2G ems initial

include/nettle/chacha.h

@@ -0,0 +1,96 @@
+/* chacha.h
+
+   The ChaCha stream cipher.
+
+   Copyright (C) 2013 Joachim Strömbergson
+   Copyright (C) 2012 Simon Josefsson
+   Copyright (C) 2014 Niels Möller
+
+   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_CHACHA_H_INCLUDED
+#define NETTLE_CHACHA_H_INCLUDED
+
+#include "nettle-types.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Name mangling */
+#define chacha_set_key nettle_chacha_set_key
+#define chacha_set_nonce nettle_chacha_set_nonce
+#define chacha_set_nonce96 nettle_chacha_set_nonce96
+#define chacha_crypt nettle_chacha_crypt
+#define _chacha_core _nettle_chacha_core
+
+/* Currently, only 256-bit keys are supported. */
+#define CHACHA_KEY_SIZE 32
+#define CHACHA_BLOCK_SIZE 64
+#define CHACHA_NONCE_SIZE 8
+#define CHACHA_NONCE96_SIZE 12
+
+#define _CHACHA_STATE_LENGTH 16
+
+struct chacha_ctx
+{
+  /* Indices 0-3 holds a constant (SIGMA or TAU).
+     Indices 4-11 holds the key.
+     Indices 12-13 holds the block counter.
+     Indices 14-15 holds the IV:
+
+     This creates the state matrix:
+     C C C C
+     K K K K
+     K K K K
+     B B I I
+  */
+  uint32_t state[_CHACHA_STATE_LENGTH];
+};
+
+void
+chacha_set_key(struct chacha_ctx *ctx, const uint8_t *key);
+
+void
+chacha_set_nonce(struct chacha_ctx *ctx, const uint8_t *nonce);
+
+void
+chacha_set_nonce96(struct chacha_ctx *ctx, const uint8_t *nonce);
+
+void
+chacha_crypt(struct chacha_ctx *ctx, size_t length, 
+             uint8_t *dst, const uint8_t *src);
+
+void
+_chacha_core(uint32_t *dst, const uint32_t *src, unsigned rounds);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* NETTLE_CHACHA_H_INCLUDED */