github.com/pingcap/tiflow@v0.0.0-20240520035814-5bf52d54e205/dm/pkg/encrypt/encrypt_test.go (about)

     1  // Copyright 2019 PingCAP, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package encrypt
    15  
    16  import (
    17  	"crypto/aes"
    18  	"crypto/rand"
    19  	"testing"
    20  
    21  	"github.com/stretchr/testify/require"
    22  )
    23  
    24  func removeChar(input []byte, c byte) []byte {
    25  	i := 0
    26  	for _, x := range input {
    27  		if x != c {
    28  			input[i] = x
    29  			i++
    30  		}
    31  	}
    32  	return input[:i]
    33  }
    34  
    35  func TestCipher(t *testing.T) {
    36  	key := make([]byte, 32)
    37  	_, err := rand.Read(key)
    38  	require.NoError(t, err)
    39  
    40  	t.Cleanup(func() {
    41  		InitCipher(nil)
    42  	})
    43  	InitCipher(nil)
    44  	require.IsType(t, &notInitializedCipher{}, defaultCipher)
    45  
    46  	InitCipher(key)
    47  	require.IsType(t, &aesCipher{}, defaultCipher)
    48  
    49  	plaintext := []byte("a plain text")
    50  
    51  	// encrypt
    52  	ciphertext, err := Encrypt(plaintext)
    53  	require.NoError(t, err)
    54  
    55  	// decrypt
    56  	plaintext2, err := Decrypt(ciphertext)
    57  	require.NoError(t, err)
    58  	require.Equal(t, plaintext, plaintext2)
    59  
    60  	// invalid length
    61  	_, err = Decrypt(ciphertext[:len(ciphertext)-len(plaintext)-1])
    62  	require.Error(t, err)
    63  
    64  	// invalid content
    65  	_, err = Decrypt(removeChar(ciphertext, ivSep[0]))
    66  	require.Error(t, err)
    67  
    68  	// a special case, we construct a ciphertext that can be decrypted but the
    69  	// plaintext is not what we want. This is because currently encrypt mechanism
    70  	// doesn't keep enough information to decide whether the new ciphertext is valid
    71  	block, err := aes.NewCipher(key)
    72  	require.NoError(t, err)
    73  	blockSize := block.BlockSize()
    74  	require.Greater(t, len(ciphertext), blockSize+2)
    75  	plaintext3, err := Decrypt(append(ciphertext[1:blockSize+1], append([]byte{ivSep[0]}, ciphertext[blockSize+2:]...)...))
    76  	require.NoError(t, err)
    77  	require.NotEqual(t, plaintext, plaintext3)
    78  }