gpgme: working gpgme unit test prototype

Affects ElektraInitiative#896 , ElektraInitiative#1973 , ElektraInitiative#2008

src/plugins/README.md

@@ -167,6 +167,7 @@ Transformations:
 Doing other stuff:
 
 - [crypto](crypto/) encrypts / decrypts confidential values
+- [gpgme](gpgme/) encrypts / decrypts confidential values (with GPGME)
 - [fcrypt](fcrypt/) encrypts / decrypts entire backend files
 - [iconv](iconv/) makes sure the configuration will have correct
   character encoding

src/plugins/gpgme/CMakeLists.txt

@@ -0,0 +1,28 @@
+include (LibAddPlugin)
+
+if (DEPENDENCY_PHASE)
+
+	find_package (LibGpgme)
+	if (NOT LIBGPGME_FOUND)
+		remove_plugin ("gpgme" "GPGME development files not found")
+	endif ()
+
+endif ()
+
+set(GPGME_SOURCE_FILES gpgme.h gpgme.c)
+
+#
+# Compile Variant: OpenSSL
+#
+add_plugin (gpgme
+	    SOURCES ${GPGME_SOURCE_FILES}
+	    INCLUDE_DIRECTORIES ${LIBGPGME_INCLUDE_DIR}
+	    LINK_LIBRARIES ${LIBGPGME_LIBRARIES}
+	    COMPILE_DEFINITIONS ELEKTRA_PLUGIN_NAME=\"gpgme\"
+)
+
+if (ADDTESTING_PHASE)
+
+	add_plugintest (gpgme LINK_PLUGIN "gpgme")
+
+endif ()

src/plugins/gpgme/README.md

@@ -0,0 +1,13 @@
+- infos = Information about gpgme plugin is in keys below
+- infos/author = Peter Nirschl <peter.nirschl@gmail.com>
+- infos/licence = BSD
+- infos/provides = crypto
+- infos/needs =
+- infos/recommends =
+- infos/placements = postgetstorage presetstorage
+- infos/status = unittest configurable unfinished discouraged
+- infos/metadata = crypto/encrypt
+- infos/description = Cryptographic operations wit GnuPG Made Easy (GPGME)
+
+## Introduction
+

src/plugins/gpgme/contract.h

@@ -0,0 +1,17 @@
+/**
+ * @file
+ *
+ * @brief
+ *
+ * @copyright BSD License (see LICENSE.md or https://www.libelektra.org)
+ */
+
+keyNew ("system/elektra/modules/" ELEKTRA_PLUGIN_NAME, KEY_VALUE, "gpgme plugin waits for your orders", KEY_END),
+	keyNew ("system/elektra/modules/" ELEKTRA_PLUGIN_NAME "/exports", KEY_END),
+	keyNew ("system/elektra/modules/" ELEKTRA_PLUGIN_NAME "/exports/open", KEY_FUNC, elektraGpgmeOpen, KEY_END),
+	keyNew ("system/elektra/modules/" ELEKTRA_PLUGIN_NAME "/exports/close", KEY_FUNC, elektraGpgmeClose, KEY_END),
+	keyNew ("system/elektra/modules/" ELEKTRA_PLUGIN_NAME "/exports/get", KEY_FUNC, elektraGpgmeGet, KEY_END),
+	keyNew ("system/elektra/modules/" ELEKTRA_PLUGIN_NAME "/exports/set", KEY_FUNC, elektraGpgmeSet, KEY_END),
+	keyNew ("system/elektra/modules/" ELEKTRA_PLUGIN_NAME "/exports/checkconf", KEY_FUNC, elektraGpgmeCheckconf, KEY_END),
+#include ELEKTRA_README (gpgme)
+	keyNew ("system/elektra/modules/" ELEKTRA_PLUGIN_NAME "/infos/version", KEY_VALUE, PLUGINVERSION, KEY_END),

src/plugins/gpgme/gpgme.c

@@ -0,0 +1,194 @@
+/**
+ * @file
+ *
+ * @brief filter plugin providing cryptographic operations using GPGME
+ *
+ * @copyright BSD License (see LICENSE.md or https://www.libelektra.org)
+ *
+ */
+
+#ifndef HAVE_KDBCONFIG
+#include "kdbconfig.h"
+#endif
+#include "gpgme.h"
+#include <gpgme.h>
+#include <kdb.h>
+#include <kdberrors.h>
+#include <kdbtypes.h>
+#include <locale.h>
+#include <stdlib.h>
+#include <string.h>
+
+/**
+ * @brief checks if a Key has been marked for encryption by checking the Key's metadata.
+ *
+ * If the metakey ELEKTRA_CRYPTO_META_ENCRYPT has the value "1" it is considered to be true.
+ * Every other value or the non-existence of the metakey is considered to be false.
+ *
+ * @param k the Key to be checked
+ * @retval 0 if the Key has not been marked for encryption
+ * @retval 1 if the Key has been marked for encryption
+ */
+static int isMarkedForEncryption (const Key * k)
+{
+	const Key * metaEncrypt = keyGetMeta (k, ELEKTRA_GPGME_META_ENCRYPT);
+	if (metaEncrypt && strcmp (keyString (metaEncrypt), "1") == 0)
+	{
+		return 1;
+	}
+	return 0;
+}
+
+/**
+ * @brief checks if a given Key k is in the spec namespace.
+ * @retval 0 if the Key k is in the spec namespace.
+ * @retval 1 if the Key k is NOT in the spec namespace.
+ */
+static inline int isSpecNamespace (const Key * k)
+{
+	return (keyGetNamespace (k) == KEY_NS_SPEC);
+}
+
+/**
+ * @brief Encrypt all Keys in the KeySet "data" that have a meta-key "gpg/encrpyt" set.
+ * @see isMarkedForEncryption (const Key * k)
+ * @param handle holds the plugin configuration.
+ * @param data the KeySet to be encrypted.
+ * @param errorKey will hold and error description if an operation fails.
+ * @retval 1 on success.
+ * @retval -1 on failure. In this case errorKey will provide a description.
+ */
+static int gpgEncrypt (ELEKTRA_UNUSED Plugin * handle, KeySet * data, ELEKTRA_UNUSED Key * errorKey)
+{
+	Key * k;
+	// TODO KeySet * pluginConfig = elektraPluginGetConfig (handle);
+
+	// TODO convert pluginConfig to an array of recipient keys
+
+	ksRewind (data);
+	while ((k = ksNext (data)) != 0)
+	{
+		if (!isMarkedForEncryption (k) || isSpecNamespace (k))
+		{
+			continue;
+		}
+
+		// TODO use gpgme to encrypt the value of k
+	}
+	return 1;
+}
+
+/**
+ * @brief Decrypt all Keys in the KeySet "data" that have a meta-key "gpg/encrpyt" set.
+ * @see isMarkedForEncryption (const Key * k)
+ * @param handle holds the plugin configuration.
+ * @param data the KeySet to be decrypted.
+ * @param errorKey will hold and error description if an operation fails.
+ * @retval 1 on success.
+ * @retval -1 on failure. In this case errorKey will provide a description.
+ */
+static int gpgDecrypt (ELEKTRA_UNUSED Plugin * handle, KeySet * data, ELEKTRA_UNUSED Key * errorKey)
+{
+	Key * k;
+	// TODO KeySet * pluginConfig = elektraPluginGetConfig (handle);
+
+	gpgme_ctx_t ctx;
+	gpgme_error_t err;
+
+	err = gpgme_new (&ctx);
+
+	ksRewind (data);
+	while ((k = ksNext (data)) != 0)
+	{
+		if (!isMarkedForEncryption (k) || isSpecNamespace (k))
+		{
+			continue;
+		}
+
+		// TODO use gpgme to decrypt the value of k
+		gpgme_data_t in;
+		gpgme_data_t out;
+		gpgme_decrypt_result_t dec_result;
+
+		// TODO error handling
+		// TODO consider original data type (string, binary, null)
+
+		err = gpgme_data_new_from_mem (&in, keyValue (k), keyGetValueSize (k), 0);
+		err = gpgme_data_new (&out);
+
+		err = gpgme_op_decrypt (ctx, out, in);
+		dec_result = gpgme_op_decrypt_result (ctx);
+		// TODO handle gppme errors
+
+		// TODO finish here
+
+		gpgme_data_release (out);
+		gpgme_data_release (in);
+	}
+	gpgme_release (ctx);
+	return 1;
+}
+
+int elektraGpgmeOpen (ELEKTRA_UNUSED Plugin * handle, ELEKTRA_UNUSED Key * errorKey)
+{
+	gpgme_error_t err;
+
+	gpgme_check_version (NULL);
+	setlocale (LC_ALL, "");
+	gpgme_set_locale (NULL, LC_CTYPE, setlocale (LC_CTYPE, NULL));
+#ifndef HAVE_W32_SYSTEM
+	gpgme_set_locale (NULL, LC_MESSAGES, setlocale (LC_MESSAGES, NULL));
+#endif
+
+	err = gpgme_engine_check_version (GPGME_PROTOCOL_OpenPGP);
+	if (err)
+	{
+		// TODO set errorKey
+		return -1; // failure
+	}
+	return 1; // success
+}
+
+int elektraGpgmeClose (ELEKTRA_UNUSED Plugin * handle, ELEKTRA_UNUSED Key * errorKey)
+{
+	// at the moment there is nothing to do
+	return 1; // success
+}
+
+int elektraGpgmeGet (Plugin * handle, KeySet * ks, Key * parentKey)
+{
+	// publish the module configuration to Elektra (establish the contract)
+	if (!strcmp (keyName (parentKey), "system/elektra/modules/" ELEKTRA_PLUGIN_NAME))
+	{
+		KeySet * moduleConfig = ksNew (30,
+#include "contract.h"
+					       KS_END);
+		ksAppend (ks, moduleConfig);
+		ksDel (moduleConfig);
+		return 1; // success
+	}
+
+	return gpgEncrypt (handle, ks, parentKey);
+}
+
+int elektraGpgmeSet (Plugin * handle, KeySet * ks, Key * parentKey)
+{
+	return gpgDecrypt (handle, ks, parentKey);
+}
+
+int elektraGpgmeCheckconf (ELEKTRA_UNUSED Key * errorKey, ELEKTRA_UNUSED KeySet * conf)
+{
+	// TODO verify that at least one gpg recipient is available in conf
+	return 1; // success
+}
+
+Plugin * ELEKTRA_PLUGIN_EXPORT (gpgme)
+{
+	// clang-format off
+	return elektraPluginExport(ELEKTRA_PLUGIN_NAME,
+			ELEKTRA_PLUGIN_OPEN,  &elektraGpgmeOpen,
+			ELEKTRA_PLUGIN_CLOSE, &elektraGpgmeClose,
+			ELEKTRA_PLUGIN_GET,   &elektraGpgmeGet,
+			ELEKTRA_PLUGIN_SET,   &elektraGpgmeSet,
+			ELEKTRA_PLUGIN_END);
+}

src/plugins/gpgme/gpgme.h

@@ -0,0 +1,27 @@
+/**
+ * @file
+ *
+ * @brief filter plugin providing cryptographic operations using GPGME
+ *
+ * @copyright BSD License (see LICENSE.md or https://www.libelektra.org)
+ *
+ */
+
+#ifndef ELEKTRA_PLUGIN_GPGME_H
+#define ELEKTRA_PLUGIN_GPGME_H
+
+#include <kdbplugin.h>
+
+// meta-keys
+#define ELEKTRA_GPGME_META_ENCRYPT "gpg/encrypt"
+
+// kdb functions
+int elektraGpgmeOpen (Plugin * handle, Key * errorKey);
+int elektraGpgmeClose (Plugin * handle, Key * errorKey);
+int elektraGpgmeGet (Plugin * handle, KeySet * ks, Key * parentKey);
+int elektraGpgmeSet (Plugin * handle, KeySet * ks, Key * parentKey);
+int elektraGpgmeCheckconf (Key * errorKey, KeySet * conf);
+
+Plugin * ELEKTRA_PLUGIN_EXPORT (gpgme);
+
+#endif