botan: Add Botan plugin to libstrongswan

2018-09-12 16:25:00 +02:00
parent 66c4735f99
commit af26cc4d85
29 changed files with 5250 additions and 0 deletions
@@ -0,0 +1,248 @@
+/*
+ * 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_ec_diffie_hellman.h"
+
+#include <botan/build.h>
+
+#ifdef BOTAN_HAS_ECDH
+
+#include <utils/debug.h>
+
+#include <botan/ffi.h>
+
+typedef struct private_botan_ec_diffie_hellman_t
+	private_botan_ec_diffie_hellman_t;
+
+/**
+ * Private data of a botan_ec_diffie_hellman_t object.
+ */
+struct private_botan_ec_diffie_hellman_t {
+	/**
+	 * Public botan_ec_diffie_hellman_t interface
+	 */
+	botan_ec_diffie_hellman_t public;
+
+	/**
+	 * Diffie Hellman group
+	 */
+	diffie_hellman_group_t group;
+
+	/**
+	 * EC curve name
+	 */
+	const char* curve_name;
+
+	/**
+	 * EC private key
+	 */
+	botan_privkey_t key;
+
+	/**
+	 * Shared secret
+	 */
+	chunk_t shared_secret;
+
+	/**
+	 * True if shared secret is computed
+	 */
+	bool computed;
+};
+
+METHOD(diffie_hellman_t, set_other_public_value, bool,
+	private_botan_ec_diffie_hellman_t *this, chunk_t value)
+{
+	if (!diffie_hellman_verify_value(this->group, value))
+	{
+		return FALSE;
+	}
+
+	botan_pk_op_ka_t ka;
+	if (botan_pk_op_key_agreement_create(&ka, this->key, "Raw", 0))
+	{
+		return FALSE;
+	}
+
+	/* prepend 0x04 to indicate uncompressed point format */
+	uint8_t indic = 0x04;
+	value = chunk_cata("cc", chunk_from_thing(indic), value);
+	size_t out_len = 0;
+	if (botan_pk_op_key_agreement(ka, NULL, &out_len, value.ptr, value.len,
+								  NULL, 0)
+		!= BOTAN_FFI_ERROR_INSUFFICIENT_BUFFER_SPACE)
+	{
+		botan_pk_op_key_agreement_destroy(ka);
+		return FALSE;
+	}
+
+	if (out_len == 0)
+	{
+		botan_pk_op_key_agreement_destroy(ka);
+		return FALSE;
+	}
+
+	chunk_clear(&this->shared_secret);
+	this->shared_secret = chunk_alloc(out_len);
+	if (botan_pk_op_key_agreement(ka, this->shared_secret.ptr,
+								  &this->shared_secret.len, value.ptr,
+								  value.len, NULL, 0))
+	{
+		chunk_clear(&this->shared_secret);
+		botan_pk_op_key_agreement_destroy(ka);
+		return FALSE;
+	}
+
+	botan_pk_op_key_agreement_destroy(ka);
+	this->computed = TRUE;
+	return TRUE;
+}
+
+METHOD(diffie_hellman_t, get_my_public_value, bool,
+	private_botan_ec_diffie_hellman_t *this, chunk_t *value)
+{
+	chunk_t pkey = chunk_empty;
+	if (botan_pk_op_key_agreement_export_public(this->key, NULL, &pkey.len)
+		!= BOTAN_FFI_ERROR_INSUFFICIENT_BUFFER_SPACE)
+	{
+		return FALSE;
+	}
+
+	pkey = chunk_alloca(pkey.len);
+	if (botan_pk_op_key_agreement_export_public(this->key, pkey.ptr, &pkey.len))
+	{
+		return FALSE;
+	}
+
+	/* skip 0x04 byte prepended by botan */
+	*value = chunk_clone(chunk_skip(pkey, 1));
+	return TRUE;
+}
+
+METHOD(diffie_hellman_t, set_private_value, bool,
+	private_botan_ec_diffie_hellman_t *this, chunk_t value)
+{
+	botan_mp_t scalar;
+	if (botan_mp_init(&scalar))
+	{
+		return FALSE;
+	}
+
+	if (botan_mp_from_bin(scalar, value.ptr, value.len))
+	{
+		botan_mp_destroy(scalar);
+		return FALSE;
+	}
+
+	if (botan_privkey_destroy(this->key))
+	{
+		botan_mp_destroy(scalar);
+		return FALSE;
+	}
+
+	if (botan_privkey_load_ecdh(&this->key, scalar, this->curve_name))
+	{
+		botan_mp_destroy(scalar);
+		return FALSE;
+	}
+
+	botan_mp_destroy(scalar);
+	this->computed = FALSE;
+	return TRUE;
+}
+
+METHOD(diffie_hellman_t, get_shared_secret, bool,
+	private_botan_ec_diffie_hellman_t *this, chunk_t *secret)
+{
+	if (!this->computed)
+	{
+		return FALSE;
+	}
+	*secret = chunk_clone(this->shared_secret);
+	return TRUE;
+}
+
+METHOD(diffie_hellman_t, get_dh_group, diffie_hellman_group_t,
+	private_botan_ec_diffie_hellman_t *this)
+{
+	return this->group;
+}
+
+METHOD(diffie_hellman_t, destroy, void,
+	private_botan_ec_diffie_hellman_t *this)
+{
+	botan_privkey_destroy(this->key);
+	chunk_clear(&this->shared_secret);
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+botan_ec_diffie_hellman_t *
+botan_ec_diffie_hellman_create(diffie_hellman_group_t group)
+{
+	private_botan_ec_diffie_hellman_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,
+				.set_private_value = _set_private_value,
+				.get_dh_group = _get_dh_group,
+				.destroy = _destroy,
+			},
+		},
+		.group = group,
+	);
+
+	switch (group)
+	{
+		case ECP_256_BIT:
+			this->curve_name = "secp256r1";
+			break;
+		case ECP_384_BIT:
+			this->curve_name = "secp384r1";
+			break;
+		case ECP_521_BIT:
+			this->curve_name = "secp521r1";
+			break;
+		case ECP_256_BP:
+			this->curve_name = "brainpool256r1";
+			break;
+		case ECP_384_BP:
+			this->curve_name = "brainpool384r1";
+			break;
+		case ECP_512_BP:
+			this->curve_name = "brainpool512r1";
+			break;
+		default:
+			free(this);
+			return NULL;
+	}
+
+	return &this->public;
+}
+
+#endif