NPDRM

The info on this page is an extract (and simplify) of talk page, conversations and forum posts, please digest the info and move it this page

Once the user is trying to start a SELF, the vsh looks for the appinfo header type. If the type is 8, then the control digest element type 3 (NPD element) is located. From this NPD header the vsh gets the License Types (network license, local or free).

• Network License (type 1): if a remote paid content is to be loaded, the vsh loads the act.dat and the rif associated to the content (will download to vsh process memory).

• Local (type 2): For this paid content too, the vsh locate a file with the same title id on NPD element (CONTENT_ID), then the signature is checked (last 0x28 bytes of both RIF and act.dat).

• Free (type 3): if a free content (no license check) is detected then a generic klicense will be use for further steps (go to LV2).

Using the RIF_KEY it will obtain the actdatIndex, and finally having the actDat key index the execution pass to LV2 Syscalls 471.

This function has different parameters depending if the content is debug, paid (type 1 & 2) or free (type 3):

PAID: syscall471(npd.type, &npd.titleID, NULL, &actdat.keyTable[rif.actDatIndex], &rif.key, npd.license, &npd);
FREE: syscall471(npd.type, &npd.titleID, freeklicensee, NULL, NULL, npd.license, &npd);

*PAID can also include free games/apps too but require this licensing check

The lv2 keeps a memory table with contentID and the associated key:

• Paid content: the rif.key is converted to the klicensee (by using a constant value on lv2, IDPS and the act.dat) and once transformed it is stored on memory table.
• free content: copies the titleID and the klicensee to the table.

From there, the lv1 hypervisor by loading Appldr, will transform (again) this key by using the klic_dec_key and finally remove the NPDRM layer for start the SELF.

act.dat header(encrypted) structure

Name	Offset	Size	Example	Remark
Version Number	0x0	0x4	00000001
License Type	0x4	0x4	00000001
User Number	0x8	0x8	N.A
KeyTable Retail	0x10	0x800	N.A
KeyTable Debug?	0x810	0x800	N.A
Signature	0x1010	0x28	N.A

rif file(encrypted) structure

The rif holds the klicensee for both SELF and paid EDAT.

Name	Offset	Size	Example	Remark
Version Number	0x0	0x4	00 00 00 01
License Type	0x4	0x4	00 01 00 02
User Number	0x8	0x8	00 00 00 00 00 00 00 02	Used on Rap2Rif header
CONTENT ID	0x10	0x30	N.A	Content ID
Random Padding	0x40	0xC	N.A
act.dat index key	0x4C	0x4	N.A
encrypted klic	0x50	0x10	N.A
bought on/ start	0x60	0x8	00 00 01 2F 41 5C 00 00	For human readable, convert to decimal and use one Epoch-Unix converter time format online.
expires in	0x68	0x8	00 00 00 00 00 00 00 00	If zeroed,-, there is no time limit. Used on PS+ for example.
Signature	0x70	0x28	11	Patched on some cfw. See Rif_Junk on Rap2Rif by Flatz

• Rap2Rif source code by Flatz

• Rap2Rif Key souce code by Flatz

• Link download & usage