feat(sbom): ship a CycloneDX bill of materials with every build
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An air-gapped site cannot be scanned from anywhere else, so when a CVE lands the
only way to answer 'is that component here, and at what version' was to RDP in
and go looking. The frontend was the real blind spot: nothing recorded which
version of leaflet, dompurify, jspdf or html2canvas ends up inside the compiled
SPA.

scripts/generate_sbom.py emits CycloneDX 1.6 covering both ecosystems - every pin
in requirements.txt with the sha256 the installer enforces, and every package in
package-lock.json. Build-only npm packages are marked scope 'excluded' rather
than dropped, so 'not here' stays distinguishable from 'not looked for'.
Dependency edges are real: uv's '# via' comments give the Python graph and
package-lock gives the npm one.

Hand-rolled rather than cyclonedx-py plus cyclonedx-npm because both inputs are
already pinned and committed - this is a format translation, not a scan - and
because the build box may be a work PC with nothing but Python and Node. It is
deterministic by construction: same inputs, byte-identical output, so
regenerating does not churn.

Staged into the application tree by both builders, so it installs onto the
server with the app. shopdb-admin.ps1 verify reports it and searches it by
component name, which is the question actually being asked.

Packages appearing at several depths in package-lock (node_modules/vite and
node_modules/vitest/node_modules/vite) are merged, and a copy reachable outside
the dev tree makes the component count as shipped. Emitting both produced
duplicate bom-refs, which CycloneDX forbids and scanners reject; getting the dev
merge backwards would have hidden a shipped package from a CVE search.

Not covered by bundle-lock.json on purpose: its provenance is git, not the
third-party payload.
This commit is contained in:
cproudlock
2026-08-03 13:15:27 -04:00
parent 1bf3cb2e1c
commit 3606d8d696
6 changed files with 579 additions and 0 deletions

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@@ -139,6 +139,32 @@ For the West Jefferson production server specifically, this is a **migration, no
an upgrade** - prod runs Python 3.13 against a hand-built deployment, so it needs an upgrade** - prod runs Python 3.13 against a hand-built deployment, so it needs
a deliberate window, a database backup, and web.config reconciled by hand. a deliberate window, a database backup, and web.config reconciled by hand.
## Bill of materials
Every build stages a CycloneDX 1.6 SBOM at `sbom.cdx.json`, inside the
application tree, so it installs onto the server with the app. Both ecosystems,
in one document:
- **Python** — every pin in `requirements.txt`, with the sha256 the installer
enforces. Environment markers are ignored: a `sys_platform == 'win32'`
dependency still installs on the target.
- **npm** — every package in `frontend/package-lock.json`. Build-only packages
are marked `scope: excluded` rather than dropped, so "not here" is
distinguishable from "not looked for".
It ships to the server because an air-gapped site cannot be scanned from
anywhere else. When a CVE lands, the answer is already on the box:
```powershell
shopdb-admin.ps1 verify # counts, and which bundle this is
shopdb-admin.ps1 verify -Path leaflet # is that component here, at what version
```
Generated by `scripts/generate_sbom.py` from files that are already pinned and
committed, so it is a translation rather than a scan — no network, no extra
toolchain on the build box, and byte-identical output for the same inputs. It is
deliberately not in `bundle-lock.json`: its provenance is git, not the payload.
## Client IP addresses ## Client IP addresses
IIS does not set `X-Forwarded-For` on its own, and HttpPlatformHandler connects IIS does not set `X-Forwarded-For` on its own, and HttpPlatformHandler connects

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@@ -166,6 +166,15 @@ if (Test-Path $cfgSrc) {
Copy-Item $cfgSrc (Join-Path $AppOut 'deploy\windows') -Force Copy-Item $cfgSrc (Join-Path $AppOut 'deploy\windows') -Force
} }
# A CycloneDX SBOM of everything this tree depends on, Python and npm together.
# Staged INTO the tree so it installs onto the server with the application: an
# air-gapped site cannot be scanned remotely, so the only way to answer "are we
# exposed to this CVE, and where" is for the answer to be sitting on the box.
Step 'Generating SBOM'
& $python.Source (Join-Path $RepoRoot 'scripts\generate_sbom.py') $RepoRoot `
-o (Join-Path $AppOut 'sbom.cdx.json') | ForEach-Object { Say " $_" 'White' }
if ($LASTEXITCODE -ne 0) { Die 'SBOM generation failed' }
# Stage the profile INTO the tree: `flask plugin apply-profile` at provisioning # Stage the profile INTO the tree: `flask plugin apply-profile` at provisioning
# reads the same profile the tree was staged from, so the installed plugin set # reads the same profile the tree was staged from, so the installed plugin set
# and the shipped plugin code cannot drift. # and the shipped plugin code cannot drift.

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@@ -496,6 +496,39 @@ function Invoke-Verify {
Say ' no bundle-lock.json recorded (installed before payload locking, or by hand)' 'Yellow' Say ' no bundle-lock.json recorded (installed before payload locking, or by hand)' 'Yellow'
} }
# The SBOM travels with the application, because a server on a vaulted
# network cannot be scanned from anywhere else. When a CVE lands, this is
# what answers "is that component here, and at what version" without needing
# the build box, the internet, or anyone's memory.
$sbom = Join-Path $AppRoot 'sbom.cdx.json'
if (Test-Path $sbom) {
try {
$b = Get-Content $sbom -Raw | ConvertFrom-Json
$shipped = @($b.components | Where-Object { $_.scope -eq 'required' }).Count
Say (" components : {0} ({1} shipped), CycloneDX {2}" -f `
$b.components.Count, $shipped, $b.specVersion)
Say (" bill of materials: {0}" -f $sbom) 'DarkGray'
Say ' search it with : shopdb-admin.ps1 verify -Path <name>' 'DarkGray'
} catch { Say ' sbom.cdx.json is present but unreadable' 'Yellow' }
# A named component turns this into the actual question being asked.
# Guarded on $b: an unreadable SBOM leaves it unset, and querying it then
# would report 'none', which reads as "you are not affected".
if ($Path -and $b) {
Say ''
Say (" matches for '{0}':" -f $Path) 'Cyan'
$hits = @($b.components | Where-Object { $_.name -like ('*' + $Path + '*') })
if (-not $hits) { Say ' none - this server does not carry it' 'Green' }
foreach ($h in $hits) {
$tag = if ($h.scope -eq 'required') { 'SHIPPED' } else { 'build only' }
Say (" {0,-40} {1,-14} {2}" -f $h.name, $h.version, $tag) `
$(if ($h.scope -eq 'required') { 'Yellow' } else { 'DarkGray' })
}
}
} else {
Say ' no SBOM recorded (installed before SBOMs shipped, or by hand)' 'Yellow'
}
# pip's own audit. It re-reads the metadata of what is actually installed and # pip's own audit. It re-reads the metadata of what is actually installed and
# reports anything missing or version-inconsistent, which is the part that # reports anything missing or version-inconsistent, which is the part that
# can still drift after install - a hand-run `pip install` on the server. # can still drift after install - a hand-run `pip install` on the server.

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@@ -77,6 +77,15 @@ if [ -f "$REPO/deploy/windows/web.config" ]; then
cp -a "$REPO/deploy/windows/web.config" "$OUT/deploy/windows/" cp -a "$REPO/deploy/windows/web.config" "$OUT/deploy/windows/"
fi fi
# A CycloneDX SBOM of everything this tree depends on, Python and npm together.
# Staged INTO the tree so it installs onto the server with the application: an
# air-gapped site cannot be scanned remotely, so the only way to answer "are we
# exposed to this CVE, and where" is for the answer to be sitting on the box.
# Generated from requirements.txt and package-lock.json, both already pinned and
# committed, so it is a translation rather than a scan - and deterministic.
echo "==> Generating SBOM ..."
python3 "$REPO/scripts/generate_sbom.py" "$REPO" -o "$OUT/sbom.cdx.json"
# Stage the profile INTO the tree. This is what makes the set self-describing: # Stage the profile INTO the tree. This is what makes the set self-describing:
# `flask plugin apply-profile` at provisioning time reads the same profile the # `flask plugin apply-profile` at provisioning time reads the same profile the
# tree was staged from, so the installed plugin set and the shipped plugin code # tree was staged from, so the installed plugin set and the shipped plugin code

348
scripts/generate_sbom.py Normal file
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@@ -0,0 +1,348 @@
#!/usr/bin/env python3
"""Emit a CycloneDX 1.6 SBOM for this application: Python and npm together.
Why this is hand-rolled rather than cyclonedx-py plus cyclonedx-npm:
- It has to run on the machine that builds the installer, which may be a work
PC with nothing but Python and Node. Two more toolchains to install, keep
current and match versions across build boxes is a real cost for output this
small.
- Both inputs are already fully pinned and committed - requirements.txt with a
sha256 per package, package-lock.json with an integrity per package - so
there is nothing to resolve. This is a format translation, not a scan.
- It is deterministic by construction, which the packaged tools are not
without extra flags. Same inputs, byte-identical output.
WHAT IT COVERS
Python every pin in requirements.txt, with the sha256 the installer enforces.
Environment markers are ignored on purpose: a requirement guarded by
sys_platform == 'win32' still installs on the target, which is Windows.
npm every package in frontend/package-lock.json. Development-only packages
are included but marked scope 'excluded', because they do not ship
inside the compiled SPA - a reader answering "are we exposed" needs to
see the distinction, not a list with them silently missing.
Dependency edges are real, not flat: uv writes '# via <parent>' comments into
requirements.txt, and package-lock records each package's dependencies.
NOT COVERED: the application's own source, which git records, and the operating
system. See deploy/windows/installer/bundle-lock.json for the third-party
binaries (Python installer, IIS MSIs) that ship alongside this.
Usage:
generate_sbom.py <repo-root> [-o out.json] [--timestamp ISO8601] [--appversion X]
"""
import argparse
import base64
import binascii
import hashlib
import json
import os
import re
import sys
import uuid
from datetime import datetime, timezone
SPEC_VERSION = '1.6'
GENERATOR = 'scripts/generate_sbom.py'
# Fixed namespace so the same component set always yields the same serial number.
# A random UUID per run would make every SBOM differ from the last for no reason.
SERIAL_NAMESPACE = uuid.UUID('6f9d1a1e-2b3c-4d5e-8f90-a1b2c3d4e5f6')
def normalize(name):
return re.sub(r'[^A-Za-z0-9.]+', '_', name).lower()
def read_app_version(repo):
init = os.path.join(repo, 'shopdb', '__init__.py')
try:
with open(init) as fh:
match = re.search(r"^__version__\s*=\s*'([^']+)'", fh.read(), re.M)
if match:
return match.group(1)
except OSError:
pass
return '0.0.0'
def parse_requirements(path):
"""Pins, their sha256 list, and which package pulled each one in.
uv emits, per entry:
flask==3.1.3 \\
--hash=sha256:... \\
--hash=sha256:...
# via
# -r requirements.in
# flask-migrate
'-r <file>' means the site asked for it directly; anything else is a parent.
"""
components, order = {}, []
current = None
in_via = False
with open(path) as fh:
for raw in fh:
line = raw.rstrip('\n')
stripped = line.strip()
match = re.match(r'^([A-Za-z0-9._-]+)==([^\s;\\]+)', stripped)
if match and not stripped.startswith('#'):
current = normalize(match.group(1))
in_via = False
if current not in components:
order.append(current)
components[current] = {
'name': match.group(1), 'version': match.group(2),
'hashes': [], 'parents': [], 'direct': False,
}
continue
if current is None:
continue
hash_match = re.search(r'--hash=sha256:([a-f0-9]{64})', stripped)
if hash_match:
components[current]['hashes'].append(hash_match.group(1))
continue
if stripped.startswith('#'):
body = stripped.lstrip('#').strip()
if body == 'via':
in_via = True
continue
if body.startswith('via '):
in_via = True
body = body[4:].strip()
if in_via and body:
if body.startswith('-r ') or body.startswith('-c '):
components[current]['direct'] = True
else:
components[current]['parents'].append(normalize(body))
continue
in_via = False
return [components[key] for key in order]
def integrity_to_hash(integrity):
"""npm 'sha512-<base64>' becomes a CycloneDX hash entry."""
if not integrity or '-' not in integrity:
return None
algorithm, _, encoded = integrity.partition('-')
algorithms = {'sha512': 'SHA-512', 'sha256': 'SHA-256', 'sha1': 'SHA-1'}
if algorithm not in algorithms:
return None
try:
digest = base64.b64decode(encoded)
except (binascii.Error, ValueError):
return None
return {'alg': algorithms[algorithm], 'content': digest.hex()}
def parse_package_lock(path):
"""Every locked package, plus the names the project depends on DIRECTLY.
The direct set comes from the lockfile's root entry. Without it the SBOM
claimed the application depended directly on all ~110 shipped packages,
which flattens the graph and makes 'what did we choose' unanswerable.
"""
with open(path) as fh:
data = json.load(fh)
packages = data.get('packages', {})
root = packages.get('', {})
direct = sorted((root.get('dependencies') or {}).keys())
# Keyed by (name, version), because npm installs the same package at several
# depths: node_modules/vite AND node_modules/vitest/node_modules/vite are two
# entries for one component. Emitting both produced duplicate bom-refs, which
# CycloneDX forbids and scanners reject.
merged = {}
for key, meta in packages.items():
if not key.startswith('node_modules/'):
continue
# Nested paths (a/node_modules/b) name the package after the LAST segment.
name = key.split('node_modules/')[-1]
version = meta.get('version')
if not version:
continue
entry = merged.get((name, version))
if entry is None:
merged[(name, version)] = {
'name': name,
'version': version,
'dev': bool(meta.get('dev') or meta.get('devOptional')),
'license': meta.get('license'),
'hash': integrity_to_hash(meta.get('integrity')),
'deps': set((meta.get('dependencies') or {}).keys()),
}
continue
# One copy reachable outside the dev tree means the component ships, so
# 'dev' only survives while EVERY instance is dev. Getting this backwards
# would mark a shipped package build-only and hide it from a CVE search.
entry['dev'] = entry['dev'] and bool(meta.get('dev') or meta.get('devOptional'))
entry['license'] = entry['license'] or meta.get('license')
entry['hash'] = entry['hash'] or integrity_to_hash(meta.get('integrity'))
entry['deps'] |= set((meta.get('dependencies') or {}).keys())
out = []
for entry in merged.values():
entry['deps'] = sorted(entry['deps'])
out.append(entry)
out.sort(key=lambda component: (component['name'], component['version']))
return out, direct
def purl(ecosystem, name, version):
from urllib.parse import quote
return 'pkg:%s/%s@%s' % (ecosystem, quote(name, safe='@/'), quote(version, safe=''))
def build(repo, timestamp, app_version):
requirements = os.path.join(repo, 'requirements.txt')
lockfile = os.path.join(repo, 'frontend', 'package-lock.json')
components, dependencies = [], []
root_ref = 'shopdb-flask@%s' % app_version
root_deps = []
pips = parse_requirements(requirements) if os.path.exists(requirements) else []
by_normalized = {}
for pin in pips:
ref = purl('pypi', pin['name'], pin['version'])
by_normalized[normalize(pin['name'])] = ref
entry = {
'type': 'library',
'bom-ref': ref,
'name': pin['name'],
'version': pin['version'],
'purl': ref,
'scope': 'required',
'properties': [{'name': 'shopdb:ecosystem', 'value': 'python'}],
}
if pin['hashes']:
entry['hashes'] = [{'alg': 'SHA-256', 'content': value}
for value in sorted(pin['hashes'])]
components.append(entry)
for pin in pips:
ref = by_normalized[normalize(pin['name'])]
if pin['direct']:
root_deps.append(ref)
for parent in pin['parents']:
parent_ref = by_normalized.get(parent)
if parent_ref:
dependencies.append((parent_ref, ref))
npms, npm_direct = parse_package_lock(lockfile) if os.path.exists(lockfile) else ([], [])
npm_refs = {}
for package in npms:
ref = purl('npm', package['name'], package['version'])
npm_refs.setdefault(package['name'], ref)
entry = {
'type': 'library',
'bom-ref': ref,
'name': package['name'],
'version': package['version'],
'purl': ref,
# Development packages do not ship inside the compiled SPA. Recorded
# rather than dropped so the distinction is visible.
'scope': 'excluded' if package['dev'] else 'required',
'properties': [{'name': 'shopdb:ecosystem', 'value': 'npm'}],
}
if package['hash']:
entry['hashes'] = [package['hash']]
if isinstance(package['license'], str):
entry['licenses'] = [{'license': {'id': package['license']}}]
components.append(entry)
for name in npm_direct:
ref = npm_refs.get(name)
if ref:
root_deps.append(ref)
for package in npms:
ref = npm_refs.get(package['name'])
for name in package['deps']:
child = npm_refs.get(name)
if child and ref:
dependencies.append((ref, child))
graph = {}
for parent, child in dependencies:
graph.setdefault(parent, set()).add(child)
depends_on = [{'ref': root_ref, 'dependsOn': sorted(set(root_deps))}]
for ref in sorted(graph):
depends_on.append({'ref': ref, 'dependsOn': sorted(graph[ref])})
components.sort(key=lambda component: component['bom-ref'])
fingerprint = hashlib.sha256(
json.dumps([component['bom-ref'] for component in components],
sort_keys=True).encode()).hexdigest()
serial = uuid.uuid5(SERIAL_NAMESPACE, fingerprint)
return {
'bomFormat': 'CycloneDX',
'specVersion': SPEC_VERSION,
'serialNumber': 'urn:uuid:%s' % serial,
'version': 1,
'metadata': {
'timestamp': timestamp,
'tools': {'components': [{
'type': 'application', 'name': GENERATOR, 'version': app_version,
}]},
'authors': [{'name': 'GE Aerospace'}],
'supplier': {'name': 'GE Aerospace'},
'component': {
'type': 'application',
'bom-ref': root_ref,
'name': 'shopdb-flask',
'version': app_version,
'description': 'Asset management for the shop floor.',
},
},
'components': components,
'dependencies': depends_on,
}
def main():
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument('repo')
parser.add_argument('-o', '--output', default='-')
# Pinned by the caller, or by SOURCE_DATE_EPOCH, so two builds of one commit
# produce byte-identical files.
parser.add_argument('--timestamp', default=None)
parser.add_argument('--appversion', default=None)
args = parser.parse_args()
timestamp = args.timestamp
if not timestamp:
epoch = os.environ.get('SOURCE_DATE_EPOCH')
moment = (datetime.fromtimestamp(int(epoch), timezone.utc) if epoch
else datetime.now(timezone.utc))
timestamp = moment.strftime('%Y-%m-%dT%H:%M:%SZ')
version = args.appversion or read_app_version(args.repo)
document = build(args.repo, timestamp, version)
text = json.dumps(document, indent=2, sort_keys=False) + '\n'
if args.output == '-':
sys.stdout.write(text)
else:
directory = os.path.dirname(args.output)
if directory and not os.path.isdir(directory):
os.makedirs(directory)
with open(args.output, 'w') as fh:
fh.write(text)
counts = {}
for component in document['components']:
key = component['properties'][0]['value']
counts[key] = counts.get(key, 0) + 1
shipped = sum(1 for component in document['components']
if component['scope'] == 'required')
print('%s: %d components (%s), %d shipped' % (
args.output, len(document['components']),
', '.join('%s %d' % (k, counts[k]) for k in sorted(counts)), shipped))
return 0
if __name__ == '__main__':
sys.exit(main())

154
tests/test_sbom.py Normal file
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@@ -0,0 +1,154 @@
"""The generated SBOM: shape, completeness, and the properties it is relied on for.
The point of shipping an SBOM to an air-gapped site is answering "are we exposed
to this CVE, and where" without scanning the box. That only works if the document
actually lists everything that ships, at the right versions, with identifiers a
scanner recognises. These tests hold it to that.
"""
import json
import subprocess
import sys
from pathlib import Path
import pytest
REPO = Path(__file__).resolve().parents[1]
GENERATOR = REPO / 'scripts' / 'generate_sbom.py'
FIXED_TIMESTAMP = '2026-01-01T00:00:00Z'
def generate(tmp_path, name='sbom.cdx.json'):
out = tmp_path / name
result = subprocess.run(
[sys.executable, str(GENERATOR), str(REPO), '-o', str(out),
'--timestamp', FIXED_TIMESTAMP],
capture_output=True, text=True)
assert result.returncode == 0, result.stderr
return json.loads(out.read_text()), out
@pytest.fixture(scope='module')
def sbom(tmp_path_factory):
document, _ = generate(tmp_path_factory.mktemp('sbom'))
return document
def test_is_valid_cyclonedx(sbom):
assert sbom['bomFormat'] == 'CycloneDX'
assert sbom['specVersion'] == '1.6'
assert sbom['serialNumber'].startswith('urn:uuid:')
assert sbom['version'] == 1
def test_carries_the_ntia_minimum_elements(sbom):
"""Supplier, component name, version, unique identifier, dependency
relationship, author, timestamp."""
meta = sbom['metadata']
assert meta['supplier']['name']
assert meta['authors']
assert meta['timestamp'] == FIXED_TIMESTAMP
assert meta['component']['name'] and meta['component']['version']
assert sbom['dependencies']
for component in sbom['components']:
assert component['name']
assert component['version']
assert component['purl'], '%s has no unique identifier' % component['name']
def test_every_python_pin_is_present(sbom):
"""The SBOM must not be quietly narrower than what the installer installs."""
import re
pinned = set()
for line in (REPO / 'requirements.txt').read_text().splitlines():
match = re.match(r'^([A-Za-z0-9._-]+)==([^\s;\\]+)', line.strip())
if match:
pinned.add((match.group(1).lower().replace('_', '-'), match.group(2)))
listed = {(c['name'].lower().replace('_', '-'), c['version'])
for c in sbom['components'] if c['purl'].startswith('pkg:pypi/')}
assert pinned == listed
def test_marked_out_dependencies_are_still_listed(sbom):
"""colorama is win32-only. It installs on the target, so it must appear -
the same blind spot that left it out of the wheelhouse."""
names = {c['name'] for c in sbom['components'] if c['purl'].startswith('pkg:pypi/')}
assert 'colorama' in names
def test_frontend_packages_are_covered(sbom):
"""The npm tree is the reason this exists: nothing else records what version
of leaflet or dompurify ends up inside the compiled SPA."""
npm = {c['name']: c for c in sbom['components'] if c['purl'].startswith('pkg:npm/')}
assert len(npm) > 100
for shipped in ('leaflet', 'dompurify', 'vue'):
assert shipped in npm, '%s is missing from the SBOM' % shipped
assert npm[shipped]['scope'] == 'required'
def test_build_only_packages_are_marked_not_dropped(sbom):
"""Dev packages do not ship. Recorded as 'excluded' rather than omitted, so a
reader can tell 'not here' from 'not looked for'."""
npm = {c['name']: c for c in sbom['components'] if c['purl'].startswith('pkg:npm/')}
assert npm['vite']['scope'] == 'excluded'
assert any(c['scope'] == 'required' for c in npm.values())
def test_bom_refs_are_unique(sbom):
"""CycloneDX forbids duplicate bom-refs, and scanners reject a document that
has them. npm installs the same package at several depths - node_modules/vite
and node_modules/vitest/node_modules/vite - which emitted it twice."""
refs = [c['bom-ref'] for c in sbom['components']]
duplicates = {ref for ref in refs if refs.count(ref) > 1}
assert not duplicates, 'duplicate bom-refs: %s' % sorted(duplicates)[:5]
def test_a_package_present_outside_the_dev_tree_counts_as_shipped(tmp_path):
"""Merging duplicates must not mark a shipped package build-only, which would
hide it from a CVE search on the server."""
sys.path.insert(0, str(REPO / 'scripts'))
import generate_sbom
lock = tmp_path / 'package-lock.json'
lock.write_text(json.dumps({'lockfileVersion': 3, 'packages': {
'': {'name': 'x', 'version': '1.0.0', 'dependencies': {'shared': '^1'}},
'node_modules/shared': {'version': '1.0.0'},
'node_modules/builder': {'version': '2.0.0', 'dev': True},
'node_modules/builder/node_modules/shared': {'version': '1.0.0', 'dev': True},
}}))
packages, direct = generate_sbom.parse_package_lock(str(lock))
shared = [p for p in packages if p['name'] == 'shared']
assert len(shared) == 1, 'the two copies of shared were not merged'
assert shared[0]['dev'] is False
assert direct == ['shared']
def test_components_carry_integrity_hashes(sbom):
missing = [c['name'] for c in sbom['components'] if not c.get('hashes')]
assert not missing, 'components without a hash: %s' % missing[:5]
def test_dependency_graph_is_real_not_flat(sbom):
"""A flat 'root depends on everything' graph cannot answer what was chosen
versus what was dragged in."""
root = sbom['metadata']['component']['bom-ref']
edges = {entry['ref']: entry['dependsOn'] for entry in sbom['dependencies']}
assert root in edges
assert len(edges) > 1, 'no edges below the root'
assert len(edges[root]) < len(sbom['components']), 'root depends on everything'
refs = {c['bom-ref'] for c in sbom['components']}
for ref, children in edges.items():
if ref == root:
continue
assert ref in refs, 'edge from an unknown component: %s' % ref
for child in children:
assert child in refs, 'edge to an unknown component: %s' % child
def test_output_is_byte_identical_across_runs(tmp_path):
"""Regenerating must not churn. A document that differs every build gets
re-committed without being read."""
first, first_path = generate(tmp_path, 'a.json')
_, second_path = generate(tmp_path, 'b.json')
assert first_path.read_bytes() == second_path.read_bytes()
assert first['serialNumber'] == json.loads(second_path.read_text())['serialNumber']