eap-aka-3gpp2: Fix SQN generation

Same as the previous commit.

Fixes: 424ddf801c ("Do not use monotonic time for AKA sequence numbers, it has an undefined starting point")

src/libcharon/plugins/eap_aka_3gpp2/eap_aka_3gpp2_provider.c

@@ -71,14 +71,15 @@ bool eap_aka_3gpp2_get_k(identification_t *id, char k[AKA_K_LEN])
 void eap_aka_3gpp2_get_sqn(char sqn[AKA_SQN_LEN], int offset)
 {
 	timeval_t time;
+	uint32_t sec, usec;
 
 	gettimeofday(&time, NULL);
 	/* set sqn to an integer containing 4 bytes seconds + 2 bytes usecs */
-	time.tv_sec = htonl(time.tv_sec + offset);
+	sec = htonl((uint32_t)(time.tv_sec + offset));
 	/* usec's are never larger than 0x000f423f, so we shift the 12 first bits */
-	time.tv_usec = htonl(time.tv_usec << 12);
-	memcpy(sqn, (char*)&time.tv_sec + sizeof(time_t) - 4, 4);
-	memcpy(sqn + 4, &time.tv_usec, 2);
+	usec = htonl((uint32_t)time.tv_usec << 12);
+	memcpy(sqn, &sec, 4);
+	memcpy(sqn + 4, &usec, 2);
 }
 
 METHOD(simaka_provider_t, get_quintuplet, bool,