// optimized implementation of CBC decryption, like crypto/aes.
// NewCBCDecrypter will check for this interface and return the specific
// BlockMode if found.
type cbcDecAble interface {
	NewCBCDecrypter(iv []byte) BlockMode
}

// NewCBCDecrypter returns a BlockMode which decrypts in cipher block chaining
// mode, using the given Block. The length of iv must be the same as the

	b := cipher.Block(&testBlock{})
	if _, ok := b.(cbcDecAble); !ok {
		t.Fatalf("testBlock does not implement the cbcDecAble interface")
	}
	bm := cipher.NewCBCDecrypter(b, []byte{})
	if _, ok := bm.(testInterface); !ok {
		t.Fatalf("cipher.NewCBCDecrypter did not use cbcDecAble interface")
	}
}

// testStream implements the cipher.Stream interface.
type testStream struct{}

import (
	"bytes"
	"crypto/aes"
	"crypto/cipher"
	"crypto/des"
	"testing"
)

func TestCryptBlocks(t *testing.T) {
	buf := make([]byte, 16)
	block, _ := aes.NewCipher(buf)

	mode := cipher.NewCBCDecrypter(block, buf)
	mustPanic(t, "crypto/cipher: input not full blocks", func() { mode.CryptBlocks(buf, buf[:3]) })
	mustPanic(t, "crypto/cipher: output smaller than input", func() { mode.CryptBlocks(buf[:3], buf) })

}

// cbcDecAble is implemented by cipher.Blocks that can provide an optimized
// implementation of CBC decryption through the cipher.BlockMode interface.
// See crypto/cipher/cbc.go.
type cbcDecAble interface {
	NewCBCDecrypter(iv []byte) cipher.BlockMode
}

// ctrAble is implemented by cipher.Blocks that can provide an optimized
// implementation of CTR through the cipher.Stream interface.
// See crypto/cipher/ctr.go.

	iv [BlockSize]byte
}

func (b *aesCipherAsm) NewCBCEncrypter(iv []byte) cipher.BlockMode {
	var c cbc
	c.b = b
	c.c = b.function
	copy(c.iv[:], iv)
	return &c
}

func (b *aesCipherAsm) NewCBCDecrypter(iv []byte) cipher.BlockMode {
	var c cbc
	c.b = b
	c.c = b.function + 128 // decrypt function code is encrypt + 128
	copy(c.iv[:], iv)
	return &c
}

func (x *cbc) BlockSize() int { return BlockSize }

	iv  [BlockSize]byte
}

func (b *aesCipherAsm) NewCBCEncrypter(iv []byte) cipher.BlockMode {
	var c cbc
	c.b = b
	c.enc = cbcEncrypt
	copy(c.iv[:], iv)
	return &c
}

func (b *aesCipherAsm) NewCBCDecrypter(iv []byte) cipher.BlockMode {
	var c cbc
	c.b = b
	c.enc = cbcDecrypt
	copy(c.iv[:], iv)
	return &c
}

func (x *cbc) BlockSize() int { return BlockSize }

			if !bytes.Equal(outdata, outgeneric) {
				t.Fatalf("AES-CBC encryption does not match reference result: %x and %x, please report this error to ******@****.***", outdata, outgeneric)
			}
		}

		cbcAsm = cipher.NewCBCDecrypter(c, commonIV)
		cbcGeneric = cipher.NewCBCGenericDecrypter(c, commonIV)

		if testing.Short() {
			timeout = time.NewTimer(10 * time.Millisecond)
		} else {
			timeout = time.NewTimer(2 * time.Second)
		}

	for _, test := range cbcAESTests {
		c, err := aes.NewCipher(test.key)
		if err != nil {
			t.Errorf("%s: NewCipher(%d bytes) = %s", test.name, len(test.key), err)
			continue
		}

		decrypter := cipher.NewCBCDecrypter(c, test.iv)

		data := make([]byte, len(test.out))
		copy(data, test.out)

		decrypter.CryptBlocks(data, data)
		if !bytes.Equal(test.in, data) {

	}
}

func BenchmarkAESCBCDecrypt1K(b *testing.B) {
	buf := make([]byte, 1024)
	b.SetBytes(int64(len(buf)))

	var key [16]byte
	var iv [16]byte
	aes, _ := aes.NewCipher(key[:])
	cbc := cipher.NewCBCDecrypter(aes, iv[:])
	for i := 0; i < b.N; i++ {
		cbc.CryptBlocks(buf, buf)
	}

type aesCipher struct {
	key []byte
	enc C.GO_AES_KEY
	dec C.GO_AES_KEY
}

type extraModes interface {
	// Copied out of crypto/aes/modes.go.
	NewCBCEncrypter(iv []byte) cipher.BlockMode
	NewCBCDecrypter(iv []byte) cipher.BlockMode
	NewCTR(iv []byte) cipher.Stream
	NewGCM(nonceSize, tagSize int) (cipher.AEAD, error)
}

var _ extraModes = (*aesCipher)(nil)

func NewAESCipher(key []byte) (cipher.Block, error) {