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Fix AES-OFB and Misc Issues on .mbe file playback; #329 WIP

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lwvmobile
2026-01-01 23:00:41 -05:00
parent 48b0c4025b
commit e95cd4dd3a
1 changed files with 30 additions and 18 deletions
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48
src/dsd_file.c
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@@ -1447,7 +1447,7 @@ void read_sdrtrunk_json_format (dsd_opts * opts, dsd_state * state)
uint8_t ks_bytes[375]; memset(ks_bytes, 0, sizeof(ks_bytes));
uint8_t kiv[32]; memset(kiv, 0, sizeof(kiv));
//RC4
//RC4 (v1 tested and working on P25, v2 should be okay now)
if ( (alg_id == 0xAA || alg_id == 0x21) && state->R != 0 )
{
@@ -1482,7 +1482,7 @@ void read_sdrtrunk_json_format (dsd_opts * opts, dsd_state * state)
}
//P25 DES
//P25 DES (v1 tested and working on P1, v2 should be okay now)
else if (alg_id == 0x81 && state->R != 0)
{
@@ -1522,7 +1522,7 @@ void read_sdrtrunk_json_format (dsd_opts * opts, dsd_state * state)
}
//P25 AES (untested)
//P25 AES (v1 and v2 tested working on P1)
else if ( (alg_id == 0x84 || alg_id == 0x89) && state->aes_key_loaded[0] == 1 )
{
@@ -1530,7 +1530,7 @@ void read_sdrtrunk_json_format (dsd_opts * opts, dsd_state * state)
memset(aes_key, 0, sizeof(aes_key));
//Load key from A1 - A4
for (i = 0; i < 8; i++)
for (int i = 0; i < 8; i++)
{
aes_key[i+0] = (state->A1[0] >> (56-(i*8))) & 0xFF;
aes_key[i+8] = (state->A2[0] >> (56-(i*8))) & 0xFF;
@@ -1538,41 +1538,47 @@ void read_sdrtrunk_json_format (dsd_opts * opts, dsd_state * state)
aes_key[i+24] = (state->A4[0] >> (56-(i*8))) & 0xFF;
}
uint8_t aes_iv[16];
memset(aes_iv, 0, sizeof(aes_iv));
//load the str_buffer into the IV portion of aes_iv
parse_raw_user_string(str_buffer, aes_iv);
//backup copy of current IV to reverse and expand, if needed
uint8_t backup_iv[16];
memset(backup_iv, 0, sizeof(backup_iv));
uint8_t aes_last_iv[16];
memset(aes_last_iv, 0, sizeof(aes_last_iv));
for (int i = 0; i < 8; i++)
backup_iv[i] = kiv[i+5];
aes_last_iv[i] = aes_iv[i];
//Resolve the longer IV from the shorter one
lfsr_64_to_128(kiv+5);
lfsr_64_to_128(aes_iv);
if (alg_id == 0x89) //128, or 256
aes_ofb_keystream_output(kiv+5, aes_key, ks_bytes, 0, 16); //16*16=256
else aes_ofb_keystream_output(kiv+5, aes_key, ks_bytes, 2, 16); //16*16=256
aes_ofb_keystream_output(aes_iv, aes_key, ks_bytes, 0, 16); //16*16=256
else aes_ofb_keystream_output(aes_iv, aes_key, ks_bytes, 2, 16); //16*16=256
if (protocol == 1) //Phase 1 IMBE start on 27 for AES-OFB (16 discard + 9 LCW + 2 reserved)
unpack_byte_array_into_bit_array(ks_bytes+27, ks, 256-19); //unpack starting after discard
unpack_byte_array_into_bit_array(ks_bytes+27, ks, 256-27); //unpack starting after discard
else if (protocol == 2) //Phase 2 AMBE+2 start on 16 after discard round for AES-OFB
unpack_byte_array_into_bit_array(ks_bytes+16, ks, 256-8); //unpack starting after discard
unpack_byte_array_into_bit_array(ks_bytes+16, ks, 256-16); //unpack starting after discard
//reverse lfsr on IV and create keystream with that as well
//due to out of order execution on P25p1 ESS sync.
if (protocol == 1 && version == 1)
{
reverse_lfsr_64_to_len (opts, backup_iv, 64);
reverse_lfsr_64_to_len (opts, aes_last_iv, 64);
//Resolve the longer IV from the shorter one
lfsr_64_to_128(backup_iv);
lfsr_64_to_128(aes_last_iv);
memset(ks_bytes, 0, sizeof(ks_bytes));
if (alg_id == 0x89) //128, or 256
aes_ofb_keystream_output(backup_iv, aes_key, ks_bytes, 0, 16); //16*16=256
else aes_ofb_keystream_output(backup_iv, aes_key, ks_bytes, 2, 16); //16*16=256
aes_ofb_keystream_output(aes_last_iv, aes_key, ks_bytes, 0, 16); //16*16=256
else aes_ofb_keystream_output(aes_last_iv, aes_key, ks_bytes, 2, 16); //16*16=256
unpack_byte_array_into_bit_array(ks_bytes+27, ks_i, 256-19); //unpack starting after discard
unpack_byte_array_into_bit_array(ks_bytes+27, ks_i, 256-27); //unpack starting after discard
}
ks_available = 1;
@@ -1604,6 +1610,9 @@ void read_sdrtrunk_json_format (dsd_opts * opts, dsd_state * state)
imbe_counter++;
//debug
// fprintf (stderr, "\n IMBE# %02d; KS_IDX: %d; KS_IDX_I: %d; ", imbe_counter, ks_idx, ks_idx_i);
//36 hex characters on 'hex' which is the IMBE interleaved C codewords
if (version == 1)
ks_idx_i = imbe_str_to_decode(opts, state, str_buffer, ks_i, ks_idx_i, is_enc, ks_available);
@@ -1611,7 +1620,10 @@ void read_sdrtrunk_json_format (dsd_opts * opts, dsd_state * state)
//skip LSD bits in-between these two IMBE voice frames
if (imbe_counter == 8 || imbe_counter == 17)
{
ks_idx_i += 16;
ks_idx += 16;
}
//juggle keystreams and reset the I counter (if version 1)
if (imbe_counter == 9 && version == 1)
@@ -1632,7 +1644,7 @@ void read_sdrtrunk_json_format (dsd_opts * opts, dsd_state * state)
}
//debug
// fprintf (stderr, " # %02d; KS_IDX_I: %04d;", imbe_counter, ks_idx_i);
// fprintf (stderr, "\n IMBE# %02d; KS_IDX: %d; KS_IDX_I: %d; ", imbe_counter, ks_idx, ks_idx_i);
//debug
// if (is_enc == 1 && ks_available == 0)