dsd-fme_20_06_2023/src/dmr_pi.c

156 lines
4.3 KiB
C

/*-------------------------------------------------------------------------------
* dmr_pi.c
* DMR Privacy Indicator and LFSR Function
*
* LFSR code courtesy of https://github.com/mattames/LFSR/
*
* LWVMOBILE
* 2022-12 DSD-FME Florida Man Edition
*-----------------------------------------------------------------------------*/
#include "dsd.h"
void dmr_pi (dsd_opts * opts, dsd_state * state, uint8_t PI_BYTE[], uint32_t CRCCorrect, uint32_t IrrecoverableErrors)
{
if((IrrecoverableErrors == 0))
{
if (state->currentslot == 0)
{
state->payload_algid = PI_BYTE[0];
state->payload_keyid = PI_BYTE[2];
state->payload_mi = ( ((PI_BYTE[3]) << 24) + ((PI_BYTE[4]) << 16) + ((PI_BYTE[5]) << 8) + (PI_BYTE[6]) );
if (state->payload_algid < 0x26)
{
fprintf (stderr, "%s ", KYEL);
fprintf (stderr, "\n Slot 1");
fprintf (stderr, " DMR PI H- ALG ID: 0x%02X KEY ID: 0x%02X MI: 0x%08X", state->payload_algid, state->payload_keyid, state->payload_mi);
fprintf (stderr, "%s ", KNRM);
if (state->payload_algid != 0x21)
{
fprintf (stderr, "\n");
LFSR64 (state);
}
}
if (state->payload_algid >= 0x26)
{
state->payload_algid = 0;
state->payload_keyid = 0;
state->payload_mi = 0;
}
}
if (state->currentslot == 1)
{
state->payload_algidR = PI_BYTE[0];
state->payload_keyidR = PI_BYTE[2];
state->payload_miR = ( ((PI_BYTE[3]) << 24) + ((PI_BYTE[4]) << 16) + ((PI_BYTE[5]) << 8) + (PI_BYTE[6]) );
if (state->payload_algidR < 0x26)
{
fprintf (stderr, "%s ", KYEL);
fprintf (stderr, "\n Slot 2");
fprintf (stderr, " DMR PI H- ALG ID: 0x%02X KEY ID: 0x%02X MI: 0x%08X", state->payload_algidR, state->payload_keyidR, state->payload_miR);
fprintf (stderr, "%s ", KNRM);
if (state->payload_algidR != 0x21)
{
fprintf (stderr, "\n");
LFSR64 (state);
}
}
if (state->payload_algidR >= 0x26)
{
state->payload_algidR = 0;
state->payload_keyidR = 0;
state->payload_miR = 0;
}
}
}
}
void LFSR(dsd_state * state)
{
int lfsr = 0;
if (state->currentslot == 0)
{
lfsr = state->payload_mi;
}
else lfsr = state->payload_miR;
uint8_t cnt = 0;
for(cnt=0;cnt<32;cnt++)
{
// Polynomial is C(x) = x^32 + x^4 + x^2 + 1
int bit = ((lfsr >> 31) ^ (lfsr >> 3) ^ (lfsr >> 1)) & 0x1;
lfsr = (lfsr << 1) | (bit);
}
if (state->currentslot == 0)
{
fprintf (stderr, "%s", KYEL);
fprintf (stderr, " Slot 1");
fprintf (stderr, " DMR PI C- ALG ID: 0x%02X KEY ID: 0x%02X", state->payload_algid, state->payload_keyid);
fprintf(stderr, " MI: 0x%08X", lfsr);
fprintf (stderr, "%s", KNRM);
state->payload_mi = lfsr;
}
if (state->currentslot == 1)
{
fprintf (stderr, "%s", KYEL);
fprintf (stderr, " Slot 2");
fprintf (stderr, " DMR PI C- ALG ID: 0x%02X KEY ID: 0x%02X", state->payload_algidR, state->payload_keyidR);
fprintf(stderr, " MI: 0x%08X", lfsr);
fprintf (stderr, "%s", KNRM);
state->payload_miR = lfsr;
}
}
void LFSR64(dsd_state * state)
{
{
unsigned long long int lfsr = 0;
if (state->currentslot == 0)
{
lfsr = (uint64_t) state->payload_mi;
}
else lfsr = (uint64_t) state->payload_miR;
uint8_t cnt = 0;
for(cnt=0;cnt<32;cnt++)
{
unsigned long long int bit = ( (lfsr >> 31) ^ (lfsr >> 21) ^ (lfsr >> 1) ^ (lfsr >> 0) ) & 0x1;
lfsr = (lfsr << 1) | bit;
}
if (state->currentslot == 0)
{
fprintf (stderr, "%s", KYEL);
fprintf (stderr, " Slot 1");
fprintf (stderr, " DMR PI C- ALG ID: 0x%02X KEY ID: 0x%02X", state->payload_algid, state->payload_keyid);
fprintf (stderr, " MI: 0x%016llX", lfsr);
fprintf (stderr, "%s", KNRM);
state->payload_mi = lfsr & 0xFFFFFFFF; //truncate for next repitition and le verification
}
if (state->currentslot == 1)
{
fprintf (stderr, "%s", KYEL);
fprintf (stderr, " Slot 2");
fprintf (stderr, " DMR PI C- ALG ID: 0x%02X KEY ID: 0x%02X", state->payload_algidR, state->payload_keyidR);
fprintf (stderr, " MI: 0x%016llX", lfsr);
fprintf (stderr, "%s", KNRM);
state->payload_miR = lfsr & 0xFFFFFFFF; //truncate for next repitition and le verification
}
}
}