1 files changed, 94 insertions, 0 deletions
diff --git a/src/libtpmtss/plugins/tpm/tpm_rng.c b/src/libtpmtss/plugins/tpm/tpm_rng.c
new file mode 100644
index 000000000..d96bc4936
--- /dev/null
+++ b/src/libtpmtss/plugins/tpm/tpm_rng.c
@@ -0,0 +1,94 @@
+/*
+ * Copyright (C) 2017 Andreas Steffen
+ * HSR 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.
+ */
+
+#include "tpm_rng.h"
+
+#include <tpm_tss.h>
+#include <utils/debug.h>
+
+typedef struct private_tpm_rng_t private_tpm_rng_t;
+
+/**
+ * Private data of an tpm_rng_t object.
+ */
+struct private_tpm_rng_t {
+
+	/**
+	 * Public interface.
+	 */
+	tpm_rng_t public;
+
+	/**
+	 * Trusted Platform Module
+	 */
+	tpm_tss_t *tpm;
+
+};
+
+METHOD(rng_t, get_bytes, bool,
+	private_tpm_rng_t *this, size_t bytes, uint8_t *buffer)
+{
+	return this->tpm->get_random(this->tpm, bytes, buffer);
+}
+
+METHOD(rng_t, allocate_bytes, bool,
+	private_tpm_rng_t *this, size_t bytes, chunk_t *chunk)
+{
+	*chunk = chunk_alloc(bytes);
+	if (!get_bytes(this, chunk->len, chunk->ptr))
+	{
+		chunk_clear(chunk);
+		return FALSE;
+	}
+	return TRUE;
+}
+
+METHOD(rng_t, destroy, void,
+	private_tpm_rng_t *this)
+{
+	this->tpm->destroy(this->tpm);
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+tpm_rng_t *tpm_rng_create(rng_quality_t quality)
+{
+	private_tpm_rng_t *this;
+	tpm_tss_t *tpm;
+
+	/* try to find a TPM 2.0 */
+	tpm = tpm_tss_probe(TPM_VERSION_2_0);
+	if (!tpm)
+	{
+		DBG1(DBG_LIB, "no TPM 2.0 found");
+		return NULL;	
+	}
+
+	INIT(this,
+		.public = {
+			.rng = {
+				.get_bytes = _get_bytes,
+				.allocate_bytes = _allocate_bytes,
+				.destroy = _destroy,
+			},
+		},
+		.tpm = tpm,
+	);
+
+	return &this->public;
+}
+