[gnome-build-meta/abderrahim/cve-report: 4/4] cve-report: use the json feed

[Abderrahim Kitouni <akitouni src gnome org>]

commit eb4811e9d8afad91d1af1ee33ef7eb5d4212e896
Author: Abderrahim Kitouni <akitouni gnome org>
Date:   Wed Oct 23 15:03:33 2019 +0100

    cve-report: use the json feed
    
    See https://gitlab.com/freedesktop-sdk/freedesktop-sdk/merge_requests/1940

 .gitlab-ci.yml                     |   2 -
 utils/update-local-cve-database.py | 104 ++++++++++++++++++++++++++-----------
 2 files changed, 74 insertions(+), 32 deletions(-)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 8f985245..135a1c3f 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -304,8 +304,6 @@ cve_report:
   stage: reports
   dependencies: [track]
   script:
-  - pip3 install --user lxml
-
   - ${BST} pull platform-manifest.bst sdk-manifest.bst
 
   - ${BST} checkout platform-manifest.bst platform-manifest/
diff --git a/utils/update-local-cve-database.py b/utils/update-local-cve-database.py
index ab3d293c..4082ffdc 100755
--- a/utils/update-local-cve-database.py
+++ b/utils/update-local-cve-database.py
@@ -21,34 +21,38 @@ import datetime
 import itertools
 import urllib.request
 import urllib.parse
-from contextlib import contextmanager
-
-from lxml import etree as ET
-
-namespaces = {
-    "feed": "http://scap.nist.gov/schema/feed/vulnerability/2.0";,
-    "vuln": "http://scap.nist.gov/schema/vulnerability/0.4";,
-    "cvss": "http://scap.nist.gov/schema/cvss-v2/0.2";,
-}
+from contextlib import contextmanager, ExitStack
+import signal
+import socket
+import json
 
 def extract_vulns(tree):
-    for entry in tree.iterfind("feed:entry", namespaces=namespaces):
-        cve_id = entry.find("vuln:cve-id", namespaces=namespaces).text
-        summary = entry.find("vuln:summary", namespaces=namespaces).text
-        score = entry.find("vuln:cvss/cvss:base_metrics/cvss:score", namespaces=namespaces)
-        yield cve_id, summary, score.text if score is not None else None
+    for item in tree['CVE_Items']:
+        cve_id = item['cve']['CVE_data_meta']['ID']
+        summary = item['cve']['description']['description_data'][0]['value']
+        score = item['impact'].get('baseMetricV2', {}).get('cvssV2', {}).get('baseScore')
+        yield cve_id, summary, score
 
-def extract_product_vulns(tree):
-    for entry in tree.iterfind("feed:entry", namespaces=namespaces):
-        cve_id = entry.find("vuln:cve-id", namespaces=namespaces).text
-        for vuln_software in entry.iterfind("vuln:vulnerable-software-list", namespaces=namespaces):
-            for product in vuln_software.iterfind("vuln:product", namespaces=namespaces):
-                product_name = product.text
+
+def extract_product_vulns_sub(cve_id, node):
+    if "cpe_match" in node:
+        for vuln_software in node["cpe_match"]:
+            if vuln_software["vulnerable"]:
+                product_name = vuln_software["cpe23Uri"]
                 try:
-                    vendor, name, version = product_name.split(':')[2:5]
+                    vendor, name, version = product_name.split(':')[3:6]
                 except ValueError:
                     continue
                 yield cve_id, vendor, name, version
+    else:
+        for child in node.get("children", []):
+            yield from extract_product_vulns_sub(cve_id, child)
+
+def extract_product_vulns(tree):
+    for item in tree['CVE_Items']:
+        cve_id = item['cve']['CVE_data_meta']['ID']
+        for node in item['configurations']["nodes"]:
+            yield from extract_product_vulns_sub(cve_id, node)
 
 def ensure_tables(c):
     c.execute("""CREATE TABLE IF NOT EXISTS etags
@@ -59,8 +63,40 @@ def ensure_tables(c):
                  (cve_id TEXT, name TEXT, vendor TEXT, version TEXT,
                   UNIQUE(cve_id, name, vendor, version))""")
 
-def update_year(c, year):
-    url = 'https://nvd.nist.gov/feeds/xml/cve/2.0/nvdcve-2.0-{}.xml.gz'.format(year)
+
+class UrlOpenTimeout:
+
+    def __init__(self):
+        self._max = 120
+        self._min = 5
+        self._timeout = self._max
+
+    @contextmanager
+    def open(self, req):
+        with ExitStack() as stack:
+            def _timeout(signum, frame):
+                raise TimeoutError()
+            try:
+                signal.signal(signal.SIGALRM, _timeout)
+                signal.alarm(self._timeout)
+                resp = stack.enter_context(urllib.request.urlopen(req, timeout=self._timeout))
+                self._timeout = self._max
+            except TimeoutError:
+                self._timeout = max(int(self._timeout/2), self._min)
+                raise
+            except urllib.error.URLError as e:
+                if isinstance(e.reason, socket.timeout):
+                    self._timeout = max(int(self._timeout/2), self._min)
+                    raise TimeoutError()
+                else:
+                    raise
+            finally:
+                signal.alarm(0)
+
+            yield resp
+
+def update_year(c, year, url_timeout):
+    url = 'https://nvd.nist.gov/feeds/json/cve/1.1/nvdcve-1.1-{}.json.gz'.format(year)
     c.execute("SELECT etag FROM etags WHERE year=?", (year,))
     row = c.fetchone()
     if row is not None:
@@ -71,26 +107,33 @@ def update_year(c, year):
     request = urllib.request.Request(url)
     if etag is not None:
         request.add_header('If-None-Match', etag)
+        url_opener = url_timeout.open
+    else:
+        url_opener = urllib.request.urlopen
     try:
-        with urllib.request.urlopen(request) as resp:
+        with url_opener(request) as resp:
             new_etag = resp.getheader('ETag')
             assert new_etag is not None
             if new_etag is not None:
                 c.execute("INSERT OR REPLACE INTO etags (year, etag) VALUES (?, ?)", (year, new_etag))
-            with open('nvdcve-2.0-{}.xml.gz'.format(year), 'wb') as f:
+            with open('nvdcve-1.1-{}.json.gz'.format(year), 'wb') as f:
                 while True:
                     buf = resp.read(4096)
                     if not buf:
                         print("Downloaded {}".format(f.name))
                         break
                     f.write(buf)
+    except TimeoutError:
+        if etag is None:
+            raise
+        print("Timeout, using cache for {}".format('nvdcve-1.1-{}.json.gz'.format(year)))
     except urllib.error.HTTPError as error:
         if error.code != 304:
             raise
-        print("Cached {}".format('nvdcve-2.0-{}.xml.gz'.format(year)))
+        print("Cached {}".format('nvdcve-1.1-{}.json.gz'.format(year)))
 
-    with gzip.open('nvdcve-2.0-{}.xml.gz'.format(year)) as f:
-        tree = ET.parse(f)
+    with gzip.open('nvdcve-1.1-{}.json.gz'.format(year)) as f:
+        tree = json.load(f)
         for cve_id, summary, score in extract_vulns(tree):
             c.execute("INSERT OR REPLACE INTO cve (id, summary, score) VALUES (?, ?, ?)", (cve_id, summary, 
score))
 
@@ -102,9 +145,10 @@ if __name__ == '__main__':
     c = conn.cursor()
     try:
         ensure_tables(c)
+        url_timeout = UrlOpenTimeout()
         for year in range(2002, datetime.datetime.now().year + 1):
-            update_year(c, str(year))
-        update_year(c, 'Modified')
+            update_year(c, str(year), url_timeout)
+        update_year(c, 'Modified', url_timeout)
         conn.commit()
     finally:
         conn.close()