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P25p1: More Misc PDU Tweaks;

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lwvmobile
2025-03-12 12:16:31 -04:00
parent c13ffbc9b2
commit 0c8a11c607
3 changed files with 16 additions and 23 deletions
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2
include/dsd.h
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@@ -1302,7 +1302,7 @@ void dmr_locn (dsd_opts * opts, dsd_state * state, uint16_t len, uint8_t * DMR_P
//p25 pdu handling
uint8_t p25_decrypt_pdu(dsd_opts * opts, dsd_state * state, uint8_t * input, uint8_t alg_id, uint16_t key_id, unsigned long long int mi, int len);
uint8_t p25_decode_es_header(dsd_opts * opts, dsd_state * state, uint8_t * input, uint8_t * sap, int * ptr, int len);
uint8_t p25_decode_es_header_2(dsd_opts * opts, dsd_state * state, uint8_t * input, uint8_t * sap, int * ptr, int len);
uint8_t p25_decode_es_header_2(dsd_opts * opts, dsd_state * state, uint8_t * input, int * ptr, int len);
void p25_decode_extended_address(dsd_opts * opts, dsd_state * state, uint8_t * input, uint8_t * sap, int * ptr);
void p25_decode_pdu_trunking(dsd_opts * opts, dsd_state * state, uint8_t * mpdu_byte);
void p25_decode_pdu_header(dsd_opts * opts, dsd_state * state, uint8_t * input);

3
src/dmr_pdu.c
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@@ -302,6 +302,9 @@ void decode_ip_pdu (dsd_opts * opts, dsd_state * state, uint16_t len, uint8_t *
uint16_t udp_chk = (input[26] << 8) | input[27];
fprintf (stderr, "\n UDP Protocol; Datagram Len: %d; UDP Checksum: %04X; ", udp_len, udp_chk);
//if dst port and src prt don't match, then make it so
if (port2 != port1) port1 = port2;
if (port1 == 231 && port2 == 231)
{
fprintf (stderr, "Cellocator;");

34
src/p25p1_pdu_data.c
View File

@@ -117,40 +117,30 @@ uint8_t p25_decode_es_header(dsd_opts * opts, dsd_state * state, uint8_t * input
}
//alternate configuration for this
uint8_t p25_decode_es_header_2(dsd_opts * opts, dsd_state * state, uint8_t * input, uint8_t * sap, int * ptr, int len)
//alternate configuration for this (no Aux SAP)
uint8_t p25_decode_es_header_2(dsd_opts * opts, dsd_state * state, uint8_t * input, int * ptr, int len)
{
uint8_t encrypted = 0;
uint8_t bits[13*8]; memset (bits, 0, sizeof(bits));
unpack_byte_array_into_bit_array(input, bits, 13);
uint8_t bits[12*8]; memset (bits, 0, sizeof(bits));
unpack_byte_array_into_bit_array(input, bits, 12);
fprintf (stderr, "%s",KYEL);
uint8_t alg_id = (uint8_t)ConvertBitIntoBytes(bits+0, 8);
uint16_t key_id = (uint16_t)ConvertBitIntoBytes(bits+8, 16);
unsigned long long int mi = (unsigned long long int)ConvertBitIntoBytes(bits+24, 64);
uint8_t mi_res = (uint8_t)ConvertBitIntoBytes(bits+64+24, 8);
uint8_t alg_id = (uint8_t)ConvertBitIntoBytes(bits+16, 8);
uint16_t key_id = (uint16_t)ConvertBitIntoBytes(bits, 16);
fprintf (stderr, "\n ES Aux Encryption Header 2; ALG: %02X; KEY ID: %04X; MI: %016llX; ", alg_id, key_id, mi);
uint8_t mi_res = (uint8_t)ConvertBitIntoBytes(bits+88, 8);
fprintf (stderr, "\n ES Aux Encryption Header 2; ALG: %02X; KEY ID: %04X; MI: %016llX;", alg_id, key_id, mi);
if (mi_res != 0)
fprintf (stderr, " RES: %02X;", mi_res);
//The Auxiliary Header signals the actual SAP value of the encrypted message (this byte is not encrypted)
uint8_t aux_res = (uint8_t)ConvertBitIntoBytes(&bits[96], 2); //these two bits should always be signalled as 1's, so 0b11, and if combined with the 2ndary SAP, 0xC0 if SAP == 0x00
uint8_t aux_sap = (uint8_t)ConvertBitIntoBytes(&bits[98], 6); //the SAP of the message that is encrypted immediately after
char aux_sap_string[99];
p25_decode_sap (aux_sap, aux_sap_string);
fprintf (stderr, "%s",KNRM);
UNUSED(aux_res);
if (alg_id != 0x80)
encrypted = 1;
//Decrypt PDU
encrypted = p25_decrypt_pdu(opts, state, input+13, alg_id, key_id, mi, len-13);
if (alg_id != 0x80)
encrypted = p25_decrypt_pdu(opts, state, input+12, alg_id, key_id, mi, len-12);
*sap = aux_sap;
*ptr += 13;
*ptr += 12;
return encrypted;
@@ -266,7 +256,7 @@ void p25_decode_pdu_data(dsd_opts * opts, dsd_state * state, uint8_t * input, in
}
else
{
fprintf (stderr, "Encrypted PDU;");
fprintf (stderr, " Encrypted PDU;");
}
}