NPA - Revision history

Orin: /* Addition Notes */

2019-09-12T16:58:50Z

Addition Notes

← Older revision		Revision as of 16:58, 12 September 2019
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	\|}		\|}

			*Only one game has been tested so it is an assumption that there can be different keys thus a list of specific games and the key they used will be recorded here.

	== Tools ==		== Tools ==
	Coming soon...		Coming soon...

Orin: /* Structure */

2019-09-12T16:56:58Z

Structure

← Older revision		Revision as of 16:56, 12 September 2019
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	\| 4 Bytes \|\| Index Size \|\|		\| 4 Bytes \|\| Index Size \|\|
	\|-		\|-
	\| * Bytes \|\| Index Data (protected) \|\|		\| x Bytes \|\| Index Data (protected) \|\|
	\|-		\|-
	\| * Bytes \|\| File Data (protected) \|\|		\| x Bytes \|\| File Data (protected) \|\|
	\|}		\|}

Orin: /* Structure */

2019-09-12T16:56:13Z

Structure

← Older revision		Revision as of 16:56, 12 September 2019
Line 12:		Line 12:
	\| 4 Bytes \|\| Index Size \|\|		\| 4 Bytes \|\| Index Size \|\|
	\|-		\|-
	\| ? Bytes \|\| Index Data (protected) \|\|		\| * Bytes \|\| Index Data (protected) \|\|
	\|-		\|-
	\| ? Bytes \|\| File Data (protected) \|\|		\| * Bytes \|\| File Data (protected) \|\|
	\|}		\|}

Orin: /* Addition Notes */

2017-07-27T06:44:19Z

Addition Notes

← Older revision		Revision as of 06:44, 27 July 2017
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	== Addition Notes ==		== Addition Notes ==
	This format obscures the data it stores. Both the index and data are protected in the same way. The first data read is 4 bytes at the start of the file. This is the size of the index and it's value is not obscured. Next the full index is read into memory and decoded by XOR'ing it by the key. Once the index is processed, data can be loaded but the data is protected the same way the index is, XOR'ed by a key. The game makes use of the XMM registers (SSE) and the assembly code ends up being a small, tight loop with just a few assembly instructions such as MOVDQA and PXOR.		This format obscures the data it stores. Both the index and data are protected in the same way. The first data read is 4 bytes at the start of the file. This is the size of the index and it's value is not obscured. Next the full index is read into memory and decoded by XOR'ing it by the key. Once the index is processed, data can be loaded but the data is protected the same way the index is, XOR'ed by a key. The game makes use of the XMM registers (SSE) and the assembly code ends up being a small, tight loop with just a few assembly instructions such as MOVDQA and PXOR. Unsure what the C++ equivalent would be. Probably uses some libraries I'm not used to but if I can find those, compile a sample program and disassemble it, might be able to make a more optimized program. Although for a extractor/packing program, speed or efficiency is more or less irrelevant baring extreme cases.

	{\| class="wikitable"		{\| class="wikitable"

Orin: /* Addition Notes */

2015-12-14T21:23:59Z

Addition Notes

← Older revision		Revision as of 21:23, 14 December 2015
Line 38:		Line 38:

	== Addition Notes ==		== Addition Notes ==
	This format ~~obscure~~ the data it stores. Both the index and data are protected in the same way. The first data read is 4 bytes at the start of the file. This is the size of the index and it's value is not obscured. Next the full index is read into memory and decoded by XOR'ing it by the key. Once the index is processed, data can be loaded but the data is protected the same way the index is, XOR'ed by a key. The game makes use of the XMM registers (SSE) and the assembly code ends up being a small, tight loop with just a few assembly instructions such as MOVDQA and PXOR.		This format obscures the data it stores. Both the index and data are protected in the same way. The first data read is 4 bytes at the start of the file. This is the size of the index and it's value is not obscured. Next the full index is read into memory and decoded by XOR'ing it by the key. Once the index is processed, data can be loaded but the data is protected the same way the index is, XOR'ed by a key. The game makes use of the XMM registers (SSE) and the assembly code ends up being a small, tight loop with just a few assembly instructions such as MOVDQA and PXOR.

	{\| class="wikitable"		{\| class="wikitable"

Orin: /* Addition Notes */

2015-12-14T21:23:49Z

Addition Notes

← Older revision		Revision as of 21:23, 14 December 2015
Line 38:		Line 38:

	== Addition Notes ==		== Addition Notes ==
	This format ~~obsurse~~ the data it stores. Both the index and data are protected in the same way. The first data read is 4 bytes at the start of the file. This is the size of the index and it's value is not ~~obsured~~. Next the full index is read into memory and decoded by XOR'ing it by the key. Once the index is processed, data can be loaded but the data is protected the same way the index is, XOR'ed by a key. The ~~program~~ makes use of the XMM registers (SSE) and the assembly code ends up being a small, tight loop with just a few assembly instructions such as MOVDQA and PXOR.		This format obscure the data it stores. Both the index and data are protected in the same way. The first data read is 4 bytes at the start of the file. This is the size of the index and it's value is not obscured. Next the full index is read into memory and decoded by XOR'ing it by the key. Once the index is processed, data can be loaded but the data is protected the same way the index is, XOR'ed by a key. The game makes use of the XMM registers (SSE) and the assembly code ends up being a small, tight loop with just a few assembly instructions such as MOVDQA and PXOR.

	{\| class="wikitable"		{\| class="wikitable"

Orin: /* Addition Notes */

2015-12-14T20:19:00Z

Addition Notes

← Older revision		Revision as of 20:19, 14 December 2015
Line 38:		Line 38:

	== Addition Notes ==		== Addition Notes ==
	This format obsurse the data it stores. Both the index and data are protected in the same way. The first data read is 4 bytes at the start of the file. This is the size of the index and it's value is not obsured. Next the full index is read into memory and decoded by XOR'ing it by the key. Once the index is processed, data can be loaded but the data is protected the same way the index is~~. It's~~ XOR'ed by a key. The program makes use of the XMM registers (SSE) and the assembly code ends up being a small, tight loop with just a few assembly instructions such as MOVDQA and PXOR.		This format obsurse the data it stores. Both the index and data are protected in the same way. The first data read is 4 bytes at the start of the file. This is the size of the index and it's value is not obsured. Next the full index is read into memory and decoded by XOR'ing it by the key. Once the index is processed, data can be loaded but the data is protected the same way the index is, XOR'ed by a key. The program makes use of the XMM registers (SSE) and the assembly code ends up being a small, tight loop with just a few assembly instructions such as MOVDQA and PXOR.

	{\| class="wikitable"		{\| class="wikitable"

Orin at 20:16, 14 December 2015

2015-12-14T20:16:48Z

← Older revision		Revision as of 20:16, 14 December 2015
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	\|}		\|}

	== ~~Research~~ ==		== Addition Notes ==
	~~The~~ index data is protected. The ~~way the program reads and processes this space~~ is ~~by first loading~~ 4 bytes at the start of the file ~~that~~ is the size of the ~~protected~~ index. ~~It then loads~~ the ~~whole~~ index into memory~~. It then puts some data into the XMM0 register, which looks like~~ the key. ~~So far~~, ~~it looks like it's static~~ but ~~I'll have to check if that's true for other files. It then enters~~ the ~~main decoding loop and loads 16 bytes into~~ the ~~next register, XMM1~~. It ~~then~~ XOR ~~XMM1~~ by ~~XMM0~~. ~~It then puts~~ the ~~decoded part back into memory. By using SIMD related stuff~~, ~~the program can decode 16 bytes at once~~ with just a few instructions ~~compared to exponentiation more steps to decode 1 byte at a time with a different key, constantly moving data in~~ and ~~out of the general registers. Just need to figure out if I can find a C/C++ implementation that can let me do the same. (128bit number xor? o~~.~~O wut...)~~		This format obsurse the data it stores. Both the index and data are protected in the same way. The first data read is 4 bytes at the start of the file. This is the size of the index and it's value is not obsured. Next the full index is read into memory and decoded by XOR'ing it by the key. Once the index is processed, data can be loaded but the data is protected the same way the index is. It's XOR'ed by a key. The program makes use of the XMM registers (SSE) and the assembly code ends up being a small, tight loop with just a few assembly instructions such as MOVDQA and PXOR.

	~~Some notes about structure. File names appear to be 2 byte char strings~~ (~~wstrings?~~).		{\| class="wikitable"
			\|-
			! Key !! Game(s)
			\|-
			\| BD AA BC B4 AB B6 BC B4 \|\| Steins;Gate (JAST USA)

	~~Key = BD AA BC B4 AB B6 BC B4 Unsure if this applies to other games but it works for Steins;Gate.~~		\|}

	~~Also, file data is protected in the same way the index data is.~~

	~~File names are not in an easy encoding to deal with. As soon as you get into character encoding/code pages, things start to become complex fast.~~

	== Tools ==		== Tools ==
	Coming soon...		Coming soon...

Orin: /* Structure */

2015-12-14T19:55:09Z

Structure

← Older revision		Revision as of 19:55, 14 December 2015
Line 12:		Line 12:
	\| 4 Bytes \|\| Index Size \|\|		\| 4 Bytes \|\| Index Size \|\|
	\|-		\|-
	\| ? Bytes \|\| ~~Protected~~ Index Data \|\|		\| ? Bytes \|\| Index Data (protected) \|\|
	\|-		\|-
	\| ? Bytes \|\| ~~Protected~~ File Data \|\|		\| ? Bytes \|\| File Data (protected) \|\|
	\|}		\|}

Orin at 05:22, 25 July 2015

2015-07-25T05:22:27Z

← Older revision		Revision as of 05:22, 25 July 2015
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	Also, file data is protected in the same way the index data is.		Also, file data is protected in the same way the index data is.

			File names are not in an easy encoding to deal with. As soon as you get into character encoding/code pages, things start to become complex fast.

	== Tools ==		== Tools ==
	Coming soon...		Coming soon...