From 7356d6ec50ea24bc9449187e1c2b3ecd717b789f Mon Sep 17 00:00:00 2001
From: Werner Koch <wk@gnupg.org>
Date: Sun, 21 Jan 2018 16:42:29 +0100
Subject: [PATCH] gpg: Support EAX if for latest Libgcrypt.

* g10/cipher-aead.c (MY_GCRY_CIPHER_MODE_EAX): New.
(write_header): Use it.
* g10/decrypt-data.c (MY_GCRY_CIPHER_MODE_EAX): New.
(decrypt_data): Use it.
* g10/misc.c (openpgp_aead_test_algo): Allow EAX.
--

This allows the use of EAX when the latest Libgcrypt master is used.

Signed-off-by: Werner Koch <wk@gnupg.org>
---
 g10/cipher-aead.c  | 10 ++++++++++
 g10/decrypt-data.c |  9 ++++++---
 g10/misc.c         |  1 -
 3 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/g10/cipher-aead.c b/g10/cipher-aead.c
index f247a83de..1d7263419 100644
--- a/g10/cipher-aead.c
+++ b/g10/cipher-aead.c
@@ -33,6 +33,11 @@
 #include "options.h"
 #include "main.h"
 
+/* FIXME: Libgcrypt 1.9 will support EAX.  Until we kame this a
+ * requirement we hardwire the enum used for EAX.  */
+#define MY_GCRY_CIPHER_MODE_EAX 14
+
+
 /* The size of the buffer we allocate to encrypt the data.  This must
  * be a multiple of the OCB blocksize (16 byte).  */
 #define AEAD_ENC_BUFFER_SIZE (64*1024)
@@ -151,6 +156,11 @@ write_header (cipher_filter_context_t *cfx, iobuf_t a)
       startivlen = 15;
       break;
 
+    case AEAD_ALGO_EAX:
+      ciphermode = MY_GCRY_CIPHER_MODE_EAX;
+      startivlen = 16;
+      break;
+
     default:
       log_error ("unsupported AEAD algo %d\n", cfx->dek->use_aead);
       err = gpg_error (GPG_ERR_NOT_IMPLEMENTED);
diff --git a/g10/decrypt-data.c b/g10/decrypt-data.c
index 80e16ecb7..79e255480 100644
--- a/g10/decrypt-data.c
+++ b/g10/decrypt-data.c
@@ -31,6 +31,10 @@
 #include "../common/status.h"
 #include "../common/compliance.h"
 
+/* FIXME: Libgcrypt 1.9 will support EAX.  Until we kame this a
+ * requirement we hardwire the enum used for EAX.  */
+#define MY_GCRY_CIPHER_MODE_EAX 14
+
 
 static int aead_decode_filter (void *opaque, int control, iobuf_t a,
                                byte *buf, size_t *ret_len);
@@ -278,9 +282,8 @@ decrypt_data (ctrl_t ctrl, void *procctx, PKT_encrypted *ed, DEK *dek)
           break;
         case AEAD_ALGO_EAX:
           startivlen = 16;
-          log_error ("unsupported AEAD algo %d\n", ed->aead_algo);
-          rc = gpg_error (GPG_ERR_NOT_IMPLEMENTED);
-          goto leave;
+          ciphermode = MY_GCRY_CIPHER_MODE_EAX;
+          break;
         default:
           log_error ("unknown AEAD algo %d\n", ed->aead_algo);
           rc = gpg_error (GPG_ERR_INV_CIPHER_MODE);
diff --git a/g10/misc.c b/g10/misc.c
index 2da0d270c..f7ac3c708 100644
--- a/g10/misc.c
+++ b/g10/misc.c
@@ -591,7 +591,6 @@ openpgp_aead_test_algo (aead_algo_t algo)
     case AEAD_ALGO_NONE:
       break;
     case AEAD_ALGO_EAX:
-      return gpg_error (GPG_ERR_NOT_SUPPORTED);
     case AEAD_ALGO_OCB:
       return 0;
     }