/** * @file eap_payload.c * * @brief Implementation of eap_payload_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 "eap_payload.h" #include typedef struct private_eap_payload_t private_eap_payload_t; /** * Private data of an eap_payload_t object. * */ struct private_eap_payload_t { /** * Public eap_payload_t interface. */ eap_payload_t public; /** * Next payload type. */ u_int8_t next_payload; /** * Critical flag. */ bool critical; /** * Length of this payload. */ u_int16_t payload_length; /** * EAP message data, if available */ chunk_t data; }; /** * Encoding rules to parse or generate a EAP payload. * * The defined offsets are the positions in a object of type * private_eap_payload_t. * */ encoding_rule_t eap_payload_encodings[] = { /* 1 Byte next payload type, stored in the field next_payload */ { U_INT_8, offsetof(private_eap_payload_t, next_payload) }, /* the critical bit */ { FLAG, offsetof(private_eap_payload_t, critical) }, /* 7 Bit reserved bits, nowhere stored */ { RESERVED_BIT, 0 }, { RESERVED_BIT, 0 }, { RESERVED_BIT, 0 }, { RESERVED_BIT, 0 }, { RESERVED_BIT, 0 }, { RESERVED_BIT, 0 }, { RESERVED_BIT, 0 }, /* Length of the whole payload*/ { PAYLOAD_LENGTH, offsetof(private_eap_payload_t, payload_length) }, /* chunt to data, starting at "code" */ { EAP_DATA, offsetof(private_eap_payload_t, data) }, }; /* 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ! Next Payload !C! RESERVED ! Payload Length ! +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ! Code ! Identifier ! Length ! +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ ! Type ! Type_Data... +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- */ /** * Implementation of payload_t.verify. */ static status_t verify(private_eap_payload_t *this) { u_int16_t length; u_int8_t code; if (this->data.len < 4) { DBG1(DBG_ENC, "EAP payloads EAP message too short (%d)", this->data.len); return FAILED; } code = *this->data.ptr; length = htons(*(u_int16_t*)(this->data.ptr + 2)); if (this->data.len != length) { DBG1(DBG_ENC, "EAP payload length (%d) does not match contained message length (%d)", this->data.len, length); return FAILED; } switch (code) { case EAP_REQUEST: case EAP_RESPONSE: { if (this->data.len < 4) { DBG1(DBG_ENC, "EAP Request/Response does not have any data"); return FAILED; } break; } case EAP_SUCCESS: case EAP_FAILURE: { if (this->data.len != 4) { DBG1(DBG_ENC, "EAP Success/Failure has data"); return FAILED; } break; } default: return FAILED; } return SUCCESS; } /** * Implementation of eap_payload_t.get_encoding_rules. */ static void get_encoding_rules(private_eap_payload_t *this, encoding_rule_t **rules, size_t *rule_count) { *rules = eap_payload_encodings; *rule_count = sizeof(eap_payload_encodings) / sizeof(encoding_rule_t); } /** * Implementation of payload_t.get_type. */ static payload_type_t get_payload_type(private_eap_payload_t *this) { return EXTENSIBLE_AUTHENTICATION; } /** * Implementation of payload_t.get_next_type. */ static payload_type_t get_next_type(private_eap_payload_t *this) { return (this->next_payload); } /** * Implementation of payload_t.set_next_type. */ static void set_next_type(private_eap_payload_t *this,payload_type_t type) { this->next_payload = type; } /** * Implementation of payload_t.get_length. */ static size_t get_length(private_eap_payload_t *this) { return this->payload_length; } /** * Implementation of eap_payload_t.get_data. */ static chunk_t get_data(private_eap_payload_t *this) { return this->data; } /** * Implementation of eap_payload_t.set_data. */ static void set_data(private_eap_payload_t *this, chunk_t data) { chunk_free(&this->data); this->data = chunk_clone(data); this->payload_length = this->data.len + 4; } /** * Implementation of eap_payload_t.get_code. */ static eap_code_t get_code(private_eap_payload_t *this) { if (this->data.len > 0) { return *this->data.ptr; } /* should not happen, as it is verified */ return 0; } /** * Implementation of eap_payload_t.get_identifier. */ static u_int8_t get_identifier(private_eap_payload_t *this) { if (this->data.len > 1) { return *(this->data.ptr + 1); } /* should not happen, as it is verified */ return 0; } /** * Implementation of eap_payload_t.get_type. */ static eap_type_t get_type(private_eap_payload_t *this, u_int32_t *vendor) { eap_type_t type; *vendor = 0; if (this->data.len > 4) { type = *(this->data.ptr + 4); if (type != EAP_EXPANDED) { return type; } if (this->data.len >= 12) { *vendor = ntohl(*(u_int32_t*)(this->data.ptr + 4)) & 0x00FFFFFF; return ntohl(*(u_int32_t*)(this->data.ptr + 8)); } } return 0; } /** * Implementation of payload_t.destroy and eap_payload_t.destroy. */ static void destroy(private_eap_payload_t *this) { chunk_free(&this->data); free(this); } /* * Described in header */ eap_payload_t *eap_payload_create() { private_eap_payload_t *this = malloc_thing(private_eap_payload_t); /* interface functions */ 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_payload_type; this->public.payload_interface.destroy = (void (*) (payload_t *))destroy; /* public functions */ this->public.destroy = (void (*) (eap_payload_t *)) destroy; this->public.get_data = (chunk_t (*) (eap_payload_t*))get_data; this->public.set_data = (void (*) (eap_payload_t *,chunk_t))set_data; this->public.get_code = (eap_code_t (*) (eap_payload_t*))get_code; this->public.get_identifier = (u_int8_t (*) (eap_payload_t*))get_identifier; this->public.get_type = (eap_type_t (*) (eap_payload_t*,u_int32_t*))get_type; /* private variables */ this->critical = FALSE; this->next_payload = NO_PAYLOAD; this->payload_length = EAP_PAYLOAD_HEADER_LENGTH; this->data = chunk_empty; return &(this->public); } /* * Described in header */ eap_payload_t *eap_payload_create_data(chunk_t data) { eap_payload_t *this = eap_payload_create(); this->set_data(this, data); return this; } /* * Described in header */ eap_payload_t *eap_payload_create_code(eap_code_t code, u_int8_t identifier) { eap_payload_t *this = eap_payload_create(); chunk_t data = chunk_alloca(4); *(data.ptr + 0) = code; *(data.ptr + 1) = identifier; *(u_int16_t*)(data.ptr + 2) = htons(data.len); this->set_data(this, data); return this; } /* * Described in header */ eap_payload_t *eap_payload_create_nak(u_int8_t identifier) { eap_payload_t *this = eap_payload_create(); chunk_t data = chunk_alloca(5); *(data.ptr + 0) = EAP_RESPONSE; *(data.ptr + 1) = identifier; *(u_int16_t*)(data.ptr + 2) = htons(data.len); *(data.ptr + 4) = EAP_NAK; this->set_data(this, data); return this; }