cve-check: backport rewrite from master

As detailed at [1] the XML feeds provided by NIST are being discontinued on
October 9th 2019.  As cve-check-tool uses these feeds, cve-check.bbclass will be
inoperable after this date.

To ensure that cve-check continues working, backport the following commits from
master to move away from the unmaintained cve-check-tool to our own Python code
that fetches the JSON:

546d14135c5 cve-update-db: New recipe to update CVE database
bc144b028f6 cve-check: Remove dependency to cve-check-tool-native
7f62a20b32a cve-check: Manage CVE_PRODUCT with more than one name
3bf63bc6084 cve-check: Consider CVE that affects versions with less than operator
c0eabd30d7b cve-update-db: Use std library instead of urllib3
27eb839ee65 cve-check: be idiomatic
09be21f4d17 cve-update-db: Manage proxy if needed.
975793e3825 cve-update-db: do_populate_cve_db depends on do_fetch
0325dd72714 cve-update-db: Catch request.urlopen errors.
4078da92b49 cve-check: Depends on cve-update-db-native
f7676e9a38d cve-update-db: Use NVD CPE data to populate PRODUCTS table
bc0195be1b1 cve-check: Update unpatched CVE matching
c807c2a6409 cve-update-db-native: Skip recipe when cve-check class is not loaded.
07bb8b25e17 cve-check: remove redundant readline CVE whitelisting
5388ed6d137 cve-check-tool: remove
270ac00cb43 cve-check.bbclass: initialize to_append
e6bf9000987 cve-check: allow comparison of Vendor as well as Product
91770338f76 cve-update-db-native: use SQL placeholders instead of format strings
7069302a4cc cve-check: Replace CVE_CHECK_CVE_WHITELIST by CVE_CHECK_WHITELIST
78de2cb39d7 cve-update-db-native: Remove hash column from database.
4b301030cf9 cve-update-db-native: use os.path.join instead of +
f0d822fad2a cve-update-db: actually inherit native
b309840b6aa cve-update-db-native: use executemany() to optimise CPE insertion
bb4e53af33d cve-update-db-native: improve metadata parsing
94227459792 cve-update-db-native: clean up JSON fetching
95438d52b73 cve-update-db-native: fix https proxy issues
1f9a963b9ff glibc: exclude child recipes from CVE scanning

[1] https://nvd.nist.gov/General/News/XML-Vulnerability-Feed-Retirement

(From OE-Core rev: 8c87e78547c598cada1bce92e7b25d85b994e2eb)

Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Armin Kuster <akuster808@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 87 insertions, 55 deletions

diff --git a/meta/classes/cve-check.bbclass b/meta/classes/cve-check.bbclass
index 743bc08a4f..c00d2910be 100644
--- a/meta/classes/cve-check.bbclass
+++ b/meta/classes/cve-check.bbclass
@@ -26,7 +26,7 @@ CVE_PRODUCT ??= "${BPN}"
 CVE_VERSION ??= "${PV}"
 
 CVE_CHECK_DB_DIR ?= "${DL_DIR}/CVE_CHECK"
-CVE_CHECK_DB_FILE ?= "${CVE_CHECK_DB_DIR}/nvd.db"
+CVE_CHECK_DB_FILE ?= "${CVE_CHECK_DB_DIR}/nvdcve_1.0.db"
 
 CVE_CHECK_LOG ?= "${T}/cve.log"
 CVE_CHECK_TMP_FILE ?= "${TMPDIR}/cve_check"
@@ -37,32 +37,33 @@ CVE_CHECK_COPY_FILES ??= "1"
 CVE_CHECK_CREATE_MANIFEST ??= "1"
 
 # Whitelist for packages (PN)
-CVE_CHECK_PN_WHITELIST = "\
-    glibc-locale \
-"
+CVE_CHECK_PN_WHITELIST ?= ""
 
-# Whitelist for CVE and version of package
-CVE_CHECK_CVE_WHITELIST = "{\
-    'CVE-2014-2524': ('6.3','5.2',), \
-}"
+# Whitelist for CVE. If a CVE is found, then it is considered patched.
+# The value is a string containing space separated CVE values:
+# 
+# CVE_CHECK_WHITELIST = 'CVE-2014-2524 CVE-2018-1234'
+# 
+CVE_CHECK_WHITELIST ?= ""
 
 python do_cve_check () {
     """
     Check recipe for patched and unpatched CVEs
     """
 
-    if os.path.exists(d.getVar("CVE_CHECK_TMP_FILE")):
+    if os.path.exists(d.getVar("CVE_CHECK_DB_FILE")):
         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")
+        bb.note("No CVE database found, skipping CVE check")
+
 }
 
 addtask cve_check after do_unpack before do_build
-do_cve_check[depends] = "cve-check-tool-native:do_populate_sysroot cve-check-tool-native:do_populate_cve_db"
+do_cve_check[depends] = "cve-update-db-native:do_populate_cve_db"
 do_cve_check[nostamp] = "1"
 
 python cve_check_cleanup () {
@@ -163,65 +164,94 @@ def get_patches_cves(d):
 
 def check_cves(d, patched_cves):
     """
-    Run cve-check-tool looking for patched and unpatched CVEs.
+    Connect to the NVD database and find unpatched cves.
     """
-
     import ast, csv, tempfile, subprocess, io
+    from distutils.version import LooseVersion
 
-    cves_patched = []
     cves_unpatched = []
-    bpn = d.getVar("CVE_PRODUCT")
+    # CVE_PRODUCT can contain more than one product (eg. curl/libcurl)
+    products = d.getVar("CVE_PRODUCT").split()
     # If this has been unset then we're not scanning for CVEs here (for example, image recipes)
-    if not bpn:
+    if not products:
         return ([], [])
     pv = d.getVar("CVE_VERSION").split("+git")[0]
-    cves = " ".join(patched_cves)
-    cve_db_dir = d.getVar("CVE_CHECK_DB_DIR")
-    cve_whitelist = ast.literal_eval(d.getVar("CVE_CHECK_CVE_WHITELIST"))
-    cve_cmd = "cve-check-tool"
-    cmd = [cve_cmd, "--no-html", "--skip-update", "--csv", "--not-affected", "-t", "faux", "-d", cve_db_dir]
 
     # If the recipe has been whitlisted we return empty lists
     if d.getVar("PN") in d.getVar("CVE_CHECK_PN_WHITELIST").split():
         bb.note("Recipe has been whitelisted, skipping check")
         return ([], [])
 
-    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:
-            for pn in bpn.split():
-                f.write("%s,%s,%s,\n" % (pn, pv, cves))
-        cmd.append(faux)
-
-        output = subprocess.check_output(cmd).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))
+    old_cve_whitelist =  d.getVar("CVE_CHECK_CVE_WHITELIST")
+    if old_cve_whitelist:
+        bb.warn("CVE_CHECK_CVE_WHITELIST is deprecated, please use CVE_CHECK_WHITELIST.")
+    cve_whitelist = d.getVar("CVE_CHECK_WHITELIST").split()
+
+    import sqlite3
+    db_file = d.getVar("CVE_CHECK_DB_FILE")
+    conn = sqlite3.connect(db_file)
+
+    for product in products:
+        c = conn.cursor()
+        if ":" in product:
+            vendor, product = product.split(":", 1)
+            c.execute("SELECT * FROM PRODUCTS WHERE PRODUCT IS ? AND VENDOR IS ?", (product, vendor))
+        else:
+            c.execute("SELECT * FROM PRODUCTS WHERE PRODUCT IS ?", (product,))
+
+        for row in c:
+            cve = row[0]
+            version_start = row[3]
+            operator_start = row[4]
+            version_end = row[5]
+            operator_end = row[6]
+
+            if cve in cve_whitelist:
+                bb.note("%s-%s has been whitelisted for %s" % (product, pv, cve))
+            elif cve in patched_cves:
+                bb.note("%s has been patched" % (cve))
+            else:
+                to_append = False
+                if (operator_start == '=' and pv == version_start):
+                    cves_unpatched.append(cve)
                 else:
+                    if operator_start:
+                        try:
+                            to_append_start =  (operator_start == '>=' and LooseVersion(pv) >= LooseVersion(version_start))
+                            to_append_start |= (operator_start == '>' and LooseVersion(pv) > LooseVersion(version_start))
+                        except:
+                            bb.note("%s: Failed to compare %s %s %s for %s" %
+                                    (product, pv, operator_start, version_start, cve))
+                            to_append_start = False
+                    else:
+                        to_append_start = False
+
+                    if operator_end:
+                        try:
+                            to_append_end  = (operator_end == '<=' and LooseVersion(pv) <= LooseVersion(version_end))
+                            to_append_end |= (operator_end == '<' and LooseVersion(pv) < LooseVersion(version_end))
+                        except:
+                            bb.note("%s: Failed to compare %s %s %s for %s" %
+                                    (product, pv, operator_end, version_end, cve))
+                            to_append_end = False
+                    else:
+                        to_append_end = False
+
+                    if operator_start and operator_end:
+                        to_append = to_append_start and to_append_end
+                    else:
+                        to_append = to_append_start or to_append_end
+
+                if to_append:
                     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))
+                bb.debug(2, "%s-%s is not patched for %s" % (product, pv, cve))
+    conn.close()
 
-    return (cves_patched, cves_unpatched)
+    return (list(patched_cves), cves_unpatched)
 
 def get_cve_info(d, cves):
     """
-    Get CVE information from the database used by cve-check-tool.
+    Get CVE information from the database.
 
     Unfortunately the only way to get CVE info is set the output to
     html (hard to parse) or query directly the database.
@@ -241,9 +271,10 @@ def get_cve_info(d, cves):
     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]
+        cve_data[row[0]]["scorev2"] = row[2]
+        cve_data[row[0]]["scorev3"] = row[3]
+        cve_data[row[0]]["modified"] = row[4]
+        cve_data[row[0]]["vector"] = row[5]
     conn.close()
 
     return cve_data
@@ -270,7 +301,8 @@ def cve_write_data(d, patched, unpatched, cve_data):
             unpatched_cves.append(cve)
             write_string += "CVE STATUS: Unpatched\n"
         write_string += "CVE SUMMARY: %s\n" % cve_data[cve]["summary"]
-        write_string += "CVSS v2 BASE SCORE: %s\n" % cve_data[cve]["score"]
+        write_string += "CVSS v2 BASE SCORE: %s\n" % cve_data[cve]["scorev2"]
+        write_string += "CVSS v3 BASE SCORE: %s\n" % cve_data[cve]["scorev3"]
         write_string += "VECTOR: %s\n" % cve_data[cve]["vector"]
         write_string += "MORE INFORMATION: %s%s\n\n" % (nvd_link, cve)