCDEF"),
+		[]byte("Hello World Hello World Hello World Hello World Hello World Hell"),
 		[]byte{
-			0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
-			0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
-			0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
-			0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10,
-			0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
-			0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
-		},
-		[]byte{
-			0xbc, 0x71, 0x0d, 0x76, 0x2d, 0x07, 0x0b, 0x26, 0x36, 0x1d, 0xa8, 0x2b, 0x54, 0x56, 0x5e, 0x46,
-			0xb0, 0x2b, 0x3d, 0xbd, 0xdd, 0x50, 0xd5, 0xb4, 0x58, 0xae, 0xcc, 0xb2, 0x5d, 0xa1, 0x05, 0xe1,
-			0x6a, 0xd7, 0x0b, 0xc0, 0x11, 0x75, 0xad, 0x43, 0xb0, 0x80, 0x6a, 0x2e, 0x7b, 0x9c, 0xa5, 0x45,
-			0x60, 0x24, 0x59, 0xa0, 0x6b, 0x7d, 0x13, 0x0d, 0xde, 0x42, 0xa3, 0xe0, 0x47, 0x68, 0x18, 0xd2,
-			0x00, 0xb8, 0x33, 0x1a, 0x66, 0x57, 0xd6, 0xbe, 0xb8, 0x5b, 0x72, 0x4f, 0x55, 0x0c, 0xd5, 0x2d,
-			0x96, 0xf3, 0xe4, 0x12, 0x37, 0xa2, 0x07, 0x44, 0x43, 0xa5, 0x43, 0x3a, 0x41, 0x33, 0x0d, 0xca,
+			0xd3, 0x1e, 0x36, 0x83, 0xe4, 0xfc, 0x9b, 0x51, 0x6a, 0x2c, 0x0f, 0x98, 0x36, 0x76, 0xa9, 0xeb,
+			0x1f, 0xdc, 0xc3, 0x2a, 0xf3, 0x84, 0x08, 0x97, 0x81, 0x57, 0xa2, 0x06, 0x5d, 0xe3, 0x4c, 0x6a,
+			0xe0, 0x02, 0xd6, 0xe4, 0xf5, 0x66, 0x87, 0xc4, 0xcc, 0x54, 0x1d, 0x1f, 0x1c, 0xc4, 0x2f, 0xe6,
+			0xe5, 0x1d, 0xea, 0x52, 0xb8, 0x0c, 0xc8, 0xbe, 0xae, 0xcc, 0x44, 0xa8, 0x51, 0x81, 0x08, 0x60,
+			0x34, 0x6e, 0x9d, 0xad, 0xe1, 0x8a, 0xf4, 0xa1, 0x83, 0x69, 0x57, 0xb9, 0x37, 0x26, 0x7e, 0x03,
 		},
 	},
 	{
-		"8 blocks",
-		[]byte{0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c},
-		[]byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f},
+		"Five blocks",
+		[]byte("0123456789ABCDEF"),
+		[]byte("0123456789ABCDEF"),
+		[]byte("Hello World Hello World Hello World Hello World Hello World Hello World Hello Wo"),
 		[]byte{
-			0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
-			0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
-			0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
-			0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10,
-			0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
-			0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
-			0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
-			0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10,
+			0xd3, 0x1e, 0x36, 0x83, 0xe4, 0xfc, 0x9b, 0x51, 0x6a, 0x2c, 0x0f, 0x98, 0x36, 0x76, 0xa9, 0xeb,
+			0x1f, 0xdc, 0xc3, 0x2a, 0xf3, 0x84, 0x08, 0x97, 0x81, 0x57, 0xa2, 0x06, 0x5d, 0xe3, 0x4c, 0x6a,
+			0xe0, 0x02, 0xd6, 0xe4, 0xf5, 0x66, 0x87, 0xc4, 0xcc, 0x54, 0x1d, 0x1f, 0x1c, 0xc4, 0x2f, 0xe6,
+			0xe5, 0x1d, 0xea, 0x52, 0xb8, 0x0c, 0xc8, 0xbe, 0xae, 0xcc, 0x44, 0xa8, 0x51, 0x81, 0x08, 0x60,
+			0xb6, 0x09, 0x7b, 0xb8, 0x7e, 0xdb, 0x53, 0x4b, 0xea, 0x2a, 0xc6, 0xa1, 0xe5, 0xa0, 0x2a, 0xe9,
+			0x62, 0xb5, 0xe7, 0x50, 0x44, 0xea, 0x24, 0xcc, 0x9b, 0x5e, 0x07, 0x48, 0x04, 0x89, 0xa2, 0x74,
 		},
+	},
+	{
+		"7 blocks",
+		[]byte("0123456789ABCDEF"),
+		[]byte("0123456789ABCDEF"),
+		[]byte("Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hell"),
 		[]byte{
-			0xbc, 0x71, 0x0d, 0x76, 0x2d, 0x07, 0x0b, 0x26, 0x36, 0x1d, 0xa8, 0x2b, 0x54, 0x56, 0x5e, 0x46,
-			0xb0, 0x2b, 0x3d, 0xbd, 0xdd, 0x50, 0xd5, 0xb4, 0x58, 0xae, 0xcc, 0xb2, 0x5d, 0xa1, 0x05, 0xe1,
-			0x6a, 0xd7, 0x0b, 0xc0, 0x11, 0x75, 0xad, 0x43, 0xb0, 0x80, 0x6a, 0x2e, 0x7b, 0x9c, 0xa5, 0x45,
-			0x60, 0x24, 0x59, 0xa0, 0x6b, 0x7d, 0x13, 0x0d, 0xde, 0x42, 0xa3, 0xe0, 0x47, 0x68, 0x18, 0xd2,
-			0x00, 0xb8, 0x33, 0x1a, 0x66, 0x57, 0xd6, 0xbe, 0xb8, 0x5b, 0x72, 0x4f, 0x55, 0x0c, 0xd5, 0x2d,
-			0x96, 0xf3, 0xe4, 0x12, 0x37, 0xa2, 0x07, 0x44, 0x43, 0xa5, 0x43, 0x3a, 0x41, 0x33, 0x0d, 0xca,
-			0x41, 0xb7, 0x3a, 0x57, 0x17, 0x65, 0xef, 0x3d, 0xbb, 0xd1, 0x04, 0x5d, 0xb7, 0xf8, 0x71, 0x39,
-			0xff, 0x82, 0x01, 0x19, 0x75, 0xaf, 0x8a, 0x01, 0x8a, 0x0a, 0x26, 0x93, 0x85, 0xfd, 0x04, 0x5f,
+			0xd3, 0x1e, 0x36, 0x83, 0xe4, 0xfc, 0x9b, 0x51, 0x6a, 0x2c, 0x0f, 0x98, 0x36, 0x76, 0xa9, 0xeb,
+			0x1f, 0xdc, 0xc3, 0x2a, 0xf3, 0x84, 0x08, 0x97, 0x81, 0x57, 0xa2, 0x06, 0x5d, 0xe3, 0x4c, 0x6a,
+			0xe0, 0x02, 0xd6, 0xe4, 0xf5, 0x66, 0x87, 0xc4, 0xcc, 0x54, 0x1d, 0x1f, 0x1c, 0xc4, 0x2f, 0xe6,
+			0xe5, 0x1d, 0xea, 0x52, 0xb8, 0x0c, 0xc8, 0xbe, 0xae, 0xcc, 0x44, 0xa8, 0x51, 0x81, 0x08, 0x60,
+			0xb6, 0x09, 0x7b, 0xb8, 0x7e, 0xdb, 0x53, 0x4b, 0xea, 0x2a, 0xc6, 0xa1, 0xe5, 0xa0, 0x2a, 0xe9,
+			0x22, 0x65, 0x5b, 0xa3, 0xb9, 0xcc, 0x63, 0x92, 0x16, 0x0e, 0x2f, 0xf4, 0x3b, 0x93, 0x06, 0x82,
+			0xb3, 0x8c, 0x26, 0x2e, 0x06, 0x51, 0x34, 0x2c, 0xe4, 0x3d, 0xd0, 0xc7, 0x2b, 0x8f, 0x31, 0x15,
+			0xb7, 0x8f, 0xd0, 0x47, 0x45, 0x40, 0xec, 0x02, 0x1b, 0xef, 0xc1, 0xd2, 0xe5, 0xa2, 0x35, 0xd2,
+		},
+	},
+	{
+		"9 blocks",
+		[]byte("0123456789ABCDEF"),
+		[]byte("0123456789ABCDEF"),
+		[]byte("Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World"),
+		[]byte{
+			0xd3, 0x1e, 0x36, 0x83, 0xe4, 0xfc, 0x9b, 0x51, 0x6a, 0x2c, 0x0f, 0x98, 0x36, 0x76, 0xa9, 0xeb,
+			0x1f, 0xdc, 0xc3, 0x2a, 0xf3, 0x84, 0x08, 0x97, 0x81, 0x57, 0xa2, 0x06, 0x5d, 0xe3, 0x4c, 0x6a,
+			0xe0, 0x02, 0xd6, 0xe4, 0xf5, 0x66, 0x87, 0xc4, 0xcc, 0x54, 0x1d, 0x1f, 0x1c, 0xc4, 0x2f, 0xe6,
+			0xe5, 0x1d, 0xea, 0x52, 0xb8, 0x0c, 0xc8, 0xbe, 0xae, 0xcc, 0x44, 0xa8, 0x51, 0x81, 0x08, 0x60,
+			0xb6, 0x09, 0x7b, 0xb8, 0x7e, 0xdb, 0x53, 0x4b, 0xea, 0x2a, 0xc6, 0xa1, 0xe5, 0xa0, 0x2a, 0xe9,
+			0x22, 0x65, 0x5b, 0xa3, 0xb9, 0xcc, 0x63, 0x92, 0x16, 0x0e, 0x2f, 0xf4, 0x3b, 0x93, 0x06, 0x82,
+			0xb3, 0x8c, 0x26, 0x2e, 0x06, 0x51, 0x34, 0x2c, 0xe4, 0x3d, 0xd0, 0xc7, 0x2b, 0x8f, 0x31, 0x15,
+			0x30, 0xa8, 0x96, 0x1c, 0xbc, 0x8e, 0xf7, 0x4f, 0x6b, 0x69, 0x9d, 0xc9, 0x40, 0x89, 0xd7, 0xe8,
+			0xf7, 0x90, 0x47, 0x74, 0xaf, 0x40, 0xfd, 0x72, 0xc6, 0x17, 0xeb, 0xc0, 0x8b, 0x01, 0x71, 0x5c,
+		},
+	},
+	{
+		"10 blocks",
+		[]byte("0123456789ABCDEF"),
+		[]byte("0123456789ABCDEF"),
+		[]byte("Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World"),
+		[]byte{
+			0xd3, 0x1e, 0x36, 0x83, 0xe4, 0xfc, 0x9b, 0x51, 0x6a, 0x2c, 0x0f, 0x98, 0x36, 0x76, 0xa9, 0xeb, 
+			0x1f, 0xdc, 0xc3, 0x2a, 0xf3, 0x84, 0x08, 0x97, 0x81, 0x57, 0xa2, 0x06, 0x5d, 0xe3, 0x4c, 0x6a, 
+			0xe0, 0x02, 0xd6, 0xe4, 0xf5, 0x66, 0x87, 0xc4, 0xcc, 0x54, 0x1d, 0x1f, 0x1c, 0xc4, 0x2f, 0xe6, 
+			0xe5, 0x1d, 0xea, 0x52, 0xb8, 0x0c, 0xc8, 0xbe, 0xae, 0xcc, 0x44, 0xa8, 0x51, 0x81, 0x08, 0x60, 
+			0xb6, 0x09, 0x7b, 0xb8, 0x7e, 0xdb, 0x53, 0x4b, 0xea, 0x2a, 0xc6, 0xa1, 0xe5, 0xa0, 0x2a, 0xe9, 
+			0x22, 0x65, 0x5b, 0xa3, 0xb9, 0xcc, 0x63, 0x92, 0x16, 0x0e, 0x2f, 0xf4, 0x3b, 0x93, 0x06, 0x82, 
+			0xb3, 0x8c, 0x26, 0x2e, 0x06, 0x51, 0x34, 0x2c, 0xe4, 0x3d, 0xd0, 0xc7, 0x2b, 0x8f, 0x31, 0x15, 
+			0x30, 0xa8, 0x96, 0x1c, 0xbc, 0x8e, 0xf7, 0x4f, 0x6b, 0x69, 0x9d, 0xc9, 0x40, 0x89, 0xd7, 0xe8, 
+			0x2a, 0xe8, 0xc3, 0x3d, 0xcb, 0x8a, 0x1c, 0xb3, 0x70, 0x7d, 0xe9, 0xe6, 0x88, 0x36, 0x65, 0x21, 
+			0x97, 0x0d, 0x27, 0xc6, 0x74, 0x49, 0x05, 0xa8, 0x28, 0x73, 0x65, 0x48, 0xb8, 0x81, 0x37, 0x6b,
+		},
+	},
+	{
+		"11 blocks",
+		[]byte("0123456789ABCDEF"),
+		[]byte("0123456789ABCDEF"),
+		[]byte("Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World"),
+		[]byte{
+			0xd3, 0x1e, 0x36, 0x83, 0xe4, 0xfc, 0x9b, 0x51, 0x6a, 0x2c, 0x0f, 0x98, 0x36, 0x76, 0xa9, 0xeb, 
+			0x1f, 0xdc, 0xc3, 0x2a, 0xf3, 0x84, 0x08, 0x97, 0x81, 0x57, 0xa2, 0x06, 0x5d, 0xe3, 0x4c, 0x6a, 
+			0xe0, 0x02, 0xd6, 0xe4, 0xf5, 0x66, 0x87, 0xc4, 0xcc, 0x54, 0x1d, 0x1f, 0x1c, 0xc4, 0x2f, 0xe6, 
+			0xe5, 0x1d, 0xea, 0x52, 0xb8, 0x0c, 0xc8, 0xbe, 0xae, 0xcc, 0x44, 0xa8, 0x51, 0x81, 0x08, 0x60, 
+			0xb6, 0x09, 0x7b, 0xb8, 0x7e, 0xdb, 0x53, 0x4b, 0xea, 0x2a, 0xc6, 0xa1, 0xe5, 0xa0, 0x2a, 0xe9, 
+			0x22, 0x65, 0x5b, 0xa3, 0xb9, 0xcc, 0x63, 0x92, 0x16, 0x0e, 0x2f, 0xf4, 0x3b, 0x93, 0x06, 0x82, 
+			0xb3, 0x8c, 0x26, 0x2e, 0x06, 0x51, 0x34, 0x2c, 0xe4, 0x3d, 0xd0, 0xc7, 0x2b, 0x8f, 0x31, 0x15, 
+			0x30, 0xa8, 0x96, 0x1c, 0xbc, 0x8e, 0xf7, 0x4f, 0x6b, 0x69, 0x9d, 0xc9, 0x40, 0x89, 0xd7, 0xe8, 
+			0x2a, 0xe8, 0xc3, 0x3d, 0xcb, 0x8a, 0x1c, 0xb3, 0x70, 0x7d, 0xe9, 0xe6, 0x88, 0x36, 0x65, 0x21, 
+			0x7b, 0x34, 0xac, 0x73, 0x8d, 0x4f, 0x11, 0xde, 0xd4, 0x21, 0x45, 0x9f, 0x1f, 0x3e, 0xe8, 0xcf, 
+			0x73, 0x8e, 0x70, 0xa7, 0x00, 0xc4, 0x27, 0x67, 0xa0, 0x9f, 0x91, 0xf4, 0xe3, 0x9e, 0x76, 0x15, 
+		},
+	},
+	{
+		"12 blocks",
+		[]byte("0123456789ABCDEF"),
+		[]byte("0123456789ABCDEF"),
+		[]byte("Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello"),
+		[]byte{
+			0xd3, 0x1e, 0x36, 0x83, 0xe4, 0xfc, 0x9b, 0x51, 0x6a, 0x2c, 0x0f, 0x98, 0x36, 0x76, 0xa9, 0xeb, 
+			0x1f, 0xdc, 0xc3, 0x2a, 0xf3, 0x84, 0x08, 0x97, 0x81, 0x57, 0xa2, 0x06, 0x5d, 0xe3, 0x4c, 0x6a, 
+			0xe0, 0x02, 0xd6, 0xe4, 0xf5, 0x66, 0x87, 0xc4, 0xcc, 0x54, 0x1d, 0x1f, 0x1c, 0xc4, 0x2f, 0xe6, 
+			0xe5, 0x1d, 0xea, 0x52, 0xb8, 0x0c, 0xc8, 0xbe, 0xae, 0xcc, 0x44, 0xa8, 0x51, 0x81, 0x08, 0x60, 
+			0xb6, 0x09, 0x7b, 0xb8, 0x7e, 0xdb, 0x53, 0x4b, 0xea, 0x2a, 0xc6, 0xa1, 0xe5, 0xa0, 0x2a, 0xe9, 
+			0x22, 0x65, 0x5b, 0xa3, 0xb9, 0xcc, 0x63, 0x92, 0x16, 0x0e, 0x2f, 0xf4, 0x3b, 0x93, 0x06, 0x82, 
+			0xb3, 0x8c, 0x26, 0x2e, 0x06, 0x51, 0x34, 0x2c, 0xe4, 0x3d, 0xd0, 0xc7, 0x2b, 0x8f, 0x31, 0x15, 
+			0x30, 0xa8, 0x96, 0x1c, 0xbc, 0x8e, 0xf7, 0x4f, 0x6b, 0x69, 0x9d, 0xc9, 0x40, 0x89, 0xd7, 0xe8, 
+			0x2a, 0xe8, 0xc3, 0x3d, 0xcb, 0x8a, 0x1c, 0xb3, 0x70, 0x7d, 0xe9, 0xe6, 0x88, 0x36, 0x65, 0x21, 
+			0x7b, 0x34, 0xac, 0x73, 0x8d, 0x4f, 0x11, 0xde, 0xd4, 0x21, 0x45, 0x9f, 0x1f, 0x3e, 0xe8, 0xcf, 
+			0x50, 0x92, 0x8c, 0xa4, 0x79, 0x58, 0x3a, 0x26, 0x01, 0x7b, 0x99, 0x5c, 0xff, 0x8d, 0x66, 0x5b, 
+			0x2e, 0x7d, 0x4e, 0xda, 0x3b, 0xe0, 0xef, 0x9d, 0x33, 0x2d, 0x2f, 0x6d, 0x47, 0x3f, 0x56, 0x8d, 
+		},
+	},
+	{
+		"13 blocks",
+		[]byte("0123456789ABCDEF"),
+		[]byte("0123456789ABCDEF"),
+		[]byte("Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World"),
+		[]byte{
+			0xd3, 0x1e, 0x36, 0x83, 0xe4, 0xfc, 0x9b, 0x51, 0x6a, 0x2c, 0x0f, 0x98, 0x36, 0x76, 0xa9, 0xeb, 
+			0x1f, 0xdc, 0xc3, 0x2a, 0xf3, 0x84, 0x08, 0x97, 0x81, 0x57, 0xa2, 0x06, 0x5d, 0xe3, 0x4c, 0x6a, 
+			0xe0, 0x02, 0xd6, 0xe4, 0xf5, 0x66, 0x87, 0xc4, 0xcc, 0x54, 0x1d, 0x1f, 0x1c, 0xc4, 0x2f, 0xe6, 
+			0xe5, 0x1d, 0xea, 0x52, 0xb8, 0x0c, 0xc8, 0xbe, 0xae, 0xcc, 0x44, 0xa8, 0x51, 0x81, 0x08, 0x60, 
+			0xb6, 0x09, 0x7b, 0xb8, 0x7e, 0xdb, 0x53, 0x4b, 0xea, 0x2a, 0xc6, 0xa1, 0xe5, 0xa0, 0x2a, 0xe9, 
+			0x22, 0x65, 0x5b, 0xa3, 0xb9, 0xcc, 0x63, 0x92, 0x16, 0x0e, 0x2f, 0xf4, 0x3b, 0x93, 0x06, 0x82, 
+			0xb3, 0x8c, 0x26, 0x2e, 0x06, 0x51, 0x34, 0x2c, 0xe4, 0x3d, 0xd0, 0xc7, 0x2b, 0x8f, 0x31, 0x15, 
+			0x30, 0xa8, 0x96, 0x1c, 0xbc, 0x8e, 0xf7, 0x4f, 0x6b, 0x69, 0x9d, 0xc9, 0x40, 0x89, 0xd7, 0xe8, 
+			0x2a, 0xe8, 0xc3, 0x3d, 0xcb, 0x8a, 0x1c, 0xb3, 0x70, 0x7d, 0xe9, 0xe6, 0x88, 0x36, 0x65, 0x21, 
+			0x7b, 0x34, 0xac, 0x73, 0x8d, 0x4f, 0x11, 0xde, 0xd4, 0x21, 0x45, 0x9f, 0x1f, 0x3e, 0xe8, 0xcf, 
+			0x50, 0x92, 0x8c, 0xa4, 0x79, 0x58, 0x3a, 0x26, 0x01, 0x7b, 0x99, 0x5c, 0xff, 0x8d, 0x66, 0x5b, 
+			0x07, 0x86, 0x0e, 0x22, 0xb4, 0xb4, 0x83, 0x74, 0x33, 0x79, 0xd0, 0x54, 0x9f, 0x03, 0x6b, 0x60, 
+			0x4f, 0xae, 0xbd, 0x43, 0x34, 0x43, 0xb4, 0xee, 0x34, 0x22, 0xcc, 0xc5, 0xcd, 0xbd, 0x2d, 0x63, 
+		},
+	},
+	{
+		"14 blocks",
+		[]byte("0123456789ABCDEF"),
+		[]byte("0123456789ABCDEF"),
+		[]byte("Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World"),
+		[]byte{
+			0xd3, 0x1e, 0x36, 0x83, 0xe4, 0xfc, 0x9b, 0x51, 0x6a, 0x2c, 0x0f, 0x98, 0x36, 0x76, 0xa9, 0xeb, 
+			0x1f, 0xdc, 0xc3, 0x2a, 0xf3, 0x84, 0x08, 0x97, 0x81, 0x57, 0xa2, 0x06, 0x5d, 0xe3, 0x4c, 0x6a, 
+			0xe0, 0x02, 0xd6, 0xe4, 0xf5, 0x66, 0x87, 0xc4, 0xcc, 0x54, 0x1d, 0x1f, 0x1c, 0xc4, 0x2f, 0xe6, 
+			0xe5, 0x1d, 0xea, 0x52, 0xb8, 0x0c, 0xc8, 0xbe, 0xae, 0xcc, 0x44, 0xa8, 0x51, 0x81, 0x08, 0x60, 
+			0xb6, 0x09, 0x7b, 0xb8, 0x7e, 0xdb, 0x53, 0x4b, 0xea, 0x2a, 0xc6, 0xa1, 0xe5, 0xa0, 0x2a, 0xe9, 
+			0x22, 0x65, 0x5b, 0xa3, 0xb9, 0xcc, 0x63, 0x92, 0x16, 0x0e, 0x2f, 0xf4, 0x3b, 0x93, 0x06, 0x82, 
+			0xb3, 0x8c, 0x26, 0x2e, 0x06, 0x51, 0x34, 0x2c, 0xe4, 0x3d, 0xd0, 0xc7, 0x2b, 0x8f, 0x31, 0x15, 
+			0x30, 0xa8, 0x96, 0x1c, 0xbc, 0x8e, 0xf7, 0x4f, 0x6b, 0x69, 0x9d, 0xc9, 0x40, 0x89, 0xd7, 0xe8, 
+			0x2a, 0xe8, 0xc3, 0x3d, 0xcb, 0x8a, 0x1c, 0xb3, 0x70, 0x7d, 0xe9, 0xe6, 0x88, 0x36, 0x65, 0x21, 
+			0x7b, 0x34, 0xac, 0x73, 0x8d, 0x4f, 0x11, 0xde, 0xd4, 0x21, 0x45, 0x9f, 0x1f, 0x3e, 0xe8, 0xcf, 
+			0x50, 0x92, 0x8c, 0xa4, 0x79, 0x58, 0x3a, 0x26, 0x01, 0x7b, 0x99, 0x5c, 0xff, 0x8d, 0x66, 0x5b, 
+			0x07, 0x86, 0x0e, 0x22, 0xb4, 0xb4, 0x83, 0x74, 0x33, 0x79, 0xd0, 0x54, 0x9f, 0x03, 0x6b, 0x60, 
+			0xa1, 0x52, 0x3c, 0x61, 0x1d, 0x91, 0xbf, 0x50, 0x00, 0xfb, 0x62, 0x58, 0xfa, 0xd3, 0xbd, 0x17, 
+			0x28, 0x95, 0x7b, 0x51, 0x7e, 0x07, 0x6f, 0xfb, 0x8f, 0x9a, 0x4c, 0xbf, 0x33, 0xd5, 0xd7, 0xb6,
+		},
+	},
+	{
+		"15 blocks",
+		[]byte("0123456789ABCDEF"),
+		[]byte("0123456789ABCDEF"),
+		[]byte("Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello"),
+		[]byte{
+			0xd3, 0x1e, 0x36, 0x83, 0xe4, 0xfc, 0x9b, 0x51, 0x6a, 0x2c, 0x0f, 0x98, 0x36, 0x76, 0xa9, 0xeb, 
+			0x1f, 0xdc, 0xc3, 0x2a, 0xf3, 0x84, 0x08, 0x97, 0x81, 0x57, 0xa2, 0x06, 0x5d, 0xe3, 0x4c, 0x6a, 
+			0xe0, 0x02, 0xd6, 0xe4, 0xf5, 0x66, 0x87, 0xc4, 0xcc, 0x54, 0x1d, 0x1f, 0x1c, 0xc4, 0x2f, 0xe6, 
+			0xe5, 0x1d, 0xea, 0x52, 0xb8, 0x0c, 0xc8, 0xbe, 0xae, 0xcc, 0x44, 0xa8, 0x51, 0x81, 0x08, 0x60, 
+			0xb6, 0x09, 0x7b, 0xb8, 0x7e, 0xdb, 0x53, 0x4b, 0xea, 0x2a, 0xc6, 0xa1, 0xe5, 0xa0, 0x2a, 0xe9, 
+			0x22, 0x65, 0x5b, 0xa3, 0xb9, 0xcc, 0x63, 0x92, 0x16, 0x0e, 0x2f, 0xf4, 0x3b, 0x93, 0x06, 0x82, 
+			0xb3, 0x8c, 0x26, 0x2e, 0x06, 0x51, 0x34, 0x2c, 0xe4, 0x3d, 0xd0, 0xc7, 0x2b, 0x8f, 0x31, 0x15, 
+			0x30, 0xa8, 0x96, 0x1c, 0xbc, 0x8e, 0xf7, 0x4f, 0x6b, 0x69, 0x9d, 0xc9, 0x40, 0x89, 0xd7, 0xe8, 
+			0x2a, 0xe8, 0xc3, 0x3d, 0xcb, 0x8a, 0x1c, 0xb3, 0x70, 0x7d, 0xe9, 0xe6, 0x88, 0x36, 0x65, 0x21, 
+			0x7b, 0x34, 0xac, 0x73, 0x8d, 0x4f, 0x11, 0xde, 0xd4, 0x21, 0x45, 0x9f, 0x1f, 0x3e, 0xe8, 0xcf, 
+			0x50, 0x92, 0x8c, 0xa4, 0x79, 0x58, 0x3a, 0x26, 0x01, 0x7b, 0x99, 0x5c, 0xff, 0x8d, 0x66, 0x5b, 
+			0x07, 0x86, 0x0e, 0x22, 0xb4, 0xb4, 0x83, 0x74, 0x33, 0x79, 0xd0, 0x54, 0x9f, 0x03, 0x6b, 0x60, 
+			0xa1, 0x52, 0x3c, 0x61, 0x1d, 0x91, 0xbf, 0x50, 0x00, 0xfb, 0x62, 0x58, 0xfa, 0xd3, 0xbd, 0x17, 
+			0x7d, 0x6f, 0xda, 0x76, 0x9a, 0xdb, 0x01, 0x96, 0x97, 0xc9, 0x5f, 0x64, 0x20, 0x3c, 0x70, 0x7a, 
+			0xa3, 0xae, 0x6c, 0xce, 0x49, 0x31, 0x7a, 0xd3, 0x98, 0x01, 0xb0, 0x96, 0x2b, 0x4e, 0x81, 0x98, 
 		},
 	},
 	{
 		"16 blocks",
-		[]byte{0x2b, 0x7e, 0x15, 0x16, 0x28, 0xae, 0xd2, 0xa6, 0xab, 0xf7, 0x15, 0x88, 0x09, 0xcf, 0x4f, 0x3c},
-		[]byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f},
+		[]byte("0123456789ABCDEF"),
+		[]byte("0123456789ABCDEF"),
+		[]byte("Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World"),
 		[]byte{
-			0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
-			0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
-			0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
-			0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10,
-			0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
-			0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
-			0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
-			0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10,
-			0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
-			0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
-			0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
-			0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10,
-			0x6b, 0xc1, 0xbe, 0xe2, 0x2e, 0x40, 0x9f, 0x96, 0xe9, 0x3d, 0x7e, 0x11, 0x73, 0x93, 0x17, 0x2a,
-			0xae, 0x2d, 0x8a, 0x57, 0x1e, 0x03, 0xac, 0x9c, 0x9e, 0xb7, 0x6f, 0xac, 0x45, 0xaf, 0x8e, 0x51,
-			0x30, 0xc8, 0x1c, 0x46, 0xa3, 0x5c, 0xe4, 0x11, 0xe5, 0xfb, 0xc1, 0x19, 0x1a, 0x0a, 0x52, 0xef,
-			0xf6, 0x9f, 0x24, 0x45, 0xdf, 0x4f, 0x9b, 0x17, 0xad, 0x2b, 0x41, 0x7b, 0xe6, 0x6c, 0x37, 0x10,
+			0xd3, 0x1e, 0x36, 0x83, 0xe4, 0xfc, 0x9b, 0x51, 0x6a, 0x2c, 0x0f, 0x98, 0x36, 0x76, 0xa9, 0xeb, 
+			0x1f, 0xdc, 0xc3, 0x2a, 0xf3, 0x84, 0x08, 0x97, 0x81, 0x57, 0xa2, 0x06, 0x5d, 0xe3, 0x4c, 0x6a, 
+			0xe0, 0x02, 0xd6, 0xe4, 0xf5, 0x66, 0x87, 0xc4, 0xcc, 0x54, 0x1d, 0x1f, 0x1c, 0xc4, 0x2f, 0xe6, 
+			0xe5, 0x1d, 0xea, 0x52, 0xb8, 0x0c, 0xc8, 0xbe, 0xae, 0xcc, 0x44, 0xa8, 0x51, 0x81, 0x08, 0x60, 
+			0xb6, 0x09, 0x7b, 0xb8, 0x7e, 0xdb, 0x53, 0x4b, 0xea, 0x2a, 0xc6, 0xa1, 0xe5, 0xa0, 0x2a, 0xe9, 
+			0x22, 0x65, 0x5b, 0xa3, 0xb9, 0xcc, 0x63, 0x92, 0x16, 0x0e, 0x2f, 0xf4, 0x3b, 0x93, 0x06, 0x82, 
+			0xb3, 0x8c, 0x26, 0x2e, 0x06, 0x51, 0x34, 0x2c, 0xe4, 0x3d, 0xd0, 0xc7, 0x2b, 0x8f, 0x31, 0x15, 
+			0x30, 0xa8, 0x96, 0x1c, 0xbc, 0x8e, 0xf7, 0x4f, 0x6b, 0x69, 0x9d, 0xc9, 0x40, 0x89, 0xd7, 0xe8, 
+			0x2a, 0xe8, 0xc3, 0x3d, 0xcb, 0x8a, 0x1c, 0xb3, 0x70, 0x7d, 0xe9, 0xe6, 0x88, 0x36, 0x65, 0x21, 
+			0x7b, 0x34, 0xac, 0x73, 0x8d, 0x4f, 0x11, 0xde, 0xd4, 0x21, 0x45, 0x9f, 0x1f, 0x3e, 0xe8, 0xcf, 
+			0x50, 0x92, 0x8c, 0xa4, 0x79, 0x58, 0x3a, 0x26, 0x01, 0x7b, 0x99, 0x5c, 0xff, 0x8d, 0x66, 0x5b, 
+			0x07, 0x86, 0x0e, 0x22, 0xb4, 0xb4, 0x83, 0x74, 0x33, 0x79, 0xd0, 0x54, 0x9f, 0x03, 0x6b, 0x60, 
+			0xa1, 0x52, 0x3c, 0x61, 0x1d, 0x91, 0xbf, 0x50, 0x00, 0xfb, 0x62, 0x58, 0xfa, 0xd3, 0xbd, 0x17, 
+			0x7d, 0x6f, 0xda, 0x76, 0x9a, 0xdb, 0x01, 0x96, 0x97, 0xc9, 0x5f, 0x64, 0x20, 0x3c, 0x70, 0x7a, 
+			0x40, 0x1f, 0x35, 0xc8, 0x22, 0xf2, 0x76, 0x6d, 0x8e, 0x4a, 0x78, 0xd7, 0x8d, 0x52, 0x51, 0x60, 
+			0x71, 0xa7, 0x42, 0x07, 0xb2, 0x32, 0x3b, 0xa8, 0x5b, 0x15, 0x8f, 0x4e, 0x56, 0xef, 0xe0, 0x0a,
 		},
+	},		
+	{
+		"17 blocks",
+		[]byte("0123456789ABCDEF"),
+		[]byte("0123456789ABCDEF"),
+		[]byte("Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World Hello World"),
 		[]byte{
-			0xbc, 0x71, 0x0d, 0x76, 0x2d, 0x07, 0x0b, 0x26, 0x36, 0x1d, 0xa8, 0x2b, 0x54, 0x56, 0x5e, 0x46,
-			0xb0, 0x2b, 0x3d, 0xbd, 0xdd, 0x50, 0xd5, 0xb4, 0x58, 0xae, 0xcc, 0xb2, 0x5d, 0xa1, 0x05, 0xe1,
-			0x6a, 0xd7, 0x0b, 0xc0, 0x11, 0x75, 0xad, 0x43, 0xb0, 0x80, 0x6a, 0x2e, 0x7b, 0x9c, 0xa5, 0x45,
-			0x60, 0x24, 0x59, 0xa0, 0x6b, 0x7d, 0x13, 0x0d, 0xde, 0x42, 0xa3, 0xe0, 0x47, 0x68, 0x18, 0xd2,
-			0x00, 0xb8, 0x33, 0x1a, 0x66, 0x57, 0xd6, 0xbe, 0xb8, 0x5b, 0x72, 0x4f, 0x55, 0x0c, 0xd5, 0x2d,
-			0x96, 0xf3, 0xe4, 0x12, 0x37, 0xa2, 0x07, 0x44, 0x43, 0xa5, 0x43, 0x3a, 0x41, 0x33, 0x0d, 0xca,
-			0x41, 0xb7, 0x3a, 0x57, 0x17, 0x65, 0xef, 0x3d, 0xbb, 0xd1, 0x04, 0x5d, 0xb7, 0xf8, 0x71, 0x39,
-			0xff, 0x82, 0x01, 0x19, 0x75, 0xaf, 0x8a, 0x01, 0x8a, 0x0a, 0x26, 0x93, 0x85, 0xfd, 0x04, 0x5f,
-			0x73, 0xd4, 0xc6, 0x3a, 0x81, 0x0a, 0x91, 0xe3, 0xb9, 0x17, 0x89, 0xdf, 0x4c, 0xcd, 0xe8, 0xe3,
-			0x4e, 0xe7, 0x8d, 0x52, 0x89, 0x93, 0xb9, 0xef, 0x42, 0xe7, 0x5d, 0x67, 0xa8, 0x25, 0xad, 0xf0,
-			0xe2, 0x45, 0x9d, 0x8c, 0x30, 0x61, 0x8a, 0x26, 0x90, 0x4f, 0x52, 0x61, 0xa0, 0x61, 0x62, 0xfb,
-			0x36, 0xc8, 0x95, 0xe2, 0x8d, 0x75, 0x86, 0xf5, 0xbf, 0x22, 0x1c, 0xdd, 0xc9, 0x52, 0x71, 0x5a,
-			0x7e, 0xb0, 0x56, 0xd6, 0x8a, 0x7e, 0xfa, 0x4f, 0xda, 0x6b, 0x97, 0x95, 0x23, 0xa7, 0xa8, 0x39,
-			0x76, 0x31, 0x10, 0x79, 0x47, 0x98, 0x5b, 0x71, 0xbf, 0xc9, 0x4c, 0xce, 0xb7, 0xd4, 0x19, 0x86,
-			0x04, 0x87, 0xc0, 0xba, 0xe8, 0xa5, 0x4c, 0xc8, 0x48, 0x9c, 0x28, 0xd3, 0x4b, 0x4d, 0xfc, 0x3f,
-			0x9b, 0xbc, 0xf3, 0xd1, 0x9d, 0x25, 0x43, 0x47, 0x37, 0xea, 0xb7, 0x5e, 0x0d, 0xdb, 0x58, 0xf1,
+			0xd3, 0x1e, 0x36, 0x83, 0xe4, 0xfc, 0x9b, 0x51, 0x6a, 0x2c, 0x0f, 0x98, 0x36, 0x76, 0xa9, 0xeb,
+			0x1f, 0xdc, 0xc3, 0x2a, 0xf3, 0x84, 0x08, 0x97, 0x81, 0x57, 0xa2, 0x06, 0x5d, 0xe3, 0x4c, 0x6a,
+			0xe0, 0x02, 0xd6, 0xe4, 0xf5, 0x66, 0x87, 0xc4, 0xcc, 0x54, 0x1d, 0x1f, 0x1c, 0xc4, 0x2f, 0xe6,
+			0xe5, 0x1d, 0xea, 0x52, 0xb8, 0x0c, 0xc8, 0xbe, 0xae, 0xcc, 0x44, 0xa8, 0x51, 0x81, 0x08, 0x60,
+			0xb6, 0x09, 0x7b, 0xb8, 0x7e, 0xdb, 0x53, 0x4b, 0xea, 0x2a, 0xc6, 0xa1, 0xe5, 0xa0, 0x2a, 0xe9,
+			0x22, 0x65, 0x5b, 0xa3, 0xb9, 0xcc, 0x63, 0x92, 0x16, 0x0e, 0x2f, 0xf4, 0x3b, 0x93, 0x06, 0x82,
+			0xb3, 0x8c, 0x26, 0x2e, 0x06, 0x51, 0x34, 0x2c, 0xe4, 0x3d, 0xd0, 0xc7, 0x2b, 0x8f, 0x31, 0x15,
+			0x30, 0xa8, 0x96, 0x1c, 0xbc, 0x8e, 0xf7, 0x4f, 0x6b, 0x69, 0x9d, 0xc9, 0x40, 0x89, 0xd7, 0xe8,
+			0x2a, 0xe8, 0xc3, 0x3d, 0xcb, 0x8a, 0x1c, 0xb3, 0x70, 0x7d, 0xe9, 0xe6, 0x88, 0x36, 0x65, 0x21,
+			0x7b, 0x34, 0xac, 0x73, 0x8d, 0x4f, 0x11, 0xde, 0xd4, 0x21, 0x45, 0x9f, 0x1f, 0x3e, 0xe8, 0xcf,
+			0x50, 0x92, 0x8c, 0xa4, 0x79, 0x58, 0x3a, 0x26, 0x01, 0x7b, 0x99, 0x5c, 0xff, 0x8d, 0x66, 0x5b,
+			0x07, 0x86, 0x0e, 0x22, 0xb4, 0xb4, 0x83, 0x74, 0x33, 0x79, 0xd0, 0x54, 0x9f, 0x03, 0x6b, 0x60,
+			0xa1, 0x52, 0x3c, 0x61, 0x1d, 0x91, 0xbf, 0x50, 0x00, 0xfb, 0x62, 0x58, 0xfa, 0xd3, 0xbd, 0x17,
+			0x7d, 0x6f, 0xda, 0x76, 0x9a, 0xdb, 0x01, 0x96, 0x97, 0xc9, 0x5f, 0x64, 0x20, 0x3c, 0x70, 0x7a,
+			0x40, 0x1f, 0x35, 0xc8, 0x22, 0xf2, 0x76, 0x6d, 0x8e, 0x4a, 0x78, 0xd7, 0x8d, 0x52, 0x51, 0x60,
+			0x39, 0x14, 0xd8, 0xcd, 0xc7, 0x4b, 0x3f, 0xb3, 0x16, 0xdf, 0x52, 0xba, 0xcb, 0x98, 0x56, 0xaa,
+			0x97, 0x8b, 0xab, 0xa7, 0xbf, 0xe8, 0x0f, 0x16, 0x27, 0xbb, 0x56, 0xce, 0x10, 0xe5, 0x90, 0x05,
 		},
 	},
+	{
+		"A.1",
+		[]byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10},
+		[]byte{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0},
+		[]byte{0x01, 0x23, 0x45, 0x67, 0x89, 0xab, 0xcd, 0xef, 0xfe, 0xdc, 0xba, 0x98, 0x76, 0x54, 0x32, 0x10},
+		[]byte{
+			0x68, 0x1e, 0xdf, 0x34, 0xd2, 0x06, 0x96, 0x5e, 0x86, 0xb3, 0xe9, 0x4f, 0x53, 0x6e, 0x42, 0x46,
+			0x67, 0x7d, 0x30, 0x7e, 0x84, 0x4d, 0x7a, 0xa2, 0x45, 0x79, 0xd5, 0x56, 0x49, 0x0d, 0xc7, 0xaa},
+	},
 }
 
-func TestCTR_SM4(t *testing.T) {
-	for _, tt := range ctrSM4Tests {
-		test := tt.name
-
-		c, err := sm4.NewCipher(tt.key)
+func TestCBCEncrypterSM4(t *testing.T) {
+	pkcs7 := padding.NewPKCS7Padding(sm4.BlockSize)
+	for _, test := range cbcSM4Tests {
+		c, err := sm4.NewCipher(test.key)
 		if err != nil {
-			t.Errorf("%s: NewCipher(%d bytes) = %s", test, len(tt.key), err)
+			t.Errorf("%s: NewCipher(%d bytes) = %s", test.name, len(test.key), err)
 			continue
 		}
 
-		for j := 0; j <= 5; j += 5 {
-			in := tt.in[0 : len(tt.in)-j]
-			ctr := cipher.NewCTR(c, tt.iv)
-			encrypted := make([]byte, len(in))
-			ctr.XORKeyStream(encrypted, in)
-			if out := tt.out[0:len(in)]; !bytes.Equal(out, encrypted) {
-				t.Errorf("%s/%d: CTR\ninpt %x\nhave %x\nwant %x", test, len(in), in, encrypted, out)
-			}
-		}
+		encrypter := cipher.NewCBCEncrypter(c, test.iv)
 
-		for j := 0; j <= 7; j += 7 {
-			in := tt.out[0 : len(tt.out)-j]
-			ctr := cipher.NewCTR(c, tt.iv)
-			plain := make([]byte, len(in))
-			ctr.XORKeyStream(plain, in)
-			if out := tt.in[0:len(in)]; !bytes.Equal(out, plain) {
-				t.Errorf("%s/%d: CTRReader\nhave %x\nwant %x", test, len(out), plain, out)
-			}
-		}
+		plainText := pkcs7.Pad(test.in)
+		data := make([]byte, len(plainText))
+		copy(data, plainText)
 
-		if t.Failed() {
-			break
+		encrypter.CryptBlocks(data, data)
+		if !bytes.Equal(test.out, data) {
+			t.Errorf("%s: CBCEncrypter\nhave %s\nwant %x", test.name, hex.EncodeToString(data), test.out)
+			for i := 0; i < len(data); i++ {
+				fmt.Printf("0x%02x, ", data[i])
+				if (i+1)%16 == 0 {
+					fmt.Println()
+				}
+			}
 		}
 	}
 }
 
-func TestCTRStream(t *testing.T) {
-	t.Run("SM4", func(t *testing.T) {
-		rng := newRandReader(t)
-
-		key := make([]byte, 16)
-		rng.Read(key)
-
-		block, err := sm4.NewCipher(key)
+func TestCBCDecrypterSM4(t *testing.T) {
+	pkcs7 := padding.NewPKCS7Padding(sm4.BlockSize)
+	for _, test := range cbcSM4Tests {
+		c, err := sm4.NewCipher(test.key)
 		if err != nil {
-			panic(err)
+			t.Errorf("%s: NewCipher(%d bytes) = %s", test.name, len(test.key), err)
+			continue
 		}
 
-		cryptotest.TestStreamFromBlock(t, block, cipher.NewCTR)
-	})
+		decrypter := cipher.NewCBCDecrypter(c, test.iv)
+
+		data := make([]byte, len(test.out))
+		copy(data, test.out)
+
+		decrypter.CryptBlocks(data, data)
+		data, err = pkcs7.Unpad(data)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !bytes.Equal(test.in, data) {
+			t.Errorf("%s: CBCDecrypter\nhave %x\nwant %x", test.name, data, test.in)
+		}
+	}
+}
+
+func TestSM4CBCRandom(t *testing.T) {
+	key := []byte("0123456789ABCDEF")
+	c, err := sm4.NewCipher(key)
+	if err != nil {
+		t.Fatal(err)
+	}
+	encrypter := cipher.NewCBCEncrypter(c, key)
+	decrypter := cipher.NewCBCDecrypter(c, key)
+	for i:=1; i<=50; i++ {
+		plaintext := make([]byte, i*16)
+		ciphertext := make([]byte, i*16)
+		got := make([]byte, i*16)
+		io.ReadFull(rand.Reader, plaintext)
+		encrypter.CryptBlocks(ciphertext, plaintext)
+		decrypter.CryptBlocks(got, ciphertext)
+		if !bytes.Equal(got, plaintext) {
+			t.Errorf("test %v blocks failed", i)
+		}
+	}
 }
diff --git a/sm4/cbc_arm64.s b/sm4/cbc_arm64.s
index 5f62c88..b7a1f49 100644
--- a/sm4/cbc_arm64.s
+++ b/sm4/cbc_arm64.s
@@ -170,6 +170,9 @@ cbcSm4Single:
 
 	// 4 blocks
 	VLD1 (srcPtr), [t0.S4, t1.S4, t2.S4, t3.S4]
+	VMOV t0.B16, V6.B16
+	VMOV t1.B16, V7.B16
+	VMOV t2.B16, V8.B16
 	VREV32 t0.B16, t0.B16
 	VREV32 t1.B16, t1.B16
 	VREV32 t2.B16, t2.B16
@@ -192,7 +195,6 @@ cbc4BlocksLoop64:
 	VREV32 t2.B16, t2.B16
 	VREV32 t3.B16, t3.B16
 
-	VLD1 (srcPtr), [V6.S4, V7.S4, V8.S4]
 	VEOR IV.B16, t0.B16, t0.B16
 	VEOR V6.B16, t1.B16, t1.B16
 	VEOR V7.B16, t2.B16, t2.B16
@@ -232,6 +234,7 @@ cbc4BlocksLoop16:
 
 cbcSm4Single32:
 	VLD1 (srcPtr), [t0.S4, t1.S4]
+	VMOV t0.B16, V6.B16
 	VREV32 t0.B16, t0.B16
 	VREV32 t1.B16, t1.B16
 	PRE_TRANSPOSE_MATRIX(t0, t1, t2, t3, x, y, XTMP6, XTMP7)
@@ -250,7 +253,6 @@ cbc4BlocksLoop32:
 	VREV32 t0.B16, t0.B16
 	VREV32 t1.B16, t1.B16
 
-	VLD1 (srcPtr), [V6.S4]
 	VEOR IV.B16, t0.B16, t0.B16
 	VEOR V6.B16, t1.B16, t1.B16
 
@@ -259,6 +261,8 @@ cbc4BlocksLoop32:
 
 cbcSm4Single48:
 	VLD1 (srcPtr), [t0.S4, t1.S4, t2.S4]
+	VMOV t0.B16, V6.B16
+	VMOV t1.B16, V7.B16
 	VREV32 t0.B16, t0.B16
 	VREV32 t1.B16, t1.B16
 	VREV32 t2.B16, t2.B16
@@ -279,7 +283,6 @@ cbc4BlocksLoop48:
 	VREV32 t1.B16, t1.B16
 	VREV32 t2.B16, t2.B16
 
-	VLD1 (srcPtr), [V6.S4, V7.S4]
 	VEOR IV.B16, t0.B16, t0.B16
 	VEOR V6.B16, t1.B16, t1.B16
 	VEOR V7.B16, t2.B16, t2.B16