gpg: New commands --add-recipients and --change-recipients.

* g10/gpg.c (aAddRecipients, aChangeRecipients): New consts.
(opts): Add --add-recipients and --change-recipients.
(main): Handle them.
* g10/gpg.h (struct server_control_s): Add fields modify_recipients,
clear_recipients, and last_read_ctb.
* g10/armor.c (was_armored): New.
* g10/decrypt.c (decrypt_message): Add optional arg 'remusr'.  Handle
re-encryption if desired.
* g10/encrypt.c (write_pubkey_enc): Factor info printing out to ...
(show_encrypted_for_user_info): new.
(reencrypt_to_new_recipients): New.
* g10/packet.h (struct parse_packet_ctx_s): Add fields only_fookey_enc
and last_ctb.
(init_parse_packet): Clear them.
* g10/parse-packet.c (parse): Store CTB in the context.  Early return
on pubkey_enc and symkey_enc packets if requested.
* g10/mainproc.c (proc_encrypted): Allow for PKT being NULL.  Return
early in modify-recipients mode.
(proc_encryption_packets): Add two optional args 'r_dek' and 'r_list'.
Adjust callers.  Call do_proc_packets in modify-recipients mode
depending on the optional args.
(do_proc_packets): Add arg 'keep_dek_and_list'.  Adjust callers.  Save
the last read CTB in CTRL and return after the last fooenc_enc
packets.
--

This basically works but does not yet handle symmetric encrypted
packets (symkey_enc).

GnuPG-bug-id: 1825
(Yes, this is an at least 9 year old feature request)

1 files changed, 8 insertions, 1 deletions

diff --git a/g10/packet.h b/g10/packet.h
index 80238fcea..5cef17543 100644
--- a/g10/packet.h
+++ b/g10/packet.h
@@ -644,7 +644,10 @@ int proc_signature_packets (ctrl_t ctrl, void *ctx, iobuf_t a,
 			    strlist_t signedfiles, const char *sigfile );
 int proc_signature_packets_by_fd (ctrl_t ctrl, void *anchor, IOBUF a,
                                   gnupg_fd_t signed_data_fd);
-int proc_encryption_packets (ctrl_t ctrl, void *ctx, iobuf_t a);
+gpg_error_t proc_encryption_packets (ctrl_t ctrl, void *ctx, iobuf_t a,
+                                     DEK **r_dek,
+                                     struct pubkey_enc_list **r_list);
+
 int list_packets( iobuf_t a );
 
 const byte *issuer_fpr_raw (PKT_signature *sig, size_t *r_len);
@@ -673,7 +676,9 @@ struct parse_packet_ctx_s
   struct packet_struct last_pkt; /* The last parsed packet.  */
   int free_last_pkt; /* Indicates that LAST_PKT must be freed.  */
   int skip_meta;     /* Skip ring trust packets.  */
+  int only_fookey_enc;  /* Stop if the packet is not {sym,pub}key_enc. */
   unsigned int n_parsed_packets;	/* Number of parsed packets.  */
+  int last_ctb;      /* The last CTB read.  */
 };
 typedef struct parse_packet_ctx_s *parse_packet_ctx_t;
 
@@ -683,7 +688,9 @@ typedef struct parse_packet_ctx_s *parse_packet_ctx_t;
     (a)->last_pkt.pkt.generic= NULL;\
     (a)->free_last_pkt = 0;         \
     (a)->skip_meta = 0;             \
+    (a)->only_fookey_enc = 0;       \
     (a)->n_parsed_packets = 0;      \
+    (a)->last_ctb = 1;              \
   } while (0)
 
 #define deinit_parse_packet(a) do { \