HDD Encryption: Difference between revisions

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bi $lr
bi $lr
</pre>
</pre>
http://pastie.org/4503109


==Result==
==Result==

Revision as of 05:14, 16 August 2012

Introduction

  • The following information was reverse engineered from LV1, Storage Manager in LPAR1 and sb_iso_spu_module.self.
  • I'm able to decrypt/encrypt my PS3 HDD and VFLASH on PC now.

HDD Encryption

  • XTS-AES-128 is used to encrypt all data on PS3 HDD.
  • XTS is NOT CBC !!! It's AES-ECB with tweak XORing. AES-CBC is impractical for HDD encryption. Each sector can be encrypted/decrypted independantly from other HDD sectors.
  • Good paper about XTS-AES: http://ntnu.diva-portal.org/smash/get/diva2:347753/FULLTEXT01
  • VFLASH is encrypted twice. First with ENCDEC keys and then with ATA keys.
  • Tweak and data XTS keys are of size 32 bytes but only the first 16 bytes are used.
  • You can set and clear ATA keys with my Linux ps3encdec device driver which i use to test HDD/VFLASH encryption. But be careful, never set/clear ATA keys while some HDD regions/partitions are mounted !!! You will corrupt your data on your HDD !!!

Dumping ATA Keys

  • I modified sb_iso_spu_module.self to dump ATA keys.
  • ATA keys are passed as parameters to sb_iso_spu_module.self.

Program

My SPU program to dump ATA tweak and data XTS keys to PPU memory with spuisofs: 

/*
 * Dump ATA keys
 *
 * Copyright (C) 2012 glevand <[email protected]>
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published
 * by the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

.text

start:

	ila		$2, 0x3dfa0
	lr		$sp, $2

	ila		$80, 0x3e000
	lr		$81, $3

	stqd		$7, 0($80)	# store upper 16bytes of ATA data key
	stqd		$8, 0x10($80)	# store lower 16bytes of ATA data key
	stqd		$9, 0x20($80)
	stqd		$10, 0x30($80)
	stqd		$11, 0x40($80)	# store upper 16bytes of ATA tweak key
	stqd		$12, 0x50($80)	# store lower 16bytes of ATA tweak key

	lr		$3, $80
	lr		$4, $81
	il		$5, 0x60
	il		$6, 0x7
	il		$7, 0x20
	brsl		$lr, 0x10	# mfc_dma_xfer

	il		$3, 0x7
	brsl		$lr, 0x28	# mfc_dma_wait

	stop		0x666		# our evil stop code :)

/*
 * r3 - LSA
 * r4 - EA
 * r5 - size
 * r6 - tag
 * r7 - cmd
 */
mfc_dma_xfer:

	wrch		$ch16, $3
	wrch		$ch17, $4
	shlqbyi		$4, $4, 4
	wrch		$ch18, $4
	wrch		$ch19, $5
	wrch		$ch20, $6
	wrch		$ch21, $7

	bi		$lr

/*
 * r3 - tag
 */
mfc_dma_wait:

	il		$2, 0
	nop		$127
	hbra		2f, 1f
	wrch		$ch23, $2

1:

	rchcnt		$2, $ch23
	ceqi		$2, $2, 1
	nop		$127
	nop		$127
	nop		$127
	nop		$127
	nop		$127

2:

	brz		$2, 1b
	hbr		3f, $lr
	rdch		$2, $ch24
	il		$2, 1
	shl		$2, $2, $3
	wrch		$ch22, $2
	il		$2, 2
	wrch		$ch23, $2
	rdch		$2, $ch24
	nop		$127

3:

	bi		$lr

http://pastie.org/4503109

Result

[glevand@arch dump_ata_keys]$ ./dump_ata_keys ../dump_ata_keys.self ../eid4
spuisofs found at /mnt
arg1 kernel virtual address d000000000722000
shadow: spe_execution_status 7
priv2: puint_mb_R 2
shadow: spe_execution_status b
problem: spu_status_R 6660082
[glevand@arch dump_ata_keys]$ hexdump -C /mnt/arg1 
...
Here are your ATA tweak and data XTS keys
Data key is at offset 0x0 (32 bytes)
Tweak key is at offset 0x40 (32 bytes)
...

Dumping ENCDEC Keys

  • VFLASH is encrypted twice. First with ENCDEC keys and then with ATA keys.
  • You cannot dump ENCDEC keys with sb_iso_spu_module.self. They are set in lv1ldr only.
  • I used a modified lv1ldr with my Linux spuldrfs driver and dumped ENCDEC keys.
  • XTS-AES-128 with 128bit tweak key and 128bit data key, just like ATA keys.
  • ENCDEC tweak and data keys are passed to lv1ldr NOT in clear text.
  • ENCDEC keys are computed by lv1ldr with AES-CBC-256 by encrypting 32byte seeds.
  • metldr passes to lv1ldr AES-CBC-256 IV and key which are used to compute ENCDEC keys.
  • I tested my ENCDEC keys with my ps3encdec Linux driver and set them again, and VFLASH was still working fine. As soon as i changed some bits in these keys, VFLASH could not be decrypted properly anymore :) It means keys are correct.

ENCDEC Key Seeds

  • Use the dumped ENCDEC IV and key to encrypt these seeds and you will get your ENCDEC keys for VFLASH.
  • You can find these seeds in lv1ldr.

Tweak key seed: 

glevand@debian:~$ hexdump -C data1.bin
00000000  e2 d0 5d 40 71 94 5b 01  c3 6d 51 51 e8 8c b8 33  |..]@q.[..mQQ...3|
00000010  4a aa 29 80 81 d8 c4 4f  18 5d c6 60 ed 57 56 86  |J.)....O.].`.WV.|
00000020

Data key seed: 

glevand@debian:~$ hexdump -C data2.bin
00000000  02 08 32 92 c3 05 d5 38  bc 50 e6 99 71 0c 0a 3e  |..2....8.P..q..>|
00000010  55 f5 1c ba a5 35 a3 80  30 b6 7f 79 c9 05 bd a3  |U....5..0..y....|
00000020

Program

Here is my SPU program which i used to dump ENCDEC keys: 

/*
 * Dump ENCDEC keys
 *
 * Copyright (C) 2012 glevand <[email protected]>
 * All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published
 * by the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

.text

start:

	ila		$2, 0x3dfa0
	lr		$sp, $2

	ila		$3, 0x666
	wrch		$ch30, $3

	# wait until we get message from PPU

1:

	brsl		$lr, 0x54	# in_mbox_count
	brz		$3, 1b

	brsl		$lr, 0x54	# in_mbox_read

	ila		$80, 0x3e000
	lqd		$81, 0($80)	# load PPU EA
	ila		$82, 0x0

	lqd		$83, 0($82)
	stqd		$83, 0($80)	# store upper 16bytes of ENCDEC key
	lqd		$83, 0x10($82)
	stqd		$83, 0x10($80)	# store lower 16bytes of ENCDEC key
	lqd		$83, 0x20($82)
	stqd		$83, 0x20($80)	# store ENCDEC IV

	lr		$3, $80
	lr		$4, $81
	il		$5, 0x30
	il		$6, 0x7
	il		$7, 0x20
	brsl		$lr, 0x20	# mfc_dma_xfer

	il		$3, 0x7
	brsl		$lr, 0x38	# mfc_dma_wait

	stop		0x666		# our evil stop code :)

/*
 * no input parameters
 */
in_mbox_count:
	rchcnt		$3, $ch29
	bi		$lr

/*
 * no input parameters
 */
in_mbox_read:
	rdch		$3, $ch29
	bi		$lr

/*
 * r3 - LSA
 * r4 - EA
 * r5 - size
 * r6 - tag
 * r7 - cmd
 */
mfc_dma_xfer:

	wrch		$ch16, $3
	wrch		$ch17, $4
	shlqbyi		$4, $4, 4
	wrch		$ch18, $4
	wrch		$ch19, $5
	wrch		$ch20, $6
	wrch		$ch21, $7

	bi		$lr

/*
 * r3 - tag
 */
mfc_dma_wait:

	il		$2, 0
	nop		$127
	hbra		2f, 1f
	wrch		$ch23, $2

1:

	rchcnt		$2, $ch23
	ceqi		$2, $2, 1
	nop		$127
	nop		$127
	nop		$127
	nop		$127
	nop		$127

2:

	brz		$2, 1b
	hbr		3f, $lr
	rdch		$2, $ch24
	il		$2, 1
	shl		$2, $2, $3
	wrch		$ch22, $2
	il		$2, 2
	wrch		$ch23, $2
	rdch		$2, $ch24
	nop		$127

3:

	bi		$lr

Result

  • Test run with spuldrfs on Linux 3.5.1
glevand@debian:~/dump_encdec_keys$ ./dump_encdec_keys ../ps3/metldr ../dump_encdec_keys.self 
spuldrfs found at /mnt
buf1 kernel virtual address d000000004311000
buf2 kernel virtual address d000000004412000
priv2: puint_mb_R 1
problem: pu_mb_R 1
priv2: puint_mb_R 666
problem: spu_status_R 2
glevand@debian:~/dump_encdec_keys$ hexdump -C /mnt/buf2
...
Here are your ENCDEC keys
ENCDEC keys key is at offset 0x0 (32 bytes)
ENCDEC keys IV is at offset 0x20 (16 bytes)
...
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