invoxiplaygames.uk
my research and reverse engineering notes/utilities relating to the Xbox 360 (Mirrored from https://github.com/InvoxiPlayGames/x360-research)
system link encryption
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official-software/README.md
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official-software/README.md
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* BDES Header - The "BDES" header found at the start of system update XZP
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files.
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* System Software
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* Security Overview - A rough high-level overview of the security features
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and system of the Xbox 360.
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* Software Updates - A rough overview of the software update process.
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-
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* Hypervisor
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* Key Derivation - Notes on how the hypervisor derives decryption keys for
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various parts of the system.
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* Kernel
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* Memory Map - information about the way memory is mapped out in the official
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Xbox 360 kernel.
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* Networking - **no information here is about Xbox Live.**
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* System Link - The system link / LAN multiplayer connection and encryption
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process.
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* System Software
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* Security Overview - A rough high-level overview of the security features
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and system of the Xbox 360.
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* Software Updates - A rough overview of the software update process.
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official-software/bootloaders/cd.md
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official-software/bootloaders/cd.md
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**Emma's Xbox 360 Research Notes - Bootloaders**
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Updated 2nd February 2024.
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Updated 23rd October 2024.
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Stub page, for the most part. Needs some work.
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···
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## Launching the Hypervisor
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Since CD bootloader runs in a 32-bit translated address space, it can't just
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jump to the hypervisor's entrypoint/reset vector. When loading into
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It does the following:
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jump to the hypervisor's entrypoint/reset vector. When loading into the
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hypervisor, it does the following:
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* Clears out any bootloader stages from instruction and data cache
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* Flushes any bootloader stages from cache and into RAM(?)
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* Clears some special purpose registers
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* Invalidates the translation lookaside buffer
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* Disables instruction and data address translation in the MSR
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```
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launch_hypervisor:
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; flush CE/CF/CG from data and instruction cache (i think? check)
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; store CE/CF/CG into data cache and invalidate instruction cache
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; (i think? check)
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cache_flush:
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lis r3, 0x28 ; r3 = 0x280000
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li r4, 0x2a00
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official-software/networking/system_link.md
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official-software/networking/system_link.md
···
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**Emma's Xbox 360 Research Notes - Networking**
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Updated 23rd October 2024.
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Stub page.
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# System Link
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To protect network traffic on LAN multiplayer games from being tampered with,
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the Xbox 360 employs network encryption as well as non-standard networking on
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local LAN multiplayer.
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This article also applies to Games for Windows - LIVE, in sections discussing
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cross-platform system link.
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## Encryption Key Initialisation
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When a title initialises WinSock and XNet, `CXnIp::IpInit` initialises several
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encryption keys, likely for three different cryptography types, AES, 3DES and
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DES. *(TODO: Check)* Pseudocode for the derivation process is as follows:
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(Note that this is pseudocode of just key initialisation - it is not C that can
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be compiled nor is it any specific CXnIp function)
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```c
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void initialise_ip_encryption(CXnIp *this) {
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struct {
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char id;
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uint8_t key[0x10];
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} config_buffer; // sizeof(config_buffer) = 0x11
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struct {
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uint8_t key1[0x14];
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uint8_t key2[0x14];
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uint8_t key3[0x14];
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} key_buffer; // sizeof(key_buffer) = 0x3c
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// fetch the LAN key from the executable (360) or config file (GfWL)
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uint8_t *lan_key = get_lan_key();
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if (lan_key == NULL) // no key set = use random key, useless lmao
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XeCryptRandom(config_buffer.key, sizeof(config_buffer.key));
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else
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memcpy(config_buffer.key, lan_key, sizeof(config_buffer.key));
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// only 360 takes this path, GfWL always goes down the cross-platform path
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#ifdef XBOX360
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if (use_cross_platform() == false) {
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XeCryptRandom(&key_buffer, sizeof(key_buffer));
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config_buffer.id = 0;
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XeCryptHmacSha(ROAMABLE_KEY, &config_buffer, sizeof(config_buffer), NULL, 0, NULL, 0, key_buffer.key1, 0x14);
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config_buffer.id = 1;
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XeCryptHmacSha(ROAMABLE_KEY, &config_buffer, sizeof(config_buffer), NULL, 0, NULL, 0, key_buffer.key2, 0x14);
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config_buffer.id = 2;
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XeCryptHmacSha(ROAMABLE_KEY, &config_buffer, sizeof(config_buffer), NULL, 0, NULL, 0, key_buffer.key3, 0x14);
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} else
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#endif
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{
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// encrypt the title key with the cross-platform system link key,
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// protected by the hypervisor / some mad x86 fuckery
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int r = XeKeysAesCbc(XPLAT_SYSLINK_KEY, config_buffer.key, 0x10, config_buffer.key, &key_buffer /*this is IV, what?*/, ENCRYPT);
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if (!r) // encryption failed, use random key, useless
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XeCryptRandom(config_buffer.key, sizeof(config_buffer.key))
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config_buffer.id = 0;
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XeCryptSha(&config_buffer, 0x11, NULL, 0, NULL, 0, key_buffer.key1, 0x14);
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config_buffer.id = 1;
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XeCryptSha(&config_buffer, 0x11, NULL, 0, NULL, 0, key_buffer.key2, 0x14);
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config_buffer.id = 2;
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XeCryptSha(&config_buffer, 0x11, NULL, 0, NULL, 0, key_buffer.key3, 0x14);
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}
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// use first 0x10 bytes of key1 for some 0x10 byte key, likely AES
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memcpy(this->lan_aes_key, key_buffer.key1, sizeof(this->lan_aes_key)); // 0x10
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// use the next 0x4 bytes of key1 and all of key2 for some 0x18 byte key, likely 3DES
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memcpy(this->lan_3des_key, key_buffer + 0x10, sizeof(this->lan_3des_key)); // 0x18
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XeCryptDesParity(this->lan_3des_key, sizeof(this->lan_3des_key), this->lan_3des_key);
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// use the first 0x8 bytes of key3 for some 0x8 byte key, likely DES
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memcpy(this->lan_des_key, key_buffer.key3, sizeof(this->lan_des_key));
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}
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```