core: New function gpgme_op_setownertrust

* src/Makefile.am (main_sources): Add new file.
* src/context.h (ctx_op_data_id_t): Add OPDATA_SETOWNERTRUST.
* src/engine.c, src/engine.h (_gpgme_engine_op_setownertrust): New.
* src/engine-backend.h (engine_ops): Add 'setownertrust' and adjust all
engine initializers.
* src/engine-gpg.c (gpg_setownertrust): New.
(_gpgme_engine_ops_gpg): Set setownertrust to gpg_setownertrust.
* src/gpgme.h.in (gpgme_op_setownertrust_start, gpgme_op_setownertrust):
New.
* src/gpgme.def, src/libgpgme.vers: Add new functions.
* src/setownertrust.c: New.

* doc/gpgme.texi: Document new functions.

* tests/Makefile.am (noinst_PROGRAMS): Add new test program.
* tests/run-setownertrust.c: New.

* tests/gpg/Makefile.am (c_tests): Add new file. (LDADD): Add
@GPG_ERROR_LIBS@.
* tests/gpg/t-setownertrust.c: New.
* tests/gpg/t-support.h (have_gpg_version): New.

--

This extends GPGME to support the --quick-set-ownertrust command added
by GnuPG 2.4.6. This allows changing the owner trust of keys and
enabling/disabling keys without using the editinteractor interface.

GnuPG-bug-id: 7239

5 files changed, 284 insertions, 4 deletions

diff --git a/tests/Makefile.am b/tests/Makefile.am
index 99b6fb46..0147b4b7 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -42,7 +42,7 @@ noinst_HEADERS = run-support.h
 noinst_PROGRAMS = $(TESTS) run-keylist run-export run-import run-sign \
 		  run-verify run-encrypt run-identify run-decrypt run-genkey \
 		  run-keysign run-tofu run-swdb run-threaded \
-		  run-receive-keys
+		  run-receive-keys run-setownertrust
 
 run_threaded_CPPFLAGS = -I$(top_builddir)/src @GPG_ERROR_MT_CFLAGS@
 run_threaded_LDADD = ../src/libgpgme.la \
diff --git a/tests/gpg/Makefile.am b/tests/gpg/Makefile.am
index dc3642a6..a70c7a7b 100644
--- a/tests/gpg/Makefile.am
+++ b/tests/gpg/Makefile.am
@@ -40,6 +40,7 @@ c_tests = \
 	t-decrypt t-verify t-decrypt-verify t-sig-notation t-export	\
 	t-import t-edit t-keylist t-keylist-sig t-keylist-secret-sig t-wait \
 	t-encrypt-large t-file-name t-gpgconf t-encrypt-mixed t-edit-sign \
+	t-setownertrust							\
 	$(tests_unix)
 
 TESTS = initial.test $(c_tests) final.test
@@ -67,7 +68,7 @@ BUILT_SOURCES = gpg.conf gpg-agent.conf pubring-stamp \
            gpg-sample.stamp
 AM_CPPFLAGS = -I$(top_builddir)/src @GPG_ERROR_CFLAGS@
 AM_LDFLAGS = -no-install
-LDADD = ../../src/libgpgme.la @LDADD_FOR_TESTS_KLUDGE@
+LDADD = ../../src/libgpgme.la @GPG_ERROR_LIBS@ @LDADD_FOR_TESTS_KLUDGE@
 
 WITH_THREAD_CPPFLAGS =  -I$(top_builddir)/src @GPG_ERROR_MT_CFLAGS@
 WITH_THREAD_LDADD = ../../src/libgpgme.la \
diff --git a/tests/gpg/t-setownertrust.c b/tests/gpg/t-setownertrust.c
new file mode 100644
index 00000000..dd2c723d
--- /dev/null
+++ b/tests/gpg/t-setownertrust.c
@@ -0,0 +1,132 @@
+/* t-setownertrust.c - Regression test.
+ * Copyright (C) 2024 g10 Code 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, see <https://gnu.org/licenses/>.
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+/* We need to include config.h so that we know whether we are building
+   with large file system (LFS) support. */
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#define PGM "t-setownertrust"
+#include "t-support.h"
+
+#include <gpgme.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+
+
+static gpgme_key_t
+list_one_key (gpgme_ctx_t ctx, const char *pattern, int secret_only)
+{
+  gpgme_error_t err;
+  gpgme_key_t key = NULL;
+
+  err = gpgme_op_keylist_start (ctx, pattern, secret_only);
+  fail_if_err (err);
+  err = gpgme_op_keylist_next (ctx, &key);
+  fail_if_err (err);
+  err = gpgme_op_keylist_end (ctx);
+  fail_if_err (err);
+
+  return key;
+}
+
+
+int
+main (int argc, char **argv)
+{
+  gpgme_ctx_t ctx;
+  gpgme_error_t err;
+  gpgme_key_t key = NULL;
+  const char *pattern = "Alpha";
+
+  (void)argc;
+  (void)argv;
+
+  if (!have_gpg_version ("2.4.6"))
+    {
+      printf ("Testsuite skipped. Minimum GnuPG version (2.4.6) "
+              "not found.\n");
+      exit(0);
+    }
+
+  init_gpgme (GPGME_PROTOCOL_OpenPGP);
+
+  err = gpgme_new (&ctx);
+  fail_if_err (err);
+
+  key = list_one_key (ctx, pattern, 0);
+  err = gpgme_op_setownertrust (ctx, key, "disable");
+  fail_if_err (err);
+  gpgme_key_unref (key);
+
+  key = list_one_key (ctx, pattern, 0);
+  if (!key->disabled)
+    {
+      fprintf (stderr, "%s:%i: Key is unexpectedly not disabled\n",
+               PGM, __LINE__);
+      exit (1);
+    }
+  gpgme_key_unref (key);
+
+  key = list_one_key (ctx, pattern, 0);
+  err = gpgme_op_setownertrust (ctx, key, "enable");
+  fail_if_err (err);
+  gpgme_key_unref (key);
+
+  key = list_one_key (ctx, pattern, 0);
+  if (key->disabled)
+    {
+      fprintf (stderr, "%s:%i: Key is unexpectedly disabled\n",
+               PGM, __LINE__);
+      exit (1);
+    }
+  gpgme_key_unref (key);
+
+  /* Check error handling */
+  err = gpgme_op_setownertrust (ctx, NULL, "ultimate");
+  if (gpgme_err_code (err) != GPG_ERR_INV_VALUE)
+    {
+      fprintf (stderr, "%s:%i: Unexpected error code: %s\n",
+	       PGM, __LINE__, gpgme_strerror (err));
+      exit (1);
+    }
+  key = list_one_key (ctx, pattern, 0);
+  err = gpgme_op_setownertrust (ctx, key, NULL);
+  if (gpgme_err_code (err) != GPG_ERR_INV_VALUE)
+    {
+      fprintf (stderr, "%s:%i: Unexpected error code: %s\n",
+	       PGM, __LINE__, gpgme_strerror (err));
+      exit (1);
+    }
+  err = gpgme_op_setownertrust (ctx, key, "");
+  if (gpgme_err_code (err) != GPG_ERR_INV_VALUE)
+    {
+      fprintf (stderr, "%s:%i: Unexpected error code: %s\n",
+	       PGM, __LINE__, gpgme_strerror (err));
+      exit (1);
+    }
+  gpgme_key_unref (key);
+
+  gpgme_release (ctx);
+
+  return 0;
+}
diff --git a/tests/gpg/t-support.h b/tests/gpg/t-support.h
index ae70cecc..40b03b7f 100644
--- a/tests/gpg/t-support.h
+++ b/tests/gpg/t-support.h
@@ -19,19 +19,21 @@
  * SPDX-License-Identifier: LGPL-2.1-or-later
  */
 
+#include <gpgme.h>
+#include <gpg-error.h>
+
 #include <unistd.h>
 #include <errno.h>
 #include <stdlib.h>
 #include <locale.h>
 #include <limits.h>
 #include <ctype.h>
+#include <string.h>
 
 #ifdef HAVE_W32_SYSTEM
 #include <windows.h>
 #endif
 
-#include <gpgme.h>
-
 #ifndef PGM
 #define PGM "unknown program; define PGM before including t-support.h"
 #endif
@@ -271,3 +273,21 @@ print_import_result (gpgme_import_result_t r)
           r->not_imported,
           r->skipped_v3_keys);
 }
+
+
+/* Return true if the gpg engine's version is at least REQ_VERSION.  */
+int
+have_gpg_version (const char *req_version)
+{
+  gpgme_engine_info_t engine_info;
+  init_gpgme (GPGME_PROTOCOL_OpenPGP);
+
+  fail_if_err (gpgme_get_engine_info (&engine_info));
+  for (; engine_info; engine_info = engine_info->next)
+    if (engine_info->protocol == GPGME_PROTOCOL_OpenPGP)
+      break;
+
+  test (engine_info);
+
+  return gpgrt_cmp_version (engine_info->version, req_version, 3) >= 0;
+}
diff --git a/tests/run-setownertrust.c b/tests/run-setownertrust.c
new file mode 100644
index 00000000..4ed2bf98
--- /dev/null
+++ b/tests/run-setownertrust.c
@@ -0,0 +1,127 @@
+/* run-setownertrust.c  - Test tool to perform ownertrust changes
+ * Copyright (C) 2024 g10 Code 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, see <https://gnu.org/licenses/>.
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ */
+
+/* We need to include config.h so that we know whether we are building
+   with large file system (LFS) support. */
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <gpgme.h>
+
+#define PGM "run-setownertrust"
+
+#include "run-support.h"
+
+
+static gpg_error_t
+status_cb (void *opaque, const char *keyword, const char *value)
+{
+  (void)opaque;
+  fprintf (stderr, "status_cb: %s %s\n", nonnull(keyword), nonnull(value));
+  return 0;
+}
+
+
+static int
+show_usage (int ex)
+{
+  fputs ("usage: " PGM " [options] USERID VALUE\n"
+         "Options:\n"
+         "  --status         print status lines from the backend\n"
+         , stderr);
+  exit (ex);
+}
+
+
+int
+main (int argc, char **argv)
+{
+  int last_argc = -1;
+  gpgme_error_t err;
+  gpgme_ctx_t ctx;
+  gpgme_protocol_t protocol = GPGME_PROTOCOL_OpenPGP;
+  int print_status = 0;
+  const char *userid;
+  const char *value;
+  gpgme_key_t key;
+
+  if (argc)
+    { argc--; argv++; }
+
+  while (argc && last_argc != argc )
+    {
+      last_argc = argc;
+      if (!strcmp (*argv, "--"))
+        {
+          argc--; argv++;
+          break;
+        }
+      else if (!strcmp (*argv, "--help"))
+        show_usage (0);
+      else if (!strcmp (*argv, "--status"))
+        {
+          print_status = 1;
+          argc--; argv++;
+        }
+      else if (!strncmp (*argv, "--", 2))
+        show_usage (1);
+    }
+
+  if (argc != 2)
+    show_usage (1);
+  userid = argv[0];
+  value = argv[1];
+
+  init_gpgme (protocol);
+
+  err = gpgme_new (&ctx);
+  fail_if_err (err);
+  gpgme_set_protocol (ctx, protocol);
+  gpgme_set_armor (ctx, 1);
+  if (print_status)
+    {
+      gpgme_set_status_cb (ctx, status_cb, NULL);
+      gpgme_set_ctx_flag (ctx, "full-status", "1");
+    }
+
+  err = gpgme_get_key (ctx, userid, &key, 0);
+  if (err)
+    {
+      fprintf (stderr, PGM ": error getting public key for '%s': %s\n",
+               userid, gpg_strerror (err));
+      exit (1);
+    }
+  err = gpgme_op_setownertrust (ctx, key, value);
+  if (err)
+    {
+      fprintf (stderr, PGM ": gpgme_op_setownertrust failed: %s\n",
+               gpg_strerror (err));
+      exit (1);
+    }
+  gpgme_key_unref (key);
+
+  gpgme_release (ctx);
+  return 0;
+}