NPDRM

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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).

Type 1 (Network License): 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).

Type 2 (Local): 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).

Type 3 (Free): if a free content (no license check: no need for rif/act.dat) is detected then a generic klicense will be use for further steps (go to LV2).

Using the RIF_KEY with the act.dat index decryption 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 generic 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 decryption.

act.dat header(encrypted) structure

Name	Offset	Size	Example	Remark
Version Number	0x0	0x4	00000001
License Type	0x4	0x4	00000001
Account ID	0x8	0x8	B4 1F 2C 0B DC 1B 43 31
Data Hash Table Retail	0x10	0x800	N.A
Data Hash Table 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 00 00 02
Account ID	0x8	0x8	B4 1F 2C 0B DC 1B 43 31	Used on Rap2Rif header
CONTENT ID	0x10	0x30	UP900-UCUS98721_00-PATAPONPSNDEMO08	Content ID
Index hash	0x40	0x10	N.A
Header hash	0x50	0x10	N.A
License start time	0x60	0x4	00 00 01 1F	For human readable, convert to decimal and use one Epoch-Unix converter time format online. Should be 0x08 lenght
License expiration time	~~0x64~~ 0x68	0x4	C5 16 7B D8	If zeroed,-, there is no time limit. Used on PS+ for example. should be 0x08
NULL	0x68	0x8		~~Null Padding~~
Signature	0x70	0x28	11	Patched in some CFW to allow unsigned. See Rif_Junk on Rap2Rif by Flatz