[PATCH] spdx30: Add supplier support for image and SDK SBOMs

[stondo@gmail.com]

From: Stefano Tondo <stefano.tondo.ext@siemens.com>

This commit adds support for setting supplier information on image and SDK
SBOMs using the suppliedBy property on root elements.

New configuration variables:

  SPDX_IMAGE_SUPPLIER (optional):
    - Base variable name to describe the Agent supplying the image SBOM
    - Follows the same Agent variable pattern as SPDX_PACKAGE_SUPPLIER
    - Sets suppliedBy on all root elements of the image SBOM

  SPDX_SDK_SUPPLIER (optional):
    - Base variable name to describe the Agent supplying the SDK SBOM
    - Follows the same Agent variable pattern as SPDX_PACKAGE_SUPPLIER
    - Sets suppliedBy on all root elements of the SDK SBOM

Implementation:

  - create_image_sbom_spdx(): After create_sbom() returns, uses
    objset.new_agent() to create supplier and sets suppliedBy on
    sbom.rootElement

  - create_sdk_sbom(): After create_sbom() returns, uses objset.new_agent()
    to create supplier and sets suppliedBy on sbom.rootElement

  - Uses existing agent infrastructure (objset.new_agent()) for proper
    de-duplication and metadata handling

  - No changes to generic create_sbom() function which is used for recipes,
    images, and SDKs

Usage example in local.conf:

  SPDX_IMAGE_SUPPLIER = "acme"
  SPDX_IMAGE_SUPPLIER_acme_name = "Acme Corporation"
  SPDX_IMAGE_SUPPLIER_acme_type = "organization"
  SPDX_IMAGE_SUPPLIER_acme_id_email = "sbom@acme.com"

This enables compliance workflows that require supplier metadata on image
and SDK SBOMs while following existing OpenEmbedded SPDX patterns.

Signed-off-by: Stefano Tondo <stefano.tondo.ext@siemens.com>
---
 meta/classes/create-spdx-3.0.bbclass | 10 ++++++++++
 meta/lib/oe/spdx30_tasks.py          | 24 ++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/meta/classes/create-spdx-3.0.bbclass b/meta/classes/create-spdx-3.0.bbclass
index 96c0b9722b..9f9066eeb5 100644
--- a/meta/classes/create-spdx-3.0.bbclass
+++ b/meta/classes/create-spdx-3.0.bbclass
@@ -124,6 +124,16 @@ SPDX_ON_BEHALF_OF[doc] = "The base variable name to describe the Agent on who's
 SPDX_PACKAGE_SUPPLIER[doc] = "The base variable name to describe the Agent who \
     is supplying artifacts produced by the build"
 
+SPDX_IMAGE_SUPPLIER[doc] = "The base variable name to describe the Agent who \
+    is supplying the image SBOM. The supplier will be set on all root elements \
+    of the image SBOM using the suppliedBy property. If not set, no supplier \
+    information will be added to the image SBOM."
+
+SPDX_SDK_SUPPLIER[doc] = "The base variable name to describe the Agent who \
+    is supplying the SDK SBOM. The supplier will be set on all root elements \
+    of the SDK SBOM using the suppliedBy property. If not set, no supplier \
+    information will be added to the SDK SBOM."
+
 SPDX_PACKAGE_VERSION ??= "${PV}"
 SPDX_PACKAGE_VERSION[doc] = "The version of a package, software_packageVersion \
     in software_Package"
diff --git a/meta/lib/oe/spdx30_tasks.py b/meta/lib/oe/spdx30_tasks.py
index c86b088b61..2883e2202a 100644
--- a/meta/lib/oe/spdx30_tasks.py
+++ b/meta/lib/oe/spdx30_tasks.py
@@ -1305,6 +1305,18 @@ def create_image_sbom_spdx(d):
 
     objset, sbom = oe.sbom30.create_sbom(d, image_name, root_elements)
 
+    # Set supplier on root elements if SPDX_IMAGE_SUPPLIER is defined
+    supplier = objset.new_agent("SPDX_IMAGE_SUPPLIER", add=False)
+    if supplier is not None:
+        supplier_id = supplier if isinstance(supplier, str) else supplier._id
+        # Add supplier to objset if it's not already there
+        if not isinstance(supplier, str):
+            objset.add(supplier)
+        # Set suppliedBy on all root elements
+        for elem in sbom.rootElement:
+            if hasattr(elem, "suppliedBy"):
+                elem.suppliedBy = supplier_id
+
     oe.sbom30.write_jsonld_doc(d, objset, spdx_path)
 
     def make_image_link(target_path, suffix):
@@ -1416,6 +1428,18 @@ def create_sdk_sbom(d, sdk_deploydir, spdx_work_dir, toolchain_outputname):
         d, toolchain_outputname, sorted(list(files)), [rootfs_objset]
     )
 
+    # Set supplier on root elements if SPDX_SDK_SUPPLIER is defined
+    supplier = objset.new_agent("SPDX_SDK_SUPPLIER", add=False)
+    if supplier is not None:
+        supplier_id = supplier if isinstance(supplier, str) else supplier._id
+        # Add supplier to objset if it's not already there
+        if not isinstance(supplier, str):
+            objset.add(supplier)
+        # Set suppliedBy on all root elements
+        for elem in sbom.rootElement:
+            if hasattr(elem, "suppliedBy"):
+                elem.suppliedBy = supplier_id
+
     oe.sbom30.write_jsonld_doc(
         d, objset, sdk_deploydir / (toolchain_outputname + ".spdx.json")
     )
-- 
2.52.0