gpg: Add option and preference framework for AEAD.

* common/openpgpdefs.h (aead_algo_t): New.
(SIGSUBPKT_PREF_AEAD): New.
* g10/gpg.c (oAEADAlgo, oPersonalAEADPreferences): New.
(opts): New options --aead-algo and --personal-aead-preferences.
(set_compliance_option): Clar aead algo.
(main): Parse and check the new options
* g10/options.h (struct opt): Add fields def_aead_algo and
personal_aead_prefs.
* g10/packet.h (PREFTYPE_AEAD): New enum value.
(PKT_user_id): Add field flags.aead.
(PKT_public_key): Add field flags.aead.
* g10/pkclist.c (select_algo_from_prefs): Support PREFTYPE_AEAD.
* g10/getkey.c (fixup_uidnode): Set AEAD flag.
(merge_selfsigs): Ditto.
* g10/kbnode.c (dump_kbnode): Show aead flag.
* g10/keyedit.c (show_prefs): Ditto.
(show_key_with_all_names_colon): Ditto.
* g10/keygen.c (aead_presf, n_aead_prefs): New vars.
(set_one_pref): Suppport PREFTYPE_AEAD.
(keygen_set_std_prefs): Parse AEAD preferences.
(keygen_get_std_prefs): Ditto.
(add_feature_aead): New.
(keygen_upd_std_prefs): Call that and build AEAD pref  packet.
* g10/main.h (DEFAULT_AEAD_ALGO): New const.
* g10/misc.c (openpgp_aead_test_algo): New.
(openpgp_aead_algo_name): New.
(string_to_aead_algo): New.
(default_aead_algo): New.
--

This is only used in --rfc4880bis mode and not really tested.

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

1 files changed, 80 insertions, 0 deletions

diff --git a/g10/misc.c b/g10/misc.c
index 9016d2770..2da0d270c 100644
--- a/g10/misc.c
+++ b/g10/misc.c
@@ -582,6 +582,41 @@ openpgp_cipher_algo_name (cipher_algo_t algo)
 }
 
 
+/* Return 0 if ALGO is supported.  Return an error if not. */
+gpg_error_t
+openpgp_aead_test_algo (aead_algo_t algo)
+{
+  switch (algo)
+    {
+    case AEAD_ALGO_NONE:
+      break;
+    case AEAD_ALGO_EAX:
+      return gpg_error (GPG_ERR_NOT_SUPPORTED);
+    case AEAD_ALGO_OCB:
+      return 0;
+    }
+
+  return gpg_error (GPG_ERR_INV_CIPHER_MODE);
+}
+
+
+/* Map the OpenPGP AEAD algorithm with ID ALGO to a string
+ * representation of the algorithm name.  For unknown algorithm IDs
+ * this function returns "?".  */
+const char *
+openpgp_aead_algo_name (aead_algo_t algo)
+{
+  switch (algo)
+    {
+    case AEAD_ALGO_NONE:  break;
+    case AEAD_ALGO_EAX:   return "EAX";
+    case AEAD_ALGO_OCB:   return "OCB";
+    }
+
+  return "?";
+}
+
+
 /* Return 0 if ALGO is a supported OpenPGP public key algorithm.  */
 int
 openpgp_pk_test_algo (pubkey_algo_t algo)
@@ -1112,6 +1147,39 @@ string_to_cipher_algo (const char *string)
   return val;
 }
 
+
+/*
+ * Map an AEAD mode string to a an AEAD algorithm number as defined by
+ * rrc4880bis.  Also support the "An" syntax as used by the preference
+ * strings.
+ */
+aead_algo_t
+string_to_aead_algo (const char *string)
+{
+  int result;
+
+  if (!string)
+    result = 0;
+  if (!ascii_strcasecmp (string, "EAX"))
+    result = 1;
+  else if (!ascii_strcasecmp (string, "OCB"))
+    result = 2;
+  else if ((string[0]=='A' || string[0]=='a'))
+    {
+      char *endptr;
+
+      string++;
+      result = strtol (string, &endptr, 10);
+      if (!*string || *endptr || result < 1 || result > 2)
+        result = 0;
+    }
+  else
+    result = 0;
+
+  return result;
+}
+
+
 /*
  * Wrapper around gcry_md_map_name to provide a fallback using the
  * "Hn" syntax as used by the preference strings.
@@ -1228,6 +1296,18 @@ default_cipher_algo(void)
     return opt.s2k_cipher_algo;
 }
 
+
+aead_algo_t
+default_aead_algo(void)
+{
+  if(opt.def_aead_algo)
+    return opt.def_aead_algo;
+  else if(opt.personal_aead_prefs)
+    return opt.personal_aead_prefs[0].value;
+  else
+    return DEFAULT_AEAD_ALGO;
+}
+
 /* There is no default_digest_algo function, but see
    sign.c:hash_for() */