Golang crypto.Encrypt函数代码示例

func TestDecryptStreamReader(t *testing.T) {
	k := crypto.NewRandomKey()

	tests := []int{5, 23, 2<<18 + 23, 1 << 20}
	if testLargeCrypto {
		tests = append(tests, 7<<20+123)
	}

	for _, size := range tests {
		data := Random(42, size)
		var err error
		ciphertext := make([]byte, size+crypto.Extension)

		// encrypt with default function
		ciphertext, err = crypto.Encrypt(k, ciphertext, data)
		OK(t, err)
		Assert(t, len(ciphertext) == len(data)+crypto.Extension,
			"wrong number of bytes returned after encryption: expected %d, got %d",
			len(data)+crypto.Extension, len(ciphertext))

		rd, err := crypto.DecryptFrom(k, bytes.NewReader(ciphertext))
		OK(t, err)

		plaintext, err := ioutil.ReadAll(rd)
		OK(t, err)

		Assert(t, bytes.Equal(data, plaintext),
			"wrong plaintext after decryption: expected %02x, got %02x",
			data, plaintext)
	}
}

// Encrypt encrypts and authenticates the plaintext and saves the result in
// ciphertext.
func (r *Repository) Encrypt(ciphertext, plaintext []byte) ([]byte, error) {
	if r.key == nil {
		return nil, errors.New("key for repository not set")
	}

	return crypto.Encrypt(r.key, ciphertext, plaintext)
}

func TestEncryptDecrypt(t *testing.T) {
	k := crypto.NewRandomKey()

	tests := []int{5, 23, 2<<18 + 23, 1 << 20}
	if testLargeCrypto {
		tests = append(tests, 7<<20+123)
	}

	for _, size := range tests {
		data := Random(42, size)
		buf := make([]byte, size+crypto.Extension)

		ciphertext, err := crypto.Encrypt(k, buf, data)
		OK(t, err)
		Assert(t, len(ciphertext) == len(data)+crypto.Extension,
			"ciphertext length does not match: want %d, got %d",
			len(data)+crypto.Extension, len(ciphertext))

		plaintext, err := crypto.Decrypt(k, nil, ciphertext)
		OK(t, err)
		Assert(t, len(plaintext) == len(data),
			"plaintext length does not match: want %d, got %d",
			len(data), len(plaintext))

		Equals(t, plaintext, data)
	}
}

func TestCornerCases(t *testing.T) {
	k := crypto.NewRandomKey()

	// nil plaintext should encrypt to the empty string
	// nil ciphertext should allocate a new slice for the ciphertext
	c, err := crypto.Encrypt(k, nil, nil)
	OK(t, err)

	Assert(t, len(c) == crypto.Extension,
		"wrong length returned for ciphertext, expected 0, got %d",
		len(c))

	// this should decrypt to nil
	p, err := crypto.Decrypt(k, nil, c)
	OK(t, err)
	Equals(t, []byte(nil), p)

	// test encryption for same slice, this should return an error
	_, err = crypto.Encrypt(k, c, c)
	Equals(t, crypto.ErrInvalidCiphertext, err)
}

func benchmarkChunkEncryptP(b *testing.PB, buf []byte, rd Rdr, key *crypto.Key) {
	ch := chunker.New(rd, testPol)

	for {
		chunk, err := ch.Next(buf)
		if err == io.EOF {
			break
		}

		// reduce length of chunkBuf
		crypto.Encrypt(key, chunk.Data, chunk.Data)
	}
}

func benchmarkChunkEncryptP(b *testing.PB, buf []byte, rd Rdr, key *crypto.Key) {
	ch := chunker.New(rd, testPol, sha256.New())

	for {
		chunk, err := ch.Next()
		if err == io.EOF {
			break
		}

		// reduce length of chunkBuf
		buf = buf[:chunk.Length]
		io.ReadFull(chunk.Reader(rd), buf)
		crypto.Encrypt(key, buf, buf)
	}
}

func BenchmarkEncrypt(b *testing.B) {
	size := 8 << 20 // 8MiB
	data := make([]byte, size)

	k := crypto.NewRandomKey()
	buf := make([]byte, len(data)+crypto.Extension)

	b.ResetTimer()
	b.SetBytes(int64(size))

	for i := 0; i < b.N; i++ {
		_, err := crypto.Encrypt(k, buf, data)
		OK(b, err)
	}
}

// Finalize writes the header for all added blobs and finalizes the pack.
// Returned are the number of bytes written, including the header. If the
// underlying writer implements io.Closer, it is closed.
func (p *Packer) Finalize() (uint, error) {
	p.m.Lock()
	defer p.m.Unlock()

	bytesWritten := p.bytes

	hdrBuf := bytes.NewBuffer(nil)
	bytesHeader, err := p.writeHeader(hdrBuf)
	if err != nil {
		return 0, err
	}

	encryptedHeader, err := crypto.Encrypt(p.k, nil, hdrBuf.Bytes())
	if err != nil {
		return 0, err
	}

	// append the header
	n, err := p.wr.Write(encryptedHeader)
	if err != nil {
		return 0, err
	}

	hdrBytes := bytesHeader + crypto.Extension
	if uint(n) != hdrBytes {
		return 0, errors.New("wrong number of bytes written")
	}

	bytesWritten += hdrBytes

	// write length
	err = binary.Write(p.wr, binary.LittleEndian, uint32(uint(len(p.blobs))*entrySize+crypto.Extension))
	if err != nil {
		return 0, err
	}
	bytesWritten += uint(binary.Size(uint32(0)))

	p.bytes = uint(bytesWritten)

	if w, ok := p.wr.(io.Closer); ok {
		return bytesWritten, w.Close()
	}

	return bytesWritten, nil
}

func TestSameBuffer(t *testing.T) {
	k := crypto.NewRandomKey()

	size := 600
	data := make([]byte, size)
	_, err := io.ReadFull(rand.Reader, data)
	OK(t, err)

	ciphertext := make([]byte, 0, size+crypto.Extension)

	ciphertext, err = crypto.Encrypt(k, ciphertext, data)
	OK(t, err)

	// use the same buffer for decryption
	ciphertext, err = crypto.Decrypt(k, ciphertext, ciphertext)
	OK(t, err)
	Assert(t, bytes.Equal(ciphertext, data),
		"wrong plaintext returned")
}

func BenchmarkDecrypt(b *testing.B) {
	size := 8 << 20 // 8MiB
	data := make([]byte, size)

	k := crypto.NewRandomKey()

	plaintext := make([]byte, size)
	ciphertext := make([]byte, size+crypto.Extension)

	ciphertext, err := crypto.Encrypt(k, ciphertext, data)
	OK(b, err)

	b.ResetTimer()
	b.SetBytes(int64(size))

	for i := 0; i < b.N; i++ {
		plaintext, err = crypto.Decrypt(k, plaintext, ciphertext)
		OK(b, err)
	}
}

func TestLargeEncrypt(t *testing.T) {
	if !testLargeCrypto {
		t.SkipNow()
	}

	k := crypto.NewRandomKey()

	for _, size := range []int{chunker.MaxSize, chunker.MaxSize + 1, chunker.MaxSize + 1<<20} {
		data := make([]byte, size)
		_, err := io.ReadFull(rand.Reader, data)
		OK(t, err)

		ciphertext, err := crypto.Encrypt(k, make([]byte, size+crypto.Extension), data)
		OK(t, err)

		plaintext, err := crypto.Decrypt(k, []byte{}, ciphertext)
		OK(t, err)

		Equals(t, plaintext, data)
	}
}

func TestSmallBuffer(t *testing.T) {
	k := crypto.NewRandomKey()

	size := 600
	data := make([]byte, size)
	_, err := io.ReadFull(rand.Reader, data)
	OK(t, err)

	ciphertext := make([]byte, size/2)
	ciphertext, err = crypto.Encrypt(k, ciphertext, data)
	// this must extend the slice
	Assert(t, cap(ciphertext) > size/2,
		"expected extended slice, but capacity is only %d bytes",
		cap(ciphertext))

	// check for the correct plaintext
	plaintext, err := crypto.Decrypt(k, nil, ciphertext)
	OK(t, err)
	Assert(t, bytes.Equal(plaintext, data),
		"wrong plaintext returned")
}

func benchmarkChunkEncrypt(b testing.TB, buf, buf2 []byte, rd Rdr, key *crypto.Key) {
	rd.Seek(0, 0)
	ch := chunker.New(rd, testPol)

	for {
		chunk, err := ch.Next(buf)

		if err == io.EOF {
			break
		}

		OK(b, err)

		// reduce length of buf
		Assert(b, uint(len(chunk.Data)) == chunk.Length,
			"invalid length: got %d, expected %d", len(chunk.Data), chunk.Length)

		_, err = crypto.Encrypt(key, buf2, chunk.Data)
		OK(b, err)
	}
}

func BenchmarkDecryptReader(b *testing.B) {
	size := 8 << 20 // 8MiB
	buf := Random(23, size)
	k := crypto.NewRandomKey()

	ciphertext := make([]byte, len(buf)+crypto.Extension)
	_, err := crypto.Encrypt(k, ciphertext, buf)
	OK(b, err)

	rd := bytes.NewReader(ciphertext)

	b.ResetTimer()
	b.SetBytes(int64(size))

	for i := 0; i < b.N; i++ {
		rd.Seek(0, 0)
		decRd, err := crypto.DecryptFrom(k, rd)
		OK(b, err)

		_, err = io.Copy(ioutil.Discard, decRd)
		OK(b, err)
	}
}

func benchmarkChunkEncrypt(b testing.TB, buf, buf2 []byte, rd Rdr, key *crypto.Key) {
	rd.Seek(0, 0)
	ch := chunker.New(rd, testPol, sha256.New())

	for {
		chunk, err := ch.Next()

		if err == io.EOF {
			break
		}

		OK(b, err)

		// reduce length of buf
		buf = buf[:chunk.Length]
		n, err := io.ReadFull(chunk.Reader(rd), buf)
		OK(b, err)
		Assert(b, uint(n) == chunk.Length, "invalid length: got %d, expected %d", n, chunk.Length)

		_, err = crypto.Encrypt(key, buf2, buf)
		OK(b, err)
	}
}