- created encoding package

1 files changed, 1125 insertions, 0 deletions

diff --git a/Source/charon/encoding/generator.c b/Source/charon/encoding/generator.c
new file mode 100644
index 000000000..734c089a0
--- /dev/null
+++ b/Source/charon/encoding/generator.c
@@ -0,0 +1,1125 @@
+/**
+ * @file generator.c
+ *
+ * @brief Generic generator class used to generate IKEv2-header and payloads.
+ *
+ */
+
+/*
+ * 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 <stdlib.h>
+#include <string.h>
+#include <arpa/inet.h>
+#include <stdio.h>
+
+
+#include "generator.h"
+
+#include <types.h>
+#include <globals.h>
+#include <utils/allocator.h>
+#include <utils/linked_list.h>
+#include <utils/logger_manager.h>
+#include <encoding/payloads/payload.h>
+#include <encoding/payloads/proposal_substructure.h>
+#include <encoding/payloads/transform_substructure.h>
+#include <encoding/payloads/sa_payload.h>
+#include <encoding/payloads/ke_payload.h>
+#include <encoding/payloads/notify_payload.h>
+#include <encoding/payloads/nonce_payload.h>
+
+/**
+ * Private part of a generator_t object
+ */
+typedef struct private_generator_s private_generator_t;
+
+struct private_generator_s {
+	/**
+	 * Public part of a generator_t object
+	 */
+	 generator_t public;
+
+	/* private functions and fields */
+
+
+	/**
+	 * Generates a U_INT-Field type and writes it to buffer.
+	 *
+	 * @param this 					private_generator_t object
+	 * @param int_type 				type of U_INT field (U_INT_4, U_INT_8, etc.)
+	 * 								ATTRIBUTE_TYPE is also generated in this function
+	 * @param offset 				offset of value in data struct
+	 * @param generator_contexts		generator_contexts_t object where the context is written or read from
+	 * @return 						- SUCCESS if succeeded
+	 * 		  						- OUT_OF_RES if out of ressources
+	 */
+	status_t (*generate_u_int_type) (private_generator_t *this,encoding_type_t int_type,u_int32_t offset);
+
+	/**
+	 * Get size of current buffer in bytes.
+	 *
+	 * @param this 					private_generator_t object
+	 * @return 						Size of buffer in bytes
+	 */
+	size_t (*get_current_buffer_size) (private_generator_t *this);
+	
+	/**
+	 * Get free space of current buffer in bytes.
+	 *
+	 * @param this 					private_generator_t object
+	 * @return 						space in buffer in bytes
+	 */
+	size_t (*get_current_buffer_space) (private_generator_t *this);
+
+	/**
+	 * Get length of data in buffer (in bytes).
+	 *
+	 * @param this 					private_generator_t object
+	 * @return 						length of data in bytes
+	 */	
+	size_t (*get_current_data_length) (private_generator_t *this);
+
+	/**
+	 * Get current offset in buffer (in bytes).
+	 *
+	 * @param this 					private_generator_t object
+	 * @return 						offset in bytes
+	 */	
+	u_int32_t (*get_current_buffer_offset) (private_generator_t *this);
+	
+	/**
+	 * Generates a RESERVED BIT field or a RESERVED BYTE field and writes 
+	 * it to the buffer.
+	 *
+	 * @param this 					private_generator_t object
+	 * @param generator_contexts		generator_contexts_t object where the context is written or read from
+	 * @param bits 					number of bits to generate
+	 * @return 						- SUCCESS if succeeded
+	 * 		  						- OUT_OF_RES if out of ressources
+	 * 								- FAILED if bit count not supported
+	 */
+	status_t (*generate_reserved_field) (private_generator_t *this,int bits);
+	
+	/**
+	 * Generates a FLAG field
+	 *
+	 * @param this 					private_generator_t object
+	 * @param generator_contexts		generator_contexts_t object where the context is written or read from
+	 * @param offset					offset of flag value in data struct
+	 * @return 						- SUCCESS if succeeded
+	 * 		  						- OUT_OF_RES if out of ressources
+	 */
+	status_t (*generate_flag) (private_generator_t *this,u_int32_t offset);
+	
+	/**
+	 * Writes the current buffer content into a chunk_t
+	 * 
+	 * Memory of specific chunk_t gets allocated.
+	 *
+ 	 * @param this				calling private_generator_t object
+	 * @param data				pointer of chunk_t to write to
+	 * @return 
+	 * 							- SUCCESSFUL if succeeded
+	 * 							- OUT_OF_RES otherwise
+	 */
+	status_t (*write_chunk) (private_generator_t *this,chunk_t *data);
+	
+	/**
+	 * Generates a bytestream from a chunk_t
+	 *
+	 * @param this 					private_generator_t object
+	 * @param offset					offset of chunk_t value in data struct
+	 * @return 						- SUCCESS if succeeded
+	 * 		  						- OUT_OF_RES if out of ressources
+	 */
+	status_t (*generate_from_chunk) (private_generator_t *this,u_int32_t offset);	
+
+	/**
+	 * Makes sure enough space is available in buffer to store amount of bits.
+     *
+	 * If buffer is to small to hold the specific amount of bits it 
+	 * is increased using reallocation function of allocator.
+	 *
+ 	 * @param this 				calling private_generator_t object
+	 * @param bits 				number of bits to make available in buffer
+	 * @return 
+	 * 							- SUCCESSFUL if succeeded
+	 * 							- OUT_OF_RES otherwise
+	 */
+	status_t (*make_space_available) (private_generator_t *this,size_t bits);
+
+	/**
+	 * Writes a specific amount of byte into the buffer.
+	 * 
+	 * If buffer is to small to hold the specific amount of bytes it 
+	 * is increased.
+	 *
+ 	 * @param this				calling private_generator_t object
+	 * @param bytes 				pointer to bytes to write
+	 * @param number_of_bytes	number of bytes to write into buffer
+	 * @return 
+	 * 							- SUCCESSFUL if succeeded
+	 * 							- OUT_OF_RES otherwise
+	 */
+	status_t (*write_bytes_to_buffer) (private_generator_t *this,void * bytes,size_t number_of_bytes);
+	
+	
+	/**
+	 * Writes a specific amount of byte into the buffer at a specific offset.
+	 * 
+	 * @warning buffer size is not check to hold the data if offset is to large.
+	 *
+ 	 * @param this				calling private_generator_t object
+	 * @param bytes 				pointer to bytes to write
+	 * @param number_of_bytes	number of bytes to write into buffer
+	 * @param offset				offset to write the data into
+	 * @return 
+	 * 							- SUCCESSFUL if succeeded
+	 * 							- OUT_OF_RES otherwise
+	 */
+	status_t (*write_bytes_to_buffer_at_offset) (private_generator_t *this,void * bytes,size_t number_of_bytes,u_int32_t offset);
+	
+	/**
+	 * Buffer used to generate the data into.
+	 */
+	u_int8_t *buffer;
+
+	/**
+	 * Current write position in buffer (one byte aligned).
+	 */
+	u_int8_t *out_position;
+
+	/**
+	 * Position of last byte in buffer.
+	 */
+	u_int8_t *roof_position;
+
+	/**
+	 * Current bit writing to in current byte (between 0 and 7).
+	 */
+	size_t current_bit;
+
+	/**
+	 * Associated data struct to read informations from.
+	 */
+	void * data_struct;
+	
+	/*
+	 * Last payload length position offset in the buffer
+	 */
+	u_int32_t last_payload_length_position_offset;
+	
+	/**
+	 * Offset of the header length field in the buffer
+	 */
+	u_int32_t header_length_position_offset;
+	
+	/**
+	 * Last SPI size
+	 */
+	u_int8_t last_spi_size;
+	
+	/*
+	 * Attribute format of the last generated transform attribute
+	 * 
+	 * Used to check if a variable value field is used or not for 
+	 * the transform attribute value.
+	 */
+	bool attribute_format;
+	
+	/*
+	 * Depending on the value of attribute_format this field is used
+	 * to hold the length of the transform attribute in bytes
+	 */
+	u_int16_t attribute_length;
+	
+	/**
+	 * Associated Logger
+	 */
+	logger_t *logger;
+};
+
+/**
+ * Implements private_generator_t's get_current_buffer_size function.
+ * See #private_generator_s.get_current_buffer_size.
+ */
+static size_t get_current_buffer_size (private_generator_t *this)
+{
+	return ((this->roof_position) - (this->buffer));
+}
+
+/**
+ * Implements private_generator_t's get_current_buffer_space function.
+ * See #private_generator_s.get_current_buffer_space.
+ */
+static size_t get_current_buffer_space (private_generator_t *this)
+{
+	/* we know, one byte more */
+	size_t space = (this->roof_position) - (this->out_position);
+	return (space);
+}
+
+/**
+ * Implements private_generator_t's get_current_buffer_space function.
+ * See #private_generator_s.get_current_buffer_space.
+ */
+static size_t get_current_data_length (private_generator_t *this)
+{
+	return (this->out_position - this->buffer);
+}
+
+/**
+ * Implements private_generator_t's get_current_buffer_offset function.
+ * See #private_generator_s.get_current_buffer_offset.
+ */
+static u_int32_t get_current_buffer_offset (private_generator_t *this)
+{
+	return (this->out_position - this->buffer);
+}
+
+
+/**
+ * Implements private_generator_t's generate_u_int_type function.
+ * See #private_generator_s.generate_u_int_type.
+ */
+static status_t generate_u_int_type (private_generator_t *this,encoding_type_t int_type,u_int32_t offset)
+{
+	size_t number_of_bits = 0;
+	status_t status;
+
+	/* find out number of bits of each U_INT type to check for enough space 
+	   in buffer */
+	switch (int_type)
+	{
+			case U_INT_4:
+				number_of_bits = 4;
+				break;
+			case U_INT_8:
+				number_of_bits = 8;
+				break;
+			case U_INT_16:
+				number_of_bits = 16;
+				break;
+			case U_INT_32:
+				number_of_bits = 32;
+				break;
+			case U_INT_64:
+				number_of_bits = 64;
+				break;
+			case ATTRIBUTE_TYPE:
+				number_of_bits = 15;
+				break;
+			case IKE_SPI:
+				number_of_bits = 64;
+				break;
+
+			default:
+			return FAILED;
+	}
+	/* U_INT Types of multiple then 8 bits must be aligned */
+	if (((number_of_bits % 8) == 0) && (this->current_bit != 0))
+	{
+		this->logger->log(this->logger, ERROR, "U_INT Type %s is not 8 Bit aligned", 
+							mapping_find(encoding_type_m,int_type));
+		/* current bit has to be zero for values multiple of 8 bits */
+		return FAILED;
+	}
+	
+	/* make sure enough space is available in buffer */
+	status = this->make_space_available(this,number_of_bits);
+	if (status != SUCCESS)
+	{
+		return status;
+	}
+	/* now handle each u int type differently */
+	switch (int_type)
+	{
+			case U_INT_4:
+			{
+				if (this->current_bit == 0)
+				{
+					/* highval of current byte in buffer has to be set to the new value*/
+					u_int8_t high_val = *((u_int8_t *)(this->data_struct + offset)) << 4;
+					/* lowval in buffer is not changed */
+					u_int8_t low_val = *(this->out_position) & 0x0F;
+					/* highval is set, low_val is not changed */
+					*(this->out_position) = high_val | low_val;
+					this->logger->log(this->logger, RAW|MOST, "   => 0x%x", *(this->out_position));
+					/* write position is not changed, just bit position is moved */
+					this->current_bit = 4;
+				}
+				else if (this->current_bit == 4)
+				{
+					/* highval in buffer is not changed */
+					u_int high_val = *(this->out_position) & 0xF0;
+					/* lowval of current byte in buffer has to be set to the new value*/
+					u_int low_val = *((u_int8_t *)(this->data_struct + offset)) & 0x0F;
+					*(this->out_position) = high_val | low_val;
+					this->logger->log(this->logger, RAW|MOST, "   => 0x%x", *(this->out_position));
+					this->out_position++;
+					this->current_bit = 0;
+
+				}
+				else
+				{
+					this->logger->log(this->logger, ERROR, "U_INT_4 Type is not 4 Bit aligned");
+					/* 4 Bit integers must have a 4 bit alignment */
+					return FAILED;
+				};
+				break;
+			}
+			case U_INT_8:
+			{
+				/* 8 bit values are written as they are */
+				*this->out_position = *((u_int8_t *)(this->data_struct + offset));
+				this->logger->log(this->logger, RAW|MOST, "   => 0x%x", *(this->out_position));
+				this->out_position++;
+				break;
+
+			}
+			case ATTRIBUTE_TYPE:
+			{
+				/* attribute type must not change first bit uf current byte ! */
+				if (this->current_bit != 1)
+				{
+					this->logger->log(this->logger, ERROR, "ATTRIBUTE FORMAT flag is not set");
+					/* first bit has to be set! */
+					return FAILED;
+				}
+				/* get value of attribute format flag */
+				u_int8_t attribute_format_flag = *(this->out_position) & 0x80;
+				/* get attribute type value as 16 bit integer*/
+				u_int16_t int16_val = htons(*((u_int16_t*)(this->data_struct + offset)));
+				/* last bit must be unset */
+				int16_val = int16_val & 0xFF7F;
+				
+				int16_val = int16_val | attribute_format_flag;
+				this->logger->log(this->logger, RAW|MOST, "   => 0x%x", int16_val);
+				/* write bytes to buffer (set bit is overwritten)*/				
+				this->write_bytes_to_buffer(this,&int16_val,sizeof(u_int16_t));
+				this->current_bit = 0;
+				break;
+				
+			}
+			case U_INT_16:
+			{
+				u_int16_t int16_val = htons(*((u_int16_t*)(this->data_struct + offset)));
+				this->logger->log_bytes(this->logger, RAW|MOST, "   =>", (void*)&int16_val, sizeof(int16_val));
+				this->write_bytes_to_buffer(this,&int16_val,sizeof(u_int16_t));
+				break;
+			}
+			case U_INT_32:
+			{
+				u_int32_t int32_val = htonl(*((u_int32_t*)(this->data_struct + offset)));
+				this->logger->log_bytes(this->logger, RAW|MOST, "   =>", (void*)&int32_val, sizeof(int32_val));
+				this->write_bytes_to_buffer(this,&int32_val,sizeof(u_int32_t));
+				break;
+			}
+			case U_INT_64:
+			{
+				/* 64 bit integers are written as two 32 bit integers */
+				u_int32_t int32_val_low = htonl(*((u_int32_t*)(this->data_struct + offset)));
+				u_int32_t int32_val_high = htonl(*((u_int32_t*)(this->data_struct + offset) + 1));
+				this->logger->log_bytes(this->logger, RAW|MOST, "   => (low)", (void*)&int32_val_low, sizeof(int32_val_low));
+				this->logger->log_bytes(this->logger, RAW|MOST, "   => (high)", (void*)&int32_val_high, sizeof(int32_val_high));
+				/* TODO add support for big endian machines */
+				this->write_bytes_to_buffer(this,&int32_val_high,sizeof(u_int32_t));
+				this->write_bytes_to_buffer(this,&int32_val_low,sizeof(u_int32_t));
+				break;
+			}
+			
+			case IKE_SPI:
+			{
+				/* 64 bit are written as they come :-) */
+				this->write_bytes_to_buffer(this,(this->data_struct + offset),sizeof(u_int64_t));
+				this->logger->log_bytes(this->logger, RAW|MOST, "   =>", (void*)(this->data_struct + offset), sizeof(u_int64_t));
+				break;
+			}
+
+			default:
+			this->logger->log(this->logger, ERROR, "U_INT Type %s is not supported", mapping_find(encoding_type_m,int_type));
+			return FAILED;
+	}
+	return SUCCESS;
+}
+
+/**
+ * Implements private_generator_t's generate_reserved_field function.
+ * See #private_generator_s.generate_reserved_field.
+ */
+static status_t generate_reserved_field(private_generator_t *this,int bits)
+{
+	status_t status;
+	
+	/* only one bit or 8 bit fields are supported */
+	if ((bits != 1) && (bits != 8))
+	{
+		this->logger->log(this->logger, ERROR, "Reserved field of %d bits cannot be generated", bits);
+		return FAILED;
+	}
+	/* make sure enough space is available in buffer */
+	status = this->make_space_available(this,bits);
+	if (status != SUCCESS)
+	{
+		return status;
+	}
+	
+	if (bits == 1)
+	{	
+		/* one bit processing */
+		u_int8_t reserved_bit = ~(1 << (7 - this->current_bit));
+		*(this->out_position) = *(this->out_position) & reserved_bit;
+		if (this->current_bit == 0)
+		{
+			/* memory must be zero */
+			*(this->out_position) = 0x00;
+		}
+
+
+		this->current_bit++;
+		if (this->current_bit >= 8)
+		{
+			this->current_bit = this->current_bit % 8;
+			this->out_position++;
+		}
+	}
+	else
+	{
+		/* one byte processing*/
+		if (this->current_bit > 0)
+		{
+			this->logger->log(this->logger, ERROR, 
+								"Reserved field cannot be written cause allignement of current bit is %d",
+								this->current_bit);
+			return FAILED;
+		}
+		*(this->out_position) = 0x00;
+		this->out_position++;
+	}
+
+	return SUCCESS;
+		
+		
+}
+
+/**
+ * Implements private_generator_t's generate_flag function.
+ * See #private_generator_s.generate_flag.
+ */
+static status_t generate_flag (private_generator_t *this,u_int32_t offset)
+{
+	status_t status;
+	/* value of current flag */
+	u_int8_t flag_value;
+	/* position of flag in current byte */
+	u_int8_t flag;
+	
+	/* if the value in the data_struct is TRUE, flag_value is set to 1, 0 otherwise */
+	flag_value = (*((bool *) (this->data_struct + offset))) ? 1 : 0;
+	/* get flag position */
+	flag = (flag_value << (7 - this->current_bit));
+	
+	/* make sure one bit is available in buffer */
+	status = this->make_space_available(this,1);
+	if (status != SUCCESS)
+	{
+		return status;
+	}
+	if (this->current_bit == 0)
+	{
+		/* memory must be zero */
+		*(this->out_position) = 0x00;
+	}
+
+	*(this->out_position) = *(this->out_position) | flag;
+	
+	
+	this->logger->log(this->logger, RAW|MOST, "   => 0x0%x", *(this->out_position));
+
+	this->current_bit++;
+	if (this->current_bit >= 8)
+	{
+		this->current_bit = this->current_bit % 8;
+		this->out_position++;
+	}
+	return SUCCESS;
+}
+
+/**
+ * Implements private_generator_t's generate_from_chunk function.
+ * See #private_generator_s.generate_from_chunk.
+ */
+static status_t generate_from_chunk (private_generator_t *this,u_int32_t offset)
+{
+	if (this->current_bit != 0)
+	{
+		this->logger->log(this->logger, ERROR, "can not generate a chunk at Bitpos %d", this->current_bit);
+		return FAILED;
+	}
+	
+	/* position in buffer */
+	chunk_t *attribute_value = (chunk_t *)(this->data_struct + offset);
+	
+	this->logger->log_chunk(this->logger, RAW|MOST, "   =>", attribute_value);
+	
+	/* use write_bytes_to_buffer function to do the job */
+	return this->write_bytes_to_buffer(this,attribute_value->ptr,attribute_value->len);
+	
+}
+
+/**
+ * Implements private_generator_t's generator_context_make_space_available function.
+ * See #private_generator_s.generator_context_make_space_available.
+ */
+static status_t make_space_available (private_generator_t *this, size_t bits)
+{
+	while (((this->get_current_buffer_space(this) * 8) - this->current_bit) < bits)
+	{
+		/* must increase buffer */
+		u_int8_t *new_buffer;
+		size_t old_buffer_size = this->get_current_buffer_size(this);
+		size_t new_buffer_size = old_buffer_size + GENERATOR_DATA_BUFFER_INCREASE_VALUE;
+		size_t out_position_offset = ((this->out_position) - (this->buffer));
+
+		this->logger->log(this->logger, CONTROL|MOST, "increased gen buffer from %d to %d byte", 
+							old_buffer_size, new_buffer_size);
+		
+		/* Reallocate space for new buffer */
+		new_buffer = allocator_realloc(this->buffer,new_buffer_size);
+		if (new_buffer == NULL)
+		{
+			this->logger->log(this->logger, ERROR, "reallocation of gen buffer failed!!!");
+			return OUT_OF_RES;
+		}
+
+		this->buffer = new_buffer;
+
+		this->out_position = (this->buffer + out_position_offset);
+		this->roof_position = (this->buffer + new_buffer_size);
+	}
+	return SUCCESS;
+}
+
+/**
+ * Implements private_generator_t's write_bytes_to_buffer function.
+ * See #private_generator_s.write_bytes_to_buffer.
+ */
+static status_t write_bytes_to_buffer (private_generator_t *this,void * bytes, size_t number_of_bytes)
+{
+	int i;
+	status_t status;
+	u_int8_t *read_position = (u_int8_t *) bytes;
+	
+	status = this->make_space_available(this,number_of_bytes * 8);
+	if (status != SUCCESS)
+	{
+		return status;
+	}
+
+	for (i = 0; i < number_of_bytes; i++)
+	{
+		*(this->out_position) = *(read_position);
+		read_position++;
+		this->out_position++;
+	}
+	return status;
+}
+
+/**
+ * Implements private_generator_t's write_bytes_to_buffer_at_offset function.
+ * See #private_generator_s.write_bytes_to_buffer_at_offset.
+ */
+static status_t write_bytes_to_buffer_at_offset (private_generator_t *this,void * bytes,size_t number_of_bytes,u_int32_t offset)
+{
+	int i;
+	status_t status;
+	u_int8_t *read_position = (u_int8_t *) bytes;
+	u_int8_t *write_position;
+	u_int32_t free_space_after_offset = (this->get_current_buffer_size(this) - offset);
+
+	/* check first if enough space for new data is available */	
+	if (number_of_bytes > free_space_after_offset)
+	{
+		status = this->make_space_available(this,(number_of_bytes - free_space_after_offset) * 8);
+	}
+	
+	write_position = this->buffer + offset;
+	for (i = 0; i < number_of_bytes; i++)
+	{
+		*(write_position) = *(read_position);
+		read_position++;
+		write_position++;
+	}
+	return SUCCESS;
+}
+
+/**
+ * Implements generator_t's write_chunk function.
+ * See #generator_s.write_chunk.
+ */
+static status_t write_to_chunk (private_generator_t *this,chunk_t *data)
+{
+	size_t data_length = this->get_current_data_length(this);
+	u_int32_t header_length_field = data_length;
+	
+	/* write length into header length field */
+	if (this->header_length_position_offset > 0)
+	{
+		u_int32_t int32_val = htonl(header_length_field);
+		this->write_bytes_to_buffer_at_offset(this,&int32_val,sizeof(u_int32_t),this->header_length_position_offset);
+	}
+
+	if (this->current_bit > 0)
+	data_length++;
+	data->ptr = allocator_alloc(data_length);
+	if (data->ptr == NULL)
+	{
+		data->len = 0;
+		this->logger->log(this->logger, ERROR, "not enougth ressources to allocate chunk");
+		return OUT_OF_RES;
+	}
+	memcpy(data->ptr,this->buffer,data_length);
+	data->len = data_length;
+	
+	this->logger->log_chunk(this->logger, RAW, "generated data of this parser", data);
+	
+	return SUCCESS;
+}
+
+/**
+ * Implements generator_t's generate_payload function.
+ * See #generator_s.generate_payload.
+ */
+static status_t generate_payload (private_generator_t *this,payload_t *payload)
+{
+	int i;
+	status_t status;
+	this->data_struct = payload;
+	size_t rule_count;
+	encoding_rule_t *rules;
+	payload_type_t payload_type;
+	u_int8_t *payload_start;
+	
+	/* get payload type */
+	payload_type = payload->get_type(payload);
+	/* spi size has to get reseted */
+	this->last_spi_size = 0;
+	
+	payload_start = this->out_position;
+	
+	this->logger->log(this->logger, CONTROL, "generating payload of type %s",
+						mapping_find(payload_type_m,payload_type));
+	
+	/* each payload has its own encoding rules */
+	payload->get_encoding_rules(payload,&rules,&rule_count);
+
+	for (i = 0; i < rule_count;i++)
+	{
+		status = SUCCESS;
+		this->logger->log(this->logger, CONTROL|MORE, "  generating rule %d %s",
+							i, mapping_find(encoding_type_m,rules[i].type));
+		switch (rules[i].type)
+		{
+			/* all u int values, IKE_SPI and ATTRIBUTE_TYPE are generated in generate_u_int_type */
+			case U_INT_4:
+			case U_INT_8:
+			case U_INT_16:
+			case U_INT_32:
+			case U_INT_64:
+			case IKE_SPI:
+			case ATTRIBUTE_TYPE:
+			{
+				status = this->generate_u_int_type(this,rules[i].type,rules[i].offset);
+				break;
+			}
+			case RESERVED_BIT:
+			{
+				status = this->generate_reserved_field(this,1);
+				break;
+			}
+			case RESERVED_BYTE:
+			{
+				status = this->generate_reserved_field(this,8);
+				break;
+			} 
+			case FLAG:
+			{
+				status = this->generate_flag(this,rules[i].offset);
+				break;
+			}
+			case PAYLOAD_LENGTH:
+			{
+				/* position of payload lenght field is temporary stored */
+				this->last_payload_length_position_offset = this->get_current_buffer_offset(this);
+				/* payload length is generated like an U_INT_16 */
+				status = this->generate_u_int_type(this,U_INT_16,rules[i].offset);
+				break;
+			}
+			case HEADER_LENGTH:
+			{
+				/* position of header length field is temporary stored */			
+				this->header_length_position_offset = this->get_current_buffer_offset(this);	
+				/* header length is generated like an U_INT_32 */
+				status = this->generate_u_int_type(this,U_INT_32,rules[i].offset);
+				break;
+			}
+			case SPI_SIZE:
+				/* spi size is handled as 8 bit unsigned integer */
+				status = this->generate_u_int_type(this,U_INT_8,rules[i].offset);
+				/* last spi size is temporary stored */
+				this->last_spi_size = *((u_int8_t *)(this->data_struct + rules[i].offset));
+				break;
+			case SPI:
+			{
+				/* the SPI value is generated from chunk */
+				status = this->generate_from_chunk(this,rules[i].offset);
+				break;
+			}
+			case KEY_EXCHANGE_DATA:
+			{
+				/* the Key Exchange Data value is generated from chunk */
+				status = this->generate_from_chunk(this,rules[i].offset);
+				if (status != SUCCESS)
+				{
+					this->logger->log(this->logger, ERROR, "could no write key exchange data from chunk");	
+					return status;
+				}
+				
+				u_int32_t payload_length_position_offset = this->last_payload_length_position_offset;
+				/* Length of KE_PAYLOAD is calculated */
+				u_int16_t length_of_ke_payload = KE_PAYLOAD_HEADER_LENGTH + ((chunk_t *)(this->data_struct + rules[i].offset))->len;
+
+				u_int16_t int16_val = htons(length_of_ke_payload);			
+				status = this->write_bytes_to_buffer_at_offset(this,&int16_val,sizeof(u_int16_t),payload_length_position_offset);
+				if (status != SUCCESS)
+				{
+					this->logger->log(this->logger, ERROR, "could not write payload length into buffer");					
+					return status;
+				}
+				break;
+			}		
+			case NOTIFICATION_DATA:
+			{
+				/* the Notification Data value is generated from chunk */
+				status = this->generate_from_chunk(this,rules[i].offset);
+				if (status != SUCCESS)
+				{
+					this->logger->log(this->logger, ERROR, "Could not generate notification data from chunk");	
+					return status;
+				}
+				
+				u_int32_t payload_length_position_offset = this->last_payload_length_position_offset;
+				/* Length of Notification PAYLOAD is calculated */
+				u_int16_t length_of_notify_payload = NOTIFY_PAYLOAD_HEADER_LENGTH + ((chunk_t *)(this->data_struct + rules[i].offset))->len;
+				length_of_notify_payload += this->last_spi_size;
+				u_int16_t int16_val = htons(length_of_notify_payload);
+
+				status = this->write_bytes_to_buffer_at_offset(this,&int16_val,sizeof(u_int16_t),payload_length_position_offset);
+				if (status != SUCCESS)
+				{
+					this->logger->log(this->logger, ERROR, "could not write payload length into buffer");					
+					return status;
+				}
+				break;
+			}		
+			case NONCE_DATA:
+			{
+				/* the Nonce Data value is generated from chunk */
+				status = this->generate_from_chunk(this, rules[i].offset);
+				
+				if (status != SUCCESS)
+				{
+					this->logger->log(this->logger, ERROR, "could not write nonce data from chunk");	
+					return status;
+				}
+				
+				u_int32_t payload_length_position_offset = this->last_payload_length_position_offset;
+				/* Length of nonce PAYLOAD is calculated */
+				u_int16_t length_of_nonce_payload = NONCE_PAYLOAD_HEADER_LENGTH + ((chunk_t *)(this->data_struct + rules[i].offset))->len;
+				u_int16_t int16_val = htons(length_of_nonce_payload);
+
+				status = this->write_bytes_to_buffer_at_offset(this,&int16_val,sizeof(u_int16_t),payload_length_position_offset);
+				if (status != SUCCESS)
+				{
+					this->logger->log(this->logger, ERROR, "could not write payload length into buffer");					
+					return status;
+				}
+				break;
+			}
+			case PROPOSALS:
+			{
+				/* before iterative generate the transforms, store the current payload length position */
+				u_int32_t payload_length_position_offset = this->last_payload_length_position_offset;
+				/* Length of SA_PAYLOAD is calculated */
+				u_int16_t length_of_sa_payload = SA_PAYLOAD_HEADER_LENGTH;
+				u_int16_t int16_val;
+				/* proposals are stored in a linked list and so accessed */
+				linked_list_t *proposals = *((linked_list_t **)(this->data_struct + rules[i].offset));
+
+				linked_list_iterator_t *iterator;
+				/* create forward iterator */
+				status = proposals->create_iterator(proposals,&iterator,TRUE);
+				if (status != SUCCESS)
+				{
+					this->logger->log(this->logger, ERROR, "could not create iterator for proposals");
+					return status;
+				}
+				/* every proposal is processed (iterative call )*/
+				while (iterator->has_next(iterator))
+				{
+					payload_t *current_proposal;
+					u_int32_t before_generate_position_offset;
+					u_int32_t after_generate_position_offset;
+					
+					status = iterator->current(iterator,(void **)&current_proposal);
+					if (status != SUCCESS)
+					{
+						iterator->destroy(iterator);	
+						return status;
+					}
+					before_generate_position_offset = this->get_current_buffer_offset(this);
+					status = this->public.generate_payload(&(this->public),current_proposal);
+					after_generate_position_offset = this->get_current_buffer_offset(this);
+					if (status != SUCCESS)
+					{
+						iterator->destroy(iterator);	
+						return status;
+					}
+					
+					/* increase size of transform */
+					length_of_sa_payload += (after_generate_position_offset - before_generate_position_offset);
+				}
+				iterator->destroy(iterator);
+				
+				int16_val = htons(length_of_sa_payload);
+				status = this->write_bytes_to_buffer_at_offset(this,&int16_val,sizeof(u_int16_t),payload_length_position_offset);
+				if (status != SUCCESS)
+				{
+					this->logger->log(this->logger, ERROR, "could not write payload length into buffer");					
+					return status;
+				}
+				break;
+			}	
+
+			case TRANSFORMS:
+			{	
+				/* before iterative generate the transforms, store the current length position */
+				u_int32_t payload_length_position_offset = this->last_payload_length_position_offset;
+				u_int16_t length_of_proposal = PROPOSAL_SUBSTRUCTURE_HEADER_LENGTH + this->last_spi_size;
+				u_int16_t int16_val;
+				linked_list_t *transforms = *((linked_list_t **)(this->data_struct + rules[i].offset));
+				linked_list_iterator_t *iterator;
+								
+				/* create forward iterator */
+				status = transforms->create_iterator(transforms,&iterator,TRUE);
+				if (status != SUCCESS)
+				{
+					return status;
+				}
+				while (iterator->has_next(iterator))
+				{
+					payload_t *current_transform;
+					u_int32_t before_generate_position_offset;
+					u_int32_t after_generate_position_offset;
+					
+					status = iterator->current(iterator,(void **)&current_transform);
+					if (status != SUCCESS)
+					{
+						iterator->destroy(iterator);	
+						return status;
+					}
+					
+					before_generate_position_offset = this->get_current_buffer_offset(this);
+					status = this->public.generate_payload(&(this->public),current_transform);
+					after_generate_position_offset = this->get_current_buffer_offset(this);
+					if (status != SUCCESS)
+					{
+						iterator->destroy(iterator);	
+						return status;
+					}
+					
+					/* increase size of transform */
+					length_of_proposal += (after_generate_position_offset - before_generate_position_offset);
+				}
+				
+				iterator->destroy(iterator);
+								
+				int16_val = htons(length_of_proposal);
+				this->write_bytes_to_buffer_at_offset(this,&int16_val,sizeof(u_int16_t),payload_length_position_offset);
+				
+				break;
+			}	
+			case TRANSFORM_ATTRIBUTES:
+			{
+				/* before iterative generate the transform attributes, store the current length position */
+				u_int32_t transform_length_position_offset = this->last_payload_length_position_offset;
+
+				u_int16_t length_of_transform = TRANSFORM_SUBSTRUCTURE_HEADER_LENGTH;
+				u_int16_t int16_val;
+				linked_list_t *transform_attributes =*((linked_list_t **)(this->data_struct + rules[i].offset));
+
+				linked_list_iterator_t *iterator;
+				/* create forward iterator */
+				status = transform_attributes->create_iterator(transform_attributes,&iterator,TRUE);
+				if (status != SUCCESS)
+				{
+					return status;
+				}
+				while (iterator->has_next(iterator))
+				{
+					payload_t *current_attribute;
+					u_int32_t before_generate_position_offset;
+					u_int32_t after_generate_position_offset;
+					
+					status = iterator->current(iterator,(void **)&current_attribute);
+					if (status != SUCCESS)
+					{
+						iterator->destroy(iterator);	
+						return status;
+					}
+					
+					before_generate_position_offset = this->get_current_buffer_offset(this);
+					this->public.generate_payload(&(this->public),current_attribute);
+					after_generate_position_offset = this->get_current_buffer_offset(this);
+					
+					/* increase size of transform */
+					length_of_transform += (after_generate_position_offset - before_generate_position_offset);
+				}
+				
+				iterator->destroy(iterator);
+				
+				int16_val = htons(length_of_transform);
+				this->write_bytes_to_buffer_at_offset(this,&int16_val,sizeof(u_int16_t),transform_length_position_offset);
+				
+				break;
+			}	
+			case ATTRIBUTE_FORMAT:
+			{
+				status = this->generate_flag(this,rules[i].offset);
+				/* Attribute format is a flag which is stored in context*/
+				this->attribute_format = *((bool *) (this->data_struct + rules[i].offset));
+				break;
+			}	
+
+			case ATTRIBUTE_LENGTH_OR_VALUE:
+			{
+				if (this->attribute_format == FALSE)
+				{
+					status = this->generate_u_int_type(this,U_INT_16,rules[i].offset);
+					/* this field hold the length of the attribute */
+					this->attribute_length = *((u_int16_t *)(this->data_struct + rules[i].offset));
+				}
+				else
+				{
+					status = this->generate_u_int_type(this,U_INT_16,rules[i].offset);
+//					status = this->write_bytes_to_buffer(this,(this->data_struct + rules[i].offset),2);
+				}
+				break;
+			}				
+			case ATTRIBUTE_VALUE:
+			{
+				if (this->attribute_format == FALSE)
+				{
+					this->logger->log(this->logger, CONTROL|MOST, "attribute value has not fixed size");
+					/* the attribute value is generated */
+					status = this->generate_from_chunk(this,rules[i].offset);
+				}
+				break;
+			}
+			default:
+				this->logger->log(this->logger, ERROR, "field type %s is not supported",
+									mapping_find(encoding_type_m,rules[i].type));
+				return NOT_SUPPORTED;
+		}
+	}
+	this->logger->log_bytes(this->logger, RAW|MORE, "generated data for this payload",
+							payload_start, this->out_position-payload_start);
+
+	return status;
+}
+
+/**
+ * Implements generator_t's destroy function.
+ * See #generator_s.destroy.
+ */
+static status_t destroy(private_generator_t *this)
+{
+	allocator_free(this->buffer);
+	global_logger_manager->destroy_logger(global_logger_manager,this->logger);
+	allocator_free(this);
+	return SUCCESS;
+}
+
+/*
+ * Described in header
+ */
+generator_t * generator_create()
+{
+	private_generator_t *this;
+
+	this = allocator_alloc_thing(private_generator_t);
+	if (this == NULL)
+	{
+		return NULL;
+	}
+
+	/* initiate public functions */
+	this->public.generate_payload = (status_t(*)(generator_t*, payload_t *)) generate_payload;
+	this->public.destroy = (status_t(*)(generator_t*)) destroy;
+	this->public.write_to_chunk = (status_t (*) (generator_t *,chunk_t *)) write_to_chunk;
+	
+	
+	/* initiate private functions */
+	this->get_current_buffer_size = get_current_buffer_size;
+	this->get_current_buffer_space = get_current_buffer_space;
+	this->get_current_data_length = get_current_data_length;
+	this->get_current_buffer_offset = get_current_buffer_offset;
+	this->generate_u_int_type = generate_u_int_type;
+	this->generate_reserved_field = generate_reserved_field;
+	this->generate_flag = generate_flag;
+	this->generate_from_chunk = generate_from_chunk;
+	this->make_space_available = make_space_available;
+	this->write_bytes_to_buffer = write_bytes_to_buffer;
+	this->write_bytes_to_buffer_at_offset = write_bytes_to_buffer_at_offset;
+
+
+	/* allocate memory for buffer */
+	this->buffer = allocator_alloc(GENERATOR_DATA_BUFFER_SIZE);
+	if (this->buffer == NULL)
+	{
+		allocator_free(this);
+		return NULL;
+	}
+
+	/* initiate private variables */
+	this->out_position = this->buffer;
+	this->roof_position = this->buffer + GENERATOR_DATA_BUFFER_SIZE;
+	this->data_struct = NULL;
+	this->current_bit = 0;
+	this->last_payload_length_position_offset = 0;
+	this->header_length_position_offset = 0;
+	this->logger = global_logger_manager->create_logger(global_logger_manager,GENERATOR,NULL);
+	this->logger->disable_level(this->logger, FULL);
+	this->logger->enable_level(this->logger, CONTROL);
+	
+	if (this->logger == NULL)
+	{
+		allocator_free(this->buffer);
+		allocator_free(this);
+		return NULL;
+	}	
+	return &(this->public);
+}