Implemented EdDSA for IKEv2 using a pro forma Identity hash function

src/libstrongswan/plugins/curve25519/Makefile.am

@@ -23,6 +23,7 @@ libstrongswan_curve25519_la_SOURCES = \
 	curve25519_dh.h curve25519_dh.c \
 	curve25519_drv.h curve25519_drv.c \
 	curve25519_drv_portable.h curve25519_drv_portable.c \
+	curve25519_identity_hasher.h curve25519_identity_hasher.c \
 	curve25519_plugin.h curve25519_plugin.c
 
 libstrongswan_curve25519_la_LDFLAGS = -module -avoid-version

src/libstrongswan/plugins/curve25519/curve25519_identity_hasher.c

@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2016 Andreas Steffen
+ * HSR Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program 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 General Public License
+ * for more details.
+ */
+
+#include "curve25519_identity_hasher.h"
+
+/*
+ * Described in header.
+ */
+curve25519_identity_hasher_t *curve25519_identity_hasher_create(hash_algorithm_t algo)
+{
+	/* since the identity hasher is never actually used, always return NULL */
+	return NULL;
+}

src/libstrongswan/plugins/curve25519/curve25519_identity_hasher.h

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2016 Andreas Steffen
+ * HSR Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program 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 General Public License
+ * for more details.
+ */
+
+/**
+ * @defgroup curve25519_identity_hasher curve25519_identity_hasher
+ * @{ @ingroup curve25519_p
+ */
+
+#ifndef CURVE25519_IDENTITY_HASHER_H_
+#define CURVE25519_IDENTITY_HASHER_H_
+
+typedef struct curve25519_identity_hasher_t curve25519_identity_hasher_t;
+
+#include <crypto/hashers/hasher.h>
+
+/**
+ * Implementation of hasher_t interface using the Identity algorithm.
+ */
+struct curve25519_identity_hasher_t {
+
+	/**
+	 * Implements hasher_t interface.
+	 */
+	hasher_t hasher_interface;
+};
+
+/**
+ * Creates a new curve25519_identity_hasher_t.
+ *
+ * @param algo		algorithm, must be HASH_IDENTITY
+ * @return			curve25519_identity_hasher_t object
+ */
+curve25519_identity_hasher_t *curve25519_identity_hasher_create(hash_algorithm_t algo);
+
+#endif /** CURVE25519_IDENTITY_HASHER_H_ @}*/

src/libstrongswan/plugins/curve25519/curve25519_plugin.c

@@ -20,6 +20,7 @@
 #include "curve25519_dh.h"
 #include "curve25519_private_key.h"
 #include "curve25519_public_key.h"
+#include "curve25519_identity_hasher.h"
 
 #include <library.h>
 
@@ -65,6 +66,9 @@ METHOD(plugin_t, get_features, int,
 		/* Ed25519 signature verification scheme, public */
 		PLUGIN_PROVIDE(PUBKEY_VERIFY, SIGN_ED25519),
 			PLUGIN_DEPENDS(HASHER, HASH_SHA512),
+		/* register a pro forma identity hasher */
+		PLUGIN_REGISTER(HASHER, curve25519_identity_hasher_create),
+			PLUGIN_PROVIDE(HASHER, HASH_IDENTITY),
 	};
 	*features = f;
 	return countof(f);