Verify accepts SPDX 2.3 documents that violate normative MUST rules (document SPDXID, unique SPDXIDs, documentNamespace URI)

Hi @goneall :) Hope you are doing well and having fun on all your adventures!

I came across some validation discrepancies (errors?) when comparing validation output between spdx-tools pyhon, java and the plain text spec. I am seeing the Verify command reports documents as "This SPDX Document is valid." even when they violate several normative MUST requirements of the SPDX 2.3 spec. The equivalent Python spdx-tools validator flags the same documents as invalid, so the two reference implementations disagree.

Specifically, Verify with the latest java release does not seem to enforce:

• The document's SPDXID MUST be SPDXRef-DOCUMENT (§6.3)
• Element ID uniqueness (i.e. the document identifier collides with a package identifier and is not reported) (§7.2)
• documentNamespace MUST be an absolute URI (RFC-3986). (§6.5)

Reproduction 1 — non-URI documentNamespace (§6.5):

{"spdxVersion":"SPDX-2.3","dataLicense":"CC0-1.0","SPDXID":"SPDXRef-DOCUMENT","name":"x","documentNamespace":"not-a-uri","creationInfo":{"creators":["Tool: t"],"created":"1970-01-01T00:00:00Z"},"packages":[{"name":"a","SPDXID":"SPDXRef-a","downloadLocation":"NOASSERTION","filesAnalyzed":false}],"relationships":[{"spdxElementId":"SPDXRef-DOCUMENT","relationshipType":"DESCRIBES","relatedSpdxElement":"SPDXRef-a"}]}
$ java -jar tools-java-2.0.7-jar-with-dependencies.jar Verify b-namespace.spdx.json
This SPDX Document is valid.

Reproduction 2 — document SPDXID is not SPDXRef-DOCUMENT and duplicates a package ID (§6.3 + uniqueness):

{"spdxVersion":"SPDX-2.3","dataLicense":"CC0-1.0","SPDXID":"SPDXRef-a","name":"x","documentNamespace":"https://example.com/C","creationInfo":{"creators":["Tool: t"],"created":"1970-01-01T00:00:00Z"},"packages":[{"name":"a","SPDXID":"SPDXRef-a","downloadLocation":"NOASSERTION","filesAnalyzed":false}],"relationships":[{"spdxElementId":"SPDXRef-a","relationshipType":"DESCRIBES","relatedSpdxElement":"SPDXRef-a"}]}
$ java -jar tools-java-2.0.7-jar-with-dependencies.jar Verify c-dup-doc-pkg.spdx.json
This SPDX Document is valid.

Both documents should be reported as invalid. The 2.3 spec requires:

§6.3 SPDX identifier field — the document SPDXID value MUST be SPDXRef-DOCUMENT: https://spdx.github.io/spdx-spec/v2.3/document-creation-information/#63-spdx-identifier-field
§6.5 SPDX document namespace — MUST be a unique absolute URI with no fragment: https://spdx.github.io/spdx-spec/v2.3/document-creation-information/#65-spdx-document-namespace-field
§7.2 / element identifiers — each SPDXID MUST be unique within the document: https://spdx.github.io/spdx-spec/v2.3/package-information/#72-package-spdx-identifier-field

Running the python tools on the same files seems to yield more expected results:

b-namespace.spdx.json   -> INVALID: document_namespace must be a valid URI specified in RFC-3986 and must contain no fragment (#), but is: not-a-uri
c-dup-doc-pkg.spdx.json -> INVALID: spdx_id must be SPDXRef-DOCUMENT, but is: SPDXRef-a
                                    every spdx_id must be unique within the document, but found duplicates: ['SPDXRef-a']

It's been a while so totally recognize this could be user error but wanted to open this here in case others run into it.

Start with the Verify command's validation path in tools-java and reproduce the two JSON documents from the issue using the Java release. Compare the checks for SPDXRef-DOCUMENT, duplicate SPDXIDs, and absolute documentNamespace against the SPDX 2.3 requirements and Python validator results. Done means Verify reports both documents as invalid for the stated violations.