This repository has been archived by the owner on Dec 22, 2023. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 84
/
fs.go
174 lines (144 loc) · 4.29 KB
/
fs.go
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
// Copyright 2015-present Oursky Ltd.
//
// 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 asset
import (
"bytes"
"crypto/hmac"
"crypto/sha256"
"encoding/base64"
"errors"
"fmt"
"io"
"io/ioutil"
"net/url"
"os"
"path/filepath"
"strconv"
"strings"
"time"
)
// fileStore implements Store by storing files on file system
type fileStore struct {
dir string
prefix string
secret string
public bool
}
// NewFileStore creates a new fileStore
func NewFileStore(dir, prefix, secret string, public bool) Store {
return &fileStore{dir, prefix, secret, public}
}
// GetFileReader returns a reader for reading files
func (s *fileStore) GetFileReader(name string) (io.ReadCloser, error) {
path := filepath.Join(s.dir, name)
return os.Open(path)
}
// GetRangedFileReader returns a reader for reading files within
// the specified byte range
func (s *fileStore) GetRangedFileReader(name string, fileRange FileRange) (
*FileRangedGetResult,
error,
) {
path := filepath.Join(s.dir, name)
file, err := os.Open(path)
if err != nil {
return nil, err
}
fileStat, err := file.Stat()
if err != nil {
return nil, err
}
fileSize := fileStat.Size()
if fileRange.From >= fileSize {
return nil, FileRangeNotAcceptedError{fileRange}
}
if _, err = file.Seek(fileRange.From, 0); err != nil {
return nil, err
}
acceptedRange := FileRange{
From: fileRange.From,
To: fileRange.To,
}
if acceptedRange.To > fileSize-1 {
acceptedRange.To = fileSize - 1
}
return &FileRangedGetResult{
ReadCloser: file,
AcceptedRange: acceptedRange,
TotalSize: fileSize,
}, nil
}
// PutFileReader stores a file from reader onto file system
func (s *fileStore) PutFileReader(name string, src io.Reader, length int64, contentType string) error {
path := filepath.Join(s.dir, name)
dir := filepath.Dir(path)
if err := os.MkdirAll(dir, 0755); err != nil {
return err
}
f, err := os.Create(path)
if err != nil {
return err
}
defer f.Close()
written, err := io.Copy(f, src)
if err != nil {
return err
}
if written != length {
return fmt.Errorf("got written %d bytes, expect %d", written, length)
}
return nil
}
// GeneratePostFileRequest return a PostFileRequest for uploading asset
func (s *fileStore) GeneratePostFileRequest(name string, contentType string, length int64) (*PostFileRequest, error) {
return &PostFileRequest{
Action: "/files/" + name,
}, nil
}
// SignedURL returns a signed url with expiry date
func (s *fileStore) SignedURL(name string) (string, error) {
if !s.IsSignatureRequired() {
return fmt.Sprintf("%s/%s", s.prefix, url.PathEscape(name)), nil
}
expiredAt := time.Now().Add(time.Minute * time.Duration(15))
expiredAtStr := strconv.FormatInt(expiredAt.Unix(), 10)
h := hmac.New(sha256.New, []byte(s.secret))
io.WriteString(h, name)
io.WriteString(h, expiredAtStr)
buf := bytes.Buffer{}
base64Encoder := base64.NewEncoder(base64.URLEncoding, &buf)
base64Encoder.Write(h.Sum(nil))
base64Encoder.Close()
return fmt.Sprintf(
"%s/%s?expiredAt=%s&signature=%s",
s.prefix, url.PathEscape(name), expiredAtStr, buf.String(),
), nil
}
// ParseSignature tries to parse the asset signature
func (s *fileStore) ParseSignature(signed string, name string, expiredAt time.Time) (valid bool, err error) {
base64Decoder := base64.NewDecoder(base64.URLEncoding, strings.NewReader(signed))
remoteSignature, err := ioutil.ReadAll(base64Decoder)
if err != nil {
log.Errorf("failed to decode asset url signature: %v", err)
return false, errors.New("invalid signature")
}
h := hmac.New(sha256.New, []byte(s.secret))
io.WriteString(h, name)
io.WriteString(h, strconv.FormatInt(expiredAt.Unix(), 10))
return hmac.Equal(remoteSignature, h.Sum(nil)), nil
}
// IsSignatureRequired indicates whether a signature is required
func (s *fileStore) IsSignatureRequired() bool {
return !s.public
}