Add null crypto algorithm

src/crypto/crypto_null.c

@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * 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 any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/**
+ * @file
+ *
+ * Null crypto algorithm
+ */
+
+#include <gpxe/crypto.h>
+
+static void null_init ( void *ctx __unused ) {
+	/* Do nothing */
+}
+
+static int null_setkey ( void *ctx __unused, void *key __unused,
+			 size_t keylen __unused ) {
+	/* Do nothing */
+	return 0;
+}
+
+static void null_encode ( void *ctx __unused, const void *src __unused,
+			  void *dst __unused, size_t len __unused ) {
+	/* Do nothing */
+}
+
+static void null_decode ( void *ctx __unused, const void *src __unused,
+			  void *dst __unused, size_t len __unused ) {
+	/* Do nothing */
+}
+
+static void null_final ( void *ctx __unused, void *out __unused ) {
+	/* Do nothing */
+}
+
+struct crypto_algorithm crypto_null = {
+	.name = "null",
+	.ctxsize = 0,
+	.blocksize = 1,
+	.digestsize = 0,
+	.init = null_init,
+	.setkey = null_setkey,
+	.encode = null_encode,
+	.decode = null_decode,
+	.final = null_final,
+};

src/include/gpxe/crypto.h

@@ -109,4 +109,6 @@ static inline int is_stream_cipher ( struct crypto_algorithm *crypto ) {
 	return ( crypto->blocksize == 1 );
 }
 
+extern struct crypto_algorithm crypto_null;
+
 #endif /* _GPXE_CRYPTO_H */