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gitea/models/ssh_key.go
2016-02-23 15:39:05 +01:00

810 lines
22 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"
"math/big"
"os"
"path"
"path/filepath"
"strconv"
"strings"
"sync"
"time"
"github.com/Unknwon/com"
"github.com/go-xorm/xorm"
"golang.org/x/crypto/ssh"
"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 --config='%s'",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty %s` + "\n"
)
var (
sshOpLocker = sync.Mutex{}
SSHUnknownKeyType = fmt.Errorf("unknown key type")
)
type KeyType int
const (
KEY_TYPE_USER = iota + 1
KEY_TYPE_DEPLOY
)
// PublicKey represents a SSH or deploy key.
type PublicKey struct {
ID int64 `xorm:"pk autoincr"`
OwnerID int64 `xorm:"INDEX NOT NULL"`
Name string `xorm:"NOT NULL"`
Fingerprint string `xorm:"NOT NULL"`
Content string `xorm:"TEXT NOT NULL"`
Mode AccessMode `xorm:"NOT NULL DEFAULT 2"`
Type KeyType `xorm:"NOT NULL DEFAULT 1"`
Created time.Time `xorm:"CREATED"`
Updated time.Time // Note: Updated must below Created for AfterSet.
HasRecentActivity bool `xorm:"-"`
HasUsed bool `xorm:"-"`
}
func (k *PublicKey) AfterSet(colName string, _ xorm.Cell) {
switch colName {
case "created":
k.HasUsed = k.Updated.After(k.Created)
k.HasRecentActivity = k.Updated.Add(7 * 24 * time.Hour).After(time.Now())
}
}
// 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, setting.AppPath, key.ID, setting.CustomConf, key.Content)
}
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
}
// parseKeyString parses 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.SplitN(lines[0], " ", 3)
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
}
// extract key type and length using ssh-keygen
func SSHKeyGenParsePublicKey(key string) (string, int, error) {
// The ssh-keygen in Windows does not print key type, so no need go further.
if setting.IsWindows {
return "", 0, nil
}
tmpFile, err := ioutil.TempFile(setting.SSHWorkPath, "gogs_keytest")
if err != nil {
return "", 0, err
}
tmpName := tmpFile.Name()
defer os.Remove(tmpName)
if ln, err := tmpFile.WriteString(key); err != nil {
tmpFile.Close()
return "", 0, err
} else if ln != len(key) {
tmpFile.Close()
return "", 0, fmt.Errorf("could not write complete public key (written: %d, should be: %d): %s", ln, len(key), key)
}
tmpFile.Close()
stdout, stderr, err := process.Exec("CheckPublicKeyString", setting.SSHKeyGenPath, "-lf", tmpName)
if err != nil {
return "", 0, fmt.Errorf("public key check failed with error '%s': %s", err, stderr)
}
if strings.HasSuffix(stdout, "is not a public key file.") {
return "", 0, SSHUnknownKeyType
}
fields := strings.Split(stdout, " ")
if len(fields) < 4 {
return "", 0, fmt.Errorf("invalid public key line: %s", stdout)
}
length, err := strconv.Atoi(fields[0])
if err != nil {
return "", 0, err
}
keyType := strings.Trim(fields[len(fields)-1], "()\r\n")
return strings.ToLower(keyType), length, nil
}
// extract the key type and length using the golang ssh library
func SSHNativeParsePublicKey(keyLine string) (string, int, error) {
fields := strings.Fields(keyLine)
if len(fields) < 2 {
return "", 0, fmt.Errorf("not enough fields in public key line: %s", string(keyLine))
}
raw, err := base64.StdEncoding.DecodeString(fields[1])
if err != nil {
return "", 0, err
}
pkey, err := ssh.ParsePublicKey(raw)
if err != nil {
if strings.HasPrefix(err.Error(), "ssh: unknown key algorithm") {
return "", 0, SSHUnknownKeyType
}
return "", 0, err
}
// The ssh library can parse the key, so next we find out what key exactly we
// have.
switch pkey.Type() {
case ssh.KeyAlgoDSA:
rawPub := struct {
Name string
P, Q, G, Y *big.Int
}{}
if err := ssh.Unmarshal(pkey.Marshal(), &rawPub); err != nil {
return "", 0, err
}
// as per https://bugzilla.mindrot.org/show_bug.cgi?id=1647 we should never
// see dsa keys != 1024 bit, but as it seems to work, we will not check here
return "dsa", rawPub.P.BitLen(), nil // use P as per crypto/dsa/dsa.go (is L)
case ssh.KeyAlgoRSA:
rawPub := struct {
Name string
E *big.Int
N *big.Int
}{}
if err := ssh.Unmarshal(pkey.Marshal(), &rawPub); err != nil {
return "", 0, err
}
return "rsa", rawPub.N.BitLen(), nil // use N as per crypto/rsa/rsa.go (is bits)
case ssh.KeyAlgoECDSA256:
return "ecdsa", 256, nil
case ssh.KeyAlgoECDSA384:
return "ecdsa", 384, nil
case ssh.KeyAlgoECDSA521:
return "ecdsa", 521, nil
case "ssh-ed25519": // TODO replace with ssh constant when available
return "ed25519", 256, nil
default:
return "", 0, fmt.Errorf("no support for key length detection for type %s", pkey.Type())
}
return "", 0, fmt.Errorf("SSHNativeParsePublicKey failed horribly, please investigate why")
}
// CheckPublicKeyString checks if the given public key string is recognized by SSH.
//
// The function returns the actual public key line on success.
func CheckPublicKeyString(content string) (_ string, err error) {
content, err = parseKeyString(content)
if err != nil {
return "", err
}
content = strings.TrimRight(content, "\n\r")
if strings.ContainsAny(content, "\n\r") {
return "", errors.New("only a single line with a single key please")
}
// remove any unnecessary whitespace now
content = strings.TrimSpace(content)
var (
keyType string
length int
)
if setting.SSHPublicKeyCheck == setting.SSH_PUBLICKEY_CHECK_NATIVE {
keyType, length, err = SSHNativeParsePublicKey(content)
} else if setting.SSHPublicKeyCheck == setting.SSH_PUBLICKEY_CHECK_KEYGEN {
keyType, length, err = SSHKeyGenParsePublicKey(content)
} else {
log.Error(4, "invalid public key check type: %s", setting.SSHPublicKeyCheck)
return "", fmt.Errorf("invalid public key check type")
}
if err != nil {
log.Trace("invalid public key of type '%s' with length %d: %s", keyType, length, err)
return "", fmt.Errorf("ParsePublicKey: %v", err)
}
log.Trace("Key type: %s", keyType)
if !setting.Service.EnableMinimumKeySizeCheck {
return content, nil
}
if minLen, found := setting.Service.MinimumKeySizes[keyType]; found && length >= minLen {
return content, nil
} else if found && length < minLen {
return "", fmt.Errorf("key not large enough - got %d, needs %d", length, minLen)
}
return "", fmt.Errorf("key type '%s' is not allowed", keyType)
}
// saveAuthorizedKeyFile writes SSH key content to authorized_keys file.
func saveAuthorizedKeyFile(keys ...*PublicKey) error {
sshOpLocker.Lock()
defer sshOpLocker.Unlock()
fpath := filepath.Join(setting.SSHRootPath, "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()
fi, err := f.Stat()
if err != nil {
return err
}
// FIXME: following command does not support in Windows.
if !setting.IsWindows {
// .ssh directory should have mode 700, and authorized_keys file should have mode 600.
if fi.Mode().Perm() > 0600 {
log.Error(4, "authorized_keys file has unusual permission flags: %s - setting to -rw-------", fi.Mode().Perm().String())
if err = f.Chmod(0600); err != nil {
return err
}
}
}
for _, key := range keys {
if _, err = f.WriteString(key.GetAuthorizedString()); err != nil {
return err
}
}
return nil
}
// checkKeyContent onlys checks if key content has been used as public key,
// it is OK to use same key as deploy key for multiple repositories/users.
func checkKeyContent(content string) error {
has, err := x.Get(&PublicKey{
Content: content,
Type: KEY_TYPE_USER,
})
if err != nil {
return err
} else if has {
return ErrKeyAlreadyExist{0, content}
}
return nil
}
func addKey(e Engine, key *PublicKey) (err error) {
// 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), 0644); err != nil {
return err
}
stdout, stderr, err := process.Exec("AddPublicKey", "ssh-keygen", "-lf", tmpPath)
if err != nil {
return fmt.Errorf("'ssh-keygen -lf %s' failed with error '%s': %s", tmpPath, err, stderr)
} else if len(stdout) < 2 {
return errors.New("not enough output for calculating fingerprint: " + stdout)
}
key.Fingerprint = strings.Split(stdout, " ")[1]
// Save SSH key.
if _, err = e.Insert(key); err != nil {
return err
}
// Don't need to rewrite this file if builtin SSH server is enabled.
if setting.StartSSHServer {
return nil
}
return saveAuthorizedKeyFile(key)
}
// AddPublicKey adds new public key to database and authorized_keys file.
func AddPublicKey(ownerID int64, name, content string) (*PublicKey, error) {
log.Trace(content)
if err := checkKeyContent(content); err != nil {
return nil, err
}
// Key name of same user cannot be duplicated.
has, err := x.Where("owner_id=? AND name=?", ownerID, name).Get(new(PublicKey))
if err != nil {
return nil, err
} else if has {
return nil, ErrKeyNameAlreadyUsed{ownerID, name}
}
sess := x.NewSession()
defer sessionRelease(sess)
if err = sess.Begin(); err != nil {
return nil, err
}
key := &PublicKey{
OwnerID: ownerID,
Name: name,
Content: content,
Mode: ACCESS_MODE_WRITE,
Type: KEY_TYPE_USER,
}
if err = addKey(sess, key); err != nil {
return nil, fmt.Errorf("addKey: %v", err)
}
return key, sess.Commit()
}
// 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{keyID}
}
return key, nil
}
// SearchPublicKeyByContent searches content as prefix (leak e-mail part)
// and returns public key found.
func SearchPublicKeyByContent(content string) (*PublicKey, error) {
key := new(PublicKey)
has, err := x.Where("content like ?", content+"%").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)
return keys, x.Where("owner_id=?", uid).Find(&keys)
}
// rewriteAuthorizedKeys finds and deletes corresponding line in authorized_keys file.
func rewriteAuthorizedKeys(key *PublicKey, p, tmpP string) error {
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
}
}
if !isFound {
log.Warn("SSH key %d not found in authorized_keys file for deletion", key.ID)
}
return nil
}
// UpdatePublicKey updates given public key.
func UpdatePublicKey(key *PublicKey) error {
_, err := x.Id(key.ID).AllCols().Update(key)
return err
}
func deletePublicKey(e *xorm.Session, keyID int64) error {
sshOpLocker.Lock()
defer sshOpLocker.Unlock()
key := &PublicKey{ID: keyID}
has, err := e.Get(key)
if err != nil {
return err
} else if !has {
return nil
}
if _, err = e.Id(key.ID).Delete(new(PublicKey)); err != nil {
return err
}
// Don't need to rewrite this file if builtin SSH server is enabled.
if setting.StartSSHServer {
return nil
}
fpath := filepath.Join(setting.SSHRootPath, "authorized_keys")
tmpPath := filepath.Join(setting.SSHRootPath, "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)
}
// DeletePublicKey deletes SSH key information both in database and authorized_keys file.
func DeletePublicKey(doer *User, id int64) (err error) {
key, err := GetPublicKeyByID(id)
if err != nil {
if IsErrKeyNotExist(err) {
return nil
}
return fmt.Errorf("GetPublicKeyByID: %v", err)
}
// Check if user has access to delete this key.
if !doer.IsAdmin && doer.Id != key.OwnerID {
return ErrKeyAccessDenied{doer.Id, key.ID, "public"}
}
sess := x.NewSession()
defer sessionRelease(sess)
if err = sess.Begin(); err != nil {
return err
}
if err = deletePublicKey(sess, id); err != nil {
return err
}
return sess.Commit()
}
// RewriteAllPublicKeys removes any authorized key and rewrite all keys from database again.
func RewriteAllPublicKeys() error {
sshOpLocker.Lock()
defer sshOpLocker.Unlock()
tmpPath := filepath.Join(setting.SSHRootPath, "authorized_keys.tmp")
f, err := os.OpenFile(tmpPath, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
if err != nil {
return err
}
defer os.Remove(tmpPath)
err = x.Iterate(new(PublicKey), func(idx int, bean interface{}) (err error) {
_, err = f.WriteString((bean.(*PublicKey)).GetAuthorizedString())
return err
})
f.Close()
if err != nil {
return err
}
fpath := filepath.Join(setting.SSHRootPath, "authorized_keys")
if com.IsExist(fpath) {
if err = os.Remove(fpath); err != nil {
return err
}
}
if err = os.Rename(tmpPath, fpath); err != nil {
return err
}
return nil
}
// ________ .__ ____ __.
// \______ \ ____ ______ | | ____ ___.__.| |/ _|____ ___.__.
// | | \_/ __ \\____ \| | / _ < | || <_/ __ < | |
// | ` \ ___/| |_> > |_( <_> )___ || | \ ___/\___ |
// /_______ /\___ > __/|____/\____// ____||____|__ \___ > ____|
// \/ \/|__| \/ \/ \/\/
// DeployKey represents deploy key information and its relation with repository.
type DeployKey struct {
ID int64 `xorm:"pk autoincr"`
KeyID int64 `xorm:"UNIQUE(s) INDEX"`
RepoID int64 `xorm:"UNIQUE(s) INDEX"`
Name string
Fingerprint string
Content string `xorm:"-"`
Created time.Time `xorm:"CREATED"`
Updated time.Time // Note: Updated must below Created for AfterSet.
HasRecentActivity bool `xorm:"-"`
HasUsed bool `xorm:"-"`
}
func (k *DeployKey) AfterSet(colName string, _ xorm.Cell) {
switch colName {
case "created":
k.HasUsed = k.Updated.After(k.Created)
k.HasRecentActivity = k.Updated.Add(7 * 24 * time.Hour).After(time.Now())
}
}
// GetContent gets associated public key content.
func (k *DeployKey) GetContent() error {
pkey, err := GetPublicKeyByID(k.KeyID)
if err != nil {
return err
}
k.Content = pkey.Content
return nil
}
func checkDeployKey(e Engine, keyID, repoID int64, name string) error {
// Note: We want error detail, not just true or false here.
has, err := e.Where("key_id=? AND repo_id=?", keyID, repoID).Get(new(DeployKey))
if err != nil {
return err
} else if has {
return ErrDeployKeyAlreadyExist{keyID, repoID}
}
has, err = e.Where("repo_id=? AND name=?", repoID, name).Get(new(DeployKey))
if err != nil {
return err
} else if has {
return ErrDeployKeyNameAlreadyUsed{repoID, name}
}
return nil
}
// addDeployKey adds new key-repo relation.
func addDeployKey(e *xorm.Session, keyID, repoID int64, name, fingerprint string) (*DeployKey, error) {
if err := checkDeployKey(e, keyID, repoID, name); err != nil {
return nil, err
}
key := &DeployKey{
KeyID: keyID,
RepoID: repoID,
Name: name,
Fingerprint: fingerprint,
}
_, err := e.Insert(key)
return key, err
}
// HasDeployKey returns true if public key is a deploy key of given repository.
func HasDeployKey(keyID, repoID int64) bool {
has, _ := x.Where("key_id=? AND repo_id=?", keyID, repoID).Get(new(DeployKey))
return has
}
// AddDeployKey add new deploy key to database and authorized_keys file.
func AddDeployKey(repoID int64, name, content string) (*DeployKey, error) {
if err := checkKeyContent(content); err != nil {
return nil, err
}
pkey := &PublicKey{
Content: content,
Mode: ACCESS_MODE_READ,
Type: KEY_TYPE_DEPLOY,
}
has, err := x.Get(pkey)
if err != nil {
return nil, err
}
sess := x.NewSession()
defer sessionRelease(sess)
if err = sess.Begin(); err != nil {
return nil, err
}
// First time use this deploy key.
if !has {
if err = addKey(sess, pkey); err != nil {
return nil, fmt.Errorf("addKey: %v", err)
}
}
key, err := addDeployKey(sess, pkey.ID, repoID, name, pkey.Fingerprint)
if err != nil {
return nil, fmt.Errorf("addDeployKey: %v", err)
}
return key, sess.Commit()
}
// GetDeployKeyByID returns deploy key by given ID.
func GetDeployKeyByID(id int64) (*DeployKey, error) {
key := new(DeployKey)
has, err := x.Id(id).Get(key)
if err != nil {
return nil, err
} else if !has {
return nil, ErrDeployKeyNotExist{id, 0, 0}
}
return key, nil
}
// GetDeployKeyByRepo returns deploy key by given public key ID and repository ID.
func GetDeployKeyByRepo(keyID, repoID int64) (*DeployKey, error) {
key := &DeployKey{
KeyID: keyID,
RepoID: repoID,
}
has, err := x.Get(key)
if err != nil {
return nil, err
} else if !has {
return nil, ErrDeployKeyNotExist{0, keyID, repoID}
}
return key, nil
}
// UpdateDeployKey updates deploy key information.
func UpdateDeployKey(key *DeployKey) error {
_, err := x.Id(key.ID).AllCols().Update(key)
return err
}
// DeleteDeployKey deletes deploy key from its repository authorized_keys file if needed.
func DeleteDeployKey(doer *User, id int64) error {
key, err := GetDeployKeyByID(id)
if err != nil {
if IsErrDeployKeyNotExist(err) {
return nil
}
return fmt.Errorf("GetDeployKeyByID: %v", err)
}
// Check if user has access to delete this key.
if !doer.IsAdmin {
repo, err := GetRepositoryByID(key.RepoID)
if err != nil {
return fmt.Errorf("GetRepositoryByID: %v", err)
}
yes, err := HasAccess(doer, repo, ACCESS_MODE_ADMIN)
if err != nil {
return fmt.Errorf("HasAccess: %v", err)
} else if !yes {
return ErrKeyAccessDenied{doer.Id, key.ID, "deploy"}
}
}
sess := x.NewSession()
defer sessionRelease(sess)
if err = sess.Begin(); err != nil {
return err
}
if _, err = sess.Id(key.ID).Delete(new(DeployKey)); err != nil {
return fmt.Errorf("delete deploy key[%d]: %v", key.ID, err)
}
// Check if this is the last reference to same key content.
has, err := sess.Where("key_id=?", key.KeyID).Get(new(DeployKey))
if err != nil {
return err
} else if !has {
if err = deletePublicKey(sess, key.KeyID); err != nil {
return err
}
}
return sess.Commit()
}
// ListDeployKeys returns all deploy keys by given repository ID.
func ListDeployKeys(repoID int64) ([]*DeployKey, error) {
keys := make([]*DeployKey, 0, 5)
return keys, x.Where("repo_id=?", repoID).Find(&keys)
}