chacha: Create common file to avoid code duplication

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

include/libssh/chacha.h

@@ -17,7 +17,6 @@ struct chacha_ctx {
 #define CHACHA_NONCELEN   8
 #define CHACHA_CTRLEN     8
 #define CHACHA_STATELEN   (CHACHA_NONCELEN+CHACHA_CTRLEN)
-#define CHACHA_BLOCKLEN   64
 
 void chacha_keysetup(struct chacha_ctx *x, const uint8_t *k, uint32_t kbits)
 #ifdef HAVE_GCC_BOUNDED_ATTRIBUTE

include/libssh/chacha20-poly1305-common.h

@@ -0,0 +1,54 @@
+/*
+ * This file is part of the SSH Library
+ *
+ * Copyright (c) 2020 Red Hat, Inc.
+ *
+ * Author: Jakub Jelen <jjelen@redhat.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/*
+ * chacha20-poly1305.h file
+ * This file includes definitions needed for Chacha20-poly1305 AEAD cipher
+ * using different crypto backends.
+ */
+
+#ifndef CHACHA20_POLY1305_H
+#define CHACHA20_POLY1305_H
+
+#define CHACHA20_BLOCKSIZE 64
+#define CHACHA20_KEYLEN 32
+
+#define POLY1305_TAGLEN 16
+/* size of the keys k1 and k2 as defined in specs */
+#define POLY1305_KEYLEN 32
+
+#ifdef _MSC_VER
+#pragma pack(push, 1)
+#endif
+struct ssh_packet_header {
+    uint32_t length;
+    uint8_t payload[];
+}
+#if defined(__GNUC__)
+__attribute__ ((packed))
+#endif
+#ifdef _MSC_VER
+#pragma pack(pop)
+#endif
+;
+
+#endif /* CHACHA20_POLY1305_H */

include/libssh/poly1305.h

@@ -5,9 +5,7 @@
 
 #ifndef POLY1305_H
 #define POLY1305_H
-
-#define POLY1305_KEYLEN    32
-#define POLY1305_TAGLEN    16
+#include "libssh/chacha20-poly1305-common.h"
 
 void poly1305_auth(uint8_t out[POLY1305_TAGLEN], const uint8_t *m, size_t inlen,
     const uint8_t key[POLY1305_KEYLEN])