fix f_enc_IMEI_L3() oddevenIndicator
f_gen_imei() calls f_enc_IMEI_L3() with a 14 digits argument, but the IMEI_L3
template used is hardcoded to 15 digits. So the oddevenIndicator must always
indicate odd, not depend on the digits argument.
f_gen_imei() should probably also compose a Luhn checksum, leaving that to
another patch.
Found by using the new osmo_mobile_identity API in osmo-msc, which is stricter
about odd/even and filler digits than our previous implementations.
See osmo-msc Idfc8e576e10756aeaacf5569f6178068313eb7ea .
Change-Id: Iaa9ba1214c4c15fd9620e68fe2e842fdf52912c0
diff --git a/library/L3_Templates.ttcn b/library/L3_Templates.ttcn
index 3032503..ba91180 100644
--- a/library/L3_Templates.ttcn
+++ b/library/L3_Templates.ttcn
@@ -184,11 +184,20 @@
private function f_enc_IMEI_L3(hexstring digits) return IMEI_L3 {
var IMEI_L3 l3;
var integer len := lengthof(digits);
- if (len rem 2 == 1) { /* modulo remainder */
- l3.oddevenIndicator := '1'B;
- } else {
- l3.oddevenIndicator := '0'B;
- }
+ /* IMEI_L3 is always 15 digits. That is actually a 14 digit IMEI + a Luhn checksum digit (see
+ * libosmocore/include/osmocom/gsm/protocol/gsm_23_003.h)
+ *
+ * Here, we must not make the oddevenIndicator depend on the 'digits' parameter, because:
+ * - The IMEI_L3 template assumes always 15 digits.
+ * - The 'digits' parameter, however, may also contain less digits, 14 in the case of
+ * f_gen_imei().
+ * - The IMEI_L3 template will then fill up with zeros to make 15 digits.
+ * Hence oddevenIndicator must always indicate 'odd' == '1'B.
+ *
+ * FIXME: if the caller passes less than 15 digits, the Luhn checksum digit then ends up zero == most probably
+ * wrong.
+ */
+ l3.oddevenIndicator := '1'B;
l3.digits := digits;
return l3;
}