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DMR: Add Keyloading for Hytera PDU Decryption based on Data Header Key ID first, then manually set key. #372

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lwvmobile
2026-11-07 20:22:23 -05:00
parent 544d576551
commit 34753963b8
2 changed files with 63 additions and 21 deletions
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78
src/crypt-rc4.c
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@@ -1343,21 +1343,40 @@ void hytera_ota_search_sb_rc(dsd_state * state, uint8_t * input, int ptype)
uint8_t hytera_ep_data_decrypt(dsd_opts * opts, dsd_state * state, uint8_t * input, int len)
{
//check slot for RC4 Encrypted PDU Alg 0xD0 (0x68 * alg 2)
uint8_t slot = state->currentslot;
if (slot == 0 && state->payload_algid != 0xD0)
return 0;
else if (slot == 1 && state->payload_algidR != 0xD0)
return 0;
//TODO: Attempt Load by TG value as well
//TODO: Hytera EP Data Header does have a Key ID,
//attempt loading by either TG or Key ID as well
//local copy of EP key (RC4 Enhanced)
unsigned long long int R = 0;
if (slot == 0)
R = state->R;
else R = state->RR;
//check to see if a key is loaded by key_id into the array
if (R == 0)
{
uint8_t key_id = 0;
if (slot == 0)
key_id = state->payload_keyid;
else key_id = state->payload_keyidR;
R = state->rkey_array[key_id];
}
//if R is still zero, check to see if a key is manually loaded
if (R == 0)
{
if (slot == 0)
R = state->R;
else R = state->RR;
}
//NOTE: Since data targets are more often individual, loading by tgt
//doesn't make since, loading by src makes more sense, but then again
//could be 50-50 if a request packet is replied, and that is enc'd
//if no key is loaded, return as not decrypted
if (R == 0)
return 0;
@@ -1405,21 +1424,44 @@ uint8_t hytera_bp_data_decrypt(dsd_state * state, uint8_t * input, int len)
uint8_t key[32]; memset(key, 0, sizeof(key));
uint8_t empt[32]; memset(empt, 0, sizeof(empt));
//TODO: Attempt Load by TG value as well
//TODO: Hytera BP Data Header does have a Key ID,
//attempt loading by either TG or Key ID as well
for (int i = 0; i < 8; i++)
if (key_loaded == 0)
{
key[i+0] = (state->K1) >> (56-(i*8)) & 0xFF;
key[i+8] = (state->K2) >> (56-(i*8)) & 0xFF;
key[i+16] = (state->K3) >> (56-(i*8)) & 0xFF;
key[i+24] = (state->K4) >> (56-(i*8)) & 0xFF;
uint8_t key_id = 0;
if (slot == 0)
key_id = state->payload_keyid;
else key_id = state->payload_keyidR;
for (int i = 0; i < 8; i++)
{
key[i+0] = ((state->rkey_array[key_id+0x000]) >> (56-(i*8))) & 0xFF;
key[i+8] = ((state->rkey_array[key_id+0x101]) >> (56-(i*8))) & 0xFF;
key[i+16] = ((state->rkey_array[key_id+0x201]) >> (56-(i*8))) & 0xFF;
key[i+24] = ((state->rkey_array[key_id+0x301]) >> (56-(i*8))) & 0xFF;
}
//if key is loaded with a key, then flag on the key loaded variable
if (memcmp(key, empt, sizeof(key)) != 0) key_loaded = 1;
}
//if key is loaded with a key, then flag on the key loaded variable
if (memcmp(key, empt, sizeof(key)) != 0) key_loaded = 1;
if (key_loaded == 0)
{
for (int i = 0; i < 8; i++)
{
key[i+0] = (state->K1) >> (56-(i*8)) & 0xFF;
key[i+8] = (state->K2) >> (56-(i*8)) & 0xFF;
key[i+16] = (state->K3) >> (56-(i*8)) & 0xFF;
key[i+24] = (state->K4) >> (56-(i*8)) & 0xFF;
}
//if key is loaded with a key, then flag on the key loaded variable
if (memcmp(key, empt, sizeof(key)) != 0) key_loaded = 1;
}
//NOTE: Since data targets are more often individual, loading by tgt
//doesn't make since, loading by src makes more sense, but then again
//could be 50-50 if a request packet is replied, and that is enc'd
//if no key is loaded, return as not decrypted
if (key_loaded == 0)
return 0;

6
src/dmr_block.c
View File

@@ -1087,11 +1087,11 @@ void dmr_block_assembler (dsd_opts * opts, dsd_state * state, uint8_t block_byte
kaes[i+8] = ((state->rkey_array[kid+0x101]) >> (56-(i*8))) & 0xFF;
kaes[i+16] = ((state->rkey_array[kid+0x201]) >> (56-(i*8))) & 0xFF;
kaes[i+24] = ((state->rkey_array[kid+0x301]) >> (56-(i*8))) & 0xFF;
//if kaes is loaded with a key, then flag on the key loaded variable
if (memcmp(kaes, empt, sizeof(kaes)) != 0) akl = 1;
}
//if kaes is loaded with a key, then flag on the key loaded variable
if (memcmp(kaes, empt, sizeof(kaes)) != 0) akl = 1;
//if still not akl, see if there is anything manually loaded into K1, K2, K3, K4 instead
if (akl == 0)
{