core: Add support for mixed symmetric and asym enc

* src/gpgme.h.in (gpgme_encrypt_flags_t): New flag
GPGME_ENCRYPT_SYMMETRIC.
* src/engine-gpg.c (gpg_encrypt): Also add --symmetric if the flag
is given.
* NEWS: Mention new flag.
* tests/run-encrypt.c (show_usage): Extend for --symmetric.
(main): Handle --symmetric.
(main): Set passphrase_cb in loopback mode.
(main): Fix encrypt call if no recipients are given.
* tests/gpg/t-encrypt-mixed.c: New.
* tests/gpg/Makefile.am (c_tests): Add new test.
* doc/gpgme.texi: Document new flag.

1 files changed, 126 insertions, 0 deletions

diff --git a/tests/gpg/t-encrypt-mixed.c b/tests/gpg/t-encrypt-mixed.c
new file mode 100644
index 00000000..28d8aa31
--- /dev/null
+++ b/tests/gpg/t-encrypt-mixed.c
@@ -0,0 +1,126 @@
+/* t-encrypt-mixed.c - Regression test.
+   Copyright (C) 2016 Intevation GmbH
+
+   This file is part of GPGME.
+
+   GPGME is free software; you can redistribute it and/or modify it
+   under the terms of the GNU Lesser General Public License as
+   published by the Free Software Foundation; either version 2.1 of
+   the License, or (at your option) any later version.
+
+   GPGME 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+   02111-1307, USA.  */
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <gpgme.h>
+
+#include "t-support.h"
+
+/* Tests mixed symmetric and asymetric decryption. Verifies
+   that an encrypted message can be decrypted without the
+   secret key but that the recipient is also set correctly. */
+int
+main (int argc, char *argv[])
+{
+  gpgme_ctx_t ctx;
+  gpgme_error_t err;
+  gpgme_data_t in, out;
+  gpgme_key_t key[2] = { NULL, NULL };
+  gpgme_encrypt_result_t result;
+  gpgme_decrypt_result_t dec_result;
+  gpgme_recipient_t recipient;
+  const char *text = "Hallo Leute\n";
+  char *text2;
+  size_t len;
+
+  init_gpgme (GPGME_PROTOCOL_OpenPGP);
+
+  err = gpgme_new (&ctx);
+  fail_if_err (err);
+  gpgme_set_armor (ctx, 1);
+
+  err = gpgme_data_new_from_mem (&in, text, strlen (text), 0);
+  fail_if_err (err);
+
+  err = gpgme_data_new (&out);
+  fail_if_err (err);
+
+  /* A recipient for which we don't have a secret key */
+  err = gpgme_get_key (ctx, "D695676BDCEDCC2CDD6152BCFE180B1DA9E3B0B2",
+                       &key[0], 0);
+  fail_if_err (err);
+
+  err = gpgme_op_encrypt (ctx, key,
+                          GPGME_ENCRYPT_ALWAYS_TRUST | GPGME_ENCRYPT_SYMMETRIC,
+                          in, out);
+  fail_if_err (err);
+  result = gpgme_op_encrypt_result (ctx);
+  if (result->invalid_recipients)
+    {
+      fprintf (stderr, "Invalid recipient encountered: %s\n",
+               result->invalid_recipients->fpr);
+      exit (1);
+    }
+
+  print_data (out);
+
+  /* Now try to decrypt */
+  gpgme_data_seek (out, 0, SEEK_SET);
+
+  gpgme_data_release (in);
+  err = gpgme_data_new (&in);
+  fail_if_err (err);
+
+  err = gpgme_op_decrypt (ctx, out, in);
+  fail_if_err (err);
+
+  fputs ("Begin Result Decryption:\n", stdout);
+  print_data (in);
+  fputs ("End Result.\n", stdout);
+
+  dec_result = gpgme_op_decrypt_result (ctx);
+  if (dec_result->unsupported_algorithm || dec_result->wrong_key_usage)
+    {
+      fprintf (stderr, "%s:%d: Decryption failed\n", __FILE__, __LINE__);
+      exit (1);
+    }
+
+  text2 = gpgme_data_release_and_get_mem (in, &len);
+  if (strncmp (text, text2, len))
+    {
+      fprintf (stderr, "%s:%d: Wrong plaintext\n", __FILE__, __LINE__);
+      exit (1);
+    }
+
+  recipient = dec_result->recipients;
+  if (!recipient || recipient->next)
+    {
+      fprintf (stderr, "%s:%d: Invalid recipients \n", __FILE__, __LINE__);
+      exit (1);
+    }
+
+  if (strncmp (recipient->keyid, "5381EA4EE29BA37F", 16))
+    {
+      fprintf (stderr, "%s:%d: Not encrypted to recipient's subkey \n", __FILE__, __LINE__);
+      exit (1);
+    }
+
+  gpgme_key_unref (key[0]);
+  gpgme_data_release (out);
+  gpgme_release (ctx);
+  return 0;
+}