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+# This class is used to check recipes against public CVEs.
+#
+# In order to use this class just inherit the class in the
+# local.conf file and it will add the cve_check task for
+# every recipe. The task can be used per recipe, per image,
+# or using the special cases "world" and "universe". The
+# cve_check task will print a warning for every unpatched
+# CVE found and generate a file in the recipe WORKDIR/cve
+# directory. If an image is build it will generate a report
+# in DEPLOY_DIR_IMAGE for all the packages used.
+#
+# Example:
+# bitbake -c cve_check openssl
+# bitbake core-image-sato
+# bitbake -k -c cve_check universe
+#
+# DISCLAIMER
+#
+# This class/tool is meant to be used as support and not
+# the only method to check against CVEs. Running this tool
+# doesn't guarantee your packages are free of CVEs.
+
+CVE_CHECK_DB_DIR ?= "${DL_DIR}/CVE_CHECK"
+CVE_CHECK_DB_FILE ?= "${CVE_CHECK_DB_DIR}/nvd.db"
+
+CVE_CHECK_LOCAL_DIR ?= "${WORKDIR}/cve"
+CVE_CHECK_LOCAL_FILE ?= "${CVE_CHECK_LOCAL_DIR}/cve.log"
+CVE_CHECK_TMP_FILE ?= "${TMPDIR}/cve_check"
+
+CVE_CHECK_DIR ??= "${DEPLOY_DIR}/cve"
+CVE_CHECK_MANIFEST ?= "${DEPLOY_DIR_IMAGE}/${IMAGE_NAME}${IMAGE_NAME_SUFFIX}.cve"
+CVE_CHECK_COPY_FILES ??= "1"
+CVE_CHECK_CREATE_MANIFEST ??= "1"
+
+# Whitelist for packages (PN)
+CVE_CHECK_PN_WHITELIST = "\
+ glibc-locale \
+"
+
+# Whitelist for CVE and version of package
+CVE_CHECK_CVE_WHITELIST = "{\
+ 'CVE-2014-2524': ('6.3',), \
+}"
+
+python do_cve_check () {
+ """
+ Check recipe for patched and unpatched CVEs
+ """
+
+ if os.path.exists(d.getVar("CVE_CHECK_TMP_FILE", True)):
+ patched_cves = get_patches_cves(d)
+ patched, unpatched = check_cves(d, patched_cves)
+ if patched or unpatched:
+ cve_data = get_cve_info(d, patched + unpatched)
+ cve_write_data(d, patched, unpatched, cve_data)
+ else:
+ bb.note("Failed to update CVE database, skipping CVE check")
+}
+
+addtask cve_check after do_unpack before do_build
+do_cve_check[depends] = "cve-check-tool-native:do_populate_cve_db"
+do_cve_check[nostamp] = "1"
+
+python cve_check_cleanup () {
+ """
+ Delete the file used to gather all the CVE information.
+ """
+
+ bb.utils.remove(e.data.getVar("CVE_CHECK_TMP_FILE", True))
+}
+
+addhandler cve_check_cleanup
+cve_check_cleanup[eventmask] = "bb.cooker.CookerExit"
+
+python cve_check_write_rootfs_manifest () {
+ """
+ Create CVE manifest when building an image
+ """
+
+ import shutil
+
+ if os.path.exists(d.getVar("CVE_CHECK_TMP_FILE", True)):
+ bb.note("Writing rootfs CVE manifest")
+ deploy_dir = d.getVar("DEPLOY_DIR_IMAGE", True)
+ link_name = d.getVar("IMAGE_LINK_NAME", True)
+ manifest_name = d.getVar("CVE_CHECK_MANIFEST", True)
+ cve_tmp_file = d.getVar("CVE_CHECK_TMP_FILE", True)
+
+ shutil.copyfile(cve_tmp_file, manifest_name)
+
+ if manifest_name and os.path.exists(manifest_name):
+ manifest_link = os.path.join(deploy_dir, "%s.cve" % link_name)
+ # If we already have another manifest, update symlinks
+ if os.path.exists(os.path.realpath(manifest_link)):
+ if d.getVar('RM_OLD_IMAGE', True) == "1":
+ os.remove(os.path.realpath(manifest_link))
+ os.remove(manifest_link)
+ os.symlink(os.path.basename(manifest_name), manifest_link)
+ bb.plain("Image CVE report stored in: %s" % manifest_name)
+}
+
+ROOTFS_POSTPROCESS_COMMAND_prepend = "${@'cve_check_write_rootfs_manifest; ' if d.getVar('CVE_CHECK_CREATE_MANIFEST', True) == '1' else ''}"
+
+def get_patches_cves(d):
+ """
+ Get patches that solve CVEs using the "CVE: " tag.
+ """
+
+ import re
+
+ pn = d.getVar("PN", True)
+ cve_match = re.compile("CVE:( CVE\-\d{4}\-\d+)+")
+ patched_cves = set()
+ bb.debug(2, "Looking for patches that solves CVEs for %s" % pn)
+ for url in src_patches(d):
+ patch_file = bb.fetch.decodeurl(url)[2]
+ with open(patch_file, "r", encoding="utf-8") as f:
+ try:
+ patch_text = f.read()
+ except UnicodeDecodeError:
+ bb.debug(1, "Failed to read patch %s using UTF-8 encoding"
+ " trying with iso8859-1" % patch_file)
+ f.close()
+ with open(patch_file, "r", encoding="iso8859-1") as f:
+ patch_text = f.read()
+
+ # Search for the "CVE: " line
+ match = cve_match.search(patch_text)
+ if match:
+ # Get only the CVEs without the "CVE: " tag
+ cves = patch_text[match.start()+5:match.end()]
+ for cve in cves.split():
+ bb.debug(2, "Patch %s solves %s" % (patch_file, cve))
+ patched_cves.add(cve)
+ else:
+ bb.debug(2, "Patch %s doesn't solve CVEs" % patch_file)
+
+ return patched_cves
+
+def check_cves(d, patched_cves):
+ """
+ Run cve-check-tool looking for patched and unpatched CVEs.
+ """
+
+ import ast, csv, tempfile, subprocess, io
+
+ cves_patched = []
+ cves_unpatched = []
+ bpn = d.getVar("BPN", True)
+ pv = d.getVar("PV", True).split("git+")[0]
+ cves = " ".join(patched_cves)
+ cve_db_dir = d.getVar("CVE_CHECK_DB_DIR", True)
+ cve_whitelist = ast.literal_eval(d.getVar("CVE_CHECK_CVE_WHITELIST", True))
+ cve_cmd = "cve-check-tool"
+ cmd = [cve_cmd, "--no-html", "--csv", "--not-affected", "-t", "faux", "-d", cve_db_dir]
+
+ # If the recipe has been whitlisted we return empty lists
+ if d.getVar("PN", True) in d.getVar("CVE_CHECK_PN_WHITELIST", True).split():
+ bb.note("Recipe has been whitelisted, skipping check")
+ return ([], [])
+
+ # It is needed to export the proxies to download the database using HTTP
+ bb.utils.export_proxies(d)
+
+ try:
+ # Write the faux CSV file to be used with cve-check-tool
+ fd, faux = tempfile.mkstemp(prefix="cve-faux-")
+ with os.fdopen(fd, "w") as f:
+ f.write("%s,%s,%s," % (bpn, pv, cves))
+ cmd.append(faux)
+
+ output = subprocess.check_output(cmd, stderr=subprocess.STDOUT).decode("utf-8")
+ bb.debug(2, "Output of command %s:\n%s" % ("\n".join(cmd), output))
+ except subprocess.CalledProcessError as e:
+ bb.warn("Couldn't check for CVEs: %s (output %s)" % (e, e.output))
+ finally:
+ os.remove(faux)
+
+ for row in csv.reader(io.StringIO(output)):
+ # Third row has the unpatched CVEs
+ if row[2]:
+ for cve in row[2].split():
+ # Skip if the CVE has been whitlisted for the current version
+ if pv in cve_whitelist.get(cve,[]):
+ bb.note("%s-%s has been whitelisted for %s" % (bpn, pv, cve))
+ else:
+ cves_unpatched.append(cve)
+ bb.debug(2, "%s-%s is not patched for %s" % (bpn, pv, cve))
+ # Fourth row has patched CVEs
+ if row[3]:
+ for cve in row[3].split():
+ cves_patched.append(cve)
+ bb.debug(2, "%s-%s is patched for %s" % (bpn, pv, cve))
+
+ return (cves_patched, cves_unpatched)
+
+def get_cve_info(d, cves):
+ """
+ Get CVE information from the database used by cve-check-tool.
+
+ Unfortunately the only way to get CVE info is set the output to
+ html (hard to parse) or query directly the database.
+ """
+
+ try:
+ import sqlite3
+ except ImportError:
+ from pysqlite2 import dbapi2 as sqlite3
+
+ cve_data = {}
+ db_file = d.getVar("CVE_CHECK_DB_FILE", True)
+ placeholder = ",".join("?" * len(cves))
+ query = "SELECT * FROM NVD WHERE id IN (%s)" % placeholder
+ conn = sqlite3.connect(db_file)
+ cur = conn.cursor()
+ for row in cur.execute(query, tuple(cves)):
+ cve_data[row[0]] = {}
+ cve_data[row[0]]["summary"] = row[1]
+ cve_data[row[0]]["score"] = row[2]
+ cve_data[row[0]]["modified"] = row[3]
+ cve_data[row[0]]["vector"] = row[4]
+ conn.close()
+
+ return cve_data
+
+def cve_write_data(d, patched, unpatched, cve_data):
+ """
+ Write CVE information in WORKDIR; and to CVE_CHECK_DIR, and
+ CVE manifest if enabled.
+ """
+
+ cve_file = d.getVar("CVE_CHECK_LOCAL_FILE", True)
+ nvd_link = "https://web.nvd.nist.gov/view/vuln/detail?vulnId="
+ write_string = ""
+ first_alert = True
+ bb.utils.mkdirhier(d.getVar("CVE_CHECK_LOCAL_DIR", True))
+
+ for cve in sorted(cve_data):
+ write_string += "PACKAGE NAME: %s\n" % d.getVar("PN", True)
+ write_string += "PACKAGE VERSION: %s\n" % d.getVar("PV", True)
+ write_string += "CVE: %s\n" % cve
+ if cve in patched:
+ write_string += "CVE STATUS: Patched\n"
+ else:
+ write_string += "CVE STATUS: Unpatched\n"
+ if first_alert:
+ bb.warn("Found unpatched CVE, for more information check %s" % cve_file)
+ first_alert = False
+ write_string += "CVE SUMMARY: %s\n" % cve_data[cve]["summary"]
+ write_string += "CVSS v2 BASE SCORE: %s\n" % cve_data[cve]["score"]
+ write_string += "VECTOR: %s\n" % cve_data[cve]["vector"]
+ write_string += "MORE INFORMATION: %s%s\n\n" % (nvd_link, cve)
+
+ with open(cve_file, "w") as f:
+ bb.note("Writing file %s with CVE information" % cve_file)
+ f.write(write_string)
+
+ if d.getVar("CVE_CHECK_COPY_FILES", True) == "1":
+ cve_dir = d.getVar("CVE_CHECK_DIR", True)
+ bb.utils.mkdirhier(cve_dir)
+ deploy_file = os.path.join(cve_dir, d.getVar("PN", True))
+ with open(deploy_file, "w") as f:
+ f.write(write_string)
+
+ if d.getVar("CVE_CHECK_CREATE_MANIFEST", True) == "1":
+ with open(d.getVar("CVE_CHECK_TMP_FILE", True), "a") as f:
+ f.write("%s" % write_string)