botan: Add Botan plugin to libstrongswan

src/libstrongswan/plugins/botan/botan_rng.c

@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2018 René Korthaus
+ * Rohde & Schwarz Cybersecurity GmbH
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "botan_rng.h"
+
+#include <botan/build.h>
+
+#ifdef BOTAN_HAS_HMAC_DRBG
+
+#include <botan/ffi.h>
+
+typedef struct private_botan_random_t private_botan_random_t;
+
+/**
+ * Private data of an botan_rng_t object.
+ */
+struct private_botan_random_t {
+
+	/**
+	 * Public botan_rnd_t interface.
+	 */
+	botan_random_t public;
+
+	/**
+	 * RNG quality of this instance
+	 */
+	rng_quality_t quality;
+
+	/**
+	 * RNG type
+	 */
+	const char* rng_name;
+};
+
+METHOD(rng_t, get_bytes, bool,
+	private_botan_random_t *this, size_t bytes, uint8_t *buffer)
+{
+	botan_rng_t rng;
+	if (botan_rng_init(&rng, this->rng_name))
+	{
+		return FALSE;
+	}
+
+	if (botan_rng_get(rng, buffer, bytes))
+	{
+		botan_rng_destroy(rng);
+		return FALSE;
+	}
+
+	botan_rng_destroy(rng);
+	return TRUE;
+}
+
+METHOD(rng_t, allocate_bytes, bool,
+	private_botan_random_t *this, size_t bytes, chunk_t *chunk)
+{
+	*chunk = chunk_alloc(bytes);
+	if (!get_bytes(this, chunk->len, chunk->ptr))
+	{
+		chunk_free(chunk);
+		return FALSE;
+	}
+	return TRUE;
+}
+
+METHOD(rng_t, destroy, void,
+	private_botan_random_t *this)
+{
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+botan_random_t *botan_rng_create(rng_quality_t quality)
+{
+	private_botan_random_t *this;
+	const char* rng_name;
+
+	switch (quality)
+	{
+		case RNG_WEAK:
+		case RNG_STRONG:
+			rng_name = "user";
+			break;
+		case RNG_TRUE:
+			rng_name = "system";
+			break;
+		default:
+			return NULL;
+	}
+
+	INIT(this,
+		.public = {
+			.rng = {
+				.get_bytes = _get_bytes,
+				.allocate_bytes = _allocate_bytes,
+				.destroy = _destroy,
+			},
+		},
+		.quality = quality,
+		.rng_name = rng_name,
+	);
+
+	return &this->public;
+}
+
+#endif