sqlite/sqlite.go
package sqlite
import (
"database/sql"
"database/sql/driver"
"errors"
"fmt"
"net/url"
"os"
"runtime"
"strings"
sqlcipher "github.com/mutecomm/go-sqlcipher/v4" // We require go sqlcipher that overrides default implementation
"github.com/status-im/status-go/common/dbsetup"
)
const (
// The reduced number of kdf iterations (for performance reasons) which is
// used as the default value
// https://github.com/status-im/status-go/pull/1343
// https://notes.status.im/i8Y_l7ccTiOYq09HVgoFwA
ReducedKDFIterationsNumber = 3200
// WALMode for sqlite.
WALMode = "wal"
InMemoryPath = ":memory:"
V4CipherPageSize = 8192
V3CipherPageSize = 1024
sqlMainDatabase = "main"
)
// DecryptDB completely removes the encryption from the db
func DecryptDB(oldPath string, newPath string, key string, kdfIterationsNumber int) error {
db, err := openDB(oldPath, key, kdfIterationsNumber, V4CipherPageSize)
if err != nil {
return err
}
_, err = db.Exec(`ATTACH DATABASE '` + newPath + `' AS plaintext KEY ''`)
if err != nil {
return err
}
_, err = db.Exec(`SELECT sqlcipher_export('plaintext')`)
if err != nil {
return err
}
_, err = db.Exec(`DETACH DATABASE plaintext`)
return err
}
func encryptDB(db *sql.DB, encryptedPath string, key string, kdfIterationsNumber int, onStart func(), onEnd func()) error {
if onStart != nil {
onStart()
}
if onEnd != nil {
defer onEnd()
}
attachedDbName := "encrypted"
err := attachDatabaseWithDefaultSettings(db, encryptedPath, attachedDbName, key, kdfIterationsNumber)
if err != nil {
return err
}
_, err = db.Exec(fmt.Sprintf(`SELECT sqlcipher_export('%s')`, attachedDbName))
if err != nil {
return err
}
_, err = db.Exec(fmt.Sprintf(`DETACH DATABASE %s`, attachedDbName))
return err
}
func attachDatabaseWithDefaultSettings(db *sql.DB, attachedDbPath string, attachedDbName string, key string, kdfIterationsNumber int) error {
_, err := db.Exec(fmt.Sprintf(`ATTACH DATABASE '%s' AS %s KEY '%s'`, attachedDbPath, attachedDbName, key))
if err != nil {
return err
}
if kdfIterationsNumber <= 0 {
kdfIterationsNumber = dbsetup.ReducedKDFIterationsNumber
}
if _, err := db.Exec(fmt.Sprintf(`PRAGMA %s.busy_timeout = 60000`, attachedDbName)); err != nil {
return errors.New("failed to set `busy_timeout` pragma on attached db")
}
return setDatabaseCipherSettings(db, kdfIterationsNumber, attachedDbName)
}
func setDatabaseCipherSettings(db *sql.DB, kdfIterationsNumber int, dbNameOpt ...string) error {
dbName := sqlMainDatabase
if len(dbNameOpt) > 0 {
dbName = dbNameOpt[0]
}
_, err := db.Exec(fmt.Sprintf("PRAGMA %s.kdf_iter = '%d'", dbName, kdfIterationsNumber))
if err != nil {
return err
}
if _, err := db.Exec(fmt.Sprintf("PRAGMA %s.cipher_page_size = %d", dbName, V4CipherPageSize)); err != nil {
fmt.Println("failed to set cipher_page_size pragma")
return err
}
if _, err := db.Exec(fmt.Sprintf("PRAGMA %s.cipher_hmac_algorithm = HMAC_SHA1", dbName)); err != nil {
fmt.Println("failed to set cipher_hmac_algorithm pragma")
return err
}
if _, err := db.Exec(fmt.Sprintf("PRAGMA %s.cipher_kdf_algorithm = PBKDF2_HMAC_SHA1", dbName)); err != nil {
fmt.Println("failed to set cipher_kdf_algorithm pragma")
return err
}
return nil
}
// EncryptDB takes a plaintext database and adds encryption
func EncryptDB(unencryptedPath string, encryptedPath string, key string, kdfIterationsNumber int, onStart func(), onEnd func()) error {
_ = os.Remove(encryptedPath)
db, err := OpenUnecryptedDB(unencryptedPath)
if err != nil {
return err
}
return encryptDB(db, encryptedPath, key, kdfIterationsNumber, onStart, onEnd)
}
// Export takes an encrypted database and re-encrypts it in a new file, with a new key
func ExportDB(encryptedPath string, key string, kdfIterationsNumber int, newPath string, newKey string, onStart func(), onEnd func()) error {
db, err := openDB(encryptedPath, key, kdfIterationsNumber, V4CipherPageSize)
if err != nil {
return err
}
defer db.Close()
return encryptDB(db, newPath, newKey, kdfIterationsNumber, onStart, onEnd)
}
func buildSqlcipherDSN(path string) (string, error) {
if path == InMemoryPath {
return InMemoryPath, nil
}
// Adding sqlcipher query parameter to the DSN
queryOperator := "?"
if queryStart := strings.IndexRune(path, '?'); queryStart != -1 {
params, err := url.ParseQuery(path[queryStart+1:])
if err != nil {
return "", err
}
if len(params) > 0 {
queryOperator = "&"
}
}
// We need to set txlock=immediate to avoid "database is locked" errors during concurrent write operations
// This could happen when a read transaction is promoted to write transaction
// https://www.sqlite.org/lang_transaction.html
return path + queryOperator + "_txlock=immediate", nil
}
func openDB(path string, key string, kdfIterationsNumber int, cipherPageSize int) (*sql.DB, error) {
driverName := fmt.Sprintf("sqlcipher_with_extensions-%d", len(sql.Drivers()))
sql.Register(driverName, &sqlcipher.SQLiteDriver{
ConnectHook: func(conn *sqlcipher.SQLiteConn) error {
if _, err := conn.Exec("PRAGMA foreign_keys=ON", []driver.Value{}); err != nil {
return errors.New("failed to set `foreign_keys` pragma")
}
if _, err := conn.Exec(fmt.Sprintf("PRAGMA key = '%s'", key), []driver.Value{}); err != nil {
return errors.New("failed to set `key` pragma")
}
if kdfIterationsNumber <= 0 {
kdfIterationsNumber = dbsetup.ReducedKDFIterationsNumber
}
if _, err := conn.Exec(fmt.Sprintf("PRAGMA cipher_page_size = %d", cipherPageSize), nil); err != nil {
fmt.Println("failed to set cipher_page_size pragma")
return err
}
if _, err := conn.Exec("PRAGMA cipher_hmac_algorithm = HMAC_SHA1", nil); err != nil {
fmt.Println("failed to set cipher_hmac_algorithm pragma")
return err
}
if _, err := conn.Exec("PRAGMA cipher_kdf_algorithm = PBKDF2_HMAC_SHA1", nil); err != nil {
fmt.Println("failed to set cipher_kdf_algorithm pragma")
return err
}
if _, err := conn.Exec(fmt.Sprintf("PRAGMA kdf_iter = '%d'", kdfIterationsNumber), []driver.Value{}); err != nil {
return errors.New("failed to set `kdf_iter` pragma")
}
// readers do not block writers and faster i/o operations
if _, err := conn.Exec("PRAGMA journal_mode=WAL", []driver.Value{}); err != nil && path != InMemoryPath {
return fmt.Errorf("failed to set `journal_mode` pragma: %w", err)
}
// workaround to mitigate the issue of "database is locked" errors during concurrent write operations
if _, err := conn.Exec("PRAGMA busy_timeout=60000", []driver.Value{}); err != nil {
return errors.New("failed to set `busy_timeout` pragma")
}
return nil
},
})
dsn, err := buildSqlcipherDSN(path)
if err != nil {
return nil, err
}
db, err := sql.Open(driverName, dsn)
if err != nil {
return nil, err
}
if path == InMemoryPath {
db.SetMaxOpenConns(1)
} else {
nproc := func() int {
maxProcs := runtime.GOMAXPROCS(0)
numCPU := runtime.NumCPU()
if maxProcs < numCPU {
return maxProcs
}
return numCPU
}()
db.SetMaxOpenConns(nproc)
db.SetMaxIdleConns(nproc)
}
// Dummy select to check if the key is correct. Will return last error from initialization
if _, err := db.Exec("SELECT 'Key check'"); err != nil {
db.Close()
return nil, err
}
return db, nil
}
// OpenDB opens encrypted database.
func OpenDB(path string, key string, kdfIterationsNumber int) (*sql.DB, error) {
return openDB(path, key, kdfIterationsNumber, V4CipherPageSize)
}
// OpenUnecryptedDB opens database with setting PRAGMA key.
func OpenUnecryptedDB(path string) (*sql.DB, error) {
db, err := sql.Open("sqlite3", path)
if err != nil {
return nil, err
}
// Disable concurrent access as not supported by the driver
db.SetMaxOpenConns(1)
if _, err = db.Exec("PRAGMA foreign_keys=ON"); err != nil {
return nil, err
}
// readers do not block writers and faster i/o operations
// https://www.sqlite.org/draft/wal.html
// must be set after db is encrypted
if path != InMemoryPath {
var mode string
err = db.QueryRow("PRAGMA journal_mode=WAL").Scan(&mode)
if err != nil {
return nil, err
}
if mode != WALMode {
return nil, fmt.Errorf("unable to set journal_mode to WAL. actual mode %s", mode)
}
}
return db, nil
}
func ChangeEncryptionKey(path string, key string, kdfIterationsNumber int, newKey string, onStart func(), onEnd func()) error {
if onStart != nil {
onStart()
}
if onEnd != nil {
defer onEnd()
}
if kdfIterationsNumber <= 0 {
kdfIterationsNumber = dbsetup.ReducedKDFIterationsNumber
}
db, err := openDB(path, key, kdfIterationsNumber, V4CipherPageSize)
if err != nil {
return err
}
resetKeyString := fmt.Sprintf("PRAGMA rekey = '%s'", newKey)
if _, err = db.Exec(resetKeyString); err != nil {
return errors.New("failed to set rekey pragma")
}
return nil
}
// MigrateV3ToV4 migrates database from v3 to v4 format with encryption.
func MigrateV3ToV4(v3Path string, v4Path string, key string, kdfIterationsNumber int, onStart func(), onEnd func()) error {
db, err := openDB(v3Path, key, kdfIterationsNumber, V3CipherPageSize)
if err != nil {
fmt.Println("failed to open db", err)
return err
}
defer db.Close()
return encryptDB(db, v4Path, key, kdfIterationsNumber, onStart, onEnd)
}