gpg: New option --force-aead

* g10/dek.h (DEK): Turn fields use_mdc, algo_printed and symmetric
into single bit vars.  Make sure they are always set to 1 or 0.
(DEK): New field use_aead.
* g10/options.h (struct opt): New field force_aead.
* g10/pkclist.c (select_aead_from_pklist): New.
* g10/gpg.c (oForceAEAD): New const.
(opts): New options "--force-aead".
(main): Set new option.
* g10/encrypt.c (use_aead): New.
(encrypt_simple): Implement new flags DEK.use_aead.
(encrypt_crypt): Ditto.
(encrypt_filter): Ditto.
* g10/sign.c (sign_symencrypt_file): Ditto.
--

This patch should be enough to detect whether AEAD can be used.
Not tested.

Signed-off-by: Werner Koch <[email protected]>

1 files changed, 25 insertions, 0 deletions

diff --git a/g10/pkclist.c b/g10/pkclist.c
index a759672ab..b85efa4cd 100644
--- a/g10/pkclist.c
+++ b/g10/pkclist.c
@@ -1651,6 +1651,31 @@ select_mdc_from_pklist (PK_LIST pk_list)
 }
 
 
+/* Select the AEAD flag from the pk_list.  We can only use AEAD if all
+ * recipients support this feature.  Returns true if AEAD can be used.  */
+int
+select_aead_from_pklist (PK_LIST pk_list)
+{
+  pk_list_t pkr;
+  int aead;
+
+  if (!pk_list)
+    return 0;
+
+  for (pkr = pk_list; pkr; pkr = pkr->next)
+    {
+      if (pkr->pk->user_id) /* selected by user ID */
+        aead = pkr->pk->user_id->flags.aead;
+      else
+        aead = pkr->pk->flags.aead;
+      if (!aead)
+        return 0;  /* At least one recipient does not support it. */
+    }
+
+  return 1; /* Can be used. */
+}
+
+
 /* Print a warning for all keys in PK_LIST missing the MDC feature. */
 void
 warn_missing_mdc_from_pklist (PK_LIST pk_list)