Files
mattermost/store/sql_store.go
Frank Denis 34d688ca72 SQL store: use authenticated encryption
Data were encrypted using AES-CFB, with a properly randomized IV,
but without any authenticators. This allows the data to be tampered
with, without being noticed by the application.

This diff slightly changes the encryption/decryption functions in
sql_store.go to add a HMAC-SHA256 authenticator to encrypted messages.

Two keys are derived from AtRestEncryptKey: the first half of
SHA512(AtRestEncryptKey) for the block cipher and the second half for
the MAC. This can be changed to a KDF if needed.

The decryption function also checks that base64 decoding actually
worked, and that the ciphertext is long enough to include the IV and
the MAC.

Unfortunately, it breaks backward compatibility. But if such a change
has to be made, it has to be made early.
2015-06-24 16:56:57 +02:00

399 lines
11 KiB
Go

// Copyright (c) 2015 Spinpunch, Inc. All Rights Reserved.
// See License.txt for license information.
package store
import (
l4g "code.google.com/p/log4go"
"crypto/aes"
"crypto/cipher"
"crypto/hmac"
"crypto/sha256"
"crypto/sha512"
crand "crypto/rand"
dbsql "database/sql"
"encoding/base64"
"encoding/json"
"errors"
"fmt"
"github.com/go-gorp/gorp"
_ "github.com/go-sql-driver/mysql"
"github.com/mattermost/platform/model"
"github.com/mattermost/platform/utils"
"io"
sqltrace "log"
"math/rand"
"os"
"time"
)
type SqlStore struct {
master *gorp.DbMap
replicas []*gorp.DbMap
team TeamStore
channel ChannelStore
post PostStore
user UserStore
audit AuditStore
session SessionStore
}
func NewSqlStore() Store {
sqlStore := &SqlStore{}
sqlStore.master = setupConnection("master", utils.Cfg.SqlSettings.DriverName,
utils.Cfg.SqlSettings.DataSource, utils.Cfg.SqlSettings.MaxIdleConns,
utils.Cfg.SqlSettings.MaxOpenConns, utils.Cfg.SqlSettings.Trace)
sqlStore.replicas = make([]*gorp.DbMap, len(utils.Cfg.SqlSettings.DataSourceReplicas))
for i, replica := range utils.Cfg.SqlSettings.DataSourceReplicas {
sqlStore.replicas[i] = setupConnection(fmt.Sprintf("replica-%v", i), utils.Cfg.SqlSettings.DriverName, replica,
utils.Cfg.SqlSettings.MaxIdleConns, utils.Cfg.SqlSettings.MaxOpenConns,
utils.Cfg.SqlSettings.Trace)
}
sqlStore.team = NewSqlTeamStore(sqlStore)
sqlStore.channel = NewSqlChannelStore(sqlStore)
sqlStore.post = NewSqlPostStore(sqlStore)
sqlStore.user = NewSqlUserStore(sqlStore)
sqlStore.audit = NewSqlAuditStore(sqlStore)
sqlStore.session = NewSqlSessionStore(sqlStore)
sqlStore.master.CreateTablesIfNotExists()
sqlStore.team.(*SqlTeamStore).CreateIndexesIfNotExists()
sqlStore.channel.(*SqlChannelStore).CreateIndexesIfNotExists()
sqlStore.post.(*SqlPostStore).CreateIndexesIfNotExists()
sqlStore.user.(*SqlUserStore).CreateIndexesIfNotExists()
sqlStore.audit.(*SqlAuditStore).CreateIndexesIfNotExists()
sqlStore.session.(*SqlSessionStore).CreateIndexesIfNotExists()
sqlStore.team.(*SqlTeamStore).UpgradeSchemaIfNeeded()
sqlStore.channel.(*SqlChannelStore).UpgradeSchemaIfNeeded()
sqlStore.post.(*SqlPostStore).UpgradeSchemaIfNeeded()
sqlStore.user.(*SqlUserStore).UpgradeSchemaIfNeeded()
sqlStore.audit.(*SqlAuditStore).UpgradeSchemaIfNeeded()
sqlStore.session.(*SqlSessionStore).UpgradeSchemaIfNeeded()
return sqlStore
}
func setupConnection(con_type string, driver string, dataSource string, maxIdle int, maxOpen int, trace bool) *gorp.DbMap {
db, err := dbsql.Open(driver, dataSource)
if err != nil {
l4g.Critical("Failed to open sql connection to '%v' err:%v", dataSource, err)
time.Sleep(time.Second)
panic("Failed to open sql connection" + err.Error())
}
l4g.Info("Pinging sql %v database at '%v'", con_type, dataSource)
err = db.Ping()
if err != nil {
l4g.Critical("Failed to ping db err:%v", err)
time.Sleep(time.Second)
panic("Failed to open sql connection " + err.Error())
}
db.SetMaxIdleConns(maxIdle)
db.SetMaxOpenConns(maxOpen)
var dbmap *gorp.DbMap
if driver == "sqlite3" {
dbmap = &gorp.DbMap{Db: db, TypeConverter: mattermConverter{}, Dialect: gorp.SqliteDialect{}}
} else if driver == "mysql" {
dbmap = &gorp.DbMap{Db: db, TypeConverter: mattermConverter{}, Dialect: gorp.MySQLDialect{Engine: "InnoDB", Encoding: "UTF8"}}
} else {
l4g.Critical("Failed to create dialect specific driver")
time.Sleep(time.Second)
panic("Failed to create dialect specific driver " + err.Error())
}
if trace {
dbmap.TraceOn("", sqltrace.New(os.Stdout, "sql-trace:", sqltrace.Lmicroseconds))
}
return dbmap
}
func (ss SqlStore) CreateColumnIfNotExists(tableName string, columnName string, afterName string, colType string, defaultValue string) bool {
count, err := ss.GetMaster().SelectInt(
`SELECT
COUNT(0) AS column_exists
FROM
information_schema.COLUMNS
WHERE
TABLE_SCHEMA = DATABASE()
AND TABLE_NAME = ?
AND COLUMN_NAME = ?`,
tableName,
columnName,
)
if err != nil {
l4g.Critical("Failed to check if column exists %v", err)
time.Sleep(time.Second)
panic("Failed to check if column exists " + err.Error())
}
if count > 0 {
return false
}
_, err = ss.GetMaster().Exec("ALTER TABLE " + tableName + " ADD " + columnName + " " + colType + " DEFAULT '" + defaultValue + "'" + " AFTER " + afterName)
if err != nil {
l4g.Critical("Failed to create column %v", err)
time.Sleep(time.Second)
panic("Failed to create column " + err.Error())
}
return true
}
func (ss SqlStore) RemoveColumnIfExists(tableName string, columnName string) bool {
count, err := ss.GetMaster().SelectInt(
`SELECT
COUNT(0) AS column_exists
FROM
information_schema.COLUMNS
WHERE
TABLE_SCHEMA = DATABASE()
AND TABLE_NAME = ?
AND COLUMN_NAME = ?`,
tableName,
columnName,
)
if err != nil {
l4g.Critical("Failed to check if column exists %v", err)
time.Sleep(time.Second)
panic("Failed to check if column exists " + err.Error())
}
if count == 0 {
return false
}
_, err = ss.GetMaster().Exec("ALTER TABLE " + tableName + " DROP COLUMN " + columnName)
if err != nil {
l4g.Critical("Failed to drop column %v", err)
time.Sleep(time.Second)
panic("Failed to drop column " + err.Error())
}
return true
}
func (ss SqlStore) CreateIndexIfNotExists(indexName string, tableName string, columnName string) {
ss.createIndexIfNotExists(indexName, tableName, columnName, false)
}
func (ss SqlStore) CreateFullTextIndexIfNotExists(indexName string, tableName string, columnName string) {
ss.createIndexIfNotExists(indexName, tableName, columnName, true)
}
func (ss SqlStore) createIndexIfNotExists(indexName string, tableName string, columnName string, fullText bool) {
count, err := ss.GetMaster().SelectInt("SELECT COUNT(0) AS index_exists FROM information_schema.statistics WHERE TABLE_SCHEMA = DATABASE() and table_name = ? AND index_name = ?", tableName, indexName)
if err != nil {
l4g.Critical("Failed to check index", err)
time.Sleep(time.Second)
panic("Failed to check index" + err.Error())
}
if count > 0 {
return
}
fullTextIndex := ""
if fullText {
fullTextIndex = " FULLTEXT "
}
_, err = ss.GetMaster().Exec("CREATE " + fullTextIndex + " INDEX " + indexName + " ON " + tableName + " (" + columnName + ")")
if err != nil {
l4g.Critical("Failed to create index", err)
time.Sleep(time.Second)
panic("Failed to create index " + err.Error())
}
}
func (ss SqlStore) GetMaster() *gorp.DbMap {
return ss.master
}
func (ss SqlStore) GetReplica() *gorp.DbMap {
return ss.replicas[rand.Intn(len(ss.replicas))]
}
func (ss SqlStore) GetAllConns() []*gorp.DbMap {
all := make([]*gorp.DbMap, len(ss.replicas)+1)
copy(all, ss.replicas)
all[len(ss.replicas)] = ss.master
return all
}
func (ss SqlStore) Close() {
l4g.Info("Closing SqlStore")
ss.master.Db.Close()
for _, replica := range ss.replicas {
replica.Db.Close()
}
}
func (ss SqlStore) Team() TeamStore {
return ss.team
}
func (ss SqlStore) Channel() ChannelStore {
return ss.channel
}
func (ss SqlStore) Post() PostStore {
return ss.post
}
func (ss SqlStore) User() UserStore {
return ss.user
}
func (ss SqlStore) Session() SessionStore {
return ss.session
}
func (ss SqlStore) Audit() AuditStore {
return ss.audit
}
type mattermConverter struct{}
func (me mattermConverter) ToDb(val interface{}) (interface{}, error) {
switch t := val.(type) {
case model.StringMap:
return model.MapToJson(t), nil
case model.StringArray:
return model.ArrayToJson(t), nil
case model.EncryptStringMap:
return encrypt([]byte(utils.Cfg.SqlSettings.AtRestEncryptKey), model.MapToJson(t))
}
return val, nil
}
func (me mattermConverter) FromDb(target interface{}) (gorp.CustomScanner, bool) {
switch target.(type) {
case *model.StringMap:
binder := func(holder, target interface{}) error {
s, ok := holder.(*string)
if !ok {
return errors.New("FromDb: Unable to convert StringMap to *string")
}
b := []byte(*s)
return json.Unmarshal(b, target)
}
return gorp.CustomScanner{new(string), target, binder}, true
case *model.StringArray:
binder := func(holder, target interface{}) error {
s, ok := holder.(*string)
if !ok {
return errors.New("FromDb: Unable to convert StringArray to *string")
}
b := []byte(*s)
return json.Unmarshal(b, target)
}
return gorp.CustomScanner{new(string), target, binder}, true
case *model.EncryptStringMap:
binder := func(holder, target interface{}) error {
s, ok := holder.(*string)
if !ok {
return errors.New("FromDb: Unable to convert EncryptStringMap to *string")
}
ue, err := decrypt([]byte(utils.Cfg.SqlSettings.AtRestEncryptKey), *s)
if err != nil {
return err
}
b := []byte(ue)
return json.Unmarshal(b, target)
}
return gorp.CustomScanner{new(string), target, binder}, true
}
return gorp.CustomScanner{}, false
}
func encrypt(key []byte, text string) (string, error) {
if text == "" || text == "{}" {
return "", nil
}
plaintext := []byte(text)
skey := sha512.Sum512(key)
ekey, akey := skey[:32], skey[32:]
block, err := aes.NewCipher(ekey)
if err != nil {
return "", err
}
macfn := hmac.New(sha256.New, akey)
ciphertext := make([]byte, aes.BlockSize+macfn.Size()+len(plaintext))
iv := ciphertext[:aes.BlockSize]
if _, err := io.ReadFull(crand.Reader, iv); err != nil {
return "", err
}
stream := cipher.NewCFBEncrypter(block, iv)
stream.XORKeyStream(ciphertext[aes.BlockSize+macfn.Size():], plaintext)
macfn.Write(ciphertext[aes.BlockSize+macfn.Size():])
mac := macfn.Sum(nil)
copy(ciphertext[aes.BlockSize:aes.BlockSize+macfn.Size()], mac)
return base64.URLEncoding.EncodeToString(ciphertext), nil
}
func decrypt(key []byte, cryptoText string) (string, error) {
if cryptoText == "" || cryptoText == "{}" {
return "{}", nil
}
ciphertext, err := base64.URLEncoding.DecodeString(cryptoText)
if err != nil {
return "", err
}
skey := sha512.Sum512(key)
ekey, akey := skey[:32], skey[32:]
macfn := hmac.New(sha256.New, akey)
if len(ciphertext) < aes.BlockSize+macfn.Size() {
return "", errors.New("short ciphertext")
}
macfn.Write(ciphertext[aes.BlockSize+macfn.Size():])
expectedMac := macfn.Sum(nil)
mac := ciphertext[aes.BlockSize:aes.BlockSize+macfn.Size()]
if hmac.Equal(expectedMac, mac) != true {
return "", errors.New("Incorrect MAC for the given ciphertext")
}
block, err := aes.NewCipher(ekey)
if err != nil {
return "", err
}
if len(ciphertext) < aes.BlockSize {
return "", errors.New("ciphertext too short")
}
iv := ciphertext[:aes.BlockSize]
ciphertext = ciphertext[aes.BlockSize+macfn.Size():]
stream := cipher.NewCFBDecrypter(block, iv)
stream.XORKeyStream(ciphertext, ciphertext)
return fmt.Sprintf("%s", ciphertext), nil
}