Editing SC Communication

=Introduction=

* The following information was reverse engineered from [[lv0ldr]], [[lv0]], [[Hypervisor_Reverse_Engineering#System_Controller_.28SC_or_SYSCON.29|lv1]].[[SC_Manager|self]], and [[Iso module]] sc_iso.self.
* Big thanks to graf_chokolo for a large part of the basis of this page, and to Jestero for Syscon Authentication info!

=Overview of Syscon Communication=

*Syscon lives at the mmio space of 0x24000080000.
*Communication occurs through mmio read/writes.

List of known offsets in Syscon:

{| class="wikitable FCK__ShowTableBorders"
|-
! Offset (from start of address space) !! Size !! Description
|-
|0xC000 || 0xFF0 || Syscon packet send area
|-
|0xCFF0 || 0x4   || Syscon sent packet counter
|-
|0xCFF4 || 0x4   || Syscon sent packet acknowledge counter
|-
|0xD000 || 0xFF0 || Syscon packet receive area
|-
|0xDFF0 || 0x4   || Syscon received packet counter
|-
|0xDFF4 || 0x4   || Syscon received packet acknowledge counter
|-
|0xE100 || 0x4   || Tells syscon there is a packet to be received
|}

Quick explanation of the packet counters:
* There are two counters that are incremented by each side (Cell / Syscon).
* 0xCFF0 and 0xDFF0 are incremented by the sending side (Syscon for 0xCFF0, Cell for 0xDFF0)
* 0xCFF4 and 0xDFF4 are incremented by the receiving side (Cell for 0xCFF4, Syscon for 0xDFF4)

=Syscon Services=
* To be completed... (see {{talk}} page for examples)

<pre>
SERV_INTR_NOTIF 0x17
SERV_LS 0x40
SERV STORAGE 0x50
SERV_Patch 0x2D
SERV VERS 0x18
SERV LIVELOCK 0x1B
SERV OSWDT 0x1C
SERV SIRCS 0x15
SERV NOTIF 0x16
SERV NVS 0x14
SERV DEVPM 0x10
SERV SETCFG 0x12
SERV SDA 0x3
SERV SYSPM 0x13
</pre>

{| class="wikitable FCK__ShowTableBorders"
|-
! Service ID !! Description
|-
| 0x03 || Device Access Service - Used for eeprom read/write.
|-
| 0x10 || Device Power Service (PS2 PCI Bus Power On/Off)
|-
| 0x11 || Time Zone Presence, Temperature, Thermal Alert Mode, 
|-
| 0x12 || Config Info Service (BE Count, Error Log....)
|-
| 0x13 || Power Service - Controls system power and related info. (Power Up/Power Button Mode, Wake Source, RTC too.)
|-
| 0x14 || NVS Service - Used for eeprom read/write.
|-
| 0x15 || SIRCS ??
|-
| 0x16 || Notification / (LED / Buzzer) Service - Controls the lights on the console and the ring buzzer.
|-
| 0x18 || Version Service - Versioning related (SC Type/Major-,Minor Version)
|-
| 0x1B || Livelock(?) Service - Checks for permission to use other services. 
|-
| 0x1C || OSWDT ??
|-
| 0x20 || Syscon Debug Output(?) - Used to send a string to syscon.
|-
| 0x2D || Syscon Patch Servuce
|-
| 0x30 || A/V Service.
|-
| 0x50 || Storage Service
|-
| 0x1F || Authenticated Services. (sc_secure_service)
|-
| 0xFF || Syscon Init (Seen in lv0ldr init sequence to syscon: [[User_talk:JuanNadie]])
|}

=Syscon Packet Headers=
* Some useful packet headers...
* If the header is shorter than 0x10, you must add your own size.
* If greater than 0x10, it's a full packet ;)

{| class="wikitable FCK__ShowTableBorders"
|-
! What? !! Description || Data || Notes
|-
| AUTH1 || AUTH1 Header || 0x1F, 0x01, 0x00, 0x00, 0x00, 0x00, 0x80, 0x20, 0x00, 0x00, 0x00, 0x00,<br>0x00, 0x30, 0x00, 0x30 || On AUTH1 UART SC Packets it's instead 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
|-
| AUTH2 || AUTH2 Header || 0x1F, 0x01, 0x00, 0x01, 0x00, 0x00, 0x80, 0x21, 0x00, 0x00, 0x00, 0x00,<br>0x00, 0x30, 0x00, 0x30 || On AUTH2 UART SC Packets it's instead 0x10, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
|-
| Debug Output || Sends string to Syscon TTY || 0x20, 0x01, 0x00, 0x07, 0x00, 0x00, 0x80, 0x28, 0x00, 0x00, 0x00, 0x00<br>|| Start message with 0x00. Will print as much as packet length.
|-
| Triple Beep || || 0x16, 0x01, 0x16, 0x20, 0x00, 0x00, 0x80, 0x4D, 0x00, 0x00, 0x00, 0x01,<br>0x00, 0x08, 0x00, 0x08,<br>0x20, 0x29, 0x0A, 0x00, 0x00, 0x00, 0x01, 0xB6||
|-
| Shutdown || || 0x13, 0x01, 0x00, 0x0D, 0x00, 0x00, 0x80, 0x21, 0x00, 0x00, 0x00, 0x00,<br>0x00, 0x04, 0x00, 0x04,<br>0x11, 0x00, 0x00, 0x00|| Will not gracefully shut down HD.
|-
| Soft Restart || || 0x13, 0x01, 0x00, 0x0D, 0x00, 0x00, 0x80, 0x21, 0x00, 0x00, 0x00, 0x00,<br>0x00, 0x04, 0x00, 0x04,<br>0x11, 0x00, 0x00, 0x01|| Restarts, but doesn't kill power between boots.
|-
| Hard Restart || || 0x13, 0x01, 0x00, 0x0D, 0x00, 0x00, 0x80, 0x21, 0x00, 0x00, 0x00, 0x00,<br>0x00, 0x04, 0x00, 0x04,<br>0x11, 0x00, 0x00, 0x02|| Restarts, but kills power between boots.
|-
| Panic || || 0x13, 0x01, 0x00, 0x0D, 0x00, 0x00, 0x80, 0x21, 0x00, 0x00, 0x00, 0x00,<br>0x00, 0x04, 0x00, 0x04,<br>0x11, 0x00, 0x00, 0x03|| Shuts down, beeps, and kills power LED until power button pressed, or power removed.
|}

=Syscon Authentication=
 - An IV of 0x00 is used for most AES steps.

== Step 1 - Generate Individual Seeds ==
Encrypt sc_iso metadata seeds w/ eid root key / iv.

<pre>aes256cbc_enc(eid_root_erk, eid_root_riv, sc_module_seeds, 0x40, sc_module_seeds);</pre>

== Step 2 - Generate SC_ISO encrypted keys ==
Encrypt the sc_key_seeds.

<pre>
indiv_key = sc_module_seeds + 0x20;
for (int i = 0; i < 0x100; i += 0x10)
    aes256cbc_enc(indiv_key, zero_iv, key_seeds + i, 0x10, enc_key_seeds + i);
</pre>

== Step 3 - Authenticate with Syscon ==
Pick a session_id. Must be <= 7.

=== Step 3a - Secure Packet Header ===
<pre>
struct secure_payload_header {
    u8 session_id;
    u8 seq_service_id;  //service_ID (Unsecure uses 0xFF, AUTH1 = 0x02, AUTH2 = 0x03, READ_DATA = 0x04, WRITE_DATA = 0x05)
    u8 packet_type;     //0xFF for BE->SC, 0x00 for SC->BE (if success)
    u8 magic[0x2];      //0xAD1A
    u8 prng_random[0xB] //Random shit for padding
};
</pre>

=== Step 3b - AUTH 1 to SC ===
<pre>
uint8_t random_shit[0x10];
auth_key_1_0x01 = enc_key_seeds + (session_id * (0x10*2));
auth_key_2_0x01 = enc_key_seeds + (session_id * (0x10*2) + 0x10);

//generating random payload for auth1
rnd_gen(random_shit, 0x10);

//create auth1 random data
aes128cbc_enc(auth_key_1_0x01, zero_iv, random_shit, 0x10, secure_payload_buf + 0x10);

//length = 0x20
//Create secure header/footer
// create header: 5 bytes + random stuff (0xb)
payload_header->session_id = session_id;
payload_header->seq_service_id = seq_service_id++; // starts at 0
payload_header->packet_type = 0xFF;
payload_header->magic[0] = 0xAD;
payload_header->magic[1] = 0x1A;
rnd_gen((u8*) &payload_header->prng_random, 0x0B);
    
//encrypt payload
aes128cbc_enc(be2sc_key, zero_iv, secure_payload_buf, length, secure_payload_buf);

// create footer: omac1 of the whole packet
aesOmac1Mode(secure_payload_buf + length, secure_payload_buf, length, be2sc_key, sizeof(be2sc_key)*8);

//Set regular header
memcpy(sc_packet, auth1_pkt_header, 0x10);

//Send packet. 0x40 Bytes
</pre>

=== Step 3c - Validate AUTH1 ===
First, check the header/footer.
* Calculate AES [http://en.wikipedia.org/wiki/One-key_MAC OMAC] over the packet length and compare to [http://en.wikipedia.org/wiki/One-key_MAC OMAC] from syscon. Use sc2be key.
* Decrypt internal packet with sc2be key. Use AES128CBC
* Compare returned session_id and seq_service_id.
* Check secure_payload_buf[0x2] == 0.

Then check the AUTH1 response
<pre>
// decrypt secure_payload
for (i = 0x0; i < 0x20; i += 0x10)
    aes128cbc(auth_key_2_0x01, zero_iv, secure_payload_buf + 0x10 + i, 0x10, secure_payload_buf + 0x10 + i);
    
// check if challange returned from syscon is correct
res = memcmp(secure_payload_buf + 0x10, random_shit, 0x10);
if (res != 0)
    return -1;
    
// save the new challange needed for AUTH2
memcpy(auth_challenge, secure_payload_buf + 0x20, 0x10);
</pre>

=== Step 3d - AUTH2 to SC ===
<pre>
//AUTH2 Challenge Payload
aes128cbc_enc(auth_key_1_0x01, zero_iv, auth_challenge, 0x10, secure_payload_buf + 0x10);

//length = 0x20
//Create secure header/footer
// create header: 5 bytes + random stuff (0xb)
payload_header->session_id = session_id;
payload_header->seq_service_id = seq_service_id++; // starts at 0
payload_header->packet_type = 0xFF;
payload_header->magic[0] = 0xAD;
payload_header->magic[1] = 0x1A;
rnd_gen((u8*) &payload_header->prng_random, 0x0B);
    
//encrypt payload
aes128cbc_enc(be2sc_key, zero_iv, secure_payload_buf, length, secure_payload_buf);

// create footer: omac1 of the whole packet
aesOmac1Mode(secure_payload_buf + length, secure_payload_buf, length, be2sc_key, sizeof(be2sc_key)*8);

//Set regular header
memcpy(sc_packet, auth2_pkt_header, 0x10);

//Put packet - 0x40 packet length
</pre>

=== Step 3e - Validate AUTH2 ===
Again, check the header/footer.
* Calculate AES [http://en.wikipedia.org/wiki/One-key_MAC OMAC] over the packet length and compare to [http://en.wikipedia.org/wiki/One-key_MAC OMAC] from syscon. Use sc2be key.
* Decrypt internal packet with sc2be key. Use AES128-CBC
* Compare returned session_id and seq_service_id.
* Check secure_payload_buf[0x2] == 0.

<pre>
// encrypt random_shit using auth_challenge (returned from AUTH1 reply) as key and 0 IV
aes128cbc_enc(auth_challenge, zero_iv, random_shit, 0x10, session_key);

// encrypt result in place with session_key_create[0x10 * sess_id] and IV 0 (result will be the session_key)
aes128cbc_enc(session_key_create + (session_id * 0x10), zero_iv, session_key, 0x10, session_key);

// use the session_key to decrypt auth2_payload in place (0x10)
aes128cbc(session_key, zero_iv, secure_payload_buf + 0x10, 0x10, secure_payload_buf + 0x10);
    
// compare the result with a 0x10 zero string
res = memcmp(secure_payload_buf + 0x10, zero_iv, 0x10);

//res == 0x0 is good.
</pre>

== Step 4 - Profit? ==
You are now authenticated with syscon, and can use privileged commands. Just use the session_key calculated from the AUTH2 reply to encrypt/decrypt responses.


= Some Samples from DYN-001 Syscon SPI SC Comms =

* https://mega.nz/#!2w00VAjK!u10PD2b0G-MqwUZTBD4Nv_by36QNn8P-jVIUxq0pLDM

<pre>
00 70 0B 93 FF DC CF 43 97 68 49 06 71 32 27 C1 
E8 9F D1 73 DA 4D FA A2 7C 6F 24 F7 BD 95 37 EC 
F9 17 5B BB DB 32 E8 82 55 3F 51 23 F1 71 E6 88
</pre>

{{Reverse engineering}}<noinclude>[[Category:Main]]</noinclude>