New header file cmac-internal.h

Move and rename block_mulx --> _cmac128_block_mulx.

ChangeLog

+2019-04-30  Niels Möller  <nisse@lysator.liu.se>
+
+	Based on a patch contributed by Nikos Mavrogiannopoulos.
+	* cmac.c (_cmac128_block_mulx): Renamed function...
+	(block_mulx): ... from old name.
+	* cmac-internal.h (_cmac128_block_mulx): New file, declare function.
+	* Makefile.in (DISTFILES): Added cmac-internal.h.
+
 2019-04-27  Niels Möller  <nisse@lysator.liu.se>
 
 	From Simo Sorce:

Makefile.in

@@ -229,7 +229,7 @@ DISTFILES = $(SOURCES) $(HEADERS) getopt.h getopt_int.h \
 	INSTALL NEWS ChangeLog \
 	nettle.pc.in hogweed.pc.in \
 	$(des_headers) descore.README desdata.stamp \
-	aes-internal.h camellia-internal.h serpent-internal.h \
+	aes-internal.h camellia-internal.h cmac-internal.h serpent-internal.h \
 	cast128_sboxes.h desinfo.h desCode.h \
 	ripemd160-internal.h sha2-internal.h \
 	memxor-internal.h nettle-internal.h nettle-write.h \

cmac-internal.h

+/* cmac-internal.h
+
+   CMAC mode internal functions
+
+   Copyright (C) 2017 Red Hat, Inc.
+
+   Contributed by Nikos Mavrogiannopoulos
+
+   This file is part of GNU Nettle.
+
+   GNU Nettle is free software: you can redistribute it and/or
+   modify it under the terms of either:
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at your
+       option) any later version.
+
+   or
+
+     * 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.
+
+   or both in parallel, as here.
+
+   GNU Nettle 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see http://www.gnu.org/licenses/.
+*/
+
+#ifndef NETTLE_CMAC_INTERNAL_H_INCLUDED
+#define NETTLE_CMAC_INTERNAL_H_INCLUDED
+
+#include "cmac.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#define _cmac128_block_mulx _nettle_cmac128_block_mulx
+
+void _cmac128_block_mulx(union nettle_block16 *out,
+			 const union nettle_block16 *in);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* CMAC_INTERNAL_H_INCLUDED */

cmac.c

@@ -44,13 +44,14 @@
 
 #include "memxor.h"
 #include "nettle-internal.h"
+#include "cmac-internal.h"
 #include "macros.h"
 
 /* shift one and XOR with 0x87. */
 #if WORDS_BIGENDIAN
-static void
-block_mulx(union nettle_block16 *dst,
-	   const union nettle_block16 *src)
+void
+_cmac128_block_mulx(union nettle_block16 *dst,
+		    const union nettle_block16 *src)
 {
   uint64_t carry = src->u64[0] >> 63;
   dst->u64[0] = (src->u64[0] << 1) | (src->u64[1] >> 63);
@@ -59,9 +60,9 @@ block_mulx(union nettle_block16 *dst,
 #else /* !WORDS_BIGENDIAN */
 #define LE_SHIFT(x) ((((x) & 0x7f7f7f7f7f7f7f7f) << 1) | \
                      (((x) & 0x8080808080808080) >> 15))
-static void
-block_mulx(union nettle_block16 *dst,
-	   const union nettle_block16 *src)
+void
+_cmac128_block_mulx(union nettle_block16 *dst,
+		    const union nettle_block16 *src)
 {
   uint64_t carry = (src->u64[0] & 0x80) >> 7;
   dst->u64[0] = LE_SHIFT(src->u64[0]) | ((src->u64[1] & 0x80) << 49);
@@ -83,8 +84,8 @@ cmac128_set_key(struct cmac128_ctx *ctx, const void *cipher,
   /* step 1 - generate subkeys k1 and k2 */
   encrypt(cipher, 16, L->b, const_zero);
 
-  block_mulx(&ctx->K1, L);
-  block_mulx(&ctx->K2, &ctx->K1);
+  _cmac128_block_mulx(&ctx->K1, L);
+  _cmac128_block_mulx(&ctx->K2, &ctx->K1);
 }
 
 #define MIN(x,y) ((x)<(y)?(x):(y))