PentHertz
/
srsLTE
mirror of https://github.com/PentHertz/srsLTE.git
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

srsepc: use received NAS count to calculate MAC 

this is according to 24.301 Sec 4.4.3.3 which says the receiver
should use the sequence number included in the received message
rather a local estimate
This commit is contained in:
Andre Puschmann 2020-04-03 13:45:06 +02:00
parent acc2948b45
commit 9f4e1ba62d
1 changed files with 13 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
srsepc/src/mme/nas.cc
View File

@ -1666,16 +1666,17 @@ bool nas::short_integrity_check(srslte::byte_buffer_t* pdu)
bool nas::integrity_check(srslte::byte_buffer_t* pdu)
{
uint8_t exp_mac[4] = {0x00, 0x00, 0x00, 0x00};
uint8_t* mac = &pdu->msg[1];
int i;
uint8_t exp_mac[4] = {};
const uint8_t* mac = &pdu->msg[1];
uint32_t estimated_count = (m_sec_ctx.ul_nas_count & 0xffffff00) | (pdu->msg[5] & 0xff);
switch (m_sec_ctx.integ_algo) {
case srslte::INTEGRITY_ALGORITHM_ID_EIA0:
break;
case srslte::INTEGRITY_ALGORITHM_ID_128_EIA1:
srslte::security_128_eia1(&m_sec_ctx.k_nas_int[16],
m_sec_ctx.ul_nas_count,
estimated_count,
0,
srslte::SECURITY_DIRECTION_UPLINK,
&pdu->msg[5],
@ -1684,7 +1685,7 @@ bool nas::integrity_check(srslte::byte_buffer_t* pdu)
break;
case srslte::INTEGRITY_ALGORITHM_ID_128_EIA2:
srslte::security_128_eia2(&m_sec_ctx.k_nas_int[16],
m_sec_ctx.ul_nas_count,
estimated_count,
0,
srslte::SECURITY_DIRECTION_UPLINK,
&pdu->msg[5],
@ -1693,7 +1694,7 @@ bool nas::integrity_check(srslte::byte_buffer_t* pdu)
break;
case srslte::INTEGRITY_ALGORITHM_ID_128_EIA3:
srslte::security_128_eia3(&m_sec_ctx.k_nas_int[16],
m_sec_ctx.ul_nas_count,
estimated_count,
0,
srslte::SECURITY_DIRECTION_UPLINK,
&pdu->msg[5],
@ -1704,11 +1705,12 @@ bool nas::integrity_check(srslte::byte_buffer_t* pdu)
break;
}
// Check if expected mac equals the sent mac
for (i = 0; i < 4; i++) {
for (int i = 0; i < 4; i++) {
if (exp_mac[i] != mac[i]) {
m_nas_log->warning("Integrity check failure. Algorithm=EIA%d\n", (int)m_sec_ctx.integ_algo);
m_nas_log->warning("UL Local: count=%d, MAC=[%02x %02x %02x %02x], "
m_nas_log->warning("UL Local: est_count=%d, old_count=%d, MAC=[%02x %02x %02x %02x], "
"Received: UL count=%d, MAC=[%02x %02x %02x %02x]\n",
estimated_count,
m_sec_ctx.ul_nas_count,
exp_mac[0],
exp_mac[1],
@ -1722,7 +1724,9 @@ bool nas::integrity_check(srslte::byte_buffer_t* pdu)
return false;
}
}
m_nas_log->info("Integrity check ok. Local: count=%d, Received: count=%d\n", m_sec_ctx.ul_nas_count, pdu->msg[5]);
m_nas_log->info("Integrity check ok. Local: count=%d, Received: count=%d\n", estimated_count, pdu->msg[5]);
m_sec_ctx.ul_nas_count = estimated_count;
return true;
}