gpg/decode/parse_subpackets: parse subpacket length according to RFC

2026-03-30 23:57:54 +08:00 · 2016-09-05 17:04:06 +02:00
parent 73bdf417e4
commit adcbe6e7b2
1 changed files with 8 additions and 1 deletions
--- a/trezor_agent/gpg/decode.py
+++ b/trezor_agent/gpg/decode.py
@@ -25,10 +25,17 @@ def parse_subpackets(s):

    while True:
        try:
-            subpacket_len = s.readfmt('B')
+            first = s.readfmt('B')
        except EOFError:
            break

+        if first < 192:
+            subpacket_len = first
+        elif first < 255:
+            subpacket_len = ((first - 192) << 8) + s.readfmt('B') + 192
+        else:  # first == 255
+            subpacket_len = s.readfmt('>L')
+
        subpackets.append(s.read(subpacket_len))

    return subpackets