wolfssl: Support SHAKE_256

src/libstrongswan/plugins/wolfssl/Makefile.am

@@ -29,7 +29,8 @@ libstrongswan_wolfssl_la_SOURCES = \
 	wolfssl_rng.h wolfssl_rng.c \
 	wolfssl_sha1_prf.h wolfssl_sha1_prf.c \
 	wolfssl_x_diffie_hellman.h wolfssl_x_diffie_hellman.c \
-	wolfssl_util.h wolfssl_util.c
+	wolfssl_util.h wolfssl_util.c \
+	wolfssl_xof.h wolfssl_xof.c
 
 
 libstrongswan_wolfssl_la_LDFLAGS = -module -avoid-version

src/libstrongswan/plugins/wolfssl/wolfssl_plugin.c

@@ -41,6 +41,7 @@
 #include "wolfssl_rng.h"
 #include "wolfssl_sha1_prf.h"
 #include "wolfssl_x_diffie_hellman.h"
+#include "wolfssl_xof.h"
 
 #ifndef FIPS_MODE
 #define FIPS_MODE 0
@@ -131,6 +132,10 @@ METHOD(plugin_t, get_features, int,
 #if defined(WOLFSSL_SHA3) && !defined(WOLFSSL_NOSHA3_512)
 			PLUGIN_PROVIDE(HASHER, HASH_SHA3_512),
 #endif
+#if defined(WOLFSSL_SHAKE256) && LIBWOLFSSL_VERSION_HEX >= 0x04007001
+		PLUGIN_REGISTER(XOF, wolfssl_xof_create),
+			PLUGIN_PROVIDE(XOF, XOF_SHAKE_256),
+#endif
 #ifndef NO_SHA
 		/* keyed sha1 hasher (aka prf) */
 		PLUGIN_REGISTER(PRF, wolfssl_sha1_prf_create),

src/libstrongswan/plugins/wolfssl/wolfssl_xof.c

@@ -0,0 +1,151 @@
+/*
+ * Copyright (C) 2021 Andreas Steffen, strongSec GmbH
+ *
+ * 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 <wolfssl/options.h>
+
+#ifdef WOLFSSL_SHAKE256
+
+#include <wolfssl/wolfcrypt/sha3.h>
+
+#include "wolfssl_xof.h"
+
+#define KECCAK_STATE_SIZE 200   /* 1600 bits */
+#define SHAKE256_CAPACITY  64   /*  512 bits */
+
+typedef struct private_xof_t private_xof_t;
+
+/**
+ * Private data
+ */
+struct private_xof_t {
+
+	/**
+	 * Public interface.
+	 */
+	xof_t public;
+
+	/**
+	 * Internal context
+	 */
+	wc_Shake shake;
+
+	/**
+	 * Current seed
+	 */
+	chunk_t seed;
+
+	/**
+	 * Offset into generated data
+	 */
+	size_t offset;
+};
+
+METHOD(xof_t, get_type, ext_out_function_t,
+	private_xof_t *this)
+{
+	return XOF_SHAKE_256;
+}
+
+METHOD(xof_t, get_bytes, bool,
+	private_xof_t *this, size_t out_len, uint8_t *buffer)
+{
+	bool success = FALSE;
+	chunk_t data;
+
+	/* we can call wc_Shake256_Final() only once, so to support an arbitrary
+	 * number of calls to get_bytes(), we request all the data we already
+	 * requested previously and just ignore what we already handed out */
+	if (wc_Shake256_Update(&this->shake, this->seed.ptr, this->seed.len) == 0)
+	{
+		data = chunk_alloc(out_len + this->offset);
+		if (wc_Shake256_Final(&this->shake, data.ptr, data.len) == 0)
+		{
+			memcpy(buffer, data.ptr + this->offset, out_len);
+			this->offset += out_len;
+			success = TRUE;
+		}
+		chunk_clear(&data);
+	}
+	return success;
+}
+
+METHOD(xof_t, allocate_bytes, bool,
+	private_xof_t *this, size_t out_len, chunk_t *chunk)
+{
+	*chunk = chunk_alloc(out_len);
+	return get_bytes(this, out_len, chunk->ptr);
+}
+
+METHOD(xof_t, get_block_size, size_t,
+	private_xof_t *this)
+{
+	return KECCAK_STATE_SIZE - SHAKE256_CAPACITY;
+}
+
+METHOD(xof_t, get_seed_size, size_t,
+	private_xof_t *this)
+{
+	return SHAKE256_CAPACITY;
+}
+
+METHOD(xof_t, set_seed, bool,
+	private_xof_t *this, chunk_t seed)
+{
+	chunk_clear(&this->seed);
+	this->seed = chunk_clone(seed);
+	this->offset = 0;
+	return TRUE;
+}
+
+METHOD(xof_t, destroy, void,
+	private_xof_t *this)
+{
+	wc_Shake256_Free(&this->shake);
+	chunk_clear(&this->seed);
+	free(this);
+}
+
+/*
+ * Described in header
+ */
+xof_t *wolfssl_xof_create(ext_out_function_t algorithm)
+{
+	private_xof_t *this;
+
+	if (algorithm != XOF_SHAKE_256)
+	{
+		return NULL;
+	}
+
+	INIT(this,
+		.public = {
+			.get_type = _get_type,
+			.get_bytes = _get_bytes,
+			.allocate_bytes = _allocate_bytes,
+			.get_block_size = _get_block_size,
+			.get_seed_size = _get_seed_size,
+			.set_seed = _set_seed,
+			.destroy = _destroy,
+		},
+	);
+
+	if (wc_InitShake256(&this->shake, NULL, 0) != 0)
+	{
+		free(this);
+	}
+
+	return &this->public;
+}
+
+#endif /* WOLFSSL_SHAKE256 */

src/libstrongswan/plugins/wolfssl/wolfssl_xof.h

@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2021 Andreas Steffen, strongSec GmbH
+ *
+ * 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.
+ */
+
+/**
+ * Implementation of the SHAKE128/256 XOF algorithm using OpenSSL.
+ *
+ * @defgroup wolfssl_xof wolfssl_xof
+ * @{ @ingroup wolfssl_p
+ */
+
+#ifndef WOLFSSL_XOF_H_
+#define WOLFSSL_XOF_H_
+
+#include <library.h>
+
+/**
+ * Creates a new xof_t object.
+ *
+ * @param algorithm		XOF algorithm to create
+ * @return				object, NULL if not supported
+ */
+xof_t *wolfssl_xof_create(ext_out_function_t algorithm);
+
+#endif /** WOLFSSL_XOF_H_ @}*/