SCECAF

Files from coredumps or crash reports are in SCECAF format when encrypted. The file names will be either crash_report.caf or a coredump with a filetype of .spsp2dmp. All data is in little endian format.

SCECAF Container File Structure

Structure:

• Header
• Repeating Section Meta Blocks
• Repeating Section Hash Blocks
• Header Hash
• Sections

Header

Offset	Size	Description
0x0	0x8	0x5343454341460000 magic SCECAF\0\0
0x8	0x8	Type/Version? (always 2)
0x10	0x8	HMAC Key ID (always 1)
0x18	0x8	Number of sections
0x20	0x8	Size of Header
0x28	0x8	Total Sections Size

Section Meta Block

Offset	Size	Description
0x0	0x8	Section ID (starts with 0)
0x8	0x8	Section Start Offset
0x10	0x8	Section Length
0x18	0x8	HMAC Key ID (Always 1)
0x20	0x8	Encryption Key ID (Always 2)
0x28	0x10	Encryption IV
0x38	0x8	Filler

Section Hash Block

Offset	Size	Description
0x0	0x8	Section ID (starts with 0)
0x8	0x20	HMAC Hash
0x28	0x8	Filler

Header Hash Block

Offset	Size	Description
0x0	0x20	HMAC Hash

Sections

Sections are data (normally Gzipped ELF core or CPAD padding) that is encrypted. The encryption is AES 128 in CBC mode. The IV comes from the Section Meta Header. The HMAC is the SCE-modified HMAC SHA256.

The current theory is that the key to use is specified in the Section Meta Header, though since there are no sample that vary (same ID and same key), it is just a guess.

Kernel Coredump Encrypted ELF

On FW 2.12 and greater, a SceKernelProcess coredump can be created when a critical error (such as a DABT or PABT) occurs in a syscall or kernel thread. On reboot, the data is encrypted and compressed prior to being wrapped in a SCECAF container.

Process

1. The exception handler in the kernel (SceExcpmgr) calls SMC 0x122.
2. TrustZone configures Pervasive device and SceGrab device. Need why still?
3. Reset SceDmac5Reg Device
4. Create a SceCrashDumpHeader at PA 0x58000000 on retail and 0x60000000 on DevKit (maybe only in DevKit Memory Size mode)
5. Map SceCrashDumpZero to start of DRAM at PA 0x40000000
6. Configure SceDmac5Reg and loop through all of VRAM at PA 0x20000000 in 0x1000 byte chunks
7. Configure SceDmac5Reg and loop through all of DRAM at PA 0x40200000 in 0x10000 byte chunks
8. Call SMC 0x11A to initiate a reboot in requested coredump mode
9. Upon reboot, coredump handler (SceCrashDump) will create a SCECAF container of the data from PA 0x58000000 or 0x60000000