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Add work on MACSEQ validation

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This commit is contained in:
Carles Fernandez 2023-06-13 16:41:15 +02:00
parent 5ebc544ff6
commit 30b0230680
No known key found for this signature in database
GPG Key ID: 4C583C52B0C3877D
2 changed files with 48 additions and 9 deletions
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44
src/core/libs/osnma_msg_receiver.cc
View File

@ -58,6 +58,7 @@ osnma_msg_receiver::osnma_msg_receiver(
{
d_dsm_reader = std::make_unique<OSNMA_DSM_Reader>();
d_crypto = std::make_unique<Gnss_Crypto>(pemFilePath);
d_old_mack_message.set_capacity(10);
// register OSNMA input message port from telemetry blocks
this->message_port_register_in(pmt::mp("OSNMA_from_TLM"));
// register OSNMA output message port to PVT block
@ -352,7 +353,6 @@ void osnma_msg_receiver::process_dsm_message(const std::vector<uint8_t>& dsm_msg
<< "Chain in force is " << static_cast<uint32_t>(d_osnma_data.d_nma_header.cid) << ", "
<< "Chain and Public Key Status is " << d_dsm_reader->get_cpks_status(d_osnma_data.d_nma_header.cpks) << std::endl;
}
// Validate signature
}
}
else if (d_osnma_data.d_dsm_header.dsm_id >= 12 && d_osnma_data.d_dsm_header.dsm_id < 16)
@ -437,7 +437,47 @@ void osnma_msg_receiver::read_mack_block(const std::shared_ptr<OSNMA_msg>& osnma
{
read_mack_header();
read_mack_body();
d_old_mack_message = d_osnma_data.d_mack_message;
d_old_mack_message.push_back(d_osnma_data.d_mack_message);
// MACSEQ validation
uint32_t GST_SF = osnma_msg->TOW_sf0;
// Are there flexible tags?
std::vector<uint8_t> m(5);
m[0] = static_cast<uint8_t>(osnma_msg->PRN); // PRN_A
m[1] = ((GST_SF & 0xF000) >> 24);
m[2] = ((GST_SF & 0x0F00) >> 16);
m[3] = ((GST_SF & 0x00F0) >> 8);
m[4] = (GST_SF & 0x000F);
std::vector<uint8_t> applicable_key;
// if ADKD=12, pick d_old_mack_message.front() if d_old_mack_message[10] is full
// otherwise pick d_old_mack_message.back()
applicable_key = d_old_mack_message.back().key;
std::vector<uint8_t> mac;
if (d_osnma_data.d_dsm_kroot_message.mf == 0)
{
mac = d_crypto->computeHMAC_SHA_256(applicable_key, m);
}
else if (d_osnma_data.d_dsm_kroot_message.mf == 1)
{
mac = d_crypto->computeCMAC_AES(applicable_key, m);
}
uint16_t mac_msb = 0;
if (!mac.empty())
{
mac_msb = (mac[0] << 8) + mac[1];
}
uint16_t computed_macseq = (mac_msb & 0x0FFF);
int num_tags_added = 0;
if (computed_macseq == d_osnma_data.d_mack_message.header.macseq)
{
std::cout << "OSNMA: MACSEQ authenticated for PRN_A "
<< osnma_msg->PRN << " with WN="
<< osnma_msg->WN_sf0 << ", TOW="
<< osnma_msg->TOW_sf0 << ". Tags added: "
<< num_tags_added << std::endl;
}
}
}

13
src/core/libs/osnma_msg_receiver.h
View File

@ -23,10 +23,11 @@
#include "gnss_block_interface.h" // for gnss_shared_ptr
#include "gnss_sdr_make_unique.h" // for std::make:unique in C++11
#include "osnma_data.h" // for OSNMA_data
#include <gnuradio/block.h> // for gr::block
#include <pmt/pmt.h> // for pmt::pmt_t
#include <array> // for std::array
#include <memory> // for std::shared_ptr
#include <boost/circular_buffer.hpp>
#include <gnuradio/block.h> // for gr::block
#include <pmt/pmt.h> // for pmt::pmt_t
#include <array> // for std::array
#include <memory> // for std::shared_ptr
#include <string>
#include <vector>
@ -65,12 +66,10 @@ private:
void read_dsm_block(const std::shared_ptr<OSNMA_msg>& osnma_msg);
void read_mack_block(const std::shared_ptr<OSNMA_msg>& osnma_msg);
void process_dsm_message(const std::vector<uint8_t>& dsm_msg, const std::shared_ptr<OSNMA_msg>& osnma_msg);
void read_mack_header();
void read_mack_body();
MACK_message d_old_mack_message;
boost::circular_buffer<MACK_message> d_old_mack_message;
std::unique_ptr<OSNMA_DSM_Reader> d_dsm_reader;
std::unique_ptr<Gnss_Crypto> d_crypto;