gpg: Add stub function for encrypting AEAD.

* g10/cipher.c (cipher_filter): Rename to cipher_filter_cfb.
* g10/cipher-aead.c: New.  Right now only with a stub function.
* g10/Makefile.am (gpg_sources): Add file.
* g10/encrypt.c (encrypt_simple): Push either cipher_filter_cfb or
cipher_filter_aead.
(encrypt_crypt): Ditto.
(encrypt_filter): Ditto.
* g10/sign.c (sign_symencrypt_file): Ditto.

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

7 files changed, 95 insertions, 10 deletions

diff --git a/g10/Makefile.am b/g10/Makefile.am
index cc4ef5cb6..cba65b22a 100644
--- a/g10/Makefile.am
+++ b/g10/Makefile.am
@@ -132,6 +132,7 @@ gpg_sources = server.c          \
 	      decrypt.c 	\
 	      decrypt-data.c	\
 	      cipher.c		\
+	      cipher-aead.c     \
 	      encrypt.c		\
 	      sign.c		\
 	      verify.c		\
diff --git a/g10/cipher-aead.c b/g10/cipher-aead.c
new file mode 100644
index 000000000..bf0afcfcb
--- /dev/null
+++ b/g10/cipher-aead.c
@@ -0,0 +1,67 @@
+/* cipher-aead.c - Enciphering filter for AEAD modes
+ * Copyright (C) 2018 Werner koch
+ *
+ * This file is part of GnuPG.
+ *
+ * GnuPG is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GnuPG is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <https://www.gnu.org/licenses/>.
+ * SPDX-License-Identifier: GPL-3.0+
+ */
+
+#include <config.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+
+#include "gpg.h"
+#include "../common/status.h"
+#include "../common/iobuf.h"
+#include "../common/util.h"
+#include "filter.h"
+#include "packet.h"
+#include "options.h"
+#include "main.h"
+
+
+/*
+ * This filter is used to encipher data with an AEAD algorithm
+ */
+int
+cipher_filter_aead (void *opaque, int control,
+                   iobuf_t a, byte *buf, size_t *ret_len)
+{
+  cipher_filter_context_t *cfx = opaque;
+  size_t size = *ret_len;
+  int rc = 0;
+
+  if (control == IOBUFCTRL_UNDERFLOW) /* decrypt */
+    {
+      rc = -1; /* not yet used */
+    }
+  else if (control == IOBUFCTRL_FLUSH) /* encrypt */
+    {
+      log_assert (a);
+      rc = GPG_ERR_NOT_IMPLEMENTED;
+    }
+  else if (control == IOBUFCTRL_FREE)
+    {
+      gcry_cipher_close (cfx->cipher_hd);
+    }
+  else if (control == IOBUFCTRL_DESC)
+    {
+      mem2str (buf, "cipher_filter_aead", *ret_len);
+    }
+
+  return rc;
+}
diff --git a/g10/cipher.c b/g10/cipher.c
index b950d0c3f..ad7399dec 100644
--- a/g10/cipher.c
+++ b/g10/cipher.c
@@ -1,4 +1,4 @@
-/* cipher.c - En-/De-ciphering filter
+/* cipher.c - Enciphering filter for the old CFB mode.
  * Copyright (C) 1998-2003, 2006, 2009 Free Software Foundation, Inc.
  * Copyright (C) 1998-2003, 2006, 2009, 2017 Werner koch
  *
@@ -117,7 +117,8 @@ write_header (cipher_filter_context_t *cfx, iobuf_t a)
  * This filter is used to en/de-cipher data with a symmetric algorithm
  */
 int
-cipher_filter (void *opaque, int control, iobuf_t a, byte *buf, size_t *ret_len)
+cipher_filter_cfb (void *opaque, int control,
+                   iobuf_t a, byte *buf, size_t *ret_len)
 {
   cipher_filter_context_t *cfx = opaque;
   size_t size = *ret_len;
@@ -177,7 +178,7 @@ cipher_filter (void *opaque, int control, iobuf_t a, byte *buf, size_t *ret_len)
     }
   else if (control == IOBUFCTRL_DESC)
     {
-      mem2str (buf, "cipher_filter", *ret_len);
+      mem2str (buf, "cipher_filter_cfb", *ret_len);
     }
 
   return rc;
diff --git a/g10/encrypt.c b/g10/encrypt.c
index 2951a45ff..01feb4a7d 100644
--- a/g10/encrypt.c
+++ b/g10/encrypt.c
@@ -409,7 +409,10 @@ encrypt_simple (const char *filename, int mode, int use_seskey)
 
   /* Register the cipher filter. */
   if (mode)
-    iobuf_push_filter ( out, cipher_filter, &cfx );
+    iobuf_push_filter (out,
+                       cfx.dek->use_aead? cipher_filter_aead
+                       /**/             : cipher_filter_cfb,
+                       &cfx );
 
   /* Register the compress filter. */
   if ( do_compress )
@@ -800,7 +803,10 @@ encrypt_crypt (ctrl_t ctrl, int filefd, const char *filename,
     cfx.datalen = filesize && !do_compress ? filesize : 0;
 
   /* Register the cipher filter. */
-  iobuf_push_filter (out, cipher_filter, &cfx);
+  iobuf_push_filter (out,
+                     cfx.dek->use_aead? cipher_filter_aead
+                     /**/             : cipher_filter_cfb,
+                     &cfx);
 
   /* Register the compress filter. */
   if (do_compress)
@@ -959,7 +965,10 @@ encrypt_filter (void *opaque, int control,
                 return rc;
             }
 
-          iobuf_push_filter (a, cipher_filter, &efx->cfx);
+          iobuf_push_filter (a,
+                             efx->cfx.dek->use_aead? cipher_filter_aead
+                             /**/                  : cipher_filter_cfb,
+                             &efx->cfx);
 
           efx->header_okay = 1;
         }
diff --git a/g10/filter.h b/g10/filter.h
index 9e4b1e538..29243556e 100644
--- a/g10/filter.h
+++ b/g10/filter.h
@@ -145,8 +145,12 @@ void push_compress_filter2(iobuf_t out,compress_filter_context_t *zfx,
 			   int algo,int rel);
 
 /*-- cipher.c --*/
-int cipher_filter( void *opaque, int control,
-		   iobuf_t chain, byte *buf, size_t *ret_len);
+int cipher_filter_cfb (void *opaque, int control,
+                       iobuf_t chain, byte *buf, size_t *ret_len);
+
+/*-- cipher-aead.c --*/
+int cipher_filter_aead (void *opaque, int control,
+                        iobuf_t chain, byte *buf, size_t *ret_len);
 
 /*-- textfilter.c --*/
 int text_filter( void *opaque, int control,
diff --git a/g10/gpgcompose.c b/g10/gpgcompose.c
index 8c156d279..f87983802 100644
--- a/g10/gpgcompose.c
+++ b/g10/gpgcompose.c
@@ -2573,7 +2573,7 @@ encrypted (const char *option, int argc, char *argv[], void *cookie)
 
   cfx->datalen = 0;
 
-  filter_push (out, cipher_filter, cfx, PKT_ENCRYPTED, cfx->datalen == 0);
+  filter_push (out, cipher_filter_cfb, cfx, PKT_ENCRYPTED, cfx->datalen == 0);
 
   debug ("Wrote encrypted packet:\n");
 
diff --git a/g10/sign.c b/g10/sign.c
index f8a1241a6..051ab594d 100644
--- a/g10/sign.c
+++ b/g10/sign.c
@@ -1379,7 +1379,10 @@ sign_symencrypt_file (ctrl_t ctrl, const char *fname, strlist_t locusr)
     }
 
     /* Push the encryption filter */
-    iobuf_push_filter( out, cipher_filter, &cfx );
+    iobuf_push_filter (out,
+                       cfx.dek->use_aead? cipher_filter_aead
+                       /**/             : cipher_filter_cfb,
+                       &cfx);
 
     /* Push the compress filter */
     if (default_compress_algo())