- implemented, untested

2 files changed, 259 insertions, 0 deletions

diff --git a/Source/charon/transforms/prf_plus.c b/Source/charon/transforms/prf_plus.c
new file mode 100644
index 000000000..2469fdebe
--- /dev/null
+++ b/Source/charon/transforms/prf_plus.c
@@ -0,0 +1,175 @@
+/**
+ * @file prf_plus.c
+ * 
+ * @brief Implements the prf+ function described in IKEv2 draft.
+ * 
+ */
+
+/*
+ * Copyright (C) 2005 Jan Hutter, Martin Willi
+ * 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 "prf_plus.h"
+
+#include "../utils/allocator.h"
+#include "../definitions.h"
+
+/**
+ * Private data of an prf_plus_t object.
+ * 
+ */
+typedef struct private_prf_plus_s private_prf_plus_t;
+
+struct private_prf_plus_s {
+	/**
+	 * public prf_plus_t interface
+	 */
+	prf_plus_t public;
+	
+	/**
+	 * prf to use
+	 */
+	prf_t *prf;
+	
+	/**
+	 * initial seed
+	 */
+	chunk_t seed;
+	
+	/**
+	 * buffer to store current prf result
+	 */
+	chunk_t buffer;
+		
+	/**
+	 * already given out bytes in current buffer
+	 */
+	size_t given_out;
+	
+	/**
+	 * octet which will be appended to the seed
+	 */
+	u_int8_t appending_octet;
+};
+
+
+/**
+ * implementation of prf_plus_t.get_bytes
+ */
+static status_t get_bytes(private_prf_plus_t *this, size_t length, u_int8_t *buffer)
+{	
+	chunk_t appending_chunk;
+	size_t bytes_in_round;
+	
+	appending_chunk.ptr = &(this->appending_octet);
+	appending_chunk.len = 1;
+	
+	while (length)
+	{	/* still more to do... */
+		if (this->buffer.len == this->given_out)
+		{	/* no bytes left in buffer, get next*/	
+			this->prf->get_bytes(this->prf, this->buffer, NULL);
+			this->prf->get_bytes(this->prf, this->seed, NULL);
+			this->prf->get_bytes(this->prf, appending_chunk, this->buffer.ptr);
+			this->given_out = 0;
+			this->appending_octet++;
+		}
+		/* how many bytes can we write in this round ? */
+		bytes_in_round = min(length, this->buffer.len - this->given_out);
+		/* copy bytes from buffer with offset */
+		memcpy(buffer, this->buffer.ptr + this->given_out, bytes_in_round);
+		
+		length -= bytes_in_round;
+		this->given_out += bytes_in_round;
+	}
+	return SUCCESS;
+}
+
+/**
+ * implementation of prf_plus_t.allocate_bytes
+ */	
+static status_t allocate_bytes(private_prf_plus_t *this, size_t length, chunk_t *chunk)
+{
+	chunk->ptr = allocator_alloc(length);
+	chunk->len = length;
+	if (chunk->ptr == NULL)
+	{
+		return OUT_OF_RES;	
+	}
+	return this->public.get_bytes(&(this->public), length, chunk->ptr);
+}
+
+/**
+ * implementation of prf_plus_t.destroy
+ */
+static status_t destroy(private_prf_plus_t *this)
+{
+	allocator_free(this->buffer.ptr);
+	allocator_free(this->seed.ptr);
+	allocator_free(this);
+	return SUCCESS;
+}
+
+/*
+ * Description in header
+ */
+prf_plus_t *prf_plus_create(prf_t *prf, chunk_t seed)
+{
+	private_prf_plus_t *this;
+	chunk_t appending_chunk;
+	
+	this = allocator_alloc_thing(private_prf_plus_t);
+	if (this == NULL)
+	{
+		return NULL;	
+	}
+	/* set public methods */
+	this->public.get_bytes = (size_t (*)(prf_plus_t *,size_t,u_int8_t*))get_bytes;
+	this->public.allocate_bytes = (size_t (*)(prf_plus_t *,size_t,chunk_t*))allocate_bytes;
+	this->public.destroy = (status_t (*)(prf_plus_t *))destroy;
+	
+	/* take over prf */
+	this->prf = prf;
+	
+	/* allocate buffer for prf output */
+	this->buffer.len = prf->get_block_size(prf);
+	this->buffer.ptr = allocator_alloc(this->buffer.len);
+	if (this->buffer.ptr == NULL)
+	{
+		allocator_free(this);
+		return NULL;
+	}
+	this->appending_octet = 0x01;
+	
+	/* clone seed */
+	this->seed.ptr = allocator_clone_bytes(seed.ptr, seed.len);
+	this->seed.len = seed.len;
+	if (this->seed.ptr == NULL)
+	{
+		allocator_free(this->buffer.ptr);
+		allocator_free(this);
+		return NULL;	
+	}
+	
+	/* do the first run */
+	appending_chunk.ptr = &(this->appending_octet);
+	appending_chunk.len = 1;
+	this->prf->get_bytes(this->prf, this->seed, NULL);
+	this->prf->get_bytes(this->prf, appending_chunk, this->buffer.ptr);
+	this->given_out = 0;
+	this->appending_octet++;
+	
+	return &(this->public);
+}
diff --git a/Source/charon/transforms/prf_plus.h b/Source/charon/transforms/prf_plus.h
new file mode 100644
index 000000000..6d1fb96c7
--- /dev/null
+++ b/Source/charon/transforms/prf_plus.h
@@ -0,0 +1,84 @@
+/**
+ * @file prf_plus.h
+ * 
+ * @brief Implements the prf+ function described in IKEv2 draft.
+ * 
+ */
+
+/*
+ * Copyright (C) 2005 Jan Hutter, Martin Willi
+ * 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.
+ */
+
+#ifndef PRF_PLUS_H_
+#define PRF_PLUS_H_
+
+
+#include "prfs/prf.h"
+
+
+/**
+ * Object representing a prf_plus
+ */
+typedef struct prf_plus_s prf_plus_t;
+
+struct prf_plus_s {
+	/**
+	 * @brief Get pseudo random bytes.
+	 * 
+	 * @param this			calling prf_plus
+	 * @param length		number of bytes to get
+	 * @param [out]buffer	pointer where the generated bytes will be written
+	 * @return				
+	 * 						- SUCCESS in any case
+	 */
+	status_t (*get_bytes) (prf_plus_t *this, size_t length, u_int8_t *buffer);
+	
+	/**
+	 * @brief Allocate pseudo random bytes.
+	 * 
+	 * @param this			calling prf_plus
+	 * @param length		number of bytes to get
+	 * @param [out]chunk	chunk which will hold generated bytes
+	 * @return				
+	 * 						- SUCCESS in any case
+	 * 						- OUT_OF_RES if space could not be allocated
+	 */
+	status_t (*allocate_bytes) (prf_plus_t *this, size_t length, chunk_t *chunk);
+	
+	/**
+	 * @brief Destroys a prf_plus object.
+	 *
+	 * @param this 			prf_plus_t object to destroy
+	 * @return 		
+	 * 						- SUCCESS in any case
+	 */
+	status_t (*destroy) (prf_plus_t *this);
+};
+
+/**
+ * Creates a new prf_plus_t object
+ * 
+ * Seed will be cloned. prf will
+ * not be cloned, must be destroyed outside after
+ * prf_plus usage.
+ * 
+ * @param prf				prf object to use
+ * @param seed				input seed for prf
+ * @return
+ *							- prf_plus_t if successfully
+ *							- NULL if out of ressources or hash not supported
+ */
+prf_plus_t *prf_plus_create(prf_t *prf, chunk_t seed);
+
+#endif /*PRF_PLUS_H_*/