bd-scan-yocto-via-sbom 1.0.2

BD_yocto_import_sbom - BD Script to import a Yocto project to Black Duck by scanning license.manifest and creating an SBOM file

Synopsys Scan Yocto Script - bd_scan_yocto_via_sbom.py v1.0.2

PROVISION OF THIS SCRIPT

This script is provided under the MIT license (see LICENSE file).

It does not represent any extension of licensed functionality of Synopsys software itself and is provided as-is, without warranty or liability.

If you have comments or issues, please raise a GitHub issue here. Synopsys support is not able to respond to support tickets for this OSS utility. Users of this pilot project commit to engage properly with the authors to address any identified issues.

INTRODUCTION

OVERVIEW OF BD_SCAN_YOCTO_VIA_SBOM

This utility is intended to:

• Scan a Yocto project to generate an SPDX SBOM file which can be uploaded to the specified Black Duck server to create a project version
• Filter recipes using data from the OpenEmbedded APIs to 'fix-up' recipes moved to new layers or with different versions/revisions
• Signature scan packages/downloaded archives (not from OE)
• Apply patches for locally patched CVEs identified from cve_patch if this data is available

This utility has some benefits over alternative Black Duck Yocto scan processes (including Synopsys Detect and bd-scan-yocto).

Note that, from Black Duck version 2024.7 onwards, the use of SPDX SBOM upload provides for the optional, automatic creation of custom components for recipes not matched in the BD KB. This would enable the creation of a complete SBOM including 3rd party or local, custom components.

See the RECOMMENDATIONS section below for guidance on optimising Yocto project scans.

OPTIONAL BEHAVIOUR

There are several important options to modify the behaviour of this utility including:

• Skip use of bitbake command to locate project files by specifying license.manifest and bitbake-layers output file (use --skip_bitbake)
• Use data from the OpenEmbedded API to verify recipes, layers, version to ensure they match known components in the BD KB (use --skip_oe_data to skip)
• Cache OE data in JSON files in a local folder to remove need to download on every run (use --oe_data_folder FOLDER)
• Specify semantic version distance for matching recipes against OE data (default distance is '0.0.0' - use --max_oe_version_distance X.X.X)
• Create SPDX output file and do not upload to Black Duck to create project (use --output_file OUTPUT)
• Specify license.manifest, machine, target, download_dir, package_dir, image_package_type to override values extracted from Bitbake environment
• Skip Signature scan of downloaded archives and packages (use --skip_sig_scan)

INSTALLATION

1. Create virtualenv
2. Run pip3 install bd_scan_yocto_via_sbom

Alternatively, if you want to manage the repository locally:

1. clone the repository
2. Create virtualenv
3. Build the utility python -m build
4. Install the package pip3 install dist/bd_scan_yocto_via_sbom-1.0.X-py3-none-any.whl

EXECUTION

Run the utility as a package:

1. Set the Bitbake environment (for example source oe-init-build-env)
2. Run bd-scan-yocto-via-sbom OPTIONS

Alternatively, if you have installed the repository locally:

1. Set the Bitbake environment (for example source oe-init-build-env)
2. Run python3 run.py OPTIONS

RECOMMENDATIONS

For optimal Yocto scan results, consider the following:

1. The utility will call Bitbake to extract the environment and layer information. You can override values (license.manifest, machine, target, download_dir, package_dir, image_package_type) extracted from the environment using command line options.
2. Use the --oe_data_folder FOLDER option to cache the downloaded OE data (~300MB on every run) noting that the data does not change frequently.
3. Add the cve_check class to the local.conf to ensure patched CVEs are identified and check that PHASE 6 picks up the cve-check file (see CVE PATCHING below).
4. Use the --max_oe_version_distance X.X.X option to specify fuzzy matching for OE recipes (values in the range '0.0.1' to '0.0.10' are recommended).

USAGE

  usage: bd-scan-yocto-via-sbom [-h] [--blackduck_url BLACKDUCK_URL] [--blackduck_api_token BLACKDUCK_API_TOKEN] [--blackduck_trust_cert] [-p PROJECT] [-v VERSION] [-l LICENSE_MANIFEST]
                         [-b BITBAKE_LAYERS] [-c CVE_CHECK_FILE] [-o OUTPUT] [--debug] [--logfile LOGFILE]

  Create BD Yocto project from license.manifest
  
 -h, --help            show this help message and exit
 --blackduck_url BLACKDUCK_URL
                       Black Duck server URL (REQUIRED - can use
                       BLACKDUCK_URL env var)
 --blackduck_api_token BLACKDUCK_API_TOKEN
                       Black Duck API token (REQUIRED - can use
                       BLACKDUCK_API_TOKEN env var)
 --blackduck_trust_cert
                       Black Duck trust server cert (can use
                       BLACKDUCK_TRUST_CERT env var)
 -p PROJECT, --project PROJECT
                       Black Duck project to create (REQUIRED)
 -v VERSION, --version VERSION
                       Black Duck project version to create (REQUIRED)
 -t TARGET, --target TARGET
                       Yocto target (e.g. core-image-sato - REQUIRED if
                       license.manifest not specified)
 -l LICENSE_MANIFEST, --license_manifest LICENSE_MANIFEST
                       license.manifest file path (REQUIRED - default
                       'license.manifest)
 -b BITBAKE_LAYERS, --bitbake_layers_file BITBAKE_LAYERS
                       File containing output of 'bitbake-layers show-
                       recipes' command (REQUIRED)
 -c CVE_CHECK_FILE, --cve_check_file CVE_CHECK_FILE
                       CVE check output file
 -o OUTPUT, --output OUTPUT
                       Specify output SBOM SPDX file for manual upload (if
                       specified then BD project will not be created
                       automatically and CVE patching not supported)
 --skip_oe_data        Download and use OE data to check layers, versions &
                       revisions
 --oe_data_folder OE_DATA_FOLDER
                       Folder to contain OE data files - if files do not
                       exist they will be downloaded, if files exist then
                       will be used without download
 --max_oe_version_distance MAX_OE_VERSION_DISTANCE
                       Where no exact match, use closest previous recipe
                       version up to specified distance.Distance should be
                       specified as MAJOR.MINOR.PATCH (e.g. 0.1.0)
 --build_dir BUILD_DIR
                       Alternative build folder
 --download_dir DOWNLOAD_DIR
                       Download directory where original OSS source is
                       downloaded (usually poky/build/downloads)
 --package_dir PACKAGE_DIR
                       Download directory where package files are downloaded
                       (for example poky/build/tmp/deploy/rpm/<ARCH>)
 --image_package_type IMAGE_PACKAGE_TYPE
                       Package type used for installing packages (e.g. rpm,
                       deb or ipx)
 --skip_sig_scan       Do not Signature scan downloads and packages
 --scan_all_files      Signature scan all files (only recipes not matchedfrom
                       OE data are scanned by default)
 --detect_jar_path DETECT_JAR_PATH
                       Synopsys Detect jar path
 --detect_opts DETECT_OPTS
                       Additional Synopsys Detect options
 --debug               Debug logging mode
 --logfile LOGFILE     Logging output file

OPTIONS DETAILED DESCRIPTION

--blackduck_url, --blackduck_api_token, --blackduck_trust_cert:

: Connection credentials to Black Duck server. Can also be picked up from the environment variables BLACKDUCK_URL, BLACKDUCK_API_TOKEN and BLACKDUCK_TRUST_CERT. Required to create the BD project version automatically and optionally process CVE patch status; not required if --output specified.

--output SBOM_FILE (also -o):

: Create an output SBOM file for manual upload; do not create BD project version.

--project PROJECT --version VERSION (also -p -v):

: Black Duck project and version to create - REQUIRED

--license_manifest LICENSE_MANIFEST_FILE (also -l):

: Optionally specify yocto license.manifest file created by Bitbake. Usually located in the folder tmp/deploy/licenses/<yocto-image>-<yocto-machine>/license.manifest. Should be determined from Bitbake environment by default (unless --skip_bitbake used).

--target TARGET (also -t):

: Bitbake target (e.g. core-image-sato) - required unless --skip_bitbake used.

--skip_bitbake:

: Do not extract Bitbake environment and layers information using Bitbake commands - requires license.manifest and bitbake-layers output to be specified.

--bitbake_layers_file BITBAKE_OUTPUT_FILE (also -b):

: Optionally specify output of the command bitbake-layers show-recipes stored in the specified file. Should be determined from Bitbake environment by default (unless --skip_bitbake used).

--cve_checkfile CVE_CHECK_FILE:

: Optionally specify output file from run of the cve_check custom class which generates a list of patched CVEs. Usually located in the folder build/tmp/deploy/images/XXX. Should be determined from Bitbake environment by default (unless --skip_bitbake used)

--skip_oe_data:

: Do not download layers/recipes/layers from layers.openembedded.org APIs to review origin layers and revisions used in recipes to ensure more accurate matching and complete BOMs.

--oe_data_folder FOLDER:

: Create OE data files in the specified folder if not already existing. If OE data files exist already in this folder, use them to review layers and revisions to ensure more accurate matching and complete BOMs. Allows offline usage of OE data or reduction of large data transfers if script is run frequently.

--skip_sig_scan:

: Do not send identified package and downloaded archives for Signature scanning. By default, only recipes not matched against OE data will be scanned, use --scan_all_files to scan all recipes.

--max_oe_version_distance MAJOR.MINOR.PATCH:

: Specify version distance to enable close (previous) recipe version matching against OE data. By default, when --get_oe_data is specified, OE recipe versions must match the version exactly to replace layers and revision values. Setting this value will allow close (previous) recipe version matching. The value needs to be of the format MAJOR.MINOR.PATCH (e.g. '0.10.0'). CAUTION - setting this value to a large value will cause versions of components to be matched against previous recipes maintained in the OE data, which may lead to different levels of reported vulnerabilities. It is preferable to maintain close relation between the matched versions and the ones in the project and then to identify unmatched components which can be added as custom components or manually. Consequently only consider using values which allow versions from different MINOR or MAJOR versions in exceptional circumstances (meaning the supplied value should probably be in the range 0.0.1 to 0.0.10).

EXAMPLE DISTANCE CALCULATIONS

• Recipe version is 3.2.4 - closest previous OE recipe version is 3.2.1: Distance value would need to be minimum 0.0.3
• Recipe version is 3.2.4 - closest previous OE recipe version is 3.0.1: Distance value would need to be minimum 0.2.0
• Recipe version is 3.2.4 - closest previous OE recipe version is 2.0.1: Distance value would need to be minimum 1.0.0

CVE PATCHING

For patched CVE remediation in the Black Duck project, you will need to add the cve_check bbclass to the Yocto build configuration to generate the CVE check log output. Add the following line to the build/conf/local.conf file:

   INHERIT += "cve-check"

Then rebuild the project (using for example bitbake core-image-sato) to run the CVE check action and generate the required CVE log files without a full rebuild.