Merge pull request #18193 from daytonb/fips-compatible

jkseppan · web-flow · commit 9b7f94fb194c · 2020-08-07T18:45:15.000+03:00
Allow savefig to save SVGs on FIPS enabled systems #18192
diff --git a/doc/api/next_api_changes/behavior/18193-BKB.rst b/doc/api/next_api_changes/behavior/18193-BKB.rst
@@ -0,0 +1,10 @@
+ID attribute of XML tags in SVG files now based on SHA256 rather than MD5
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+Matplotlib generates unique ID attributes for various tags in SVG files.
+Matplotlib previously generated these unique IDs using the first 10
+characters of an MD5 hash. The MD5 hashing algorithm is not available in
+Python on systems with Federal Information Processing Standards (FIPS)
+enabled. Matplotlib now uses the first 10 characters of an SHA256 hash
+instead. SVG files that would otherwise match those saved with earlier
+versions of matplotlib, will have different ID attributes.
diff --git a/lib/matplotlib/backends/backend_svg.py b/lib/matplotlib/backends/backend_svg.py
@@ -452,7 +452,7 @@ def _make_id(self, type, content):
         salt = mpl.rcParams['svg.hashsalt']
         if salt is None:
             salt = str(uuid.uuid4())
-        m = hashlib.md5()
+        m = hashlib.sha256()
         m.update(salt.encode('utf8'))
         m.update(str(content).encode('utf8'))
         return '%s%s' % (type, m.hexdigest()[:10])
