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// mgo - MongoDB driver for Go
//
// Copyright (c) 2010-2012 - Gustavo Niemeyer <gustavo@niemeyer.net>
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this
// list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
package mgo
import (
"crypto/md5"
"crypto/sha1"
"encoding/hex"
"errors"
"fmt"
"sync"
"gopkg.in/mgo.v2/bson"
"gopkg.in/mgo.v2/internal/scram"
)
type authCmd struct {
Authenticate int
Nonce string
User string
Key string
}
type startSaslCmd struct {
StartSASL int `bson:"startSasl"`
}
type authResult struct {
ErrMsg string
Ok bool
}
type getNonceCmd struct {
GetNonce int
}
type getNonceResult struct {
Nonce string
Err string "$err"
Code int
}
type logoutCmd struct {
Logout int
}
type saslCmd struct {
Start int `bson:"saslStart,omitempty"`
Continue int `bson:"saslContinue,omitempty"`
ConversationId int `bson:"conversationId,omitempty"`
Mechanism string `bson:"mechanism,omitempty"`
Payload []byte
}
type saslResult struct {
Ok bool `bson:"ok"`
NotOk bool `bson:"code"` // Server <= 2.3.2 returns ok=1 & code>0 on errors (WTF?)
Done bool
ConversationId int `bson:"conversationId"`
Payload []byte
ErrMsg string
}
type saslStepper interface {
Step(serverData []byte) (clientData []byte, done bool, err error)
Close()
}
func (socket *mongoSocket) getNonce() (nonce string, err error) {
socket.Lock()
for socket.cachedNonce == "" && socket.dead == nil {
debugf("Socket %p to %s: waiting for nonce", socket, socket.addr)
socket.gotNonce.Wait()
}
if socket.cachedNonce == "mongos" {
socket.Unlock()
return "", errors.New("Can't authenticate with mongos; see http://j.mp/mongos-auth")
}
debugf("Socket %p to %s: got nonce", socket, socket.addr)
nonce, err = socket.cachedNonce, socket.dead
socket.cachedNonce = ""
socket.Unlock()
if err != nil {
nonce = ""
}
return
}
func (socket *mongoSocket) resetNonce() {
debugf("Socket %p to %s: requesting a new nonce", socket, socket.addr)
op := &queryOp{}
op.query = &getNonceCmd{GetNonce: 1}
op.collection = "admin.$cmd"
op.limit = -1
op.replyFunc = func(err error, reply *replyOp, docNum int, docData []byte) {
if err != nil {
socket.kill(errors.New("getNonce: "+err.Error()), true)
return
}
result := &getNonceResult{}
err = bson.Unmarshal(docData, &result)
if err != nil {
socket.kill(errors.New("Failed to unmarshal nonce: "+err.Error()), true)
return
}
debugf("Socket %p to %s: nonce unmarshalled: %#v", socket, socket.addr, result)
if result.Code == 13390 {
// mongos doesn't yet support auth (see http://j.mp/mongos-auth)
result.Nonce = "mongos"
} else if result.Nonce == "" {
var msg string
if result.Err != "" {
msg = fmt.Sprintf("Got an empty nonce: %s (%d)", result.Err, result.Code)
} else {
msg = "Got an empty nonce"
}
socket.kill(errors.New(msg), true)
return
}
socket.Lock()
if socket.cachedNonce != "" {
socket.Unlock()
panic("resetNonce: nonce already cached")
}
socket.cachedNonce = result.Nonce
socket.gotNonce.Signal()
socket.Unlock()
}
err := socket.Query(op)
if err != nil {
socket.kill(errors.New("resetNonce: "+err.Error()), true)
}
}
func (socket *mongoSocket) Login(cred Credential) error {
socket.Lock()
if cred.Mechanism == "" && socket.serverInfo.MaxWireVersion >= 3 {
cred.Mechanism = "SCRAM-SHA-1"
}
for _, sockCred := range socket.creds {
if sockCred == cred {
debugf("Socket %p to %s: login: db=%q user=%q (already logged in)", socket, socket.addr, cred.Source, cred.Username)
socket.Unlock()
return nil
}
}
if socket.dropLogout(cred) {
debugf("Socket %p to %s: login: db=%q user=%q (cached)", socket, socket.addr, cred.Source, cred.Username)
socket.creds = append(socket.creds, cred)
socket.Unlock()
return nil
}
socket.Unlock()
debugf("Socket %p to %s: login: db=%q user=%q", socket, socket.addr, cred.Source, cred.Username)
var err error
switch cred.Mechanism {
case "", "MONGODB-CR", "MONGO-CR": // Name changed to MONGODB-CR in SERVER-8501.
err = socket.loginClassic(cred)
case "PLAIN":
err = socket.loginPlain(cred)
case "MONGODB-X509":
err = socket.loginX509(cred)
default:
// Try SASL for everything else, if it is available.
err = socket.loginSASL(cred)
}
if err != nil {
debugf("Socket %p to %s: login error: %s", socket, socket.addr, err)
} else {
debugf("Socket %p to %s: login successful", socket, socket.addr)
}
return err
}
func (socket *mongoSocket) loginClassic(cred Credential) error {
// Note that this only works properly because this function is
// synchronous, which means the nonce won't get reset while we're
// using it and any other login requests will block waiting for a
// new nonce provided in the defer call below.
nonce, err := socket.getNonce()
if err != nil {
return err
}
defer socket.resetNonce()
psum := md5.New()
psum.Write([]byte(cred.Username + ":mongo:" + cred.Password))
ksum := md5.New()
ksum.Write([]byte(nonce + cred.Username))
ksum.Write([]byte(hex.EncodeToString(psum.Sum(nil))))
key := hex.EncodeToString(ksum.Sum(nil))
cmd := authCmd{Authenticate: 1, User: cred.Username, Nonce: nonce, Key: key}
res := authResult{}
return socket.loginRun(cred.Source, &cmd, &res, func() error {
if !res.Ok {
return errors.New(res.ErrMsg)
}
socket.Lock()
socket.dropAuth(cred.Source)
socket.creds = append(socket.creds, cred)
socket.Unlock()
return nil
})
}
type authX509Cmd struct {
Authenticate int
User string
Mechanism string
}
func (socket *mongoSocket) loginX509(cred Credential) error {
cmd := authX509Cmd{Authenticate: 1, User: cred.Username, Mechanism: "MONGODB-X509"}
res := authResult{}
return socket.loginRun(cred.Source, &cmd, &res, func() error {
if !res.Ok {
return errors.New(res.ErrMsg)
}
socket.Lock()
socket.dropAuth(cred.Source)
socket.creds = append(socket.creds, cred)
socket.Unlock()
return nil
})
}
func (socket *mongoSocket) loginPlain(cred Credential) error {
cmd := saslCmd{Start: 1, Mechanism: "PLAIN", Payload: []byte("\x00" + cred.Username + "\x00" + cred.Password)}
res := authResult{}
return socket.loginRun(cred.Source, &cmd, &res, func() error {
if !res.Ok {
return errors.New(res.ErrMsg)
}
socket.Lock()
socket.dropAuth(cred.Source)
socket.creds = append(socket.creds, cred)
socket.Unlock()
return nil
})
}
func (socket *mongoSocket) loginSASL(cred Credential) error {
var sasl saslStepper
var err error
if cred.Mechanism == "SCRAM-SHA-1" {
// SCRAM is handled without external libraries.
sasl = saslNewScram(cred)
} else if len(cred.ServiceHost) > 0 {
sasl, err = saslNew(cred, cred.ServiceHost)
} else {
sasl, err = saslNew(cred, socket.Server().Addr)
}
if err != nil {
return err
}
defer sasl.Close()
// The goal of this logic is to carry a locked socket until the
// local SASL step confirms the auth is valid; the socket needs to be
// locked so that concurrent action doesn't leave the socket in an
// auth state that doesn't reflect the operations that took place.
// As a simple case, imagine inverting login=>logout to logout=>login.
//
// The logic below works because the lock func isn't called concurrently.
locked := false
lock := func(b bool) {
if locked != b {
locked = b
if b {
socket.Lock()
} else {
socket.Unlock()
}
}
}
lock(true)
defer lock(false)
start := 1
cmd := saslCmd{}
res := saslResult{}
for {
payload, done, err := sasl.Step(res.Payload)
if err != nil {
return err
}
if done && res.Done {
socket.dropAuth(cred.Source)
socket.creds = append(socket.creds, cred)
break
}
lock(false)
cmd = saslCmd{
Start: start,
Continue: 1 - start,
ConversationId: res.ConversationId,
Mechanism: cred.Mechanism,
Payload: payload,
}
start = 0
err = socket.loginRun(cred.Source, &cmd, &res, func() error {
// See the comment on lock for why this is necessary.
lock(true)
if !res.Ok || res.NotOk {
return fmt.Errorf("server returned error on SASL authentication step: %s", res.ErrMsg)
}
return nil
})
if err != nil {
return err
}
if done && res.Done {
socket.dropAuth(cred.Source)
socket.creds = append(socket.creds, cred)
break
}
}
return nil
}
func saslNewScram(cred Credential) *saslScram {
credsum := md5.New()
credsum.Write([]byte(cred.Username + ":mongo:" + cred.Password))
client := scram.NewClient(sha1.New, cred.Username, hex.EncodeToString(credsum.Sum(nil)))
return &saslScram{cred: cred, client: client}
}
type saslScram struct {
cred Credential
client *scram.Client
}
func (s *saslScram) Close() {}
func (s *saslScram) Step(serverData []byte) (clientData []byte, done bool, err error) {
more := s.client.Step(serverData)
return s.client.Out(), !more, s.client.Err()
}
func (socket *mongoSocket) loginRun(db string, query, result interface{}, f func() error) error {
var mutex sync.Mutex
var replyErr error
mutex.Lock()
op := queryOp{}
op.query = query
op.collection = db + ".$cmd"
op.limit = -1
op.replyFunc = func(err error, reply *replyOp, docNum int, docData []byte) {
defer mutex.Unlock()
if err != nil {
replyErr = err
return
}
err = bson.Unmarshal(docData, result)
if err != nil {
replyErr = err
} else {
// Must handle this within the read loop for the socket, so
// that concurrent login requests are properly ordered.
replyErr = f()
}
}
err := socket.Query(&op)
if err != nil {
return err
}
mutex.Lock() // Wait.
return replyErr
}
func (socket *mongoSocket) Logout(db string) {
socket.Lock()
cred, found := socket.dropAuth(db)
if found {
debugf("Socket %p to %s: logout: db=%q (flagged)", socket, socket.addr, db)
socket.logout = append(socket.logout, cred)
}
socket.Unlock()
}
func (socket *mongoSocket) LogoutAll() {
socket.Lock()
if l := len(socket.creds); l > 0 {
debugf("Socket %p to %s: logout all (flagged %d)", socket, socket.addr, l)
socket.logout = append(socket.logout, socket.creds...)
socket.creds = socket.creds[0:0]
}
socket.Unlock()
}
func (socket *mongoSocket) flushLogout() (ops []interface{}) {
socket.Lock()
if l := len(socket.logout); l > 0 {
debugf("Socket %p to %s: logout all (flushing %d)", socket, socket.addr, l)
for i := 0; i != l; i++ {
op := queryOp{}
op.query = &logoutCmd{1}
op.collection = socket.logout[i].Source + ".$cmd"
op.limit = -1
ops = append(ops, &op)
}
socket.logout = socket.logout[0:0]
}
socket.Unlock()
return
}
func (socket *mongoSocket) dropAuth(db string) (cred Credential, found bool) {
for i, sockCred := range socket.creds {
if sockCred.Source == db {
copy(socket.creds[i:], socket.creds[i+1:])
socket.creds = socket.creds[:len(socket.creds)-1]
return sockCred, true
}
}
return cred, false
}
func (socket *mongoSocket) dropLogout(cred Credential) (found bool) {
for i, sockCred := range socket.logout {
if sockCred == cred {
copy(socket.logout[i:], socket.logout[i+1:])
socket.logout = socket.logout[:len(socket.logout)-1]
return true
}
}
return false
}