Simple console program with a few features related to Dark Souls III saves:
- Pack/Unpack encrypted Dark Souls III save (SL2) files
- Pack/Unpack unencrypted BND4 archives (Supports only those with 32 byte headers)
- Patch a Dark Souls III save (SL2) file to change the linked account, allowing save transfer across accounts.
This program was specifically made for this last feature, and serves as an alternative to the DS3 Save Manager. The DS3 Save Manager seems to use some kind of DLL/code injection and may thus cause a soft ban (Note: I don't know if the author avoided this or how good the game's code integrity check is). This tool directly modifies the linked Steam account ID stored in the save file, and should pass the save consistency check, IF the provided safe is already valid. However, it is very new and some testing will be required to ensure this.
When unpacking a save, you get 12 USER_DATA XXX files. Those numbered 000 to 009 are the character save slots. I know 010 stores some global information (including the linked account ID and character slot info), but I have not looked deeply into it. Similarly, the 011 entry appears to be in the DCX format, and I did not investigate its contents.
Note that loading a modified save back into the game can lead to a softban. Either experiment on an account that is already penalized or completely block the game's connection to the Internet (being offline on Steam is NOT enough), and be sure you know what you are doing!
Dark Souls III saves are stored as BND4 archives, a binder file format used by FromSoftware since Dark Souls II. In the case of DS3, each USER_DATA XXX contains the following data:
- A 16-byte MD5 checksum of the encrypted data (including the IV)
- The 16-byte initialisation vector (IV) used for encryption
- The entry data, encrypted using 128-bit AES-CBC with the key
FD464D695E69A39A10E319A7ACE8B7FA. Credit to Atvaark for finding this key. More information about FromSoft file formats are available on his DarkSoulsIII.FileFormats repo.