/** * @file transform_substructure.h * * @brief Implementation of transform_substructure_t. * */ /* * Copyright (C) 2005-2006 Martin Willi * Copyright (C) 2005 Jan Hutter * 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 . * * 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 #include "transform_substructure.h" #include #include #include #include #include typedef struct private_transform_substructure_t private_transform_substructure_t; /** * Private data of an transform_substructure_t object. * */ struct private_transform_substructure_t { /** * Public transform_substructure_t interface. */ transform_substructure_t public; /** * Next payload type. */ u_int8_t next_payload; /** * Length of this payload. */ u_int16_t transform_length; /** * Type of the transform. */ u_int8_t transform_type; /** * Transform ID. */ u_int16_t transform_id; /** * Transforms Attributes are stored in a linked_list_t. */ linked_list_t *attributes; }; /** * Encoding rules to parse or generate a Transform substructure. * * The defined offsets are the positions in a object of type * private_transform_substructure_t. * */ encoding_rule_t transform_substructure_encodings[] = { /* 1 Byte next payload type, stored in the field next_payload */ { U_INT_8, offsetof(private_transform_substructure_t, next_payload) }, /* Reserved Byte is skipped */ { RESERVED_BYTE, 0 }, /* Length of the whole transform substructure*/ { PAYLOAD_LENGTH, offsetof(private_transform_substructure_t, transform_length) }, /* transform type is a number of 8 bit */ { U_INT_8, offsetof(private_transform_substructure_t, transform_type) }, /* Reserved Byte is skipped */ { RESERVED_BYTE, 0 }, /* tranform ID is a number of 8 bit */ { U_INT_16, offsetof(private_transform_substructure_t, transform_id) }, /* Attributes are stored in a transform attribute, offset points to a linked_list_t pointer */ { TRANSFORM_ATTRIBUTES, offsetof(private_transform_substructure_t, attributes) } }; /* 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ! 0 (last) or 3 ! RESERVED ! Transform Length ! +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ !Transform Type ! RESERVED ! Transform ID ! +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ! ! ~ Transform Attributes ~ ! ! +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */ /** * Implementation of payload_t.verify. */ static status_t verify(private_transform_substructure_t *this) { status_t status = SUCCESS; iterator_t *iterator; payload_t *current_attributes; if ((this->next_payload != NO_PAYLOAD) && (this->next_payload != 3)) { /* must be 0 or 3 */ DBG1(DBG_ENC, "inconsistent next payload"); return FAILED; } switch (this->transform_type) { case ENCRYPTION_ALGORITHM: case PSEUDO_RANDOM_FUNCTION: case INTEGRITY_ALGORITHM: case DIFFIE_HELLMAN_GROUP: case EXTENDED_SEQUENCE_NUMBERS: /* we don't check transform ID, we want to reply * cleanly with NO_PROPOSAL_CHOSEN or so if we don't support it */ break; default: { DBG1(DBG_ENC, "invalid transform type: %d", this->transform_type); return FAILED; } } iterator = this->attributes->create_iterator(this->attributes,TRUE); while(iterator->iterate(iterator, (void**)¤t_attributes)) { status = current_attributes->verify(current_attributes); if (status != SUCCESS) { DBG1(DBG_ENC, "TRANSFORM_ATTRIBUTE verification failed"); } } iterator->destroy(iterator); /* proposal number is checked in SA payload */ return status; } /** * Implementation of payload_t.get_encoding_rules. */ static void get_encoding_rules(private_transform_substructure_t *this, encoding_rule_t **rules, size_t *rule_count) { *rules = transform_substructure_encodings; *rule_count = sizeof(transform_substructure_encodings) / sizeof(encoding_rule_t); } /** * Implementation of payload_t.get_type. */ static payload_type_t get_type(private_transform_substructure_t *this) { return TRANSFORM_SUBSTRUCTURE; } /** * Implementation of payload_t.get_next_type. */ static payload_type_t get_next_type(private_transform_substructure_t *this) { return (this->next_payload); } /** * recompute the length of the payload. */ static void compute_length (private_transform_substructure_t *this) { iterator_t *iterator; payload_t *current_attribute; size_t length = TRANSFORM_SUBSTRUCTURE_HEADER_LENGTH; iterator = this->attributes->create_iterator(this->attributes,TRUE); while (iterator->iterate(iterator, (void**)¤t_attribute)) { length += current_attribute->get_length(current_attribute); } iterator->destroy(iterator); this->transform_length = length; } /** * Implementation of payload_t.get_length. */ static size_t get_length(private_transform_substructure_t *this) { compute_length(this); return this->transform_length; } /** * Implementation of transform_substructure_t.create_transform_attribute_iterator. */ static iterator_t *create_transform_attribute_iterator (private_transform_substructure_t *this,bool forward) { return this->attributes->create_iterator(this->attributes,forward); } /** * Implementation of transform_substructure_t.add_transform_attribute. */ static void add_transform_attribute (private_transform_substructure_t *this,transform_attribute_t *attribute) { this->attributes->insert_last(this->attributes,(void *) attribute); compute_length(this); } /** * Implementation of transform_substructure_t.set_is_last_transform. */ static void set_is_last_transform (private_transform_substructure_t *this, bool is_last) { this->next_payload = (is_last) ? 0: TRANSFORM_TYPE_VALUE; } /** * Implementation of transform_substructure_t.get_is_last_transform. */ static bool get_is_last_transform (private_transform_substructure_t *this) { return ((this->next_payload == TRANSFORM_TYPE_VALUE) ? FALSE : TRUE); } /** * Implementation of payload_t.set_next_type. */ static void set_next_type(private_transform_substructure_t *this,payload_type_t type) { } /** * Implementation of transform_substructure_t.set_transform_type. */ static void set_transform_type (private_transform_substructure_t *this,u_int8_t type) { this->transform_type = type; } /** * Implementation of transform_substructure_t.get_transform_type. */ static u_int8_t get_transform_type (private_transform_substructure_t *this) { return this->transform_type; } /** * Implementation of transform_substructure_t.set_transform_id. */ static void set_transform_id (private_transform_substructure_t *this,u_int16_t id) { this->transform_id = id; } /** * Implementation of transform_substructure_t.get_transform_id. */ static u_int16_t get_transform_id (private_transform_substructure_t *this) { return this->transform_id; } /** * Implementation of transform_substructure_t.clone. */ static transform_substructure_t *clone_(private_transform_substructure_t *this) { private_transform_substructure_t *clone; iterator_t *attributes; transform_attribute_t *current_attribute; clone = (private_transform_substructure_t *) transform_substructure_create(); clone->next_payload = this->next_payload; clone->transform_type = this->transform_type; clone->transform_id = this->transform_id; attributes = this->attributes->create_iterator(this->attributes, FALSE); while (attributes->iterate(attributes, (void**)¤t_attribute)) { current_attribute = current_attribute->clone(current_attribute); clone->public.add_transform_attribute(&clone->public, current_attribute); } attributes->destroy(attributes); return &clone->public; } /** * Implementation of transform_substructure_t.get_key_length. */ static status_t get_key_length(private_transform_substructure_t *this, u_int16_t *key_length) { iterator_t *attributes; transform_attribute_t *current_attribute; attributes = this->attributes->create_iterator(this->attributes, TRUE); while (attributes->iterate(attributes, (void**)¤t_attribute)) { if (current_attribute->get_attribute_type(current_attribute) == KEY_LENGTH) { *key_length = current_attribute->get_value(current_attribute); attributes->destroy(attributes); return SUCCESS; } } attributes->destroy(attributes); return FAILED; } /** * Implementation of transform_substructure_t.destroy and payload_t.destroy. */ static void destroy(private_transform_substructure_t *this) { this->attributes->destroy_offset(this->attributes, offsetof(transform_attribute_t, destroy)); free(this); } /* * Described in header. */ transform_substructure_t *transform_substructure_create() { private_transform_substructure_t *this = malloc_thing(private_transform_substructure_t); /* payload interface */ this->public.payload_interface.verify = (status_t (*) (payload_t *))verify; this->public.payload_interface.get_encoding_rules = (void (*) (payload_t *, encoding_rule_t **, size_t *) ) get_encoding_rules; this->public.payload_interface.get_length = (size_t (*) (payload_t *)) get_length; this->public.payload_interface.get_next_type = (payload_type_t (*) (payload_t *)) get_next_type; this->public.payload_interface.set_next_type = (void (*) (payload_t *,payload_type_t)) set_next_type; this->public.payload_interface.get_type = (payload_type_t (*) (payload_t *)) get_type; this->public.payload_interface.destroy = (void (*) (payload_t *))destroy; /* public functions */ this->public.create_transform_attribute_iterator = (iterator_t * (*) (transform_substructure_t *,bool)) create_transform_attribute_iterator; this->public.add_transform_attribute = (void (*) (transform_substructure_t *,transform_attribute_t *)) add_transform_attribute; this->public.set_is_last_transform = (void (*) (transform_substructure_t *,bool)) set_is_last_transform; this->public.get_is_last_transform = (bool (*) (transform_substructure_t *)) get_is_last_transform; this->public.set_transform_type = (void (*) (transform_substructure_t *,u_int8_t)) set_transform_type; this->public.get_transform_type = (u_int8_t (*) (transform_substructure_t *)) get_transform_type; this->public.set_transform_id = (void (*) (transform_substructure_t *,u_int16_t)) set_transform_id; this->public.get_transform_id = (u_int16_t (*) (transform_substructure_t *)) get_transform_id; this->public.get_key_length = (status_t (*) (transform_substructure_t *,u_int16_t *)) get_key_length; this->public.clone = (transform_substructure_t* (*) (transform_substructure_t *)) clone_; this->public.destroy = (void (*) (transform_substructure_t *)) destroy; /* set default values of the fields */ this->next_payload = NO_PAYLOAD; this->transform_length = TRANSFORM_SUBSTRUCTURE_HEADER_LENGTH; this->transform_id = 0; this->transform_type = 0; this->attributes = linked_list_create(); return (&(this->public)); } /* * Described in header */ transform_substructure_t *transform_substructure_create_type(transform_type_t transform_type, u_int16_t transform_id, u_int16_t key_length) { transform_substructure_t *transform = transform_substructure_create(); transform->set_transform_type(transform,transform_type); transform->set_transform_id(transform,transform_id); /* a keylength attribute is only created for variable length algos */ if (transform_type == ENCRYPTION_ALGORITHM && (transform_id == ENCR_AES_CBC || transform_id == ENCR_IDEA || transform_id == ENCR_CAST || transform_id == ENCR_BLOWFISH)) { transform_attribute_t *attribute = transform_attribute_create_key_length(key_length); transform->add_transform_attribute(transform,attribute); } return transform; }