base64 encode the session before passing to libolm/goolm

also log the number of imported sessions for fun

Signed-off-by: Sumner Evans <sumner@beeper.com>

crypto/keybackup.go

@@ -2,6 +2,7 @@ package crypto
 
 import (
 	"context"
+	"encoding/base64"
 	"fmt"
 	"time"
 
@@ -84,6 +85,8 @@ func (mach *OlmMachine) DownloadAndStoreLatestKeyBackup(ctx context.Context, meg
 		return err
 	}
 
+	var count int
+
 	for roomID, backup := range keys.Rooms {
 		for sessionID, keyBackupData := range backup.Sessions {
 			sessionData, err := keyBackupData.SessionData.Decrypt(megolmBackupKey)
@@ -95,9 +98,12 @@ func (mach *OlmMachine) DownloadAndStoreLatestKeyBackup(ctx context.Context, meg
 			if err != nil {
 				return err
 			}
+			count++
 		}
 	}
 
+	log.Info().Int("count", count).Msg("successfully imported sessions from backup")
+
 	return nil
 }
 
@@ -110,7 +116,7 @@ func (mach *OlmMachine) importRoomKeyFromBackup(ctx context.Context, roomID id.R
 		return fmt.Errorf("ignoring room key in backup with weird algorithm %s", keyBackupData.Algorithm)
 	}
 
-	igsInternal, err := olm.InboundGroupSessionImport([]byte(keyBackupData.SessionKey))
+	igsInternal, err := olm.InboundGroupSessionImport([]byte(base64.RawStdEncoding.EncodeToString(keyBackupData.SessionKey)))
 	if err != nil {
 		return fmt.Errorf("failed to import inbound group session: %w", err)
 	} else if igsInternal.ID() != sessionID {