scripts: zephyr_module: Add CPE support

CMakeLists.txt

@@ -1675,9 +1675,8 @@ if(CONFIG_BUILD_OUTPUT_BIN AND CONFIG_BUILD_OUTPUT_UF2)
   set(BYPRODUCT_KERNEL_UF2_NAME "${PROJECT_BINARY_DIR}/${KERNEL_UF2_NAME}" CACHE FILEPATH "Kernel uf2 file" FORCE)
 endif()
 
+set(KERNEL_META_PATH  ${PROJECT_BINARY_DIR}/${KERNEL_META_NAME} CACHE INTERNAL "")
 if(CONFIG_BUILD_OUTPUT_META)
-  set(KERNEL_META_PATH  ${PROJECT_BINARY_DIR}/${KERNEL_META_NAME} CACHE INTERNAL "")
-
   list(APPEND
     post_build_commands
     COMMAND ${PYTHON_EXECUTABLE} ${ZEPHYR_BASE}/scripts/zephyr_module.py
@@ -1691,6 +1690,9 @@ if(CONFIG_BUILD_OUTPUT_META)
     post_build_byproducts
     ${KERNEL_META_PATH}
   )
+else(CONFIG_BUILD_OUTPUT_META)
+  # Prevent spdx to use invalid data
+  file(REMOVE ${KERNEL_META_PATH})
 endif()
 
 # Cleanup intermediate files

doc/develop/modules.rst

@@ -569,6 +569,45 @@ Build files located in a ``MODULE_EXT_ROOT`` can be described as:
 This allows control of the build inclusion to be described externally to the
 Zephyr module.
 
+.. _modules-vulnerability-monitoring:
+
+Vulnerability monitoring
+========================
+
+The module description file :file:`zephyr/module.yml` can be used to improve vulnerability monitoring.
+
+If your module needs to track vulnerabilities using an external reference
+(e.g your module is forked from another repository), you can use the ``security`` section.
+It contains the field ``external-references`` that contains a list of references that needs to
+be monitored for your module. The supported formats are:
+
+- CPE (Common Platform Enumeration)
+- PURL (Package URL)
+
+.. code-block:: yaml
+
+   security:
+     external-references:
+       - <module-related-cpe>
+       - <an-other-module-related-cpe>
+       - <module-related-purl>
+
+A real life example for `mbedTLS` module could look like this:
+
+.. code-block:: yaml
+
+   security:
+     external-references:
+       - cpe:2.3:a:arm:mbed_tls:3.5.2:*:*:*:*:*:*:*
+       - pkg:github/Mbed-TLS/[email protected]
+
+.. note::
+   CPE field must follow the CPE 2.3 schema provided by `NVD
+   <https://csrc.nist.gov/projects/security-content-automation-protocol/specifications/cpe>`_.
+   PURL field must follow the PURL specification provided by `Github
+   <https://github.com/package-url/purl-spec/blob/master/PURL-SPECIFICATION.rst>`_.
+
+
 Build system integration
 ========================
 

doc/develop/west/zephyr-cmds.rst

@@ -110,6 +110,8 @@ This generates the following SPDX bill-of-materials (BOM) documents in
 - :file:`app.spdx`: BOM for the application source files used for the build
 - :file:`zephyr.spdx`: BOM for the specific Zephyr source code files used for the build
 - :file:`build.spdx`: BOM for the built output files
+- :file:`modules-deps.spdx`: BOM for modules dependencies. Check
+  :ref:`modules <modules-vulnerability-monitoring>` for more details.
 
 Each file in the bill-of-materials is scanned, so that its hashes (SHA256 and
 SHA1) can be recorded, along with any detected licenses if an

scripts/west_commands/zspdx/datatypes.py

@@ -71,6 +71,18 @@ def __init__(self):
         # primary package purpose (ex. "LIBRARY", "APPLICATION", etc.)
         self.primaryPurpose = ""
 
+        # package URL
+        self.url = ""
+
+        # package version
+        self.version = ""
+
+        # package revision
+        self.revision = ""
+
+        # package external references
+        self.externalReferences = []
+
         # the Package's declared license
         self.declaredLicense = "NOASSERTION"
 

scripts/west_commands/zspdx/sbom.py

@@ -121,4 +121,10 @@ def makeSPDX(cfg):
         log.err("SPDX writer failed for build document; bailing")
         return False
 
+    # write modules document
+    writeSPDX(os.path.join(cfg.spdxDir, "modules-deps.spdx"), w.docModulesExtRefs)
+    if not retval:
+        log.err("SPDX writer failed for modules-deps document; bailing")
+        return False
+
     return True

scripts/west_commands/zspdx/walker.py

@@ -4,6 +4,7 @@
 
 import os
 import yaml
+import re
 
 from west import log
 from west.util import west_topdir, WestNotFound
@@ -47,6 +48,7 @@ def __init__(self, cfg):
         self.docZephyr = None
         self.docApp = None
         self.docSDK = None
+        self.docModulesExtRefs = None
 
         # dict of absolute file path => the Document that owns that file
         self.allFileLinks = {}
@@ -69,6 +71,36 @@ def __init__(self, cfg):
         # SDK install path from parsed CMake cache
         self.sdkPath = ""
 
+    def _build_purl(self, url, version=None):
+        if not url:
+            return None
+
+        purl = None
+        # This is designed to match repository with the following url pattern:
+        # '<protocol><base_url>/<namespace>/<package>
+        COMMON_GIT_URL_REGEX=r'((git@|http(s)?:\/\/)(?P<base_url>[\w\.@]+)(\/|:))(?P<namespace>[\w,\-,\_]+)\/(?P<package>[\w,\-,\_]+)(.git){0,1}((\/){0,1})$'
+
+        match = re.fullmatch(COMMON_GIT_URL_REGEX, url)
+        if match:
+            purl = f'pkg:{match.group("base_url")}/{match.group("namespace")}/{match.group("package")}'
+
+        if purl and (version or len(version) > 0):
+            purl += f'@{version}'
+
+        return purl
+
+    def _add_describe_relationship(self, doc, cfgpackage):
+        # create DESCRIBES relationship data
+        rd = RelationshipData()
+        rd.ownerType = RelationshipDataElementType.DOCUMENT
+        rd.ownerDocument = doc
+        rd.otherType = RelationshipDataElementType.PACKAGEID
+        rd.otherPackageID = cfgpackage.spdxID
+        rd.rlnType = "DESCRIBES"
+
+        # add it to pending relationships queue
+        self.pendingRelationships.append(rd)
+
     # primary entry point
     def makeDocuments(self):
         # parse CMake cache file and get compiler path
@@ -163,16 +195,7 @@ def setupAppDocument(self):
         pkgApp = Package(cfgPackageApp, self.docApp)
         self.docApp.pkgs[pkgApp.cfg.spdxID] = pkgApp
 
-        # create DESCRIBES relationship data
-        rd = RelationshipData()
-        rd.ownerType = RelationshipDataElementType.DOCUMENT
-        rd.ownerDocument = self.docApp
-        rd.otherType = RelationshipDataElementType.PACKAGEID
-        rd.otherPackageID = cfgPackageApp.spdxID
-        rd.rlnType = "DESCRIBES"
-
-        # add it to pending relationships queue
-        self.pendingRelationships.append(rd)
+        self._add_describe_relationship(self.docApp, cfgPackageApp)
 
     def setupBuildDocument(self):
         # set up build document
@@ -196,7 +219,7 @@ def setupBuildDocument(self):
         # add it to pending relationships queue
         self.pendingRelationships.append(rd)
 
-    def setupZephyrDocument(self, modules):
+    def setupZephyrDocument(self, zephyr, modules):
         # set up zephyr document
         cfgZephyr = DocumentConfig()
         cfgZephyr.name = "zephyr-sources"
@@ -217,40 +240,66 @@ def setupZephyrDocument(self, modules):
         cfgPackageZephyr.spdxID = "SPDXRef-zephyr-sources"
         cfgPackageZephyr.relativeBaseDir = relativeBaseDir
 
+        zephyr_url = zephyr.get("remote", "")
+        if zephyr_url:
+            cfgPackageZephyr.url = zephyr_url
+
+        if zephyr.get("revision"):
+            cfgPackageZephyr.revision = zephyr.get("revision")
+
+        purl = None
+        zephyr_tags = zephyr.get("tags", "")
+        if zephyr_tags:
+            # Find tag vX.Y.Z
+            for tag in zephyr_tags:
+                version = re.fullmatch(r'^v(?P<version>\d+\.\d+\.\d+)$', tag)
+                purl = self._build_purl(zephyr_url, tag)
+
+                if purl:
+                    cfgPackageZephyr.externalReferences.append(purl)
+
+                # Extract version from tag once
+                if cfgPackageZephyr.version == "" and version:
+                    cfgPackageZephyr.version = version.group('version')
+
+        if len(cfgPackageZephyr.version) > 0:
+            cpe = f'cpe:2.3:o:zephyrproject:zephyr:{cfgPackageZephyr.version}:-:*:*:*:*:*:*'
+            cfgPackageZephyr.externalReferences.append(cpe)
+
         pkgZephyr = Package(cfgPackageZephyr, self.docZephyr)
         self.docZephyr.pkgs[pkgZephyr.cfg.spdxID] = pkgZephyr
 
+        self._add_describe_relationship(self.docZephyr, cfgPackageZephyr)
+
         for module in modules:
             module_name = module.get("name", None)
             module_path = module.get("path", None)
+            module_url = module.get("remote", None)
+            module_revision = module.get("revision", None)
 
             if not module_name:
                 log.err(f"cannot find module name in meta file; bailing")
                 return False
 
-            # Replace "_" by "-" since it's not allowed in spdx ID
-            module_name = module_name.replace("_", "-")
-
             # set up zephyr sources package
             cfgPackageZephyrModule = PackageConfig()
-            cfgPackageZephyrModule.name = module_name
+            cfgPackageZephyrModule.name = module_name + "-sources"
             cfgPackageZephyrModule.spdxID = "SPDXRef-" + module_name + "-sources"
             cfgPackageZephyrModule.relativeBaseDir = module_path
             cfgPackageZephyrModule.primaryPurpose = "SOURCE"
 
+            if module_revision:
+                cfgPackageZephyrModule.revision = module_revision
+
+            if module_url:
+                cfgPackageZephyrModule.url = module_url
+
             pkgZephyrModule = Package(cfgPackageZephyrModule, self.docZephyr)
             self.docZephyr.pkgs[pkgZephyrModule.cfg.spdxID] = pkgZephyrModule
 
-        # create DESCRIBES relationship data
-        rd = RelationshipData()
-        rd.ownerType = RelationshipDataElementType.DOCUMENT
-        rd.ownerDocument = self.docZephyr
-        rd.otherType = RelationshipDataElementType.PACKAGEID
-        rd.otherPackageID = cfgPackageZephyr.spdxID
-        rd.rlnType = "DESCRIBES"
+            self._add_describe_relationship(self.docZephyr, cfgPackageZephyrModule)
 
-        # add it to pending relationships queue
-        self.pendingRelationships.append(rd)
+        return True
 
     def setupSDKDocument(self):
         # set up SDK document
@@ -280,6 +329,40 @@ def setupSDKDocument(self):
         # add it to pending relationships queue
         self.pendingRelationships.append(rd)
 
+    def setupModulesDocument(self, modules):
+        # set up zephyr document
+        cfgModuleExtRef = DocumentConfig()
+        cfgModuleExtRef.name = "modules-deps"
+        cfgModuleExtRef.namespace = self.cfg.namespacePrefix + "/modules-deps"
+        cfgModuleExtRef.docRefID = "DocumentRef-modules-deps"
+        self.docModulesExtRefs = Document(cfgModuleExtRef)
+
+        for module in modules:
+            module_name = module.get("name", None)
+            module_security = module.get("security", None)
+
+            if not module_name:
+                log.err(f"cannot find module name in meta file; bailing")
+                return False
+
+            module_ext_ref = []
+            if module_security:
+                module_ext_ref = module_security.get("external-references")
+
+            # set up zephyr sources package
+            cfgPackageModuleExtRef = PackageConfig()
+            cfgPackageModuleExtRef.name = module_name + "-deps"
+            cfgPackageModuleExtRef.spdxID = "SPDXRef-" + module_name + "-deps"
+
+            for ref in module_ext_ref:
+                cfgPackageModuleExtRef.externalReferences.append(ref)
+
+            pkgModule = Package(cfgPackageModuleExtRef, self.docModulesExtRefs)
+            self.docModulesExtRefs.pkgs[pkgModule.cfg.spdxID] = pkgModule
+
+            self._add_describe_relationship(self.docModulesExtRefs, cfgPackageModuleExtRef)
+
+
     # set up Documents before beginning
     def setupDocuments(self):
         log.dbg("setting up placeholder documents")
@@ -289,7 +372,8 @@ def setupDocuments(self):
         try:
             with open(self.metaFile) as file:
                 content = yaml.load(file.read(), yaml.SafeLoader)
-                self.setupZephyrDocument(content["modules"])
+                if not self.setupZephyrDocument(content["zephyr"], content["modules"]):
+                    return False
         except (FileNotFoundError, yaml.YAMLError):
             log.err(f"cannot find a valid zephyr_meta.yml required for SPDX generation; bailing")
             return False
@@ -299,6 +383,8 @@ def setupDocuments(self):
         if self.cfg.includeSDK:
             self.setupSDKDocument()
 
+        self.setupModulesDocument(content["modules"])
+
         return True
 
     # walk through targets and gather information