#2147 fix rewrites authorized_keys when builtin SSH server is enabled

2015-12-11 05:02:33 -05:00 · 2015-12-11 05:02:33 -05:00 · bc17f2f759
commit bc17f2f759
parent 40f3142264
1 changed files with 10 additions and 0 deletions
--- a/models/ssh_key.go
+++ b/models/ssh_key.go
@ -0,0 +1,725 @@
+// 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"
+	"path"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/Unknwon/com"
+	"github.com/go-xorm/xorm"
+
+	"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{}
+var SSHPath string // SSH directory.
+
+// 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() {
+	// Determine and create .ssh path.
+	SSHPath = filepath.Join(homeDir(), ".ssh")
+	if err := os.MkdirAll(SSHPath, 0700); err != nil {
+		log.Fatal(4, "fail to create '%s': %v", SSHPath, err)
+	}
+}
+
+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
+}
+
+// CheckPublicKeyString checks if the given public key string is recognized by SSH.
+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")
+	}
+
+	// write the key to a file…
+	tmpFile, err := ioutil.TempFile(os.TempDir(), "keytest")
+	if err != nil {
+		return "", 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", "-lf", tmpPath)
+	if err != nil {
+		return "", errors.New("ssh-keygen -lf: " + stderr)
+	} else if len(stdout) < 2 {
+		return "", 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 content, nil
+	}
+
+	sshKeygenOutput := strings.Split(stdout, " ")
+	if len(sshKeygenOutput) < 4 {
+		return content, ErrKeyUnableVerify{stdout}
+	}
+
+	// Check if key type and key size match.
+	if !setting.Service.DisableMinimumKeySizeCheck {
+		keySize := com.StrTo(sshKeygenOutput[0]).MustInt()
+		if keySize == 0 {
+			return "", errors.New("cannot get key size of the given key")
+		}
+
+		keyType := strings.Trim(sshKeygenOutput[len(sshKeygenOutput)-1], " ()\n")
+		if minimumKeySize := setting.Service.MinimumKeySizes[keyType]; minimumKeySize == 0 {
+			return "", fmt.Errorf("unrecognized public key type: %s", keyType)
+		} else if keySize < minimumKeySize {
+			return "", fmt.Errorf("the minimum accepted size of a public key %s is %d", keyType, minimumKeySize)
+		}
+	}
+
+	return content, 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()
+
+	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 errors.New("ssh-keygen -lf: " + 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) {
+	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
+		}
+	}
+	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(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)
+}
+
+// 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(SSHPath, "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(SSHPath, "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)
+}