gpg: Implement AEAD for SKESK packets.

* g10/packet.h (PKT_symkey_enc): Add field aead_algo.
* g10/build-packet.c (do_symkey_enc): Support version 5 packets.
* g10/parse-packet.c (parse_symkeyenc): Ditto.
* g10/encrypt.c (encrypt_symmetric): Force using a random session
key in AEAD mode.
(encrypt_seskey): Add and support arg aead_algo.
(write_symkey_enc): Ditto.
(encrypt_simple): Adjust accordingly.
(encrypt_filter): Ditto.
* g10/gpgcompose.c (sk_esk): For now call encrypt_seskey without AEAD
support.
* g10/mainproc.c (symkey_decrypt_seskey): Support AEAD.  Nver call BUG
but return an error.
(proc_symkey_enc): Call symkey_decrypt_seskey in a bug compatible way.

* g10/import.c (check_prefs): Check AEAD preferences.
* g10/keyedit.c (show_prefs): Print AEAD preferences.
--

For easier debugging this patch also changes some diagnostics to also
print the encryption mode with the cipher algorithm.

Signed-off-by: Werner Koch <wk@gnupg.org>

1 files changed, 18 insertions, 0 deletions

diff --git a/g10/keyedit.c b/g10/keyedit.c
index 81344eb79..3ae96a3b2 100644
--- a/g10/keyedit.c
+++ b/g10/keyedit.c
@@ -3064,6 +3064,23 @@ show_prefs (PKT_user_id * uid, PKT_signature * selfsig, int verbose)
 	  tty_printf ("%s", openpgp_cipher_algo_name (CIPHER_ALGO_3DES));
 	}
       tty_printf ("\n     ");
+      tty_printf (_("AEAD: "));
+      for (i = any = 0; prefs[i].type; i++)
+	{
+	  if (prefs[i].type == PREFTYPE_AEAD)
+	    {
+	      if (any)
+		tty_printf (", ");
+	      any = 1;
+	      /* We don't want to display strings for experimental algos */
+	      if (!openpgp_aead_test_algo (prefs[i].value)
+		  && prefs[i].value < 100)
+		tty_printf ("%s", openpgp_aead_algo_name (prefs[i].value));
+	      else
+		tty_printf ("[%d]", prefs[i].value);
+	    }
+	}
+      tty_printf ("\n     ");
       tty_printf (_("Digest: "));
       for (i = any = 0; prefs[i].type; i++)
 	{
@@ -3172,6 +3189,7 @@ show_prefs (PKT_user_id * uid, PKT_signature * selfsig, int verbose)
       for (i = 0; prefs[i].type; i++)
 	{
 	  tty_printf (" %c%d", prefs[i].type == PREFTYPE_SYM ? 'S' :
+		      prefs[i].type == PREFTYPE_AEAD ? 'A' :
 		      prefs[i].type == PREFTYPE_HASH ? 'H' :
 		      prefs[i].type == PREFTYPE_ZIP ? 'Z' : '?',
 		      prefs[i].value);