pkcs11: Added support for DH.

src/libstrongswan/plugins/pkcs11/Makefile.am

@@ -17,6 +17,7 @@ libstrongswan_pkcs11_la_SOURCES = \
 	pkcs11_public_key.h pkcs11_public_key.c \
 	pkcs11_hasher.h pkcs11_hasher.c \
 	pkcs11_rng.h pkcs11_rng.c \
+	pkcs11_dh.h pkcs11_dh.c \
 	pkcs11_manager.h pkcs11_manager.c
 
 libstrongswan_pkcs11_la_LDFLAGS = -module -avoid-version

src/libstrongswan/plugins/pkcs11/pkcs11_dh.c

@@ -0,0 +1,297 @@
+/*
+ * 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_dh.h"
+
+#include <debug.h>
+#include <library.h>
+
+#include "pkcs11_manager.h"
+
+typedef struct private_pkcs11_dh_t private_pkcs11_dh_t;
+
+/**
+ * Private data of an pkcs11_dh_t object.
+ */
+struct private_pkcs11_dh_t {
+
+	/**
+	 * Public pkcs11_dh_t interface
+	 */
+	pkcs11_dh_t public;
+
+	/**
+	 * PKCS#11 library
+	 */
+	pkcs11_library_t *lib;
+
+	/**
+	 * Session handle for this objct
+	 */
+	CK_SESSION_HANDLE session;
+
+	/**
+	 * Diffie Hellman group number.
+	 */
+	u_int16_t group;
+
+	/**
+	 * Handle for own private value
+	 */
+	CK_OBJECT_HANDLE pri_key;
+
+	/**
+	 * Own public value
+	 */
+	chunk_t pub_key;
+
+	/**
+	 * Shared secret
+	 */
+	chunk_t secret;
+
+};
+
+/**
+ * Retrieve a CKA_VALUE from a CK_OBJECT_HANDLE, memory gets allocated
+ */
+static bool get_cka_value(private_pkcs11_dh_t *this, CK_OBJECT_HANDLE obj,
+						  chunk_t *value)
+{
+	CK_ATTRIBUTE attr = { CKA_VALUE, NULL, 0 };
+	CK_RV rv;
+	rv = this->lib->f->C_GetAttributeValue(this->session, obj, &attr, 1);
+	if (rv != CKR_OK)
+	{
+		DBG1(DBG_CFG, "C_GetAttributeValue(NULL) error: %N", ck_rv_names, rv);
+		return FALSE;
+	}
+	*value = chunk_alloc(attr.ulValueLen);
+	attr.pValue = value->ptr;
+	rv = this->lib->f->C_GetAttributeValue(this->session, obj, &attr, 1);
+	if (rv != CKR_OK)
+	{
+		DBG1(DBG_CFG, "C_GetAttributeValue() error: %N", ck_rv_names, rv);
+		chunk_free(value);
+		return FALSE;
+	}
+	return TRUE;
+}
+
+METHOD(diffie_hellman_t, set_other_public_value, void,
+	private_pkcs11_dh_t *this, chunk_t value)
+{
+	CK_ATTRIBUTE attr[] = {
+	};
+	CK_MECHANISM mech = {
+		CKM_DH_PKCS_DERIVE,
+		value.ptr,
+		value.len,
+	};
+	CK_OBJECT_HANDLE secret;
+	CK_RV rv;
+
+	rv = this->lib->f->C_DeriveKey(this->session, &mech, this->pri_key,
+								   attr, countof(attr), &secret);
+	if (rv != CKR_OK)
+	{
+		DBG1(DBG_CFG, "C_DeriveKey() error: %N", ck_rv_names, rv);
+		return;
+	}
+	if (!get_cka_value(this, secret, &this->secret))
+	{
+		return;
+	}
+}
+
+METHOD(diffie_hellman_t, get_my_public_value, void,
+	private_pkcs11_dh_t *this, chunk_t *value)
+{
+	*value = chunk_clone(this->pub_key);
+}
+
+METHOD(diffie_hellman_t, get_shared_secret, status_t,
+	private_pkcs11_dh_t *this, chunk_t *secret)
+{
+	if (!this->secret.ptr)
+	{
+		return FAILED;
+	}
+	*secret = chunk_clone(this->secret);
+	return SUCCESS;
+}
+
+METHOD(diffie_hellman_t, get_dh_group, diffie_hellman_group_t,
+	private_pkcs11_dh_t *this)
+{
+	return this->group;
+}
+
+METHOD(diffie_hellman_t, destroy, void,
+	private_pkcs11_dh_t *this)
+{
+	this->lib->f->C_CloseSession(this->session);
+	chunk_clear(&this->pub_key);
+	chunk_clear(&this->secret);
+	free(this);
+}
+
+/**
+ * Generate DH key pair
+ */
+static bool generate_key_pair(private_pkcs11_dh_t *this, size_t exp_len,
+							  chunk_t g, chunk_t p)
+{
+	CK_ULONG bits = exp_len * 8;
+	CK_ATTRIBUTE pub_attr[] = {
+		{ CKA_PRIME, p.ptr, p.len },
+		{ CKA_BASE, g.ptr, g.len },
+	};
+	CK_ATTRIBUTE pri_attr[] = {
+		{ CKA_VALUE_BITS, &bits, sizeof(bits) },
+	};
+	CK_MECHANISM mech = {
+		CKM_DH_PKCS_KEY_PAIR_GEN,
+		NULL,
+		0,
+	};
+	CK_OBJECT_HANDLE pub_key;
+	CK_RV rv;
+
+	rv = this->lib->f->C_GenerateKeyPair(this->session, &mech, pub_attr,
+							countof(pub_attr), pri_attr, countof(pri_attr),
+							&pub_key, &this->pri_key);
+	if (rv != CKR_OK)
+	{
+		DBG1(DBG_CFG, "C_GenerateKeyPair() error: %N", ck_rv_names, rv);
+		return FALSE;
+	}
+
+	if (!get_cka_value(this, pub_key, &this->pub_key))
+	{
+		return FALSE;
+	}
+	return TRUE;
+}
+
+/**
+ * Find a token we can use for DH algorithm
+ */
+static pkcs11_library_t *find_token(CK_SESSION_HANDLE *session)
+{
+	enumerator_t *tokens, *mechs;
+	pkcs11_manager_t *manager;
+	pkcs11_library_t *current, *found = NULL;
+	CK_MECHANISM_TYPE type;
+	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))
+	{
+		mechs = current->create_mechanism_enumerator(current, slot);
+		while (mechs->enumerate(mechs, &type, NULL))
+		{
+			/* we assume CKM_DH_PKCS_DERIVE is supported too */
+			if (type == CKM_DH_PKCS_KEY_PAIR_GEN)
+			{
+				if (current->f->C_OpenSession(slot, CKF_SERIAL_SESSION,
+											  NULL, NULL, session) == CKR_OK)
+				{
+					found = current;
+					break;
+				}
+			}
+		}
+		mechs->destroy(mechs);
+		if (found)
+		{
+			break;
+		}
+	}
+	tokens->destroy(tokens);
+	return found;
+}
+
+/*
+ * Generic internal constructor
+ */
+pkcs11_dh_t *create_generic(diffie_hellman_group_t group, size_t exp_len,
+							chunk_t g, chunk_t p)
+{
+	private_pkcs11_dh_t *this;
+
+	INIT(this,
+		.public = {
+			.dh = {
+				.get_shared_secret = _get_shared_secret,
+				.set_other_public_value = _set_other_public_value,
+				.get_my_public_value = _get_my_public_value,
+				.get_dh_group = _get_dh_group,
+				.destroy = _destroy,
+			},
+		},
+		.group = group,
+	);
+
+	this->lib = find_token(&this->session);
+	if (!this->lib)
+	{
+		free(this);
+		return NULL;
+	}
+
+	if (!generate_key_pair(this, exp_len, g, p))
+	{
+		free(this);
+		return NULL;
+	}
+	return &this->public;
+}
+
+
+/*
+ * Described in header.
+ */
+pkcs11_dh_t *pkcs11_dh_create(diffie_hellman_group_t group)
+{
+
+	diffie_hellman_params_t *params;
+
+	params = diffie_hellman_get_params(group);
+	if (!params)
+	{
+		return NULL;
+	}
+	return create_generic(group, params->exp_len,
+						  params->generator, params->prime);
+}
+
+/*
+ * Described in header.
+ */
+pkcs11_dh_t *pkcs11_dh_create_custom(diffie_hellman_group_t group,
+									 chunk_t g, chunk_t p)
+{
+	if (group == MODP_CUSTOM)
+	{
+		return create_generic(group, p.len, g, p);
+	}
+	return NULL;
+}

src/libstrongswan/plugins/pkcs11/pkcs11_dh.h

@@ -0,0 +1,59 @@
+/*
+ * 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.
+ */
+
+/**
+ * @defgroup pkcs11_dh pkcs11_dh
+ * @{ @ingroup pkcs11
+ */
+
+#ifndef PKCS11_DH_H_
+#define PKCS11_DH_H_
+
+typedef struct pkcs11_dh_t pkcs11_dh_t;
+
+#include <library.h>
+
+/**
+ * Implementation of the Diffie-Hellman algorithm via PKCS#11.
+ */
+struct pkcs11_dh_t {
+
+	/**
+	 * Implements diffie_hellman_t interface.
+	 */
+	diffie_hellman_t dh;
+};
+
+/**
+ * Creates a new pkcs11_dh_t object.
+ *
+ * @param group			Diffie Hellman group number to use
+ * @return				pkcs11_dh_t object, NULL if not supported
+ */
+pkcs11_dh_t *pkcs11_dh_create(diffie_hellman_group_t group);
+
+/**
+ * Creates a new pkcs11_dh_t object for MODP_CUSTOM.
+ *
+ * @param group			MODP_CUSTOM
+ * @param g				generator
+ * @param p				prime
+ * @return				pkcs11_dh_t object, NULL if not supported
+ */
+pkcs11_dh_t *pkcs11_dh_create_custom(diffie_hellman_group_t group,
+									 chunk_t g, chunk_t p);
+
+#endif /** PKCS11_DH_H_ @}*/
+

src/libstrongswan/plugins/pkcs11/pkcs11_plugin.c

@@ -29,6 +29,7 @@
 #include "pkcs11_public_key.h"
 #include "pkcs11_hasher.h"
 #include "pkcs11_rng.h"
+#include "pkcs11_dh.h"
 
 typedef struct private_pkcs11_plugin_t private_pkcs11_plugin_t;
 
@@ -126,6 +127,8 @@ METHOD(plugin_t, destroy, void,
 	lib->crypto->remove_hasher(lib->crypto,
 							(hasher_constructor_t)pkcs11_hasher_create);
 	lib->crypto->remove_rng(lib->crypto, (rng_constructor_t)pkcs11_rng_create);
+	lib->crypto->remove_dh(lib->crypto, (dh_constructor_t)pkcs11_dh_create_custom);
+	lib->crypto->remove_dh(lib->crypto, (dh_constructor_t)pkcs11_dh_create);
 	this->creds->destroy(this->creds);
 	lib->set(lib, "pkcs11-manager", NULL);
 	this->manager->destroy(this->manager);
@@ -192,6 +195,23 @@ plugin_t *pkcs11_plugin_create()
 	lib->creds->add_builder(lib->creds, CRED_PUBLIC_KEY, KEY_RSA, TRUE,
 							(builder_function_t)pkcs11_public_key_load);
 
+	lib->crypto->add_dh(lib->crypto, MODP_3072_BIT, get_name(this),
+					(dh_constructor_t)pkcs11_dh_create);
+	lib->crypto->add_dh(lib->crypto, MODP_4096_BIT, get_name(this),
+					(dh_constructor_t)pkcs11_dh_create);
+	lib->crypto->add_dh(lib->crypto, MODP_6144_BIT, get_name(this),
+					(dh_constructor_t)pkcs11_dh_create);
+	lib->crypto->add_dh(lib->crypto, MODP_8192_BIT, get_name(this),
+					(dh_constructor_t)pkcs11_dh_create);
+	lib->crypto->add_dh(lib->crypto, MODP_1024_BIT, get_name(this),
+					(dh_constructor_t)pkcs11_dh_create);
+	lib->crypto->add_dh(lib->crypto, MODP_1024_160, get_name(this),
+					(dh_constructor_t)pkcs11_dh_create);
+	lib->crypto->add_dh(lib->crypto, MODP_768_BIT, get_name(this),
+					(dh_constructor_t)pkcs11_dh_create);
+	lib->crypto->add_dh(lib->crypto, MODP_CUSTOM, get_name(this),
+					(dh_constructor_t)pkcs11_dh_create_custom);
+
 	enumerator = this->manager->create_token_enumerator(this->manager);
 	while (enumerator->enumerate(enumerator, &p11, &slot))
 	{