core: New global flag "require-gnupg".

* src/gpgme.c (gpgme_set_global_flag): Add flag.
* src/engine.c (engine_minimal_version): New variable.
(_gpgme_set_engine_minimal_version): New function.
(gpgme_get_engine_info): Check that flag.

* tests/run-keylist.c (main): New option --require-gnupg.

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

3 files changed, 39 insertions, 0 deletions

diff --git a/src/engine.c b/src/engine.c
index a7c016f0..f428034d 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -63,6 +63,10 @@ static struct engine_ops *engine_ops[] =
 static gpgme_engine_info_t engine_info;
 DEFINE_STATIC_LOCK (engine_info_lock);
 
+/* If non-NULL, the minimal version required for all engines.  */
+static char *engine_minimal_version;
+
+
 
 /* Get the file name of the engine for PROTOCOL.  */
 static const char *
@@ -178,6 +182,26 @@ _gpgme_engine_info_release (gpgme_engine_info_t info)
 }
 
 
+/* This is an internal function to set a mimimal required version.
+ * This function must only be called by gpgme_set_global_flag.
+ * Returns 0 on success.  */
+int
+_gpgme_set_engine_minimal_version (const char *value)
+{
+  free (engine_minimal_version);
+  if (value)
+    {
+      engine_minimal_version = strdup (value);
+      return !engine_minimal_version;
+    }
+  else
+    {
+      engine_minimal_version = NULL;
+      return 0;
+    }
+}
+
+
 /* Get the information about the configured and installed engines.  A
    pointer to the first engine in the statically allocated linked list
    is returned in *INFO.  If an error occurs, it is returned.  The
@@ -229,6 +253,17 @@ gpgme_get_engine_info (gpgme_engine_info_t *info)
           if (!*lastp && !err)
             err = gpg_error_from_syserror ();
 
+          /* Check against the optional minimal engine version.  */
+          if (!err && version && engine_minimal_version
+              && !_gpgme_compare_versions (version, engine_minimal_version))
+            {
+#if GPG_ERROR_VERSION_NUMBER < 0x011900 /* 1.25 */
+              err = gpg_error (GPG_ERR_NO_ENGINE);
+#else
+              err = gpg_error (GPG_ERR_ENGINE_TOO_OLD);
+#endif
+            }
+
           /* Now set the dummy version for pseudo engines.  */
           if (!err && !version)
             {
diff --git a/src/engine.h b/src/engine.h
index 238a21c0..b713d961 100644
--- a/src/engine.h
+++ b/src/engine.h
@@ -38,6 +38,8 @@ typedef gpgme_error_t (*engine_command_handler_t) (void *priv,
 typedef gpgme_error_t (*engine_assuan_result_cb_t) (void *priv,
                                                     gpgme_error_t result);
 
+/* Helper for gpgme_set_global_flag.  */
+int _gpgme_set_engine_minimal_version (const char *value);
 
 /* Get a deep copy of the engine info and return it in INFO.  */
 gpgme_error_t _gpgme_engine_info_copy (gpgme_engine_info_t *r_info);
diff --git a/src/gpgme.c b/src/gpgme.c
index e0cd9b05..d59f8080 100644
--- a/src/gpgme.c
+++ b/src/gpgme.c
@@ -71,6 +71,8 @@ gpgme_set_global_flag (const char *name, const char *value)
       _gpgme_dirinfo_disable_gpgconf ();
       return 0;
     }
+  else if (!strcmp (name, "require-gnupg"))
+    return _gpgme_set_engine_minimal_version (value);
   else if (!strcmp (name, "gpgconf-name"))
     return _gpgme_set_default_gpgconf_name (value);
   else if (!strcmp (name, "gpg-name"))