File: encoding.go

package info (click to toggle)
golang-gopkg-square-go-jose.v2 2.5.1-2
  • links: PTS, VCS
  • area: main
  • in suites: bullseye, experimental, sid
  • size: 1,004 kB
  • sloc: makefile: 4
file content (185 lines) | stat: -rw-r--r-- 4,635 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
/*-
 * Copyright 2014 Square Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package jose

import (
	"bytes"
	"compress/flate"
	"encoding/base64"
	"encoding/binary"
	"io"
	"math/big"
	"strings"
	"unicode"

	"gopkg.in/square/go-jose.v2/json"
)

// Helper function to serialize known-good objects.
// Precondition: value is not a nil pointer.
func mustSerializeJSON(value interface{}) []byte {
	out, err := json.Marshal(value)
	if err != nil {
		panic(err)
	}
	// We never want to serialize the top-level value "null," since it's not a
	// valid JOSE message. But if a caller passes in a nil pointer to this method,
	// MarshalJSON will happily serialize it as the top-level value "null". If
	// that value is then embedded in another operation, for instance by being
	// base64-encoded and fed as input to a signing algorithm
	// (https://github.com/square/go-jose/issues/22), the result will be
	// incorrect. Because this method is intended for known-good objects, and a nil
	// pointer is not a known-good object, we are free to panic in this case.
	// Note: It's not possible to directly check whether the data pointed at by an
	// interface is a nil pointer, so we do this hacky workaround.
	// https://groups.google.com/forum/#!topic/golang-nuts/wnH302gBa4I
	if string(out) == "null" {
		panic("Tried to serialize a nil pointer.")
	}
	return out
}

// Strip all newlines and whitespace
func stripWhitespace(data string) string {
	buf := strings.Builder{}
	buf.Grow(len(data))
	for _, r := range data {
		if !unicode.IsSpace(r) {
			buf.WriteRune(r)
		}
	}
	return buf.String()
}

// Perform compression based on algorithm
func compress(algorithm CompressionAlgorithm, input []byte) ([]byte, error) {
	switch algorithm {
	case DEFLATE:
		return deflate(input)
	default:
		return nil, ErrUnsupportedAlgorithm
	}
}

// Perform decompression based on algorithm
func decompress(algorithm CompressionAlgorithm, input []byte) ([]byte, error) {
	switch algorithm {
	case DEFLATE:
		return inflate(input)
	default:
		return nil, ErrUnsupportedAlgorithm
	}
}

// Compress with DEFLATE
func deflate(input []byte) ([]byte, error) {
	output := new(bytes.Buffer)

	// Writing to byte buffer, err is always nil
	writer, _ := flate.NewWriter(output, 1)
	_, _ = io.Copy(writer, bytes.NewBuffer(input))

	err := writer.Close()
	return output.Bytes(), err
}

// Decompress with DEFLATE
func inflate(input []byte) ([]byte, error) {
	output := new(bytes.Buffer)
	reader := flate.NewReader(bytes.NewBuffer(input))

	_, err := io.Copy(output, reader)
	if err != nil {
		return nil, err
	}

	err = reader.Close()
	return output.Bytes(), err
}

// byteBuffer represents a slice of bytes that can be serialized to url-safe base64.
type byteBuffer struct {
	data []byte
}

func newBuffer(data []byte) *byteBuffer {
	if data == nil {
		return nil
	}
	return &byteBuffer{
		data: data,
	}
}

func newFixedSizeBuffer(data []byte, length int) *byteBuffer {
	if len(data) > length {
		panic("square/go-jose: invalid call to newFixedSizeBuffer (len(data) > length)")
	}
	pad := make([]byte, length-len(data))
	return newBuffer(append(pad, data...))
}

func newBufferFromInt(num uint64) *byteBuffer {
	data := make([]byte, 8)
	binary.BigEndian.PutUint64(data, num)
	return newBuffer(bytes.TrimLeft(data, "\x00"))
}

func (b *byteBuffer) MarshalJSON() ([]byte, error) {
	return json.Marshal(b.base64())
}

func (b *byteBuffer) UnmarshalJSON(data []byte) error {
	var encoded string
	err := json.Unmarshal(data, &encoded)
	if err != nil {
		return err
	}

	if encoded == "" {
		return nil
	}

	decoded, err := base64.RawURLEncoding.DecodeString(encoded)
	if err != nil {
		return err
	}

	*b = *newBuffer(decoded)

	return nil
}

func (b *byteBuffer) base64() string {
	return base64.RawURLEncoding.EncodeToString(b.data)
}

func (b *byteBuffer) bytes() []byte {
	// Handling nil here allows us to transparently handle nil slices when serializing.
	if b == nil {
		return nil
	}
	return b.data
}

func (b byteBuffer) bigInt() *big.Int {
	return new(big.Int).SetBytes(b.data)
}

func (b byteBuffer) toInt() int {
	return int(b.bigInt().Int64())
}