status-go/services/shhext/chat/sql_lite_persistence.go

969 lines
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package chat
import (
"crypto/ecdsa"
"database/sql"
"fmt"
"os"
"strings"
"github.com/ethereum/go-ethereum/crypto"
_ "github.com/mutecomm/go-sqlcipher" // We require go sqlcipher that overrides default implementation
dr "github.com/status-im/doubleratchet"
"github.com/status-im/migrate"
"github.com/status-im/migrate/database/sqlcipher"
"github.com/status-im/migrate/source/go_bindata"
ecrypto "github.com/status-im/status-go/services/shhext/chat/crypto"
"github.com/status-im/status-go/services/shhext/chat/migrations"
)
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
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// A safe max number of rows
const maxNumberOfRows = 100000000
// SQLLitePersistence represents a persistence service tied to an SQLite database
type SQLLitePersistence struct {
db *sql.DB
keysStorage dr.KeysStorage
sessionStorage dr.SessionStorage
}
// SQLLiteKeysStorage represents a keys persistence service tied to an SQLite database
type SQLLiteKeysStorage struct {
db *sql.DB
}
// SQLLiteSessionStorage represents a session persistence service tied to an SQLite database
type SQLLiteSessionStorage struct {
db *sql.DB
}
// NewSQLLitePersistence creates a new SQLLitePersistence instance, given a path and a key
func NewSQLLitePersistence(path string, key string) (*SQLLitePersistence, error) {
s := &SQLLitePersistence{}
if err := s.Open(path, key); err != nil {
return nil, err
}
s.keysStorage = NewSQLLiteKeysStorage(s.db)
s.sessionStorage = NewSQLLiteSessionStorage(s.db)
return s, nil
}
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func MigrateDBFile(oldPath string, newPath string, oldKey string, newKey string) error {
_, err := os.Stat(oldPath)
// No files, nothing to do
if os.IsNotExist(err) {
return nil
}
// Any other error, throws
if err != nil {
return err
}
if err := os.Rename(oldPath, newPath); err != nil {
return err
}
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db, err := openDB(newPath, oldKey)
if err != nil {
return err
}
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keyString := fmt.Sprintf("PRAGMA rekey = '%s'", newKey)
if _, err = db.Exec(keyString); err != nil {
return err
}
return nil
}
func openDB(path string, key string) (*sql.DB, error) {
db, err := sql.Open("sqlite3", path)
if err != nil {
return nil, err
}
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keyString := fmt.Sprintf("PRAGMA key = '%s'", key)
// 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
}
if _, err = db.Exec(keyString); err != nil {
return nil, err
}
if _, err = db.Exec("PRAGMA cypher_page_size=4096"); err != nil {
return nil, err
}
return db, nil
}
// NewSQLLiteKeysStorage creates a new SQLLiteKeysStorage instance associated with the specified database
func NewSQLLiteKeysStorage(db *sql.DB) *SQLLiteKeysStorage {
return &SQLLiteKeysStorage{
db: db,
}
}
// NewSQLLiteSessionStorage creates a new SQLLiteSessionStorage instance associated with the specified database
func NewSQLLiteSessionStorage(db *sql.DB) *SQLLiteSessionStorage {
return &SQLLiteSessionStorage{
db: db,
}
}
// GetKeysStorage returns the associated double ratchet KeysStorage object
func (s *SQLLitePersistence) GetKeysStorage() dr.KeysStorage {
return s.keysStorage
}
// GetSessionStorage returns the associated double ratchet SessionStorage object
func (s *SQLLitePersistence) GetSessionStorage() dr.SessionStorage {
return s.sessionStorage
}
// Open opens a file at the specified path
func (s *SQLLitePersistence) Open(path string, key string) error {
db, err := openDB(path, key)
if err != nil {
return err
}
s.db = db
return s.setup()
}
// AddPrivateBundle adds the specified BundleContainer to the database
func (s *SQLLitePersistence) AddPrivateBundle(bc *BundleContainer) error {
tx, err := s.db.Begin()
if err != nil {
return err
}
for installationID, signedPreKey := range bc.GetBundle().GetSignedPreKeys() {
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
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var version uint32
stmt, err := tx.Prepare(`SELECT version
FROM bundles
WHERE installation_id = ? AND identity = ?
ORDER BY version DESC
LIMIT 1`)
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
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if err != nil {
return err
}
defer stmt.Close()
err = stmt.QueryRow(installationID, bc.GetBundle().GetIdentity()).Scan(&version)
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
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if err != nil && err != sql.ErrNoRows {
return err
}
stmt, err = tx.Prepare(`INSERT INTO bundles(identity, private_key, signed_pre_key, installation_id, version, timestamp)
VALUES(?, ?, ?, ?, ?, ?)`)
if err != nil {
return err
}
defer stmt.Close()
_, err = stmt.Exec(
bc.GetBundle().GetIdentity(),
bc.GetPrivateSignedPreKey(),
signedPreKey.GetSignedPreKey(),
installationID,
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
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version+1,
bc.GetBundle().GetTimestamp(),
)
if err != nil {
_ = tx.Rollback()
return err
}
}
if err := tx.Commit(); err != nil {
_ = tx.Rollback()
return err
}
return nil
}
// AddPublicBundle adds the specified Bundle to the database
func (s *SQLLitePersistence) AddPublicBundle(b *Bundle) error {
tx, err := s.db.Begin()
if err != nil {
return err
}
for installationID, signedPreKeyContainer := range b.GetSignedPreKeys() {
signedPreKey := signedPreKeyContainer.GetSignedPreKey()
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
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version := signedPreKeyContainer.GetVersion()
insertStmt, err := tx.Prepare(`INSERT INTO bundles(identity, signed_pre_key, installation_id, version, timestamp)
VALUES( ?, ?, ?, ?, ?)`)
if err != nil {
return err
}
defer insertStmt.Close()
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
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_, err = insertStmt.Exec(
b.GetIdentity(),
signedPreKey,
installationID,
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
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version,
b.GetTimestamp(),
)
if err != nil {
_ = tx.Rollback()
return err
}
// Mark old bundles as expired
updateStmt, err := tx.Prepare(`UPDATE bundles
SET expired = 1
WHERE identity = ? AND installation_id = ? AND version < ?`)
if err != nil {
return err
}
defer updateStmt.Close()
_, err = updateStmt.Exec(
b.GetIdentity(),
installationID,
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
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version,
)
if err != nil {
_ = tx.Rollback()
return err
}
}
return tx.Commit()
}
// GetAnyPrivateBundle retrieves any bundle from the database containing a private key
func (s *SQLLitePersistence) GetAnyPrivateBundle(myIdentityKey []byte, installationIDs []string) (*BundleContainer, error) {
/* #nosec */
statement := `SELECT identity, private_key, signed_pre_key, installation_id, timestamp, version
FROM bundles
WHERE expired = 0 AND identity = ? AND installation_id IN (?` + strings.Repeat(",?", len(installationIDs)-1) + ")"
stmt, err := s.db.Prepare(statement)
if err != nil {
return nil, err
}
defer stmt.Close()
var timestamp int64
var identity []byte
var privateKey []byte
var version uint32
args := make([]interface{}, len(installationIDs)+1)
args[0] = myIdentityKey
for i, installationID := range installationIDs {
args[i+1] = installationID
}
rows, err := stmt.Query(args...)
rowCount := 0
if err != nil {
return nil, err
}
defer rows.Close()
bundle := &Bundle{
SignedPreKeys: make(map[string]*SignedPreKey),
}
bundleContainer := &BundleContainer{
Bundle: bundle,
}
for rows.Next() {
var signedPreKey []byte
var installationID string
rowCount++
err = rows.Scan(
&identity,
&privateKey,
&signedPreKey,
&installationID,
&timestamp,
&version,
)
if err != nil {
return nil, err
}
// If there is a private key, we set the timestamp of the bundle container
if privateKey != nil {
bundle.Timestamp = timestamp
}
bundle.SignedPreKeys[installationID] = &SignedPreKey{SignedPreKey: signedPreKey, Version: version}
bundle.Identity = identity
}
// If no records are found or no record with private key, return nil
if rowCount == 0 || bundleContainer.GetBundle().Timestamp == 0 {
return nil, nil
}
return bundleContainer, nil
}
// GetPrivateKeyBundle retrieves a private key for a bundle from the database
func (s *SQLLitePersistence) GetPrivateKeyBundle(bundleID []byte) ([]byte, error) {
stmt, err := s.db.Prepare(`SELECT private_key
FROM bundles
WHERE expired = 0 AND signed_pre_key = ? LIMIT 1`)
if err != nil {
return nil, err
}
defer stmt.Close()
var privateKey []byte
err = stmt.QueryRow(bundleID).Scan(&privateKey)
switch err {
case sql.ErrNoRows:
return nil, nil
case nil:
return privateKey, nil
default:
return nil, err
}
}
// MarkBundleExpired expires any private bundle for a given identity
func (s *SQLLitePersistence) MarkBundleExpired(identity []byte) error {
stmt, err := s.db.Prepare(`UPDATE bundles
SET expired = 1
WHERE identity = ? AND private_key IS NOT NULL`)
if err != nil {
return err
}
defer stmt.Close()
_, err = stmt.Exec(identity)
return err
}
// GetPublicBundle retrieves an existing Bundle for the specified public key from the database
func (s *SQLLitePersistence) GetPublicBundle(publicKey *ecdsa.PublicKey, installationIDs []string) (*Bundle, error) {
if len(installationIDs) == 0 {
return nil, nil
}
identity := crypto.CompressPubkey(publicKey)
/* #nosec */
statement := `SELECT signed_pre_key,installation_id, version
FROM bundles
WHERE expired = 0 AND identity = ? AND installation_id IN (?` + strings.Repeat(",?", len(installationIDs)-1) + `)
ORDER BY version DESC`
stmt, err := s.db.Prepare(statement)
if err != nil {
return nil, err
}
defer stmt.Close()
args := make([]interface{}, len(installationIDs)+1)
args[0] = identity
for i, installationID := range installationIDs {
args[i+1] = installationID
}
rows, err := stmt.Query(args...)
rowCount := 0
if err != nil {
return nil, err
}
defer rows.Close()
bundle := &Bundle{
Identity: identity,
SignedPreKeys: make(map[string]*SignedPreKey),
}
for rows.Next() {
var signedPreKey []byte
var installationID string
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
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var version uint32
rowCount++
err = rows.Scan(
&signedPreKey,
&installationID,
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
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&version,
)
if err != nil {
return nil, err
}
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
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bundle.SignedPreKeys[installationID] = &SignedPreKey{
SignedPreKey: signedPreKey,
Version: version,
}
}
if rowCount == 0 {
return nil, nil
}
return bundle, nil
}
// AddRatchetInfo persists the specified ratchet info into the database
func (s *SQLLitePersistence) AddRatchetInfo(key []byte, identity []byte, bundleID []byte, ephemeralKey []byte, installationID string) error {
stmt, err := s.db.Prepare(`INSERT INTO ratchet_info_v2(symmetric_key, identity, bundle_id, ephemeral_key, installation_id)
VALUES(?, ?, ?, ?, ?)`)
if err != nil {
return err
}
defer stmt.Close()
_, err = stmt.Exec(
key,
identity,
bundleID,
ephemeralKey,
installationID,
)
return err
}
// GetRatchetInfo retrieves the existing RatchetInfo for a specified bundle ID and interlocutor public key from the database
func (s *SQLLitePersistence) GetRatchetInfo(bundleID []byte, theirIdentity []byte, installationID string) (*RatchetInfo, error) {
stmt, err := s.db.Prepare(`SELECT ratchet_info_v2.identity, ratchet_info_v2.symmetric_key, bundles.private_key, bundles.signed_pre_key, ratchet_info_v2.ephemeral_key, ratchet_info_v2.installation_id
FROM ratchet_info_v2 JOIN bundles ON bundle_id = signed_pre_key
WHERE ratchet_info_v2.identity = ? AND ratchet_info_v2.installation_id = ? AND bundle_id = ?
LIMIT 1`)
if err != nil {
return nil, err
}
defer stmt.Close()
ratchetInfo := &RatchetInfo{
BundleID: bundleID,
}
err = stmt.QueryRow(theirIdentity, installationID, bundleID).Scan(
&ratchetInfo.Identity,
&ratchetInfo.Sk,
&ratchetInfo.PrivateKey,
&ratchetInfo.PublicKey,
&ratchetInfo.EphemeralKey,
&ratchetInfo.InstallationID,
)
switch err {
case sql.ErrNoRows:
return nil, nil
case nil:
ratchetInfo.ID = append(bundleID, []byte(ratchetInfo.InstallationID)...)
return ratchetInfo, nil
default:
return nil, err
}
}
// GetAnyRatchetInfo retrieves any existing RatchetInfo for a specified interlocutor public key from the database
func (s *SQLLitePersistence) GetAnyRatchetInfo(identity []byte, installationID string) (*RatchetInfo, error) {
stmt, err := s.db.Prepare(`SELECT symmetric_key, bundles.private_key, signed_pre_key, bundle_id, ephemeral_key
FROM ratchet_info_v2 JOIN bundles ON bundle_id = signed_pre_key
WHERE expired = 0 AND ratchet_info_v2.identity = ? AND ratchet_info_v2.installation_id = ?
LIMIT 1`)
if err != nil {
return nil, err
}
defer stmt.Close()
ratchetInfo := &RatchetInfo{
Identity: identity,
InstallationID: installationID,
}
err = stmt.QueryRow(identity, installationID).Scan(
&ratchetInfo.Sk,
&ratchetInfo.PrivateKey,
&ratchetInfo.PublicKey,
&ratchetInfo.BundleID,
&ratchetInfo.EphemeralKey,
)
switch err {
case sql.ErrNoRows:
return nil, nil
case nil:
ratchetInfo.ID = append(ratchetInfo.BundleID, []byte(installationID)...)
return ratchetInfo, nil
default:
return nil, err
}
}
// RatchetInfoConfirmed clears the ephemeral key in the RatchetInfo
// associated with the specified bundle ID and interlocutor identity public key
func (s *SQLLitePersistence) RatchetInfoConfirmed(bundleID []byte, theirIdentity []byte, installationID string) error {
stmt, err := s.db.Prepare(`UPDATE ratchet_info_v2
SET ephemeral_key = NULL
WHERE identity = ? AND bundle_id = ? AND installation_id = ?`)
if err != nil {
return err
}
defer stmt.Close()
_, err = stmt.Exec(
theirIdentity,
bundleID,
installationID,
)
return err
}
// Get retrieves the message key for a specified public key and message number
func (s *SQLLiteKeysStorage) Get(pubKey dr.Key, msgNum uint) (dr.Key, bool, error) {
var keyBytes []byte
var key [32]byte
stmt, err := s.db.Prepare(`SELECT message_key
FROM keys
WHERE public_key = ? AND msg_num = ?
LIMIT 1`)
if err != nil {
return key, false, err
}
defer stmt.Close()
err = stmt.QueryRow(pubKey[:], msgNum).Scan(&keyBytes)
switch err {
case sql.ErrNoRows:
return key, false, nil
case nil:
copy(key[:], keyBytes)
return key, true, nil
default:
return key, false, err
}
}
// Put stores a key with the specified public key, message number and message key
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
2018-11-05 19:00:04 +00:00
func (s *SQLLiteKeysStorage) Put(sessionID []byte, pubKey dr.Key, msgNum uint, mk dr.Key, seqNum uint) error {
stmt, err := s.db.Prepare(`INSERT INTO keys(session_id, public_key, msg_num, message_key, seq_num)
VALUES(?, ?, ?, ?, ?)`)
if err != nil {
return err
}
defer stmt.Close()
_, err = stmt.Exec(
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
2018-11-05 19:00:04 +00:00
sessionID,
pubKey[:],
msgNum,
mk[:],
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
2018-11-05 19:00:04 +00:00
seqNum,
)
return err
}
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
2018-11-05 19:00:04 +00:00
// DeleteOldMks caps remove any key < seq_num, included
func (s *SQLLiteKeysStorage) DeleteOldMks(sessionID []byte, deleteUntil uint) error {
stmt, err := s.db.Prepare(`DELETE FROM keys
WHERE session_id = ? AND seq_num <= ?`)
if err != nil {
return err
}
defer stmt.Close()
_, err = stmt.Exec(
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
2018-11-05 19:00:04 +00:00
sessionID,
deleteUntil,
)
return err
}
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
2018-11-05 19:00:04 +00:00
// TruncateMks caps the number of keys to maxKeysPerSession deleting them in FIFO fashion
func (s *SQLLiteKeysStorage) TruncateMks(sessionID []byte, maxKeysPerSession int) error {
stmt, err := s.db.Prepare(`DELETE FROM keys
WHERE rowid IN (SELECT rowid FROM keys WHERE session_id = ? ORDER BY seq_num DESC LIMIT ? OFFSET ?)`)
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
2018-11-05 19:00:04 +00:00
if err != nil {
return err
}
defer stmt.Close()
_, err = stmt.Exec(
sessionID,
// We LIMIT to the max number of rows here, as OFFSET can't be used without a LIMIT
maxNumberOfRows,
maxKeysPerSession,
)
return err
}
// DeleteMk deletes the key with the specified public key and message key
func (s *SQLLiteKeysStorage) DeleteMk(pubKey dr.Key, msgNum uint) error {
stmt, err := s.db.Prepare(`DELETE FROM keys
WHERE public_key = ? AND msg_num = ?`)
if err != nil {
return err
}
defer stmt.Close()
_, err = stmt.Exec(
pubKey[:],
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
2018-11-05 19:00:04 +00:00
msgNum,
)
return err
}
// Count returns the count of keys with the specified public key
func (s *SQLLiteKeysStorage) Count(pubKey dr.Key) (uint, error) {
stmt, err := s.db.Prepare(`SELECT COUNT(1)
FROM keys
WHERE public_key = ?`)
if err != nil {
return 0, err
}
defer stmt.Close()
var count uint
err = stmt.QueryRow(pubKey[:]).Scan(&count)
if err != nil {
return 0, err
}
return count, nil
}
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
2018-11-05 19:00:04 +00:00
// CountAll returns the count of keys with the specified public key
func (s *SQLLiteKeysStorage) CountAll() (uint, error) {
stmt, err := s.db.Prepare(`SELECT COUNT(1)
FROM keys`)
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
2018-11-05 19:00:04 +00:00
if err != nil {
return 0, err
}
defer stmt.Close()
var count uint
err = stmt.QueryRow().Scan(&count)
if err != nil {
return 0, err
}
return count, nil
}
// All returns nil
func (s *SQLLiteKeysStorage) All() (map[dr.Key]map[uint]dr.Key, error) {
return nil, nil
}
// Save persists the specified double ratchet state
func (s *SQLLiteSessionStorage) Save(id []byte, state *dr.State) error {
dhr := state.DHr[:]
dhs := state.DHs
dhsPublic := dhs.PublicKey()
dhsPrivate := dhs.PrivateKey()
pn := state.PN
step := state.Step
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
2018-11-05 19:00:04 +00:00
keysCount := state.KeysCount
rootChainKey := state.RootCh.CK[:]
sendChainKey := state.SendCh.CK[:]
sendChainN := state.SendCh.N
recvChainKey := state.RecvCh.CK[:]
recvChainN := state.RecvCh.N
stmt, err := s.db.Prepare(`INSERT INTO sessions(id, dhr, dhs_public, dhs_private, root_chain_key, send_chain_key, send_chain_n, recv_chain_key, recv_chain_n, pn, step, keys_count)
VALUES(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`)
if err != nil {
return err
}
defer stmt.Close()
_, err = stmt.Exec(
id,
dhr,
dhsPublic[:],
dhsPrivate[:],
rootChainKey,
sendChainKey,
sendChainN,
recvChainKey,
recvChainN,
pn,
step,
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
2018-11-05 19:00:04 +00:00
keysCount,
)
return err
}
// Load retrieves the double ratchet state for a given ID
func (s *SQLLiteSessionStorage) Load(id []byte) (*dr.State, error) {
stmt, err := s.db.Prepare(`SELECT dhr, dhs_public, dhs_private, root_chain_key, send_chain_key, send_chain_n, recv_chain_key, recv_chain_n, pn, step, keys_count
FROM sessions
WHERE id = ?`)
if err != nil {
return nil, err
}
defer stmt.Close()
var (
dhr []byte
dhsPublic []byte
dhsPrivate []byte
rootChainKey []byte
sendChainKey []byte
sendChainN uint
recvChainKey []byte
recvChainN uint
pn uint
step uint
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
2018-11-05 19:00:04 +00:00
keysCount uint
)
err = stmt.QueryRow(id).Scan(
&dhr,
&dhsPublic,
&dhsPrivate,
&rootChainKey,
&sendChainKey,
&sendChainN,
&recvChainKey,
&recvChainN,
&pn,
&step,
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
2018-11-05 19:00:04 +00:00
&keysCount,
)
switch err {
case sql.ErrNoRows:
return nil, nil
case nil:
state := dr.DefaultState(toKey(rootChainKey))
state.PN = uint32(pn)
state.Step = step
Change handling of skipped/deleted keys & add version (#1261) - Skipped keys The purpose of limiting the number of skipped keys generated is to avoid a dos attack whereby an attacker would send a large N, forcing the device to compute all the keys between currentN..N . Previously the logic for handling skipped keys was: - If in the current receiving chain there are more than maxSkip keys, throw an error This is problematic as in long-lived session dropped/unreceived messages starts piling up, eventually reaching the threshold (1000 dropped/unreceived messages). This logic has been changed to be more inline with signals spec, and now it is: - If N is > currentN + maxSkip, throw an error The purpose of limiting the number of skipped keys stored is to avoid a dos attack whereby an attacker would force us to store a large number of keys, filling up our storage. Previously the logic for handling old keys was: - Once you have maxKeep ratchet steps, delete any key from currentRatchet - maxKeep. This, in combination with the maxSkip implementation, capped the number of stored keys to maxSkip * maxKeep. The logic has been changed to: - Keep a maximum of MaxMessageKeysPerSession and additionally we delete any key that has a sequence number < currentSeqNum - maxKeep - Version We check now the version of the bundle so that when we get a bundle from the same installationID with a higher version, we mark the previous bundle as expired and use the new bundle the next time a message is sent
2018-11-05 19:00:04 +00:00
state.KeysCount = keysCount
state.DHs = ecrypto.DHPair{
PrvKey: toKey(dhsPrivate),
PubKey: toKey(dhsPublic),
}
state.DHr = toKey(dhr)
state.SendCh.CK = toKey(sendChainKey)
state.SendCh.N = uint32(sendChainN)
state.RecvCh.CK = toKey(recvChainKey)
state.RecvCh.N = uint32(recvChainN)
return &state, nil
default:
return nil, err
}
}
// GetActiveInstallations returns the active installations for a given identity
func (s *SQLLitePersistence) GetActiveInstallations(maxInstallations int, identity []byte) ([]string, error) {
stmt, err := s.db.Prepare(`SELECT installation_id
FROM installations
WHERE enabled = 1 AND identity = ?
ORDER BY timestamp DESC
LIMIT ?`)
if err != nil {
return nil, err
}
var installations []string
rows, err := stmt.Query(identity, maxInstallations)
if err != nil {
return nil, err
}
for rows.Next() {
var installationID string
err = rows.Scan(
&installationID,
)
if err != nil {
return nil, err
}
installations = append(installations, installationID)
}
return installations, nil
}
// AddInstallations adds the installations for a given identity, maintaining the enabled flag
func (s *SQLLitePersistence) AddInstallations(identity []byte, timestamp int64, installationIDs []string, defaultEnabled bool) error {
tx, err := s.db.Begin()
if err != nil {
return nil
}
for _, installationID := range installationIDs {
stmt, err := tx.Prepare(`SELECT enabled
FROM installations
WHERE identity = ? AND installation_id = ?
LIMIT 1`)
if err != nil {
return err
}
defer stmt.Close()
var oldEnabled bool
err = stmt.QueryRow(identity, installationID).Scan(&oldEnabled)
if err != nil && err != sql.ErrNoRows {
return err
}
// We update timestamp if present without changing enabled
if err != sql.ErrNoRows {
stmt, err = tx.Prepare(`UPDATE installations
SET timestamp = ?, enabled = ?
WHERE identity = ? AND installation_id = ?`)
if err != nil {
return err
}
_, err = stmt.Exec(
timestamp,
oldEnabled,
identity,
installationID,
)
if err != nil {
return err
}
defer stmt.Close()
} else {
stmt, err = tx.Prepare(`INSERT INTO installations(identity, installation_id, timestamp, enabled)
VALUES (?, ?, ?, ?)`)
if err != nil {
return err
}
_, err = stmt.Exec(
identity,
installationID,
timestamp,
defaultEnabled,
)
if err != nil {
return err
}
defer stmt.Close()
}
}
if err := tx.Commit(); err != nil {
_ = tx.Rollback()
return err
}
return nil
}
// EnableInstallation enables the installation
func (s *SQLLitePersistence) EnableInstallation(identity []byte, installationID string) error {
stmt, err := s.db.Prepare(`UPDATE installations
SET enabled = 1
WHERE identity = ? AND installation_id = ?`)
if err != nil {
return err
}
_, err = stmt.Exec(identity, installationID)
return err
}
// DisableInstallation disable the installation
func (s *SQLLitePersistence) DisableInstallation(identity []byte, installationID string) error {
stmt, err := s.db.Prepare(`UPDATE installations
SET enabled = 0
WHERE identity = ? AND installation_id = ?`)
if err != nil {
return err
}
_, err = stmt.Exec(identity, installationID)
return err
}
func toKey(a []byte) dr.Key {
var k [32]byte
copy(k[:], a)
return k
}
func (s *SQLLitePersistence) setup() error {
resources := bindata.Resource(
migrations.AssetNames(),
func(name string) ([]byte, error) {
return migrations.Asset(name)
},
)
source, err := bindata.WithInstance(resources)
if err != nil {
return err
}
driver, err := sqlcipher.WithInstance(s.db, &sqlcipher.Config{})
if err != nil {
return err
}
m, err := migrate.NewWithInstance(
"go-bindata",
source,
"sqlcipher",
driver)
if err != nil {
return err
}
if err = m.Up(); err != migrate.ErrNoChange {
return err
}
return nil
}