pkcs11: Added support to generate random numbers on a token.

2011-10-31 18:45:35 +01:00
parent deba3da5b0
commit 1bb522bc34
4 changed files with 201 additions and 0 deletions
@@ -0,0 +1,137 @@
+/*
+ * Copyright (C) 2011 Tobias Brunner
+ * 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 "pkcs11_rng.h"
+
+#include <debug.h>
+
+#include "pkcs11_manager.h"
+
+typedef struct private_pkcs11_rng_t private_pkcs11_rng_t;
+
+/**
+ * Private data of an pkcs11_rng_t object.
+ */
+struct private_pkcs11_rng_t {
+
+	/**
+	 * Public interface.
+	 */
+	pkcs11_rng_t public;
+
+	/**
+	 * PKCS#11 library
+	 */
+	pkcs11_library_t *lib;
+
+	/**
+	 * Mechanism for this rng
+	 */
+	CK_SESSION_HANDLE session;
+
+};
+
+METHOD(rng_t, get_bytes, void,
+	private_pkcs11_rng_t *this, size_t bytes, u_int8_t *buffer)
+{
+	CK_RV rv;
+	rv = this->lib->f->C_GenerateRandom(this->session, buffer, bytes);
+	if (rv != CKR_OK)
+	{
+		DBG1(DBG_CFG, "C_GenerateRandom() failed: %N", ck_rv_names, rv);
+		abort();
+	}
+}
+
+METHOD(rng_t, allocate_bytes, void,
+	private_pkcs11_rng_t *this, size_t bytes, chunk_t *chunk)
+{
+	*chunk = chunk_alloc(bytes);
+	get_bytes(this, chunk->len, chunk->ptr);
+}
+
+METHOD(rng_t, destroy, void,
+	private_pkcs11_rng_t *this)
+{
+	this->lib->f->C_CloseSession(this->session);
+	free(this);
+}
+
+/**
+ * Find a token with its own RNG
+ */
+static pkcs11_library_t *find_token(CK_SESSION_HANDLE *session)
+{
+	enumerator_t *tokens;
+	pkcs11_manager_t *manager;
+	pkcs11_library_t *current, *found = NULL;
+	CK_SLOT_ID slot;
+
+	manager = lib->get(lib, "pkcs11-manager");
+	if (!manager)
+	{
+		return NULL;
+	}
+	tokens = manager->create_token_enumerator(manager);
+	while (tokens->enumerate(tokens, &current, &slot))
+	{
+		CK_TOKEN_INFO info;
+		CK_RV rv;
+		rv = current->f->C_GetTokenInfo(slot, &info);
+		if (rv != CKR_OK)
+		{
+			continue;
+		}
+		if (info.flags & CKF_RNG)
+		{
+			if (current->f->C_OpenSession(slot, CKF_SERIAL_SESSION,
+										  NULL, NULL, session) == CKR_OK)
+			{
+				found = current;
+				break;
+			}
+		}
+	}
+	tokens->destroy(tokens);
+	return found;
+}
+
+/*
+ * Described in header.
+ */
+pkcs11_rng_t *pkcs11_rng_create(rng_quality_t quality)
+{
+	private_pkcs11_rng_t *this;
+
+	INIT(this,
+		.public = {
+			.rng = {
+				.get_bytes = _get_bytes,
+				.allocate_bytes = _allocate_bytes,
+				.destroy = _destroy,
+			},
+		},
+	);
+
+	this->lib = find_token(&this->session);
+	if (!this->lib)
+	{
+		free(this);
+		return NULL;
+	}
+
+	return &this->public;
+}
+