SEC: Add Yarrow PRNG generator.

git-svn-id: https://src.develer.com/svnoss/bertos/trunk@4360 38d2e660-2303-0410-9eaa-f027e97ec537

diff --git a/bertos/sec/prng/yarrow.c b/bertos/sec/prng/yarrow.c
new file mode 100644 (file)
index 0000000..8dbaf92
--- /dev/null
+++ b/bertos/sec/prng/yarrow.c
@@ -0,0 +1,119 @@
+/**
+ * \file
+ * <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos 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
+ * (at your option) 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2010 Develer S.r.l. (http://www.develer.com/)
+ *
+ * -->
+ *
+ * \brief Yarrow implementation
+ * \author Giovanni Bajo <rasky@develer.com>
+ *
+ */
+
+#include "yarrow.h"
+#include <sec/hash/sha1.h>
+#include <cfg/macros.h>
+#include <string.h>
+
+#define CONFIG_YARROW_GENERATOR_GATE             10
+
+static void yarrow_generate(PRNG *ctx_, uint8_t *data, size_t len)
+{
+       YarrowContext *ctx = (YarrowContext *)ctx_;
+       BlockCipher *cipher = 0;
+
+       ASSERT(len != 0);
+
+       do
+       {
+               if (ctx->lastidx == sizeof(ctx->last))
+               {
+                       if (!cipher)
+                       {
+                               cipher = AES128_stackinit();
+                               ASSERT(sizeof(ctx->counter) == cipher_block_len(cipher));
+                               ASSERT(sizeof(ctx->curkey) == cipher_key_len(cipher));
+
+                               cipher_set_key(cipher, ctx->curkey);
+                               cipher_ctr_begin(cipher, ctx->counter);
+                       }
+
+                       cipher_ctr_step(cipher, ctx->last);
+
+                       if (ctx->curkey_gencount == CONFIG_YARROW_GENERATOR_GATE)
+                       {
+                               ASSERT(cipher_block_len(cipher) == cipher_key_len(cipher));
+                               cipher_set_key(cipher, ctx->last);
+                               ctx->curkey_gencount = 0;
+                               continue;
+                       }
+
+                       ctx->lastidx = 0;
+                       ctx->curkey_gencount++;
+               }
+
+               int n = MIN(len, 16U-ctx->lastidx);
+               memcpy(data, ctx->last+ctx->lastidx, n);
+               data += n;
+               len -= n;
+               ctx->lastidx += n;
+       } while (len);
+}
+
+static void yarrow_reseed(PRNG *ctx_, const uint8_t *seed)
+{
+       YarrowContext *ctx = (YarrowContext *)ctx_;
+       Hash *h = SHA1_stackinit();
+
+       hash_begin(h);
+       hash_update(h, seed, ctx->prng.seed_len);
+       hash_update(h, ctx->curkey, sizeof(ctx->curkey));
+       memcpy(ctx->curkey, hash_final(h), sizeof(ctx->curkey));
+       kprintf("Yarrow reseeding:");
+       kdump(ctx->curkey, sizeof(ctx->curkey));
+
+       // Reset the counter for the sequence
+       memset(ctx->counter, 0, sizeof(ctx->counter));
+}
+
+
+/*********************************************************************/
+
+void yarrow_init(YarrowContext *ctx)
+{
+       ctx->prng.reseed = yarrow_reseed;
+       ctx->prng.generate = yarrow_generate;
+       ctx->prng.seed_len = 16;
+       ctx->prng.seeded = 0;
+
+       ctx->lastidx = sizeof(ctx->last);
+       ctx->curkey_gencount = 0;
+       memset(ctx->curkey, 0, sizeof(ctx->curkey));
+
+       ASSERT(sizeof(ctx->counter) == sizeof(ctx->last));
+}

diff --git a/bertos/sec/prng/yarrow.h b/bertos/sec/prng/yarrow.h
new file mode 100644 (file)
index 0000000..556d573
--- /dev/null
+++ b/bertos/sec/prng/yarrow.h
@@ -0,0 +1,60 @@
+/**
+ * \file
+ * <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos 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
+ * (at your option) 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2010 Develer S.r.l. (http://www.develer.com/)
+ *
+ * -->
+ *
+ * \brief Yarrow implementation
+ * \author Giovanni Bajo <rasky@develer.com>
+ *
+ */
+
+#ifndef SEC_PRNG_YARROW_H
+#define SEC_PRNG_YARROW_H
+
+#include <sec/prng.h>
+#include <sec/cipher/aes.h>
+
+typedef struct YarrowContext
+{
+       PRNG prng;
+
+       uint8_t counter[16];
+       uint8_t curkey[16];
+       uint8_t last[16];
+       uint8_t curkey_gencount;
+       uint8_t lastidx;
+} YarrowContext;
+
+void yarrow_init(YarrowContext *ctx);
+
+#define yarrow_stackinit(...) \
+       ({ YarrowContext *ctx = alloca(sizeof(YarrowContext)); yarrow_init(ctx, ##__VA_ARGS__); &ctx->prng; })
+
+#endif /* SEC_PRNG_YARROW_H */