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| 1 | +// Copyright 2024 PingCAP, Inc. |
| 2 | +// SPDX-License-Identifier: Apache-2.0 |
| 3 | + |
| 4 | +package store |
| 5 | + |
| 6 | +import ( |
| 7 | + "crypto/aes" |
| 8 | + "crypto/cipher" |
| 9 | + "crypto/rand" |
| 10 | + "io" |
| 11 | + "os" |
| 12 | + "reflect" |
| 13 | + |
| 14 | + "github.com/pingcap/tiproxy/lib/util/errors" |
| 15 | +) |
| 16 | + |
| 17 | +var _ Writer = (*aesCTRWriter)(nil) |
| 18 | + |
| 19 | +type aesCTRWriter struct { |
| 20 | + Writer |
| 21 | + stream cipher.Stream |
| 22 | + iv []byte |
| 23 | + inited bool |
| 24 | +} |
| 25 | + |
| 26 | +func newAESCTRWriter(writer Writer, keyFile string) (*aesCTRWriter, error) { |
| 27 | + key, err := readAesKey(keyFile) |
| 28 | + if err != nil { |
| 29 | + return nil, err |
| 30 | + } |
| 31 | + block, err := aes.NewCipher(key) |
| 32 | + if err != nil { |
| 33 | + return nil, errors.WithStack(err) |
| 34 | + } |
| 35 | + iv := make([]byte, aes.BlockSize) |
| 36 | + if _, err := io.ReadFull(rand.Reader, iv); err != nil { |
| 37 | + return nil, errors.WithStack(err) |
| 38 | + } |
| 39 | + return &aesCTRWriter{ |
| 40 | + Writer: writer, |
| 41 | + stream: cipher.NewCTR(block, iv), |
| 42 | + iv: iv, |
| 43 | + }, nil |
| 44 | +} |
| 45 | + |
| 46 | +func (ctr *aesCTRWriter) Write(data []byte) error { |
| 47 | + if !ctr.inited { |
| 48 | + if err := ctr.writeIV(); err != nil { |
| 49 | + return err |
| 50 | + } |
| 51 | + ctr.inited = true |
| 52 | + } |
| 53 | + ctr.stream.XORKeyStream(data, data) |
| 54 | + return ctr.Writer.Write(data) |
| 55 | +} |
| 56 | + |
| 57 | +func (ctr *aesCTRWriter) writeIV() error { |
| 58 | + return ctr.Writer.Write(ctr.iv) |
| 59 | +} |
| 60 | + |
| 61 | +func (ctr *aesCTRWriter) Close() error { |
| 62 | + return ctr.Writer.Close() |
| 63 | +} |
| 64 | + |
| 65 | +var _ Reader = (*aesCTRReader)(nil) |
| 66 | + |
| 67 | +type aesCTRReader struct { |
| 68 | + Reader |
| 69 | + stream cipher.Stream |
| 70 | + key []byte |
| 71 | +} |
| 72 | + |
| 73 | +func newAESCTRReader(reader Reader, keyFile string) (*aesCTRReader, error) { |
| 74 | + key, err := readAesKey(keyFile) |
| 75 | + if err != nil { |
| 76 | + return nil, err |
| 77 | + } |
| 78 | + return &aesCTRReader{ |
| 79 | + Reader: reader, |
| 80 | + key: key, |
| 81 | + }, nil |
| 82 | +} |
| 83 | + |
| 84 | +func (ctr *aesCTRReader) Read(data []byte) (int, error) { |
| 85 | + if ctr.stream == nil || reflect.ValueOf(ctr.stream).IsNil() { |
| 86 | + if err := ctr.init(); err != nil { |
| 87 | + return 0, err |
| 88 | + } |
| 89 | + } |
| 90 | + n, err := ctr.Reader.Read(data) |
| 91 | + if n > 0 { |
| 92 | + ctr.stream.XORKeyStream(data[:n], data[:n]) |
| 93 | + } |
| 94 | + if err != nil { |
| 95 | + return n, err |
| 96 | + } |
| 97 | + return n, nil |
| 98 | +} |
| 99 | + |
| 100 | +func (ctr *aesCTRReader) init() error { |
| 101 | + block, err := aes.NewCipher(ctr.key) |
| 102 | + if err != nil { |
| 103 | + return errors.WithStack(err) |
| 104 | + } |
| 105 | + iv := make([]byte, aes.BlockSize) |
| 106 | + for readLen := 0; readLen < len(iv); { |
| 107 | + m, err := ctr.Reader.Read(iv[readLen:]) |
| 108 | + if err != nil { |
| 109 | + return err |
| 110 | + } |
| 111 | + readLen += m |
| 112 | + } |
| 113 | + ctr.stream = cipher.NewCTR(block, iv) |
| 114 | + return nil |
| 115 | +} |
| 116 | + |
| 117 | +func (ctr *aesCTRReader) CurFile() string { |
| 118 | + return ctr.Reader.CurFile() |
| 119 | +} |
| 120 | + |
| 121 | +func (ctr *aesCTRReader) Close() { |
| 122 | + ctr.Reader.Close() |
| 123 | +} |
| 124 | + |
| 125 | +func readAesKey(filename string) ([]byte, error) { |
| 126 | + key, err := os.ReadFile(filename) |
| 127 | + if err != nil { |
| 128 | + return nil, errors.WithStack(err) |
| 129 | + } |
| 130 | + if len(key) != 32 { |
| 131 | + return nil, errors.Errorf("invalid aes-256 key length: %d, expecting 32", len(key)) |
| 132 | + } |
| 133 | + return key, nil |
| 134 | +} |
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