gpg: Detect duplicate keys with --add-recipients.

* g10/packet.h (struct pubkey_enc_list): Change to use a union to also
store symkey_enc data.  Adjust all users accordingly.
(struct pubkey_enc_info_item): New.
* g10/free-packet.c (free_pubkey_enc_list): New.
* g10/mainproc.c (release_list): Use it here.
* g10/decrypt.c (decrypt_message): and here.

* g10/encrypt.c (reencrypt_to_new_recipients): Record the used
pubkey_enc packets and pass them to write_pubkey_enc_from_list.
(write_pubkey_enc_from_list): Add arg restrict_pk_list and use it to
skip recipients already used.
--

GnuPG-bug-id: 1825

Note that we here already prepare to better handle symkey_enc packets.

1 files changed, 16 insertions, 0 deletions

diff --git a/g10/free-packet.c b/g10/free-packet.c
index 3a9e17665..47615596a 100644
--- a/g10/free-packet.c
+++ b/g10/free-packet.c
@@ -538,6 +538,22 @@ free_packet (PACKET *pkt, parse_packet_ctx_t parsectx)
 }
 
 
+/* Free a entire list of public key encrypted data.  */
+void
+free_pubkey_enc_list (struct pubkey_enc_list *pkenc_list)
+{
+  while (pkenc_list)
+    {
+      struct pubkey_enc_list *tmp = pkenc_list->next;
+
+      if (!pkenc_list->u_sym)
+        release_pubkey_enc_parts (&pkenc_list->u.pub);
+      xfree (pkenc_list);
+      pkenc_list = tmp;
+    }
+}
+
+
 /****************
  * returns 0 if they match.
  */