1 files changed, 83 insertions, 0 deletions
diff --git a/lib/nettle/gost/acpkm.c b/lib/nettle/gost/acpkm.c
new file mode 100644
index 0000000..8b05c7a
--- /dev/null
+++ b/lib/nettle/gost/acpkm.c
@@ -0,0 +1,83 @@
+/* acpkm.c
+
+   The R 1323565.1.017-2018 cipher function. See draft-irtf-cfrg-re-keying.
+
+   Copyright (C) 2018 Dmitry Eremin-Solenikov
+
+   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/.
+*/
+
+#if HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include "acpkm.h"
+
+static uint8_t acpkm_mesh_data[ACPKM_KEY_SIZE] =
+{
+  0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+  0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
+  0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
+  0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
+};
+
+void acpkm_crypt(struct acpkm_ctx *ctx,
+		 void *cipher,
+		 nettle_cipher_func *encrypt,
+		 nettle_set_key_func *set_key,
+		 size_t length, uint8_t *dst,
+		 const uint8_t *src)
+{
+  size_t N = ctx->N;
+  size_t part;
+  uint8_t new_key[ACPKM_KEY_SIZE];
+
+  /* Less than a block, no rekeying */
+  if (ctx->pos + length < N)
+    {
+      encrypt(cipher, length, dst, src);
+      ctx->pos += length;
+      return;
+    }
+
+  for (part = N - ctx->pos; length >= part; part = N)
+    {
+      encrypt(cipher, part, dst, src);
+      src += part;
+      dst += part;
+      length -= part;
+
+      /* Rekey */
+      encrypt(cipher, ACPKM_KEY_SIZE, new_key, acpkm_mesh_data);
+      set_key(cipher, new_key);
+    }
+
+  if (length != 0)
+      encrypt(cipher, length, dst, src);
+
+  ctx->pos = length;
+}