View source for Sims 3:0x073FAA07

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Signed assemblies, encrypted .NET assemblies. They function as the game scripts.

These are the scripts that run when a Sim interacts with an object, or another Sim, or just performs its own inner metabolic processes.

Currently no way is known to get the game to accept piecemeal overrides, so global hacks for a particular assembly as of 6 / 6 / 2009 are having to replace the entire set - meaning that you can only have global hacks for a particular assembly from one creator at a time.

It is probably possible to create new scripts for new custom objects, however.   Technical details coming later.

== Where used ==
*  gameplay.package
* scripts.package
* simcore.package 
It is still to be confirmed whether assemblies with user code can reside elsewhere.

== Data format ==
(Provided by [[User:Rick|Rick]].)
 BYTE            unknown1 ;; must be 1
 DWORD           unknown2 ;; must be 0x2BC4F79F
 BYTE[64]        checksum
 WORD            count
 QWORD[count]    ''decryption table''
 BYTE[count*512] ''encrypted data''
(I think the checksum and encryption method are MD5Cng -- PLJ.)

=== Decryption method ===

Initialise the ''decryption seed'' by scanning the ''decryption table'':
 foreach(QWORD q in ''decryption table'') ''decryption seed'' += q

Truncate (mask off) the ''decryption seed'' to the length of ''decryption table'':
 ''decryption seed'' = ''decryption seed'' & (''decryption table'' Length - 1)

Now process each QWORD in the ''decryption table''.  Where an entry has bit 0 set, write 512 zero bytes to the output, otherwise, read 512 bytes into a ''buffer'' from the ''encrypted data'' and process as follows:
 foreach(byte b in ''buffer'')
 {
   byte value = b;
   b ^= ''decryption table''[''decryption seed''];
   ''decryption seed'' = (''decryption seed'' + value) % (''decryption table'' Length);
 }
Then write out the decrypted ''buffer''.

=== Encryption Method ===

To encrypt, reverse the process for [[#Decryption method |Decryption]].  There is no need to create a valid checksum and the ''decryption table'' table can be left full of zeros (which saves identifying empty 512 byte chunks).

== Data Content ==
The decrypted content is a [http://wikipedia.org/wiki/Common_Language_Runtime Common Language Runtime] [http://wikipedia.org/wiki/.NET_assembly assembly].

== How the game uses Assemblies ==
TBC
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