mautrix-signal/pkg/libsignalgo/backupkey.go

141 lines
4.1 KiB
Go

// mautrix-signal - A Matrix-signal puppeting bridge.
// Copyright (C) 2025 Tulir Asokan
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <https://www.gnu.org/licenses/>.
package libsignalgo
/*
#include "./libsignal-ffi.h"
*/
import "C"
import (
"runtime"
"unsafe"
"go.mau.fi/util/random"
)
type BackupKey [C.SignalBACKUP_KEY_LEN]byte
func (bk *BackupKey) Slice() []byte {
if bk == nil {
return nil
}
return bk[:]
}
const BackupIDLength = 16
type BackupID [BackupIDLength]byte
type BackupMetadataKey [C.SignalLOCAL_BACKUP_METADATA_KEY_LEN]byte
type BackupMediaID [C.SignalMEDIA_ID_LEN]byte
type BackupMediaKey [C.SignalMEDIA_ENCRYPTION_KEY_LEN]byte
func GenerateRandomBackupKey() *BackupKey {
return (*BackupKey)(random.Bytes(C.SignalBACKUP_KEY_LEN))
}
func BytesToBackupKey(bytes []byte) *BackupKey {
if len(bytes) != C.SignalBACKUP_KEY_LEN {
return nil
}
return (*BackupKey)(bytes)
}
func (bk *BackupKey) DeriveBackupID(aci ServiceID) (*BackupID, error) {
var out BackupID
signalFfiError := C.signal_backup_key_derive_backup_id(
(*[BackupIDLength]C.uint8_t)(unsafe.Pointer(&out)),
(*[C.SignalBACKUP_KEY_LEN]C.uint8_t)(unsafe.Pointer(bk)),
aci.CFixedBytes(),
)
runtime.KeepAlive(bk)
if signalFfiError != nil {
return nil, wrapError(signalFfiError)
}
return &out, nil
}
func (bk *BackupKey) DeriveECKey(aci ServiceID) (*PrivateKey, error) {
var out C.SignalMutPointerPrivateKey
signalFfiError := C.signal_backup_key_derive_ec_key(
&out,
(*[C.SignalBACKUP_KEY_LEN]C.uint8_t)(unsafe.Pointer(&bk)),
aci.CFixedBytes(),
)
runtime.KeepAlive(bk)
if signalFfiError != nil {
return nil, wrapError(signalFfiError)
}
return wrapPrivateKey(out.raw), nil
}
func (bk *BackupKey) DeriveLocalBackupMetadataKey() (*BackupMetadataKey, error) {
var out BackupMetadataKey
signalFfiError := C.signal_backup_key_derive_local_backup_metadata_key(
(*[C.SignalLOCAL_BACKUP_METADATA_KEY_LEN]C.uint8_t)(unsafe.Pointer(&out)),
(*[C.SignalBACKUP_KEY_LEN]C.uint8_t)(unsafe.Pointer(bk)),
)
runtime.KeepAlive(bk)
if signalFfiError != nil {
return nil, wrapError(signalFfiError)
}
return &out, nil
}
func (bk *BackupKey) DeriveMediaID(mediaName string) (*BackupMediaID, error) {
var out BackupMediaID
signalFfiError := C.signal_backup_key_derive_media_id(
(*[C.SignalMEDIA_ID_LEN]C.uint8_t)(unsafe.Pointer(&out)),
(*[C.SignalBACKUP_KEY_LEN]C.uint8_t)(unsafe.Pointer(bk)),
C.CString(mediaName),
)
runtime.KeepAlive(bk)
if signalFfiError != nil {
return nil, wrapError(signalFfiError)
}
return &out, nil
}
func (bk *BackupKey) DeriveMediaEncryptionKey(mediaID *BackupMediaID) (*BackupMediaKey, error) {
var out BackupMediaKey
signalFfiError := C.signal_backup_key_derive_media_encryption_key(
(*[C.SignalMEDIA_ENCRYPTION_KEY_LEN]C.uint8_t)(unsafe.Pointer(&out)),
(*[C.SignalBACKUP_KEY_LEN]C.uint8_t)(unsafe.Pointer(bk)),
(*[C.SignalMEDIA_ID_LEN]C.uint8_t)(unsafe.Pointer(mediaID)),
)
runtime.KeepAlive(bk)
runtime.KeepAlive(mediaID)
if signalFfiError != nil {
return nil, wrapError(signalFfiError)
}
return &out, nil
}
func (bk *BackupKey) DeriveThumbnailTransitEncryptionKey(mediaID *BackupMediaID) (*BackupMediaKey, error) {
var out BackupMediaKey
signalFfiError := C.signal_backup_key_derive_thumbnail_transit_encryption_key(
(*[C.SignalMEDIA_ENCRYPTION_KEY_LEN]C.uint8_t)(unsafe.Pointer(&out)),
(*[C.SignalBACKUP_KEY_LEN]C.uint8_t)(unsafe.Pointer(bk)),
(*[C.SignalMEDIA_ID_LEN]C.uint8_t)(unsafe.Pointer(mediaID)),
)
runtime.KeepAlive(bk)
runtime.KeepAlive(mediaID)
if signalFfiError != nil {
return nil, wrapError(signalFfiError)
}
return &out, nil
}