Difference between revisions of "Title metadata"

Latest revision as of 13:22, 28 July 2020

Title metadata is a format used to store information about a title (installed title, DLC, etc.) and all its installed contents, including which contents they consist of and their SHA256 hashes.

Code is available by trap15 to parse the available information from the 3DS format of TMDs.

Structure[edit]

All the data in the file represented in Big Endian, unless otherwise noted.

Offset	Size	Description
0x0	Y	Signature Data
Y	0xC4	Header
0xC4 + Y	0x24*64	Content Info Records.
0x9C4 + Y	0x30*ContentCount	Content Chunk Records.

Y denotes the total size of the "Signature Data" section and depends on the signature type.

Signature Data[edit]

The signature is of the header of the TMD.

Offset	Size	Description
0x0	0x4	Signature Type
0x4	X	Signature
0x4 + X		Padding Aligning the signature data to 0x40 bytes

Signature Type[edit]

Value	Signature Method	Signature Size	Padding Size
0x010000	RSA_4096 SHA1 (Unused for 3DS)	0x200	0x3C
0x010001	RSA_2048 SHA1 (Unused for 3DS)	0x100	0x3C
0x010002	Elliptic Curve with SHA1 (Unused for 3DS)	0x3C	0x40
0x010003	RSA_4096 SHA256	0x200	0x3C
0x010004	RSA_2048 SHA256	0x100	0x3C
0x010005	ECDSA with SHA256	0x3C	0x40

The hash for the signature, is calculated over the header of the TMD

Header[edit]

Offset	Size	Description
0x0	0x40	Signature Issuer
0x40	0x1	Version
0x41	0x1	ca_crl_version
0x42	0x1	signer_crl_version
0x43	0x1	Reserved
0x44	0x8	System Version
0x4C	0x8	Title ID
0x54	0x4	Title Type
0x58	0x2	Group ID
0x5A	0x4	Save Data Size in Little Endian (Bytes) (Also SRL Public Save Data Size)
0x5E	0x4	SRL Private Save Data Size in Little Endian (Bytes)
0x62	0x4	Reserved
0x66	0x1	SRL Flag
0x67	0x31	Reserved
0x98	0x4	Access Rights
0x9C	0x2	Title Version
0x9E	0x02	Content Count
0xA0	0x2	Boot Content
0xA2	0x2	Padding
0xA4	0x20	SHA-256 Hash of the Content Info Records

Content Info Records[edit]

There are 64 of these records, usually only the first is used.

Offset	Size	Description
0x00	2	Content index offset
0x02	2	Content command count [k]
0x04	0x20	SHA-256 hash of the next k content records that have not been hashed yet

Content chunk records[edit]

There is one of these for each content contained in this title. (Determined by "Content Count" in the TMD Header).

Offset	Size	Description
0x00	4	Content id
0x04	2	Content index
0x06	2	Content type
0x08	8	Content size
0x10	0x20	SHA-256 hash

Content Index[edit]

This indicates the content type:

Index	Content Type
0000	Main Content (.CXI for 3DS executable content/.CFA for 3DS Data Archives/.SRL for TWL content)
0001	Home Menu Manual (.CFA)
0002	DLP Child Container (.CFA)

This does not apply to DLC.

Content Type flags[edit]

Flags	Description
1	Encrypted
2	Disc
4	CFM (abbreviation for?)
0x4000	Optional
0x8000	Shared

Certificate Chain[edit]

If the TMD file is obtained from Nintendo's CDN, then it will have two certificates appended at the end of the file:

CERTIFICATE	SIGNATURE TYPE	RETAIL CERT NAME	DEBUG CERT NAME	DESCRIPTION
TMD	RSA-2048	CP0000000b	CP0000000a	Used to verify the TMD signature
CA	RSA-4096	CA00000003	CA00000004	Used to verify the TMD Certificate

The CA certificate is issued by 'Root', the public key for which is stored in NATIVE_FIRM.

Example code application[edit]

 enum sig_type {
         RSA_2048_SHA256 = 0x00010004,
         RSA_4096_SHA256 = 0x00010003,
         RSA_2048_SHA1   = 0x00010001,
         RSA_4096_SHA1   = 0x00010000
 };

// Sorry I removed the example struct because it is wrong.

@@ Line 2: / Line 2: @@
 '''Title metadata''' is a format used to store information about a title (installed title, DLC, etc.) and all its installed contents, including which contents they consist of and their SHA256 hashes.
-[http://git.daifukkat.su/?p=3dshax.git Code is available] by trap15 to parse the available information from the 3DS format of TMDs.
+[https://bitbucket.org/trap15/3dshax Code is available] by trap15 to parse the available information from the 3DS format of TMDs.
 == Structure ==
-All the data in the file represented in Big Endian.
+All the data in the file represented in Big Endian, unless otherwise noted.
 {| class="wikitable"
@@ Line 21: / Line 21: @@
 | 0x9C4 + Y||0x30*ContentCount||Content Chunk Records.
 |}
+Y denotes the total size of the "Signature Data" section and depends on the signature type.
 === Signature Data ===
-The total size of this section is referred to as "Y" in the overall TMD structure. The signature is of the header of the TMD.
+The signature is of the header of the TMD.
 {| class="wikitable"
 | align="center" style="background:#f0f0f0;"|'''Offset'''
@@ Line 65: / Line 67: @@
 | 0x58||0x2||Group ID
 |-
-| 0x5A||0x4||Save Data Size (Bytes) (Also SRL Public Save Data Size)
+| 0x5A||0x4||Save Data Size in Little Endian (Bytes) (Also SRL Public Save Data Size)
 |-
-| 0x5E||0x4||SRL Private Save Data Size (Bytes)
+| 0x5E||0x4||SRL Private Save Data Size in Little Endian (Bytes)
 |-
 | 0x62||0x4||Reserved
@@ Line 107: / Line 109: @@
 |-
 | 0x04
-| 32
+| 0x20
 | SHA-256 hash of the next k content records that have not been hashed yet
 |}