1 files changed, 134 insertions, 0 deletions
diff --git a/src/libstrongswan/plugins/random/random_rng.c b/src/libstrongswan/plugins/random/random_rng.c
new file mode 100644
index 000000000..1aadc88bd
--- /dev/null
+++ b/src/libstrongswan/plugins/random/random_rng.c
@@ -0,0 +1,134 @@
+/*
+ * Copyright (C) 2005-2008 Martin Willi
+ * Copyright (C) 2005 Jan Hutter
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ *
+ * $Id$
+ */
+
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <debug.h>
+
+#include "random_rng.h"
+
+#ifndef DEV_RANDOM
+# define DEV_RANDOM "/dev/random"
+#endif
+
+#ifndef DEV_URANDOM
+# define DEV_URANDOM "/dev/urandom"
+#endif
+
+typedef struct private_random_rng_t private_random_rng_t;
+
+/**
+ * Private data of an random_rng_t object.
+ */
+struct private_random_rng_t {
+
+	/**
+	 * Public random_rng_t interface.
+	 */
+	random_rng_t public;
+	
+	/**
+	 * random device, depends on quality
+	 */
+	int dev;
+	
+	/**
+	 * file we read random bytes from
+	 */
+	char *file;
+};
+
+/**
+ * Implementation of random_rng_t.get_bytes.
+ */
+static void get_bytes(private_random_rng_t *this, size_t bytes,
+					  u_int8_t *buffer)
+{
+	size_t done, got;
+	
+	done = 0;
+	
+	while (done < bytes)
+	{
+		got = read(this->dev, buffer + done, bytes - done);
+		if (got <= 0)
+		{
+			DBG1("reading from \"%s\" failed: %s, retrying...",
+				 this->file, strerror(errno));
+			close(this->dev);
+			sleep(1);
+			this->dev = open(this->file, 0);
+		}
+		done += got;
+	}
+}
+
+/**
+ * Implementation of random_rng_t.allocate_bytes.
+ */
+static void allocate_bytes(private_random_rng_t *this, size_t bytes,
+						   chunk_t *chunk)
+{
+	*chunk = chunk_alloc(bytes);
+	get_bytes(this, chunk->len, chunk->ptr);
+}
+
+/**
+ * Implementation of random_rng_t.destroy.
+ */
+static void destroy(private_random_rng_t *this)
+{
+	close(this->dev);
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+random_rng_t *random_rng_create(rng_quality_t quality)
+{
+	private_random_rng_t *this = malloc_thing(private_random_rng_t);
+
+	/* public functions */
+	this->public.rng.get_bytes = (void (*) (rng_t *, size_t, u_int8_t*)) get_bytes;
+	this->public.rng.allocate_bytes = (void (*) (rng_t *, size_t, chunk_t*)) allocate_bytes;
+	this->public.rng.destroy = (void (*) (rng_t *))destroy;
+
+	if (quality == RNG_REAL)
+	{
+		this->file = DEV_RANDOM;
+	}
+	else
+	{
+		this->file = DEV_URANDOM;
+	}
+	
+	this->dev = open(this->file, 0);
+	if (this->dev < 0)
+	{
+		DBG1("opening \"%s\" failed: %s", this->file, strerror(errno));
+		free(this);
+		return NULL;
+	}
+	return &this->public;
+}
+