_turtle_object() wrote an IRI-valued metadata value (currently only
sem:sourceUri, from the "uri" metadata key) straight into `<{value}>`
with no escaping. Turtle/N-Triples IRIREFs exclude control
characters, space, and <>"{}|^`\ unescaped, so a value shaped like
`<goodIRI> . <injected> <p> <o>` closed the reference early and let
the rest of the string be parsed as an attacker-chosen extra triple:
metadata={"uri": "https://x> . <https://injected> <https://p> <https://o"}
produced a well-formed Turtle/N-Triples document containing a triple
the caller never asked for.
RDF/XML was already safe (_rdfxml_metadata_lines runs the value
through _escape_xml before putting it in an rdf:resource attribute),
and JSON-LD is safe by construction (json.dumps makes structural
injection impossible) — only the Turtle/N-Triples "iri" literal path
in _turtle_object was unguarded.
Adds _safe_iri_ref(), a narrow percent-encoder for exactly the
characters an IRIREF may not contain unescaped. It's deliberately not
_as_turtle_iri: that also resolves registered prefixes, which a
metadata value never needs, so a dedicated guard stays simpler than
threading namespaces into a module-level helper that has no `self`.
Two regression tests, parametrised over turtle/ntriples: the `>`
delimiter-breaking payload from the report, and a control-character
(newline/tab) variant covering the other half of the excluded set.
convert_kg_to_rdf copies metadata into the RDF-ready dictionary at
rdf_exporter.py:302 and no serializer has ever read it back out. Turtle,
N-Triples, RDF/XML and RDFExporter's JSON-LD each write an entity's id,
type, text and confidence and nothing else, so an entity keeps its
confidence score and loses what produced it. JSONExporter's json-ld path
keeps the same fields, which is how one knowledge graph exported two ways
carried the user's data through one exporter and none through the other.
Measured on e3405ebc with an entity carrying four metadata keys: 3 triples
per format, 0 of them metadata. With this change: 7 triples per format,
4 of them metadata, and the same four in all four formats.
The keys Semantica itself writes are mapped to declared terms in
DEFAULT_METADATA_TERMS and declared in semantica-ns.ttl. A key the caller
supplied is not: which namespace an arbitrary key belongs in is #1146, and
that issue is open on the maintainer's modelling call, so the exporter
warns and skips rather than inventing an IRI. Callers who already know the
answer pass metadata_terms={key: iri}.
Two keys cannot keep their own name. sem:source is already the
ObjectProperty holding the subject of a reified relationship, so the Neo4j
loader's "source" is written as sem:sourceSystem and its "uri" as
sem:sourceUri, the one term whose value is a node rather than a literal.
sem:builtAt and sem:snapshotAt have range xsd:string, not xsd:dateTime.
GraphBuilder stamps with a timezone-naive datetime.now(), and #1114 is the
demonstration of what typing such a value as xsd:dateTime costs: a
timezone-qualified SPARQL filter over it silently drops the row. #1121
swept export and provenance and deliberately left kg/ alone.
Graph-level metadata is written only when the caller names the graph with
graph_uri, because this serializer has never minted a document node and
#1147 is where that default belongs once it lands.
The lexical form and datatype of a value are chosen once, in
_typed_literal_parts, so the four serializers cannot come to disagree
about them the way they disagreed about confidence in #1100. The JSON-LD
path writes explicit @value/@type rather than JSON's native numbers,
which would have made an integer xsd:double there and xsd:integer
everywhere else.
21 tests, asserting on the parsed graph in all four formats. Output is
unchanged when no metadata is present. Full-suite failure set is identical
to the parent commit: 512 = 512.
KaifAhmad1