/* * Copyright (C) 2005-2010 Martin Willi * Copyright (C) 2010 revosec AG * 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; /** * Reserved bytes */ u_int8_t reserved[2]; /** * 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) }, /* 1 Reserved Byte */ { RESERVED_BYTE, offsetof(private_transform_substructure_t, reserved[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) }, /* 1 Reserved Byte */ { RESERVED_BYTE, offsetof(private_transform_substructure_t, reserved[1]) }, /* 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 ~ ! ! +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ */ METHOD(payload_t, verify, status_t, private_transform_substructure_t *this) { status_t status = SUCCESS; enumerator_t *enumerator; payload_t *attribute; if (this->next_payload != NO_PAYLOAD && this->next_payload != 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; } } enumerator = this->attributes->create_enumerator(this->attributes); while (enumerator->enumerate(enumerator, &attribute)) { status = attribute->verify(attribute); if (status != SUCCESS) { DBG1(DBG_ENC, "TRANSFORM_ATTRIBUTE verification failed"); break; } } enumerator->destroy(enumerator); /* proposal number is checked in SA payload */ return status; } METHOD(payload_t, get_encoding_rules, void, private_transform_substructure_t *this, encoding_rule_t **rules, size_t *rule_count) { *rules = transform_substructure_encodings; *rule_count = countof(transform_substructure_encodings); } METHOD(payload_t, get_type, payload_type_t, private_transform_substructure_t *this) { return TRANSFORM_SUBSTRUCTURE; } METHOD(payload_t, get_next_type, payload_type_t, private_transform_substructure_t *this) { return this->next_payload; } /** * recompute the length of the payload. */ static void compute_length (private_transform_substructure_t *this) { enumerator_t *enumerator; payload_t *attribute; this->transform_length = TRANSFORM_SUBSTRUCTURE_HEADER_LENGTH; enumerator = this->attributes->create_enumerator(this->attributes); while (enumerator->enumerate(enumerator, &attribute)) { this->transform_length += attribute->get_length(attribute); } enumerator->destroy(enumerator); } METHOD(payload_t, get_length, size_t, private_transform_substructure_t *this) { return this->transform_length; } METHOD(transform_substructure_t, set_is_last_transform, void, private_transform_substructure_t *this, bool is_last) { this->next_payload = is_last ? 0: TRANSFORM_TYPE_VALUE; } METHOD(payload_t, set_next_type, void, private_transform_substructure_t *this,payload_type_t type) { } METHOD(transform_substructure_t, get_transform_type, u_int8_t, private_transform_substructure_t *this) { return this->transform_type; } METHOD(transform_substructure_t, get_transform_id, u_int16_t, private_transform_substructure_t *this) { return this->transform_id; } METHOD(transform_substructure_t, get_key_length, status_t, private_transform_substructure_t *this, u_int16_t *key_length) { enumerator_t *enumerator; transform_attribute_t *attribute; enumerator = this->attributes->create_enumerator(this->attributes); while (enumerator->enumerate(enumerator, &attribute)) { if (attribute->get_attribute_type(attribute) == KEY_LENGTH) { *key_length = attribute->get_value(attribute); enumerator->destroy(enumerator); return SUCCESS; } } enumerator->destroy(enumerator); return FAILED; } METHOD2(payload_t, transform_substructure_t, destroy, void, 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; INIT(this, .public = { .payload_interface = { .verify = _verify, .get_encoding_rules = _get_encoding_rules, .get_length = _get_length, .get_next_type = _get_next_type, .set_next_type = _set_next_type, .get_type = _get_type, .destroy = _destroy, }, .set_is_last_transform = _set_is_last_transform, .get_transform_type = _get_transform_type, .get_transform_id = _get_transform_id, .get_key_length = _get_key_length, .destroy = _destroy, }, .next_payload = NO_PAYLOAD, .transform_length = TRANSFORM_SUBSTRUCTURE_HEADER_LENGTH, .attributes = linked_list_create(), ); return &this->public; } /* * Described in header */ transform_substructure_t *transform_substructure_create_type( transform_type_t type, u_int16_t id, u_int16_t key_length) { private_transform_substructure_t *this; this = (private_transform_substructure_t*)transform_substructure_create(); this->transform_type = type; this->transform_id = id; if (key_length) { this->attributes->insert_last(this->attributes, (void*)transform_attribute_create_key_length(key_length)); compute_length(this); } return &this->public; }