diff --git a/srt/packet.go b/srt/packet.go
index 296ef99..1290a8a 100644
--- a/srt/packet.go
+++ b/srt/packet.go
@@ -316,7 +316,7 @@ func parse_hs_cif(cif *HandshakeCIF, buffer []byte) (error) {
 		case 3:
 			content := new(KMMSG)
 			content.key_type = extensions[7] & 0x3
-			content.key_len = extensions[19]
+			content.key_len = extensions[19] * 4
 			for i := 0; i < 4; i++ {
 				content.salt[i] = extensions[20 + i]
 			}