[media-types] [IANA #1459410] application/vnd.dai registration request

[David Dong via RT <[e-mail]>]

Hi Murray,

Could you review this request for us by September 22? Thank you.

Best regards,

David Dong
IANA Services Sr. Specialist

===

Name: Christopher Whitlow

Email: [e-mail]

Media type name: application

Media subtype name: vnd.dai

Required parameters: N/A

Optional parameters: N/A

Encoding considerations: binary

The file is a sectioned container: a header, a section table, page-aligned sections holding a JSON manifest, a zip archive of the application, and a SQLite database, and a 64-byte footer. The footer carries a generation counter and the SHA-256 of the database section.

Security considerations: A DAI container carries executable content: an HTML application intended to run only inside a host that applies the isolation defined in §4 of the specification, namely an opaque-origin sandboxed frame under a Content Security Policy that permits no network connection of any kind. A host that does not apply that isolation MUST NOT execute the content.

The container is a sectioned binary file holding a JSON manifest, a zip archive of the application, and a SQLite database. The manifest carries SHA-256 digests of every archive entry and MAY carry an ECDSA P-256 signature over them in a COSE_Sign1 envelope. A host MUST verify every digest before running anything and MUST verify the signature when a key is present. The signature covers the manifest and the application, not the database; the database section is verified separately against a SHA-256 digest held in the file's footer, and a host MUST check it. Verification proves the file is unchanged since it was signed, not who signed it. §8 and §9.6 of the specification describe what a host may and may not claim about a publisher.

Because the archive must be inflated before its manifest can be checked, a reader MUST bound decompression by the declared size of each entry, the declared total, and the entry count, and MUST refuse a file that exceeds those bounds rather than allocate for it. The manifest contains no active content.

The application may read and write the SQLite database. The format grants it no capability to reach the network, the filesystem beyond the file itself, or other origins.

Privacy: the file may contain personal data the application stored. It contains no tracking, and the specification requires that a host send nothing on open.

Interoperability considerations: The format is versioned by `manifestVersion` in the manifest. Readers accept versions 2 and 3 and refuse others by name. A conformance suite and an independent reference reader in Python are published with the specification.

Published specification: DAI Container Format v0.2, §2 (the sectioned form) and §9 (manifestVersion 3): <https://github.com/dynamicapplicationinterface/dai-core/blob/main/docs/spec-v0.2.md>

Applications which use this media: The DAI opener (<https://opendai.app>), the DAI desktop application, and the `dai` command line tool; any host implementing the specification.

Fragment identifier considerations: N/A

Restrictions on usage: N/A

Provisional registration? (standards tree only): No

Additional information:

1. Deprecated alias names for this type: N/A
2. Magic number(s): the first four bytes are `DAI` (0x44 0x41 0x49 0x00)
3. File extension(s): '.dai'
4. Macintosh file type code: N/A
5. Object Identifiers: N/A

General Comments: N/A

Person to contact for further information:

1. Name: Christopher Whitlow
2. Email: [e-mail]

Intended usage: COMMON

N/A

Author/Change controller: Christopher Whitlow / Dynamic Application Interface Opensource Project