Hello,

there is (at least) one key in my keyring that makes

	gpg --list-key --with-colons DE6162B5616BA9C9CAAC03074A55C497F744F705

emit non-UTF-8 output. I'm not sure if this is a bug in gpg as the docs
claim that "Note that the output will be encoded in UTF-8 [...]."

Passing that fingerprint to gpgparticipants-filter makes it barf:

	$ /usr/bin/gpgparticipants-filter DE6162B5616BA9C9CAAC03074A55C497F744F705
	Traceback (most recent call last):
	  File "/usr/bin/gpgparticipants-filter", line 166, in <module>
	    key_data += key_data_sets_from(gpg_output)
	  File "/usr/bin/gpgparticipants-filter", line 128, in key_data_sets_from
	    yield key_data_from(raw_data_set)
		  ~~~~~~~~~~~~~^^^^^^^^^^^^^^
	  File "/usr/bin/gpgparticipants-filter", line 120, in key_data_from
	    raw_data_set.data_field_from_lines(9, b'uid'),
	    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^
	  File "/usr/bin/gpgparticipants-filter", line 61, in data_field_from_lines
	    return [line.split(b':')[field_index].decode() for line in self.data if line.startswith(line_prefix)]
		    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^
	UnicodeDecodeError: 'utf-8' codec can't decode byte 0xf8 in position 6: invalid start byte

The following patch fixes that:

From 4f2b31e55c909dd916bdd088bc314239cbce0f9f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= <ukleinek@debian.org>
Date: Tue, 6 May 2025 18:59:28 +0200
Subject: [PATCH] gpgparticipants-filter: Somewhat handle uids with non-UTF-8
 encoding

PGP certificates with (e.g.) latin1 encoded uids result in a
UnicodeDecodeError. So only decode the key id field of gpg's output.
---
 gpgparticipants/gpgparticipants-filter | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/gpgparticipants/gpgparticipants-filter b/gpgparticipants/gpgparticipants-filter
index 7e33dc3286be..8899a28e2635 100755
--- a/gpgparticipants/gpgparticipants-filter
+++ b/gpgparticipants/gpgparticipants-filter
@@ -58,7 +58,7 @@ class RawDataSet:

     def data_field_from_lines(self, field_index, line_prefix):
         """Select all lines which start with line_prefix and return the columns denoted by field_index."""
-        return [line.split(b':')[field_index].decode() for line in self.data if line.startswith(line_prefix)]
+        return [line.split(b':')[field_index] for line in self.data if line.startswith(line_prefix)]


 class KeyDataSet:
@@ -72,7 +72,7 @@ class KeyDataSet:
         self.valid_flag = valid_flag

     def __repr__(self):
-        return self.key_id
+        return self.key_id.decode()

     def is_valid(self):
         """check that the key isn't revoked or expired"""

Best regards
Uwe

Hello,

that patch has a bug, it also needs:

diff --git a/gpgparticipants/gpgparticipants-filter b/gpgparticipants/gpgparticipants-filter
index d2c7ac3e622a..849b8bd8018c 100755
--- a/gpgparticipants/gpgparticipants-filter
+++ b/gpgparticipants/gpgparticipants-filter
@@ -76,7 +76,7 @@ class KeyDataSet:

     def is_valid(self):
         """check that the key isn't revoked or expired"""
-        return self.valid_flag not in ['e', 'r']
+        return self.valid_flag not in [b'e', b'r']


 def filter_to_gpg(filter_strings, gpg_bin, set_homedir, homedir):

because the valid_flag is a bytestring and not a plain string any more.
(But also see #1104814)

Best regards
Uwe