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
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
|
// Copyright 2014 The Gogs Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package models
import (
"bufio"
"encoding/base64"
"encoding/binary"
"errors"
"fmt"
"io"
"io/ioutil"
"os"
"os/exec"
"path"
"path/filepath"
"strings"
"sync"
"time"
"github.com/Unknwon/com"
"github.com/gogits/gogs/modules/log"
"github.com/gogits/gogs/modules/process"
"github.com/gogits/gogs/modules/setting"
)
const (
// "### autogenerated by gitgos, DO NOT EDIT\n"
_TPL_PUBLICK_KEY = `command="%s serv key-%d",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty %s` + "\n"
)
var (
ErrKeyAlreadyExist = errors.New("Public key already exist")
ErrKeyNotExist = errors.New("Public key does not exist")
ErrKeyUnableVerify = errors.New("Unable to verify public key")
)
var sshOpLocker = sync.Mutex{}
var (
SshPath string // SSH directory.
appPath string // Execution(binary) path.
)
// exePath returns the executable path.
func exePath() (string, error) {
file, err := exec.LookPath(os.Args[0])
if err != nil {
return "", err
}
return filepath.Abs(file)
}
// homeDir returns the home directory of current user.
func homeDir() string {
home, err := com.HomeDir()
if err != nil {
log.Fatal(4, "Fail to get home directory: %v", err)
}
return home
}
func init() {
var err error
if appPath, err = exePath(); err != nil {
log.Fatal(4, "fail to get app path: %v\n", err)
}
appPath = strings.Replace(appPath, "\\", "/", -1)
// Determine and create .ssh path.
SshPath = filepath.Join(homeDir(), ".ssh")
if err = os.MkdirAll(SshPath, 0700); err != nil {
log.Fatal(4, "fail to create SshPath(%s): %v\n", SshPath, err)
}
}
// PublicKey represents a SSH key.
type PublicKey struct {
Id int64
OwnerId int64 `xorm:"UNIQUE(s) INDEX NOT NULL"`
Name string `xorm:"UNIQUE(s) NOT NULL"`
Fingerprint string `xorm:"INDEX NOT NULL"`
Content string `xorm:"TEXT NOT NULL"`
Created time.Time `xorm:"CREATED"`
Updated time.Time
HasRecentActivity bool `xorm:"-"`
HasUsed bool `xorm:"-"`
}
// OmitEmail returns content of public key but without e-mail address.
func (k *PublicKey) OmitEmail() string {
return strings.Join(strings.Split(k.Content, " ")[:2], " ")
}
// GetAuthorizedString generates and returns formatted public key string for authorized_keys file.
func (key *PublicKey) GetAuthorizedString() string {
return fmt.Sprintf(_TPL_PUBLICK_KEY, appPath, key.Id, key.Content)
}
var (
MinimumKeySize = map[string]int{
"(ED25519)": 256,
"(ECDSA)": 256,
"(NTRU)": 1087,
"(MCE)": 1702,
"(McE)": 1702,
"(RSA)": 2048,
"(DSA)": 1024,
}
)
func extractTypeFromBase64Key(key string) (string, error) {
b, err := base64.StdEncoding.DecodeString(key)
if err != nil || len(b) < 4 {
return "", errors.New("Invalid key format")
}
keyLength := int(binary.BigEndian.Uint32(b))
if len(b) < 4+keyLength {
return "", errors.New("Invalid key format")
}
return string(b[4 : 4+keyLength]), nil
}
// Parse any key string in openssh or ssh2 format to clean openssh string (rfc4253)
func ParseKeyString(content string) (string, error) {
// Transform all legal line endings to a single "\n"
s := strings.Replace(strings.Replace(strings.TrimSpace(content), "\r\n", "\n", -1), "\r", "\n", -1)
lines := strings.Split(s, "\n")
var keyType, keyContent, keyComment string
if len(lines) == 1 {
// Parse openssh format
parts := strings.Fields(lines[0])
switch len(parts) {
case 0:
return "", errors.New("Empty key")
case 1:
keyContent = parts[0]
case 2:
keyType = parts[0]
keyContent = parts[1]
default:
keyType = parts[0]
keyContent = parts[1]
keyComment = parts[2]
}
// If keyType is not given, extract it from content. If given, validate it
if len(keyType) == 0 {
if t, err := extractTypeFromBase64Key(keyContent); err == nil {
keyType = t
} else {
return "", err
}
} else {
if t, err := extractTypeFromBase64Key(keyContent); err != nil || keyType != t {
return "", err
}
}
} else {
// Parse SSH2 file format.
continuationLine := false
for _, line := range lines {
// Skip lines that:
// 1) are a continuation of the previous line,
// 2) contain ":" as that are comment lines
// 3) contain "-" as that are begin and end tags
if continuationLine || strings.ContainsAny(line, ":-") {
continuationLine = strings.HasSuffix(line, "\\")
} else {
keyContent = keyContent + line
}
}
if t, err := extractTypeFromBase64Key(keyContent); err == nil {
keyType = t
} else {
return "", err
}
}
return keyType + " " + keyContent + " " + keyComment, nil
}
// CheckPublicKeyString checks if the given public key string is recognized by SSH.
func CheckPublicKeyString(content string) (bool, error) {
content = strings.TrimRight(content, "\n\r")
if strings.ContainsAny(content, "\n\r") {
return false, errors.New("only a single line with a single key please")
}
// write the key to a file…
tmpFile, err := ioutil.TempFile(os.TempDir(), "keytest")
if err != nil {
return false, err
}
tmpPath := tmpFile.Name()
defer os.Remove(tmpPath)
tmpFile.WriteString(content)
tmpFile.Close()
// Check if ssh-keygen recognizes its contents.
stdout, stderr, err := process.Exec("CheckPublicKeyString", "ssh-keygen", "-l", "-f", tmpPath)
if err != nil {
return false, errors.New("ssh-keygen -l -f: " + stderr)
} else if len(stdout) < 2 {
return false, errors.New("ssh-keygen returned not enough output to evaluate the key: " + stdout)
}
// The ssh-keygen in Windows does not print key type, so no need go further.
if setting.IsWindows {
return true, nil
}
fmt.Println(stdout)
sshKeygenOutput := strings.Split(stdout, " ")
if len(sshKeygenOutput) < 4 {
return false, ErrKeyUnableVerify
}
// Check if key type and key size match.
keySize := com.StrTo(sshKeygenOutput[0]).MustInt()
if keySize == 0 {
return false, errors.New("cannot get key size of the given key")
}
keyType := strings.TrimSpace(sshKeygenOutput[len(sshKeygenOutput)-1])
if minimumKeySize := MinimumKeySize[keyType]; minimumKeySize == 0 {
return false, errors.New("sorry, unrecognized public key type")
} else if keySize < minimumKeySize {
return false, fmt.Errorf("the minimum accepted size of a public key %s is %d", keyType, minimumKeySize)
}
return true, nil
}
// saveAuthorizedKeyFile writes SSH key content to authorized_keys file.
func saveAuthorizedKeyFile(key *PublicKey) error {
sshOpLocker.Lock()
defer sshOpLocker.Unlock()
fpath := filepath.Join(SshPath, "authorized_keys")
f, err := os.OpenFile(fpath, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0600)
if err != nil {
return err
}
defer f.Close()
finfo, err := f.Stat()
if err != nil {
return err
}
// FIXME: following command does not support in Windows.
if !setting.IsWindows {
if finfo.Mode().Perm() > 0600 {
log.Error(4, "authorized_keys file has unusual permission flags: %s - setting to -rw-------", finfo.Mode().Perm().String())
if err = f.Chmod(0600); err != nil {
return err
}
}
}
_, err = f.WriteString(key.GetAuthorizedString())
return err
}
// AddPublicKey adds new public key to database and authorized_keys file.
func AddPublicKey(key *PublicKey) (err error) {
has, err := x.Get(key)
if err != nil {
return err
} else if has {
return ErrKeyAlreadyExist
}
// Calculate fingerprint.
tmpPath := strings.Replace(path.Join(os.TempDir(), fmt.Sprintf("%d", time.Now().Nanosecond()),
"id_rsa.pub"), "\\", "/", -1)
os.MkdirAll(path.Dir(tmpPath), os.ModePerm)
if err = ioutil.WriteFile(tmpPath, []byte(key.Content), os.ModePerm); err != nil {
return err
}
stdout, stderr, err := process.Exec("AddPublicKey", "ssh-keygen", "-l", "-f", tmpPath)
if err != nil {
return errors.New("ssh-keygen -l -f: " + stderr)
} else if len(stdout) < 2 {
return errors.New("not enough output for calculating fingerprint: " + stdout)
}
key.Fingerprint = strings.Split(stdout, " ")[1]
if has, err := x.Get(&PublicKey{Fingerprint: key.Fingerprint}); err == nil && has {
return ErrKeyAlreadyExist
}
// Save SSH key.
if _, err = x.Insert(key); err != nil {
return err
} else if err = saveAuthorizedKeyFile(key); err != nil {
// Roll back.
if _, err2 := x.Delete(key); err2 != nil {
return err2
}
return err
}
return nil
}
// GetPublicKeyById returns public key by given ID.
func GetPublicKeyById(keyId int64) (*PublicKey, error) {
key := new(PublicKey)
has, err := x.Id(keyId).Get(key)
if err != nil {
return nil, err
} else if !has {
return nil, ErrKeyNotExist
}
return key, nil
}
// ListPublicKeys returns a list of public keys belongs to given user.
func ListPublicKeys(uid int64) ([]*PublicKey, error) {
keys := make([]*PublicKey, 0, 5)
err := x.Where("owner_id=?", uid).Find(&keys)
if err != nil {
return nil, err
}
for _, key := range keys {
key.HasUsed = key.Updated.After(key.Created)
key.HasRecentActivity = key.Updated.Add(7 * 24 * time.Hour).After(time.Now())
}
return keys, nil
}
// rewriteAuthorizedKeys finds and deletes corresponding line in authorized_keys file.
func rewriteAuthorizedKeys(key *PublicKey, p, tmpP string) error {
sshOpLocker.Lock()
defer sshOpLocker.Unlock()
fr, err := os.Open(p)
if err != nil {
return err
}
defer fr.Close()
fw, err := os.OpenFile(tmpP, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0600)
if err != nil {
return err
}
defer fw.Close()
isFound := false
keyword := fmt.Sprintf("key-%d", key.Id)
buf := bufio.NewReader(fr)
for {
line, errRead := buf.ReadString('\n')
line = strings.TrimSpace(line)
if errRead != nil {
if errRead != io.EOF {
return errRead
}
// Reached end of file, if nothing to read then break,
// otherwise handle the last line.
if len(line) == 0 {
break
}
}
// Found the line and copy rest of file.
if !isFound && strings.Contains(line, keyword) && strings.Contains(line, key.Content) {
isFound = true
continue
}
// Still finding the line, copy the line that currently read.
if _, err = fw.WriteString(line + "\n"); err != nil {
return err
}
if errRead == io.EOF {
break
}
}
return nil
}
// UpdatePublicKey updates given public key.
func UpdatePublicKey(key *PublicKey) error {
_, err := x.Id(key.Id).AllCols().Update(key)
return err
}
// DeletePublicKey deletes SSH key information both in database and authorized_keys file.
func DeletePublicKey(key *PublicKey) error {
has, err := x.Get(key)
if err != nil {
return err
} else if !has {
return ErrKeyNotExist
}
if _, err = x.Delete(key); err != nil {
return err
}
fpath := filepath.Join(SshPath, "authorized_keys")
tmpPath := filepath.Join(SshPath, "authorized_keys.tmp")
if err = rewriteAuthorizedKeys(key, fpath, tmpPath); err != nil {
return err
} else if err = os.Remove(fpath); err != nil {
return err
}
return os.Rename(tmpPath, fpath)
}
|