forgejo/models/ssh_key.go

792 lines
21 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 (
"encoding/base64"
"encoding/binary"
"errors"
"fmt"
"io/ioutil"
"math/big"
"os"
"path"
"path/filepath"
"strings"
"sync"
"time"
"github.com/Unknwon/com"
"github.com/go-xorm/xorm"
"golang.org/x/crypto/ssh"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/process"
"code.gitea.io/gitea/modules/setting"
)
const (
tplPublicKey = `command="%s serv key-%d --config='%s'",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty %s` + "\n"
)
var sshOpLocker sync.Mutex
// KeyType specifies the key type
type KeyType int
const (
// KeyTypeUser specifies the user key
KeyTypeUser = iota + 1
// KeyTypeDeploy specifies the deploy key
KeyTypeDeploy
)
// PublicKey represents a user or deploy SSH public 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:"-"`
CreatedUnix int64
Updated time.Time `xorm:"-"` // Note: Updated must below Created for AfterSet.
UpdatedUnix int64
HasRecentActivity bool `xorm:"-"`
HasUsed bool `xorm:"-"`
}
// BeforeInsert will be invoked by XORM before inserting a record
func (key *PublicKey) BeforeInsert() {
key.CreatedUnix = time.Now().Unix()
}
// BeforeUpdate is invoked from XORM before updating this object.
func (key *PublicKey) BeforeUpdate() {
key.UpdatedUnix = time.Now().Unix()
}
// AfterSet is invoked from XORM after setting the value of a field of this object.
func (key *PublicKey) AfterSet(colName string, _ xorm.Cell) {
switch colName {
case "created_unix":
key.Created = time.Unix(key.CreatedUnix, 0).Local()
case "updated_unix":
key.Updated = time.Unix(key.UpdatedUnix, 0).Local()
key.HasUsed = key.Updated.After(key.Created)
key.HasRecentActivity = key.Updated.Add(7 * 24 * time.Hour).After(time.Now())
}
}
// OmitEmail returns content of public key without email address.
func (key *PublicKey) OmitEmail() string {
return strings.Join(strings.Split(key.Content, " ")[:2], " ")
}
// AuthorizedString returns formatted public key string for authorized_keys file.
func (key *PublicKey) AuthorizedString() string {
return fmt.Sprintf(tplPublicKey, 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 "", fmt.Errorf("invalid key format: %v", err)
}
keyLength := int(binary.BigEndian.Uint32(b))
if len(b) < 4+keyLength {
return "", fmt.Errorf("invalid key format: not enough length %d", keyLength)
}
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".
content = strings.NewReplacer("\r\n", "\n", "\r", "\n").Replace(content)
// remove trailing newline (and beginning spaces too)
content = strings.TrimSpace(content)
lines := strings.Split(content, "\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.
t, err := extractTypeFromBase64Key(keyContent)
if err != nil {
return "", fmt.Errorf("extractTypeFromBase64Key: %v", err)
}
if len(keyType) == 0 {
keyType = t
} else if keyType != t {
return "", fmt.Errorf("key type and content does not match: %s - %s", keyType, t)
}
} 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
}
}
t, err := extractTypeFromBase64Key(keyContent)
if err != nil {
return "", fmt.Errorf("extractTypeFromBase64Key: %v", err)
}
keyType = t
}
return keyType + " " + keyContent + " " + keyComment, nil
}
// writeTmpKeyFile writes key content to a temporary file
// and returns the name of that file, along with any possible errors.
func writeTmpKeyFile(content string) (string, error) {
tmpFile, err := ioutil.TempFile(setting.SSH.KeyTestPath, "gitea_keytest")
if err != nil {
return "", fmt.Errorf("TempFile: %v", err)
}
defer tmpFile.Close()
if _, err = tmpFile.WriteString(content); err != nil {
return "", fmt.Errorf("WriteString: %v", err)
}
return tmpFile.Name(), nil
}
// SSHKeyGenParsePublicKey extracts 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
}
tmpName, err := writeTmpKeyFile(key)
if err != nil {
return "", 0, fmt.Errorf("writeTmpKeyFile: %v", err)
}
defer os.Remove(tmpName)
stdout, stderr, err := process.GetManager().Exec("SSHKeyGenParsePublicKey", setting.SSH.KeygenPath, "-lf", tmpName)
if err != nil {
return "", 0, fmt.Errorf("fail to parse public key: %s - %s", err, stderr)
}
if strings.Contains(stdout, "is not a public key file") {
return "", 0, ErrKeyUnableVerify{stdout}
}
fields := strings.Split(stdout, " ")
if len(fields) < 4 {
return "", 0, fmt.Errorf("invalid public key line: %s", stdout)
}
keyType := strings.Trim(fields[len(fields)-1], "()\r\n")
return strings.ToLower(keyType), com.StrTo(fields[0]).MustInt(), nil
}
// SSHNativeParsePublicKey extracts the key type and length using the golang SSH library.
// NOTE: ed25519 is not supported.
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", keyLine)
}
raw, err := base64.StdEncoding.DecodeString(fields[1])
if err != nil {
return "", 0, err
}
pkey, err := ssh.ParsePublicKey(raw)
if err != nil {
if strings.Contains(err.Error(), "ssh: unknown key algorithm") {
return "", 0, ErrKeyUnableVerify{err.Error()}
}
return "", 0, fmt.Errorf("ParsePublicKey: %v", 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
}
return "", 0, fmt.Errorf("unsupported key length detection for type: %s", pkey.Type())
}
// CheckPublicKeyString checks if the given public key string is recognized by SSH.
// It returns the actual public key line on success.
func CheckPublicKeyString(content string) (_ string, err error) {
if setting.SSH.Disabled {
return "", errors.New("SSH is disabled")
}
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 (
fnName string
keyType string
length int
)
if setting.SSH.StartBuiltinServer {
fnName = "SSHNativeParsePublicKey"
keyType, length, err = SSHNativeParsePublicKey(content)
} else {
fnName = "SSHKeyGenParsePublicKey"
keyType, length, err = SSHKeyGenParsePublicKey(content)
}
if err != nil {
return "", fmt.Errorf("%s: %v", fnName, err)
}
log.Trace("Key info [native: %v]: %s-%d", setting.SSH.StartBuiltinServer, keyType, length)
if !setting.SSH.MinimumKeySizeCheck {
return content, nil
}
if minLen, found := setting.SSH.MinimumKeySizes[keyType]; found && length >= minLen {
return content, nil
} else if found && length < minLen {
return "", fmt.Errorf("key length is not enough: got %d, needs %d", length, minLen)
}
return "", fmt.Errorf("key type is not allowed: %s", keyType)
}
// appendAuthorizedKeysToFile appends new SSH keys' content to authorized_keys file.
func appendAuthorizedKeysToFile(keys ...*PublicKey) error {
sshOpLocker.Lock()
defer sshOpLocker.Unlock()
fpath := filepath.Join(setting.SSH.RootPath, "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()
// Note: chmod command does not support in Windows.
if !setting.IsWindows {
fi, err := f.Stat()
if err != nil {
return err
}
// .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.AuthorizedString()); err != nil {
return err
}
}
return nil
}
// checkKeyContent only 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: KeyTypeUser,
})
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)
dir := path.Dir(tmpPath)
if err := os.MkdirAll(dir, os.ModePerm); err != nil {
return fmt.Errorf("Fail to create dir %s: %v", dir, err)
}
if err = ioutil.WriteFile(tmpPath, []byte(key.Content), 0644); err != nil {
return err
}
stdout, stderr, err := process.GetManager().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.SSH.StartBuiltinServer {
return nil
}
return appendAuthorizedKeysToFile(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: AccessModeWrite,
Type: KeyTypeUser,
}
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)
}
// UpdatePublicKey updates given public key.
func UpdatePublicKey(key *PublicKey) error {
_, err := x.Id(key.ID).AllCols().Update(key)
return err
}
// deletePublicKeys does the actual key deletion but does not update authorized_keys file.
func deletePublicKeys(e *xorm.Session, keyIDs ...int64) error {
if len(keyIDs) == 0 {
return nil
}
_, err := e.In("id", keyIDs).Delete(new(PublicKey))
return err
}
// 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 = deletePublicKeys(sess, id); err != nil {
return err
}
if err = sess.Commit(); err != nil {
return err
}
return RewriteAllPublicKeys()
}
// RewriteAllPublicKeys removes any authorized key and rewrite all keys from database again.
// Note: x.Iterate does not get latest data after insert/delete, so we have to call this function
// outside any session scope independently.
func RewriteAllPublicKeys() error {
sshOpLocker.Lock()
defer sshOpLocker.Unlock()
fpath := filepath.Join(setting.SSH.RootPath, "authorized_keys")
tmpPath := fpath + ".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)).AuthorizedString())
return err
})
f.Close()
if err != nil {
return err
}
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:"-"`
CreatedUnix int64
Updated time.Time `xorm:"-"` // Note: Updated must below Created for AfterSet.
UpdatedUnix int64
HasRecentActivity bool `xorm:"-"`
HasUsed bool `xorm:"-"`
}
// BeforeInsert will be invoked by XORM before inserting a record
func (key *DeployKey) BeforeInsert() {
key.CreatedUnix = time.Now().Unix()
}
// BeforeUpdate is invoked from XORM before updating this object.
func (key *DeployKey) BeforeUpdate() {
key.UpdatedUnix = time.Now().Unix()
}
// AfterSet is invoked from XORM after setting the value of a field of this object.
func (key *DeployKey) AfterSet(colName string, _ xorm.Cell) {
switch colName {
case "created_unix":
key.Created = time.Unix(key.CreatedUnix, 0).Local()
case "updated_unix":
key.Updated = time.Unix(key.UpdatedUnix, 0).Local()
key.HasUsed = key.Updated.After(key.Created)
key.HasRecentActivity = key.Updated.Add(7 * 24 * time.Hour).After(time.Now())
}
}
// GetContent gets associated public key content.
func (key *DeployKey) GetContent() error {
pkey, err := GetPublicKeyByID(key.KeyID)
if err != nil {
return err
}
key.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: AccessModeRead,
Type: KeyTypeDeploy,
}
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, AccessModeAdmin)
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 = deletePublicKeys(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)
}