From: Jonathan McDowell <noodles@earth.li>
Date: Fri, 14 Aug 2015 17:19:15 +0000 (+0100)
Subject: Add de-duplication of subkeys on a key
X-Git-Tag: onak-0.4.6~10
X-Git-Url: http://the.earth.li/gitweb/?p=onak.git;a=commitdiff_plain;h=e17ef1fac72bcfeff58e7c88af18eea6f9d6bc85

Add de-duplication of subkeys on a key

GnuPG will incorrectly add a pre-existing subkey that it doesn't
understand (e.g. ECC) to a key. This results in keys with a large
number of identical subkeys. Avoid this by detecting such keys and
de-duplicating the identical subkeys.

(gnupg bug report at https://bugs.gnupg.org/gnupg/issue1962)
---

diff --git a/cleankey.c b/cleankey.c
index 7d0bfe4..5608ef0 100644
--- a/cleankey.c
+++ b/cleankey.c
@@ -22,6 +22,7 @@
 #include <stdlib.h>
 
 #include "cleankey.h"
+#include "keyid.h"
 #include "keystructs.h"
 #include "log.h"
 #include "mem.h"
@@ -73,6 +74,53 @@ int dedupuids(struct openpgp_publickey *key)
 	return merged;
 }
 
+/**
+ *	dedupsubkeys - Merge duplicate subkeys on a key.
+ *	@key: The key to de-dup subkeys on.
+ *
+ *	This function attempts to merge duplicate subkeys on a key. It returns
+ *	0 if the key is unchanged, otherwise the number of dups merged.
+ */
+int dedupsubkeys(struct openpgp_publickey *key)
+{
+	struct openpgp_signedpacket_list *cursubkey = NULL;
+	struct openpgp_signedpacket_list *dup = NULL;
+	struct openpgp_signedpacket_list *tmp = NULL;
+	int                               merged = 0;
+	uint64_t                          subkeyid;
+
+	log_assert(key != NULL);
+	cursubkey = key->subkeys;
+	while (cursubkey != NULL) {
+		dup = find_signed_packet(cursubkey->next, cursubkey->packet);
+		while (dup != NULL) {
+			get_packetid(cursubkey->packet, &subkeyid);
+			logthing(LOGTHING_INFO,
+				"Found duplicate subkey: 0x%016" PRIX64,
+				subkeyid);
+			merged++;
+			merge_packet_sigs(cursubkey, dup);
+			/*
+			 * Remove the duplicate uid.
+			 */
+			tmp = cursubkey;
+			while (tmp != NULL && tmp->next != dup) {
+				tmp = tmp->next;
+			}
+			log_assert(tmp != NULL);
+			tmp->next = dup->next;
+			dup->next = NULL;
+			free_signedpacket_list(dup);
+
+			dup = find_signed_packet(cursubkey->next,
+				cursubkey->packet);
+		}
+		cursubkey = cursubkey->next;
+	}
+
+	return merged;
+}
+
 /**
  *	check_sighashes - Check that sig hashes are correct.
  *	@key - the check to check the sig hashes of.
@@ -146,6 +194,7 @@ int cleankeys(struct openpgp_publickey *keys)
 
 	while (keys != NULL) {
 		count = dedupuids(keys);
+		count += dedupsubkeys(keys);
 		if (config.check_sighash) {
 			count += clean_key_sighashes(keys);
 		}