c2pa-structured-text

C2PA manifest embedding for structured text formats

Overview

Implements the Structured Text Embedding section of the C2PA Technical Specification, which defines how to associate a C2PA Manifest Store with source code, configuration files, markup, and other text formats that support comment syntax or front matter conventions.

The manifest block uses fixed ASCII armour-style delimiters modelled on RFC 4880:

-----BEGIN C2PA MANIFEST----- <reference> -----END C2PA MANIFEST-----

Quick Start

[dependencies]
c2pa-structured-text = "0.1"

Embed a manifest reference

use c2pa_structured_text::{embed_manifest, ManifestRef};

let text = "print('hello')\n";
let signed = embed_manifest(
    text,
    ManifestRef::Url("https://example.com/manifests/abc.c2pa"),
    "#",       // comment prefix
    None,      // no comment suffix
);
// Result:
// # -----BEGIN C2PA MANIFEST----- https://example.com/manifests/abc.c2pa -----END C2PA MANIFEST-----
// print('hello')

Extract a manifest reference

use c2pa_structured_text::extract_manifest;

let text = "# -----BEGIN C2PA MANIFEST----- https://example.com/m.c2pa -----END C2PA MANIFEST-----\nprint('hello')\n";
let result = extract_manifest(text).unwrap();
assert_eq!(result.reference, "https://example.com/m.c2pa");

Supported Formats

Any text format with a comment syntax or front matter convention:

Comment Style	Formats	Example
#	Python, Ruby, Shell, YAML, TOML	# -----BEGIN C2PA MANIFEST----- ... -----END C2PA MANIFEST-----
//	JavaScript, TypeScript, Go, Rust, C++	// -----BEGIN C2PA MANIFEST----- ... -----END C2PA MANIFEST-----
--	SQL, Lua, Haskell	-- -----BEGIN C2PA MANIFEST----- ... -----END C2PA MANIFEST-----
/* */	CSS, C, Java	/* -----BEGIN C2PA MANIFEST----- ... -----END C2PA MANIFEST----- */
<!-- -->	HTML, XML, Markdown	<!-- -----BEGIN C2PA MANIFEST----- ... -----END C2PA MANIFEST----- -->
NOTE	WebVTT	NOTE -----BEGIN C2PA MANIFEST----- ... -----END C2PA MANIFEST-----
Front matter	Markdown (YAML), TOML	Multi-line form between front matter delimiters

Related Crates

Crate	Description
c2pa-text-binding	Soft binding and content fingerprinting for text assets
c2pa-text	Unstructured text embedding via Unicode Variation Selectors
c2pa-rs	Official C2PA SDK

License

Licensed under either of Apache License, Version 2.0 or MIT License at your option.

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