Talk:Savegames

Unknowns:

• Hashes at the end of each DIFI blob.
• How order / location of hash vs. partitioned blocks is determined. (since not sequentially).

I think there should be a page with infos on how to dump/restore saves. Matyapiro:So then,I show you how to do dump and restore saves. First,you should have either Nintendo DS/Lite or NDS Adapter a tool to dump DS saves. It can restore saves,but Almost saves cannot dump with NDS Adapter,but some of them can. If you have Nintendo DS or DS Lite,you should try DSaveManager. It uses FTP to dump saves,only dump. Last,I show you another save backup tool for DS. NDS Backup Tool by Rudolph. Eepinator by WinterMute

Hardware:

• NDS Adapter Plus (by hkems)
• DS/DSLite & DSaveManager
• Neo SMS4 (by neoflash, untested)

But I cannot find any key word like player name,high score or play time if I decrypt the save.

How do you think about whether any other encryption or special way to read/write save used ?Matyapiro

• I found those things in a SSFIV saved game...

The important offsets are usually constant, the values change, it's not hard to look for an offset of data that's changing predictably after you re-save.

Sometimes you have to use your imagination. To find 20,000 points in SSFIV, you'd search for "0xC8" ( 200 in decimal == "20,000" in game ) because it stores the points in multiples of 100. It's easier to see if you're editing saves in front of yourself and constantly making minor changes to it - to see where those changes show up later. --jl

So we need analyze project with each save.?Matyapiro

• Only if you're trying to figure out where the game data is. Just common sense.
• You can examine each save manually after making small changes ( while playing with it on the 3DS ) but we still don't know what all the hashes are being used for.

spell error?What's this? ~Partitions are "catted" together　 Matyapiro

• Concatenated. Attached, joined, appended. One follows after the other. lol.

I looked into that blockmap structure thing, but I fear I didn't get it right...

• sectors would be 4096 bytes. The Rayman 3D save is 128mb and has 31 blockmap entries; the Ridge Racer 3D save is 1mb but only has 127 blockmap entries (however the second half of that save is mostly a mirror of the first half, except for the first (special) sector).
• the dword at the beginning of the image tells the sector size (1<<val = sector size)?
• blockmap entries are phys_sec,alloc_cnt,checksum instead of checksum,phys_sec,alloc_cnt. There are then two spare bytes between the blockmap and the journal.
• bit7 of phys_sec in blockmap entries is set when the entry's checksum isn't zero

--Luigi2us 18:29, 4 August 2011 (CEST)

3DS Save De/Encrypter

3DS Save De/Encrypter application needs useful info on the header Blockmap\Journal foe save modification. I'm so close i can feel it. --Immortal 10:10, 18 August 2011 (GMT)

Let's look into those blockmap/journal checksums

• there's one 8bit checksum per 0x200 block
• blocks containing only 0xFF yield a checksum of 0x0F
• blocks containing only 0x00 yield a checksum of 0xB9
• checksums seem to apply to encrypted blocks. In the case of Ridge Racer, all-zero 0x200 blocks yield 0xE4 instead of Rayman3D's 0xB9. However, all-FF blocks always yield 0x0F since they aren't encrypted.

This is most likely a custom checksum algorithm. Standard CRC8 would yield zero for a zero block. Wrong. Checksums of zero blocks are actually equivalent to the checksum of the game's XOR key.

--Luigi2us 19:59, 28 August 2011 (CEST)

@Luigi2us the checksum algorithm can be a crc because XorIn as well as XorOut can be use that result in non zero results

there is a way to find out if it is a crc or something like that or something simple

xor the message by B1 than the checkbit change by C1 xor the message with B2 and the checkbyte change by C2 xor the message by (B1 xor B2) and the checkbyte should change by (C1 xor C2)

example crc in this case crc-16 but also work with crc-8

06 06 01 05 crc is 1A21

06 06 01 05 xor 01 02 03 04 = 07 04 02 01 crc is 1580

06 06 01 05 xor 08 09 01 02 = 0E 0F 00 07 crc is 2973

06 06 01 05 xor 01 02 03 04 xor 08 09 01 02 = 0F 0D 03 03 crc is 26D2 (2973 xor 1580 xor 1A21)

that also work if a unknown XorIn or XorOut is used

that don't work for most hash functions

ADD:Sorry for my bad English

--ichfly

Sounds like a good idea. We just need to find 4 blocks A,B,C,D in one save so that B=A^x, C=A^y and D=A^x^y. --Luigi2us 22:54, 29 August 2011 (CEST)