gitea/models/publickey.go
无闻 cd6376f093 Merge pull request #818 from fzerorubigd/master
add a function to rewrite all public keys on admin request
2015-02-01 16:56:34 -05:00

448 lines
11 KiB
Go

// 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(keys ...*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
}
}
}
for _, key := range keys {
_, err = f.WriteString(key.GetAuthorizedString())
if err != nil {
return err
}
}
return nil
}
// 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)
}
// RewriteAllPublicKeys remove any authorized key and re-write all key from database again
func RewriteAllPublicKeys() error {
keys := make([]*PublicKey, 0, 5)
err := x.Find(&keys)
if err != nil {
return err
}
fpath := filepath.Join(SshPath, "authorized_keys")
if _, err := os.Stat(fpath); os.IsNotExist(err) {
return saveAuthorizedKeyFile(keys...)
}
if err := os.Remove(fpath); err != nil {
return err
}
return saveAuthorizedKeyFile(keys...)
}