1 files changed, 143 insertions, 0 deletions
diff --git a/src/libstrongswan/plugins/sha3/sha3_shake.c b/src/libstrongswan/plugins/sha3/sha3_shake.c
new file mode 100644
index 000000000..0f1af39f5
--- /dev/null
+++ b/src/libstrongswan/plugins/sha3/sha3_shake.c
@@ -0,0 +1,143 @@
+/*
+ * Copyright (C) 2016 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 "sha3_shake.h"
+#include "sha3_keccak.h"
+
+typedef struct private_sha3_shake_t private_sha3_shake_t;
+
+
+/**
+ * Private data structure with hashing context for SHA-3
+ */
+struct private_sha3_shake_t {
+
+	/**
+	 * Public interface for this hasher.
+	 */
+	sha3_shake_t public;
+
+	/**
+	 * XOF algorithm to be used (XOF_SHAKE_128 or XOF_SHAKE_256)
+	 */
+	ext_out_function_t algorithm;
+
+	/**
+	 * SHA-3 Keccak state
+	 */
+	sha3_keccak_t *keccak;
+
+	/**
+	 * Capacity in bytes of the SHA-3 Keccak state
+	 */
+	u_int capacity;
+
+};
+
+METHOD(xof_t, get_type, ext_out_function_t,
+	private_sha3_shake_t *this)
+{
+	return this->algorithm;
+}
+
+METHOD(xof_t, get_bytes, bool,
+	private_sha3_shake_t *this, size_t out_len, uint8_t *buffer)
+{
+	this->keccak->squeeze(this->keccak, out_len, buffer);
+	return TRUE;
+}
+
+METHOD(xof_t, allocate_bytes, bool,
+	private_sha3_shake_t *this, size_t out_len, chunk_t *chunk)
+{
+	*chunk = chunk_alloc(out_len);
+	this->keccak->squeeze(this->keccak, out_len, chunk->ptr);
+	return TRUE;
+}
+
+METHOD(xof_t, get_block_size, size_t,
+	private_sha3_shake_t *this)
+{
+	return this->keccak->get_rate(this->keccak);
+}
+
+METHOD(xof_t, get_seed_size, size_t,
+	private_sha3_shake_t *this)
+{
+	return this->capacity;
+}
+
+METHOD(xof_t, set_seed, bool,
+	private_sha3_shake_t *this, chunk_t seed)
+{
+	this->keccak->reset(this->keccak);
+	this->keccak->absorb(this->keccak, seed);
+	this->keccak->finalize(this->keccak);
+	return TRUE;
+}
+
+
+METHOD(xof_t, destroy, void,
+	private_sha3_shake_t *this)
+{
+	this->keccak->destroy(this->keccak);
+	free(this);
+}
+
+/*
+ * Described in header.
+ */
+sha3_shake_t* sha3_shake_create(ext_out_function_t algorithm)
+{
+	private_sha3_shake_t *this;
+	u_int capacity = 0;
+
+	switch (algorithm)
+	{
+		case XOF_SHAKE_128:
+			capacity = 32;
+			break;
+		case XOF_SHAKE_256:
+			capacity = 64;
+			break;
+		default:
+			return NULL;
+	}
+
+	INIT(this,
+		.public = {
+			.xof_interface = {
+				.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,
+			},
+		},
+		.algorithm = algorithm,
+		.capacity = capacity,
+	);
+
+	this->keccak = sha3_keccak_create(capacity, 0x1f);
+	if (!this->keccak)
+	{
+		free(this);
+		return NULL;
+	}
+
+	return &this->public;
+}