Adding upstream version 4.2.2.upstream/4.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 126 insertions, 0 deletions

diff --git a/tools/make-tls-ct-logids.py b/tools/make-tls-ct-logids.py
new file mode 100755
index 0000000..0b74c51
--- /dev/null
+++ b/tools/make-tls-ct-logids.py
@@ -0,0 +1,126 @@
+#!/usr/bin/env python3
+# Generate the array of Certificate Transparency Log ID to description mappings
+# for the TLS dissector.
+#
+# To update the TLS dissector source file, run this from the source directory:
+#
+#   python3 tools/make-tls-ct-logids.py --update
+#
+
+import argparse
+from base64 import b64decode, b64encode
+from enum import Enum
+import itertools
+import os
+import requests
+from hashlib import sha256
+
+
+# Begin of comment, followed by the actual array definition
+HEADER = "/* Generated by tools/make-tls-ct-logids.py\n"
+# See also https://www.certificate-transparency.org/known-logs
+CT_JSON_URL = 'https://www.gstatic.com/ct/log_list/v3/all_logs_list.json'
+# File to be patched
+SOURCE_FILE = os.path.join('epan', 'dissectors', 'packet-tls-utils.c')
+
+# Maximum elements per line in the value array. 11 is chosen because it results
+# in output consistent with clang-format.
+BYTES_PER_LINE = 11
+
+class SourceStage(Enum):
+    BEGIN = 1
+    IN_METAINFO = 2
+    IN_BLOCK = 3
+    END = 4
+
+
+def escape_c(s):
+    return s.replace('\\', '\\\\').replace('"', '\\"')
+
+
+def byteshex(b):
+    return " ".join("0x%02x," % b for b in bytearray(b))
+
+
+def process_json(obj, lastmod):
+    logs = list(itertools.chain(*[op['logs'] for op in obj['operators']]))
+    metainfo, block = HEADER, ''
+    metainfo += " * Last-Modified %s, %s entries. */\n" % (lastmod, len(logs))
+    block += "static const bytes_string ct_logids[] = {\n"
+    for entry in logs:
+        desc = entry["description"]
+        pubkey_der = b64decode(entry["key"])
+        key_id = sha256(pubkey_der).digest()
+        block += '    { (const uint8_t[]){\n'
+        for offset in range(0, len(key_id), BYTES_PER_LINE):
+            block += '          %s\n' % \
+                byteshex(key_id[offset:offset+BYTES_PER_LINE])
+        block += '      },\n'
+        block += '      %d, "%s" },\n' % (len(key_id), escape_c(desc))
+    block += "    { NULL, 0, NULL }\n"
+    block += "};\n"
+    return metainfo, block
+
+
+def parse_source(source_path):
+    """
+    Reads the source file and tries to split it in the parts before, inside and
+    after the block.
+    """
+    begin, metainfo, block, end = '', '', '', ''
+    # Stages: BEGIN (before block), IN_METAINFO, IN_BLOCK (skip), END
+    stage = SourceStage.BEGIN
+    with open(source_path) as f:
+        for line in f:
+            if line.startswith('/* Generated by '):
+                stage = SourceStage.IN_METAINFO
+
+
+            if stage == SourceStage.BEGIN:
+                begin += line
+            elif stage == SourceStage.IN_METAINFO:
+                metainfo += line
+            elif stage == SourceStage.IN_BLOCK:
+                block += line
+                if line.startswith('}'):
+                    stage = SourceStage.END
+            elif stage == SourceStage.END:
+                end += line
+
+            if line.startswith(' * Last-Modified '):
+                stage = SourceStage.IN_BLOCK
+
+    if stage != SourceStage.END:
+        raise RuntimeError("Could not parse file (in stage %s)" % stage.name)
+    return begin, metainfo, block, end
+
+
+parser = argparse.ArgumentParser()
+parser.add_argument("--update", action="store_true",
+                    help="Update %s as needed instead of writing to stdout" % SOURCE_FILE)
+
+
+def main():
+    args = parser.parse_args()
+    this_dir = os.path.dirname(__file__)
+    r = requests.get(CT_JSON_URL)
+    j_metainfo, j_block = process_json(r.json(), lastmod=r.headers['Last-Modified'])
+    source_path = os.path.join(this_dir, '..', SOURCE_FILE)
+
+    if args.update:
+        s_begin, _, s_block, s_end = parse_source(source_path)
+        if s_block == j_block:
+            print("File is up-to-date")
+        else:
+            with open(source_path, "w") as f:
+                f.write(s_begin)
+                f.write(j_metainfo)
+                f.write(j_block)
+                f.write(s_end)
+            print("Updated %s" % source_path)
+    else:
+        print(j_metainfo, j_block)
+
+
+if __name__ == '__main__':
+    main()