1150 lines
27 KiB
C
1150 lines
27 KiB
C
/*
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* Copyright (C) 2007 Martin Willi
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* Hochschule fuer Technik Rapperswil
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2 of the License, or (at your
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* option) any later version. See <http://www.fsf.org/copyleft/gpl.txt>.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* for more details.
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*
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* $Id$
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*/
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#include "eap_sim.h"
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#include <dlfcn.h>
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#include <daemon.h>
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#include <library.h>
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#define MAX_TRIES 3
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/* number of triplets for one authentication */
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#define TRIPLET_COUNT 3
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typedef enum sim_subtype_t sim_subtype_t;
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/**
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* Subtypes of SIM messages
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*/
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enum sim_subtype_t {
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SIM_START = 10,
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SIM_CHALLENGE = 11,
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SIM_NOTIFICATION = 12,
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SIM_CLIENT_ERROR = 14,
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};
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ENUM(sim_subtype_names, SIM_START, SIM_CLIENT_ERROR,
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"SIM_START",
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"SIM_CHALLENGE",
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"SIM_NOTIFICATION",
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"SIM_13",
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"SIM_CLIENT_ERROR",
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);
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typedef enum sim_attribute_t sim_attribute_t;
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/**
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* Attributes in SIM messages
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*/
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enum sim_attribute_t {
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/** defines the end of attribute list */
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AT_END = -1,
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AT_RAND = 1,
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AT_AUTN = 2,
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AT_RES = 3,
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AT_AUTS = 4,
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AT_PADDING = 6,
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AT_NONCE_MT = 7,
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AT_PERMANENT_ID_REQ = 10,
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AT_MAC = 11,
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AT_NOTIFICATION = 12,
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AT_ANY_ID_REQ = 13,
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AT_IDENTITY = 14,
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AT_VERSION_LIST = 15,
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AT_SELECTED_VERSION = 16,
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AT_FULLAUTH_ID_REQ = 17,
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AT_COUNTER = 19,
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AT_COUNTER_TOO_SMALL = 20,
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AT_NONCE_S = 21,
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AT_CLIENT_ERROR_CODE = 22,
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AT_IV = 129,
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AT_ENCR_DATA = 130,
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AT_NEXT_PSEUDONYM = 132,
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AT_NEXT_REAUTH_ID = 133,
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AT_CHECKCODE = 134,
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AT_RESULT_IND = 135,
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};
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ENUM_BEGIN(sim_attribute_names, AT_END, AT_CLIENT_ERROR_CODE,
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"AT_END",
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"AT_0",
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"AT_RAND",
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"AT_AUTN",
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"AT_RES",
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"AT_AUTS",
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"AT_5",
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"AT_PADDING",
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"AT_NONCE_MT",
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"AT_8",
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"AT_9",
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"AT_PERMANENT_ID_REQ",
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"AT_MAC",
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"AT_NOTIFICATION",
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"AT_ANY_ID_REQ",
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"AT_IDENTITY",
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"AT_VERSION_LIST",
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"AT_SELECTED_VERSION",
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"AT_FULLAUTH_ID_REQ",
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"AT_18",
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"AT_COUNTER",
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"AT_COUNTER_TOO_SMALL",
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"AT_NONCE_S",
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"AT_CLIENT_ERROR_CODE");
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ENUM_NEXT(sim_attribute_names, AT_IV, AT_RESULT_IND, AT_CLIENT_ERROR_CODE,
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"AT_IV",
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"AT_ENCR_DATA",
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"AT_131",
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"AT_NEXT_PSEUDONYM",
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"AT_NEXT_REAUTH_ID",
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"AT_CHECKCODE",
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"AT_RESULT_IND");
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ENUM_END(sim_attribute_names, AT_RESULT_IND);
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typedef struct private_eap_sim_t private_eap_sim_t;
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/**
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* Private data of an eap_sim_t object.
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*/
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struct private_eap_sim_t {
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/**
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* Public authenticator_t interface.
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*/
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eap_sim_t public;
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/**
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* ID of ourself
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*/
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identification_t *peer;
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/**
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* hashing function
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*/
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hasher_t *hasher;
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/**
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* prf
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*/
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prf_t *prf;
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/**
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* MAC function
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*/
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signer_t *signer;
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/**
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* SIM cardreader function loaded from library
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*/
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sim_algo_t alg;
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/**
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* libraries get_triplet() function returning a triplet
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*/
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sim_get_triplet_t get_triplet;
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/**
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* handle of the loaded library
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*/
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void *handle;
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/**
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* how many times we try to authenticate
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*/
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int tries;
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/**
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* unique EAP identifier
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*/
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u_int8_t identifier;
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/**
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* EAP message type this role sends
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*/
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u_int8_t type;
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/**
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* version this implementation uses
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*/
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chunk_t version;
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/**
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* version list received from server
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*/
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chunk_t version_list;
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/**
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* Nonce value used in AT_NONCE_MT
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*/
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chunk_t nonce;
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/**
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* concatenated SRES values
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*/
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chunk_t sreses;
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/**
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* k_encr key derived from MK
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*/
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chunk_t k_encr;
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/**
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* k_auth key derived from MK, used for AT_MAC verification
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*/
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chunk_t k_auth;
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/**
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* MSK, used for EAP-SIM based IKEv2 authentication
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*/
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chunk_t msk;
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/**
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* EMSK, extendes MSK for further uses
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*/
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chunk_t emsk;
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};
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/** length of the AT_NONCE_MT nonce value */
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#define NONCE_LEN 16
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/** length of the AT_MAC value */
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#define MAC_LEN 16
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/** length of the AT_RAND value */
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#define RAND_LEN 16
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/** length of Kc */
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#define KC_LEN 8
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/** length of SRES */
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#define SRES_LEN 4
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/** length of the k_encr key */
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#define KENCR_LEN 16
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/** length of the k_auth key */
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#define KAUTH_LEN 16
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/** length of the MSK */
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#define MSK_LEN 64
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/** length of the EMSK */
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#define EMSK_LEN 64
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static char version[] = {0x00,0x01};
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/* client error codes used in AT_CLIENT_ERROR_CODE */
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char client_error_general_buf[] = {0x00, 0x01};
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char client_error_unsupported_buf[] = {0x00, 0x02};
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char client_error_insufficient_buf[] = {0x00, 0x03};
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char client_error_notfresh_buf[] = {0x00, 0x04};
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chunk_t client_error_general = chunk_from_buf(client_error_general_buf);
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chunk_t client_error_unsupported = chunk_from_buf(client_error_unsupported_buf);
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chunk_t client_error_insufficient = chunk_from_buf(client_error_insufficient_buf);
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chunk_t client_error_notfresh = chunk_from_buf(client_error_notfresh_buf);
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/**
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* Read EAP and EAP-SIM header, return SIM type
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*/
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static sim_subtype_t read_header(chunk_t *message)
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{
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sim_subtype_t type;
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if (message->len < 8)
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{
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*message = chunk_empty;
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return 0;
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}
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type = *(message->ptr + 5);
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*message = chunk_skip(*message, 8);
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return type;
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}
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/**
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* read the next attribute from the chunk data
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*/
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static sim_attribute_t read_attribute(chunk_t *message, chunk_t *data)
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{
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sim_attribute_t attribute;
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size_t length;
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DBG3(DBG_IKE, "reading attribute from %B", message);
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if (message->len < 2)
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{
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return AT_END;
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}
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attribute = *message->ptr++;
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length = *message->ptr++ * 4 - 2;
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message->len -= 2;
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DBG3(DBG_IKE, "found attribute %N with length %d",
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sim_attribute_names, attribute, length);
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if (length > message->len)
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{
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return AT_END;
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}
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data->len = length;
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data->ptr = message->ptr;
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*message = chunk_skip(*message, length);
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return attribute;
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}
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/**
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* Build an EAP-SIM payload using a variable length attribute list.
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* The variable argument takes a sim_attribute_t followed by its data in a chunk.
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*/
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static eap_payload_t *build_payload(private_eap_sim_t *this, u_int8_t identifier,
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sim_subtype_t type, ...)
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{
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chunk_t message = chunk_alloca(512);
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chunk_t pos = message;
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eap_payload_t *payload;
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va_list args;
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sim_attribute_t attr;
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u_int8_t *mac_pos = NULL;
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chunk_t mac_data = chunk_empty;
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/* write EAP header, skip length bytes */
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*pos.ptr++ = this->type;
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*pos.ptr++ = identifier;
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pos.ptr += 2;
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pos.len -= 4;
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/* write SIM header with type and subtype, zero reserved bytes */
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*pos.ptr++ = EAP_SIM;
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*pos.ptr++ = type;
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*pos.ptr++ = 0;
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*pos.ptr++ = 0;
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pos.len -= 4;
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va_start(args, type);
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while ((attr = va_arg(args, sim_attribute_t)) != AT_END)
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{
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chunk_t data = va_arg(args, chunk_t);
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DBG3(DBG_IKE, "building %N %B", sim_attribute_names, attr, &data);
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/* write attribute header */
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*pos.ptr++ = attr;
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pos.len--;
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switch (attr)
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{
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case AT_CLIENT_ERROR_CODE:
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case AT_SELECTED_VERSION:
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{
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*pos.ptr = data.len/4 + 1;
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pos = chunk_skip(pos, 1);
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memcpy(pos.ptr, data.ptr, data.len);
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pos = chunk_skip(pos, data.len);
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break;
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}
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case AT_IDENTITY:
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case AT_VERSION_LIST:
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{
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u_int16_t act_len = data.len;
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/* align up to four byte */
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if (data.len % 4)
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{
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chunk_t tmp = chunk_alloca((data.len/4)*4 + 4);
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memset(tmp.ptr, 0, tmp.len);
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memcpy(tmp.ptr, data.ptr, data.len);
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data = tmp;
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}
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*pos.ptr = data.len/4 + 1;
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pos = chunk_skip(pos, 1);
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/* actual length in bytes */
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*(u_int16_t*)pos.ptr = htons(act_len);
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pos = chunk_skip(pos, sizeof(u_int16_t));
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memcpy(pos.ptr, data.ptr, data.len);
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pos = chunk_skip(pos, data.len);
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break;
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}
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case AT_NONCE_MT:
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{
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*pos.ptr = data.len/4 + 1;
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pos = chunk_skip(pos, 1);
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memset(pos.ptr, 0, 2);
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pos = chunk_skip(pos, 2);
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memcpy(pos.ptr, data.ptr, data.len);
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pos = chunk_skip(pos, data.len);
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break;
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}
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case AT_MAC:
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{
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*pos.ptr++ = 5; pos.len--;
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*pos.ptr++ = 0; pos.len--;
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*pos.ptr++ = 0; pos.len--;
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mac_pos = pos.ptr;
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memset(mac_pos, 0, MAC_LEN);
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pos = chunk_skip(pos, MAC_LEN);
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mac_data = data;
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break;
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}
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case AT_RAND:
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{
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*pos.ptr++ = data.len/4 + 1; pos.len--;
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*pos.ptr++ = 0; pos.len--;
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*pos.ptr++ = 0; pos.len--;
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memcpy(pos.ptr, data.ptr, data.len);
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pos = chunk_skip(pos, data.len);
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break;
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}
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default:
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DBG1(DBG_IKE, "no rule to build EAP_SIM attribute %N, skipped",
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sim_attribute_names, attr);
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break;
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}
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}
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va_end(args);
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/* calculate message length, write into header */
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message.len = pos.ptr - message.ptr;
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*(u_int16_t*)(message.ptr + 2) = htons(message.len);
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/* create MAC if AT_MAC attribte was included. Append supplied va_arg
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* chunk mac_data to "to-sign" chunk */
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if (mac_pos)
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{
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this->signer->set_key(this->signer, this->k_auth);
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mac_data = chunk_cata("cc", message, mac_data);
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this->signer->get_signature(this->signer, mac_data, mac_pos);
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DBG3(DBG_IKE, "AT_MAC signature of %B\n is %b",
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&mac_data, mac_pos, MAC_LEN);
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}
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payload = eap_payload_create_data(message);
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DBG3(DBG_IKE, "created EAP message %B", &message);
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return payload;
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}
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/**
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* process an EAP-SIM/Request/Start message
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*/
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static status_t peer_process_start(private_eap_sim_t *this, eap_payload_t *in,
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eap_payload_t **out)
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{
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chunk_t message, data;
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sim_attribute_t attribute, include_id = AT_END;
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u_int8_t identifier;
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identifier = in->get_identifier(in);
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message = in->get_data(in);
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read_header(&message);
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while ((attribute = read_attribute(&message, &data)) != AT_END)
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{
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switch (attribute)
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{
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case AT_VERSION_LIST:
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{
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/* check if server supports our implementation */
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bool found = FALSE;
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if (data.len > 2)
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{
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/* read actual length first */
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data.len = min(data.len, ntohs(*(u_int16_t*)data.ptr) + 2);
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data = chunk_skip(data, 2);
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chunk_free(&this->version_list);
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this->version_list = chunk_clone(data);
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while (data.len >= this->version.len)
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{
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if (memeq(data.ptr, this->version.ptr, this->version.len))
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{
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found = TRUE;
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break;
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}
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data = chunk_skip(data, this->version.len);
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}
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}
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if (!found)
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{
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DBG1(DBG_IKE, "server does not support EAP_SIM "
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"version number %#B", &this->version);
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*out = build_payload(this, identifier, SIM_CLIENT_ERROR,
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AT_CLIENT_ERROR_CODE, client_error_unsupported,
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AT_END);
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return NEED_MORE;
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}
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break;
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}
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case AT_PERMANENT_ID_REQ:
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case AT_FULLAUTH_ID_REQ:
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case AT_ANY_ID_REQ:
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/* only include AT_IDENTITY if requested */
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include_id = AT_IDENTITY;
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break;
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case AT_NOTIFICATION:
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{
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u_int16_t code = 0;
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if (data.len == 2)
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{
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code = ntohs(*(u_int16_t*)data.ptr);
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}
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if (code <= 32767) /* no success bit */
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{
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DBG1(DBG_IKE, "received %N error %d",
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sim_attribute_names, attribute, code);
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*out = build_payload(this,
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in->get_identifier(in), SIM_CLIENT_ERROR,
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AT_CLIENT_ERROR_CODE, client_error_general,
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AT_END);
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return NEED_MORE;
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}
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else
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{
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DBG1(DBG_IKE, "received %N code %d",
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sim_attribute_names, attribute, code);
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}
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break;
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}
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default:
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DBG1(DBG_IKE, "ignoring EAP_SIM attribute %N",
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sim_attribute_names, attribute);
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break;
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}
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}
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/* build payload. If "include_id" is AT_END, AT_IDENTITY is ommited */
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*out = build_payload(this, identifier, SIM_START,
|
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AT_SELECTED_VERSION, this->version,
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AT_NONCE_MT, this->nonce,
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include_id, this->peer->get_encoding(this->peer),
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AT_END);
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return NEED_MORE;
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}
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|
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/**
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* derive EAP keys from kc
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*/
|
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static void derive_keys(private_eap_sim_t *this, chunk_t kcs)
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{
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chunk_t tmp, mk;
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int i;
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|
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/* build MK = SHA1(Identity|n*Kc|NONCE_MT|Version List|Selected Version) */
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tmp = chunk_cata("ccccc", this->peer->get_encoding(this->peer), kcs,
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this->nonce, this->version_list, this->version);
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mk = chunk_alloca(this->hasher->get_hash_size(this->hasher));
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this->hasher->get_hash(this->hasher, tmp, mk.ptr);
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DBG3(DBG_IKE, "MK = SHA1(%B\n) = %B", &tmp, &mk);
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|
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/* K_encr | K_auth | MSK | EMSK = prf() | prf() | prf() | prf()
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* FIPS PRF has 320 bit block size, we need 160 byte for keys
|
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* => run prf four times */
|
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this->prf->set_key(this->prf, mk);
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tmp = chunk_alloca(this->prf->get_block_size(this->prf) * 4);
|
|
for (i = 0; i < 4; i++)
|
|
{
|
|
this->prf->get_bytes(this->prf, chunk_empty, tmp.ptr + tmp.len / 4 * i);
|
|
}
|
|
chunk_free(&this->k_encr);
|
|
chunk_free(&this->k_auth);
|
|
chunk_free(&this->msk);
|
|
chunk_free(&this->emsk);
|
|
chunk_split(tmp, "aaaa", KENCR_LEN, &this->k_encr, KAUTH_LEN, &this->k_auth,
|
|
MSK_LEN, &this->msk, EMSK_LEN, &this->emsk);
|
|
DBG3(DBG_IKE, "K_encr %B\nK_auth %B\nMSK %B\nEMSK %B",
|
|
&this->k_encr, &this->k_auth, &this->msk, &this->emsk);
|
|
}
|
|
|
|
/**
|
|
* process an EAP-SIM/Request/Challenge message
|
|
*/
|
|
static status_t peer_process_challenge(private_eap_sim_t *this,
|
|
eap_payload_t *in, eap_payload_t **out)
|
|
{
|
|
chunk_t message, data, tmp, kcs, kc, sreses, sres;
|
|
sim_attribute_t attribute;
|
|
u_int8_t identifier;
|
|
chunk_t mac = chunk_empty, rands = chunk_empty;
|
|
|
|
if (this->tries-- <= 0)
|
|
{
|
|
/* give up without notification. This hack is required as some buggy
|
|
* server implementations won't respect our client-error. */
|
|
return FAILED;
|
|
}
|
|
|
|
identifier = in->get_identifier(in);
|
|
message = in->get_data(in);
|
|
read_header(&message);
|
|
|
|
while ((attribute = read_attribute(&message, &data)) != AT_END)
|
|
{
|
|
switch (attribute)
|
|
{
|
|
case AT_RAND:
|
|
{
|
|
rands = chunk_skip(data, 2);
|
|
break;
|
|
}
|
|
case AT_MAC:
|
|
{
|
|
/* backup MAC, zero it inline for later verification */
|
|
data = chunk_skip(data, 2);
|
|
mac = chunk_clonea(data);
|
|
memset(data.ptr, 0, data.len);
|
|
break;
|
|
}
|
|
case AT_NOTIFICATION:
|
|
{
|
|
u_int16_t code = 0;
|
|
if (data.len == 2)
|
|
{
|
|
code = ntohs(*(u_int16_t*)data.ptr);
|
|
}
|
|
if (code <= 32767) /* no success bit */
|
|
{
|
|
DBG1(DBG_IKE, "received %N error %d",
|
|
sim_attribute_names, attribute, code);
|
|
*out = build_payload(this,
|
|
in->get_identifier(in), SIM_CLIENT_ERROR,
|
|
AT_CLIENT_ERROR_CODE, client_error_general,
|
|
AT_END);
|
|
return NEED_MORE;
|
|
}
|
|
else
|
|
{
|
|
DBG1(DBG_IKE, "received %N code %d",
|
|
sim_attribute_names, attribute, code);
|
|
}
|
|
break;
|
|
}
|
|
default:
|
|
DBG1(DBG_IKE, "ignoring EAP_SIM attribute %N",
|
|
sim_attribute_names, attribute);
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* excepting two or three RAND, each 16 bytes. We require two valid
|
|
* and different RANDs */
|
|
if ((rands.len != 2 * RAND_LEN && rands.len != 3 * RAND_LEN) ||
|
|
memeq(rands.ptr, rands.ptr + RAND_LEN, RAND_LEN))
|
|
{
|
|
DBG1(DBG_IKE, "no valid AT_RAND received");
|
|
*out = build_payload(this, identifier, SIM_CLIENT_ERROR,
|
|
AT_CLIENT_ERROR_CODE, client_error_insufficient,
|
|
AT_END);
|
|
return NEED_MORE;
|
|
}
|
|
if (mac.len != MAC_LEN)
|
|
{
|
|
DBG1(DBG_IKE, "no valid AT_MAC received");
|
|
*out = build_payload(this, identifier, SIM_CLIENT_ERROR,
|
|
AT_CLIENT_ERROR_CODE, client_error_general,
|
|
AT_END);
|
|
return NEED_MORE;
|
|
}
|
|
|
|
/* get two or three KCs/SRESes from SIM using RANDs */
|
|
kcs = kc = chunk_alloca(rands.len / 2);
|
|
sreses = sres = chunk_alloca(rands.len / 4);
|
|
while (rands.len > 0)
|
|
{
|
|
int kc_len = kc.len, sres_len = sres.len;
|
|
|
|
if (this->alg(rands.ptr, RAND_LEN, sres.ptr, &sres_len, kc.ptr, &kc_len))
|
|
{
|
|
DBG1(DBG_IKE, "unable to get EAP-SIM triplet");
|
|
*out = build_payload(this, identifier, SIM_CLIENT_ERROR,
|
|
AT_CLIENT_ERROR_CODE, client_error_general,
|
|
AT_END);
|
|
return NEED_MORE;
|
|
}
|
|
DBG3(DBG_IKE, "got triplet for RAND %b\n Kc %b\n SRES %b",
|
|
rands.ptr, RAND_LEN, sres.ptr, sres_len, kc.ptr, kc_len);
|
|
kc = chunk_skip(kc, kc_len);
|
|
sres = chunk_skip(sres, sres_len);
|
|
rands = chunk_skip(rands, RAND_LEN);
|
|
}
|
|
|
|
derive_keys(this, kcs);
|
|
|
|
/* verify AT_MAC attribute, signature is over "EAP packet | NONCE_MT" */
|
|
this->signer->set_key(this->signer, this->k_auth);
|
|
tmp = chunk_cata("cc", in->get_data(in), this->nonce);
|
|
if (!this->signer->verify_signature(this->signer, tmp, mac))
|
|
{
|
|
DBG1(DBG_IKE, "AT_MAC verification failed");
|
|
*out = build_payload(this, identifier, SIM_CLIENT_ERROR,
|
|
AT_CLIENT_ERROR_CODE, client_error_general,
|
|
AT_END);
|
|
return NEED_MORE;
|
|
}
|
|
|
|
/* build response, AT_MAC is built over "EAP packet | n*SRES" */
|
|
*out = build_payload(this, identifier, SIM_CHALLENGE,
|
|
AT_MAC, sreses,
|
|
AT_END);
|
|
return NEED_MORE;
|
|
}
|
|
|
|
/**
|
|
* process an EAP-SIM/Response/Challenge message
|
|
*/
|
|
static status_t server_process_challenge(private_eap_sim_t *this,
|
|
eap_payload_t *in, eap_payload_t **out)
|
|
{
|
|
chunk_t message, data;
|
|
sim_attribute_t attribute;
|
|
chunk_t mac = chunk_empty, tmp;
|
|
|
|
message = in->get_data(in);
|
|
read_header(&message);
|
|
|
|
while ((attribute = read_attribute(&message, &data)) != AT_END)
|
|
{
|
|
switch (attribute)
|
|
{
|
|
case AT_MAC:
|
|
/* MAC has two reserved bytes */
|
|
if (data.len == MAC_LEN + 2)
|
|
{ /* clone and zero MAC for verification */
|
|
mac = chunk_clonea(chunk_skip(data, 2));
|
|
memset(data.ptr, 0, data.len);
|
|
}
|
|
break;
|
|
default:
|
|
DBG1(DBG_IKE, "ignoring EAP_SIM attribute %N",
|
|
sim_attribute_names, attribute);
|
|
break;
|
|
}
|
|
}
|
|
if (!mac.ptr)
|
|
{
|
|
DBG1(DBG_IKE, "no valid AT_MAC attribute received");
|
|
return FAILED;
|
|
}
|
|
/* verify AT_MAC attribute, signature is over "EAP packet | n*SRES" */
|
|
this->signer->set_key(this->signer, this->k_auth);
|
|
tmp = chunk_cata("cc", in->get_data(in), this->sreses);
|
|
if (!this->signer->verify_signature(this->signer, tmp, mac))
|
|
{
|
|
DBG1(DBG_IKE, "AT_MAC verification failed");
|
|
return FAILED;
|
|
}
|
|
return SUCCESS;
|
|
}
|
|
|
|
/**
|
|
* process an EAP-SIM/Response/Start message
|
|
*/
|
|
static status_t server_process_start(private_eap_sim_t *this,
|
|
eap_payload_t *in, eap_payload_t **out)
|
|
{
|
|
chunk_t message, data;
|
|
sim_attribute_t attribute;
|
|
bool supported = FALSE;
|
|
chunk_t rands, rand, kcs, kc, sreses, sres;
|
|
char id[64];
|
|
int len, i, rand_len, kc_len, sres_len;
|
|
|
|
message = in->get_data(in);
|
|
read_header(&message);
|
|
|
|
while ((attribute = read_attribute(&message, &data)) != AT_END)
|
|
{
|
|
switch (attribute)
|
|
{
|
|
case AT_NONCE_MT:
|
|
if (data.len == NONCE_LEN + 2)
|
|
{
|
|
this->nonce = chunk_clone(chunk_skip(data, 2));
|
|
}
|
|
break;
|
|
case AT_SELECTED_VERSION:
|
|
if (chunk_equals(data, this->version))
|
|
{
|
|
supported = TRUE;
|
|
}
|
|
break;
|
|
default:
|
|
DBG1(DBG_IKE, "ignoring EAP_SIM attribute %N",
|
|
sim_attribute_names, attribute);
|
|
break;
|
|
}
|
|
}
|
|
if (!supported || !this->nonce.ptr)
|
|
{
|
|
DBG1(DBG_IKE, "received incomplete EAP-SIM/Response/Start");
|
|
return FAILED;
|
|
}
|
|
len = snprintf(id, sizeof(id), "%D", this->peer);
|
|
if (len > sizeof(id) || len < 0)
|
|
{
|
|
return FAILED;
|
|
}
|
|
|
|
/* read triplets from provider */
|
|
rand = rands = chunk_alloca(RAND_LEN * TRIPLET_COUNT);
|
|
kc = kcs = chunk_alloca(KC_LEN * TRIPLET_COUNT);
|
|
sres = sreses = chunk_alloca(SRES_LEN * TRIPLET_COUNT);
|
|
rands.len = 0;
|
|
kcs.len = 0;
|
|
sreses.len = 0;
|
|
for (i = 0; i < TRIPLET_COUNT; i++)
|
|
{
|
|
rand_len = RAND_LEN;
|
|
kc_len = KC_LEN;
|
|
sres_len = SRES_LEN;
|
|
if (this->get_triplet(id, rand.ptr, &rand_len, sres.ptr, &sres_len,
|
|
kc.ptr, &kc_len))
|
|
{
|
|
DBG1(DBG_IKE, "getting EAP-SIM triplet %d failed", i);
|
|
return FAILED;
|
|
}
|
|
rands.len += rand_len;
|
|
kcs.len += kc_len;
|
|
sreses.len += sres_len;
|
|
rand = chunk_skip(rand, rand_len);
|
|
kc = chunk_skip(kc, kc_len);
|
|
sres = chunk_skip(sres, sres_len);
|
|
}
|
|
derive_keys(this, kcs);
|
|
|
|
/* build MAC over "EAP packet | NONCE_MT" */
|
|
*out = build_payload(this, this->identifier++, SIM_CHALLENGE, AT_RAND,
|
|
rands, AT_MAC, this->nonce, AT_END);
|
|
this->sreses = chunk_clone(sreses);
|
|
return NEED_MORE;
|
|
}
|
|
|
|
/**
|
|
* process an EAP-SIM/Request/Notification message
|
|
*/
|
|
static status_t peer_process_notification(private_eap_sim_t *this,
|
|
eap_payload_t *in, eap_payload_t **out)
|
|
{
|
|
chunk_t message, data;
|
|
sim_attribute_t attribute;
|
|
|
|
message = in->get_data(in);
|
|
read_header(&message);
|
|
|
|
while ((attribute = read_attribute(&message, &data)) != AT_END)
|
|
{
|
|
switch (attribute)
|
|
{
|
|
case AT_NOTIFICATION:
|
|
{
|
|
u_int16_t code = 0;
|
|
if (data.len == 2)
|
|
{
|
|
code = ntohs(*(u_int16_t*)data.ptr);
|
|
}
|
|
if (code <= 32767) /* no success bit */
|
|
{
|
|
DBG1(DBG_IKE, "received %N error %d",
|
|
sim_attribute_names, attribute, code);
|
|
*out = build_payload(this,
|
|
in->get_identifier(in), SIM_CLIENT_ERROR,
|
|
AT_CLIENT_ERROR_CODE, client_error_general,
|
|
AT_END);
|
|
return NEED_MORE;
|
|
}
|
|
else
|
|
{
|
|
DBG1(DBG_IKE, "received %N code %d",
|
|
sim_attribute_names, attribute, code);
|
|
}
|
|
break;
|
|
}
|
|
default:
|
|
DBG1(DBG_IKE, "ignoring EAP_SIM attribute %N",
|
|
sim_attribute_names, attribute);
|
|
break;
|
|
}
|
|
}
|
|
/* reply with empty notification */
|
|
*out = build_payload(this, in->get_identifier(in), SIM_NOTIFICATION, AT_END);
|
|
return NEED_MORE;
|
|
}
|
|
|
|
/**
|
|
* Process a client error
|
|
*/
|
|
static status_t server_process_client_error(private_eap_sim_t *this,
|
|
eap_payload_t *in, eap_payload_t **out)
|
|
{
|
|
chunk_t message, data;
|
|
sim_attribute_t attribute;
|
|
|
|
message = in->get_data(in);
|
|
read_header(&message);
|
|
|
|
while ((attribute = read_attribute(&message, &data)) != AT_END)
|
|
{
|
|
if (attribute == AT_CLIENT_ERROR_CODE)
|
|
{
|
|
u_int16_t code = 0;
|
|
if (data.len == 2)
|
|
{
|
|
code = ntohs(*(u_int16_t*)data.ptr);
|
|
}
|
|
DBG1(DBG_IKE, "received %N error %d",
|
|
sim_attribute_names, attribute, code);
|
|
}
|
|
else
|
|
{
|
|
DBG1(DBG_IKE, "ignoring EAP_SIM attribute %N",
|
|
sim_attribute_names, attribute);
|
|
}
|
|
}
|
|
return FAILED;
|
|
}
|
|
|
|
/**
|
|
* Implementation of eap_method_t.process for the peer
|
|
*/
|
|
static status_t peer_process(private_eap_sim_t *this,
|
|
eap_payload_t *in, eap_payload_t **out)
|
|
{
|
|
sim_subtype_t type;
|
|
chunk_t message;
|
|
|
|
message = in->get_data(in);
|
|
type = read_header(&message);
|
|
|
|
switch (type)
|
|
{
|
|
case SIM_START:
|
|
return peer_process_start(this, in, out);
|
|
case SIM_CHALLENGE:
|
|
return peer_process_challenge(this, in, out);
|
|
case SIM_NOTIFICATION:
|
|
return peer_process_notification(this, in, out);
|
|
default:
|
|
DBG1(DBG_IKE, "unable to process EAP_SIM subtype %N",
|
|
sim_subtype_names, type);
|
|
*out = build_payload(this, in->get_identifier(in), SIM_CLIENT_ERROR,
|
|
AT_CLIENT_ERROR_CODE, client_error_general, AT_END);
|
|
return NEED_MORE;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Implementation of eap_method_t.process for the server
|
|
*/
|
|
static status_t server_process(private_eap_sim_t *this,
|
|
eap_payload_t *in, eap_payload_t **out)
|
|
{
|
|
sim_subtype_t type;
|
|
chunk_t message;
|
|
|
|
message = in->get_data(in);
|
|
type = read_header(&message);
|
|
|
|
switch (type)
|
|
{
|
|
case SIM_START:
|
|
return server_process_start(this, in, out);
|
|
case SIM_CHALLENGE:
|
|
return server_process_challenge(this, in, out);
|
|
case SIM_CLIENT_ERROR:
|
|
return server_process_client_error(this, in, out);
|
|
default:
|
|
DBG1(DBG_IKE, "unable to process EAP_SIM subtype %N",
|
|
sim_subtype_names, type);
|
|
return FAILED;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Implementation of eap_method_t.initiate for the peer
|
|
*/
|
|
static status_t peer_initiate(private_eap_sim_t *this, eap_payload_t **out)
|
|
{
|
|
/* peer never initiates */
|
|
return FAILED;
|
|
}
|
|
|
|
/**
|
|
* Implementation of eap_method_t.initiate for the server
|
|
*/
|
|
static status_t server_initiate(private_eap_sim_t *this, eap_payload_t **out)
|
|
{
|
|
/* version_list to derive MK, no padding */
|
|
this->version_list = chunk_clone(this->version);
|
|
/* build_payloads adds padding itself */
|
|
*out = build_payload(this, this->identifier++, SIM_START,
|
|
AT_VERSION_LIST, this->version, AT_END);
|
|
return NEED_MORE;
|
|
}
|
|
|
|
/**
|
|
* Implementation of eap_method_t.get_type.
|
|
*/
|
|
static eap_type_t get_type(private_eap_sim_t *this, u_int32_t *vendor)
|
|
{
|
|
*vendor = 0;
|
|
return EAP_SIM;
|
|
}
|
|
|
|
/**
|
|
* Implementation of eap_method_t.get_msk.
|
|
*/
|
|
static status_t get_msk(private_eap_sim_t *this, chunk_t *msk)
|
|
{
|
|
if (this->msk.ptr)
|
|
{
|
|
*msk = this->msk;
|
|
return SUCCESS;
|
|
}
|
|
return FAILED;
|
|
}
|
|
|
|
/**
|
|
* Implementation of eap_method_t.is_mutual.
|
|
*/
|
|
static bool is_mutual(private_eap_sim_t *this)
|
|
{
|
|
return TRUE;
|
|
}
|
|
|
|
/**
|
|
* Implementation of eap_method_t.destroy.
|
|
*/
|
|
static void destroy(private_eap_sim_t *this)
|
|
{
|
|
dlclose(this->handle);
|
|
DESTROY_IF(this->hasher);
|
|
DESTROY_IF(this->prf);
|
|
DESTROY_IF(this->signer);
|
|
chunk_free(&this->nonce);
|
|
chunk_free(&this->sreses);
|
|
chunk_free(&this->version_list);
|
|
chunk_free(&this->k_auth);
|
|
chunk_free(&this->k_encr);
|
|
chunk_free(&this->msk);
|
|
chunk_free(&this->emsk);
|
|
free(this);
|
|
}
|
|
|
|
/**
|
|
* Generic constructor for both roles
|
|
*/
|
|
eap_sim_t *eap_sim_create_generic(eap_role_t role, identification_t *server,
|
|
identification_t *peer)
|
|
{
|
|
private_eap_sim_t *this;
|
|
rng_t *rng;
|
|
void *symbol;
|
|
char *name;
|
|
|
|
this = malloc_thing(private_eap_sim_t);
|
|
this->alg = NULL;
|
|
this->get_triplet = NULL;
|
|
this->nonce = chunk_empty;
|
|
this->sreses = chunk_empty;
|
|
this->peer = peer;
|
|
this->tries = MAX_TRIES;
|
|
this->version.ptr = version;
|
|
this->version.len = sizeof(version);
|
|
this->version_list = chunk_empty;
|
|
this->k_auth = chunk_empty;
|
|
this->k_encr = chunk_empty;
|
|
this->msk = chunk_empty;
|
|
this->emsk = chunk_empty;
|
|
this->identifier = random();
|
|
|
|
this->handle = dlopen(SIM_READER_LIB, RTLD_LAZY);
|
|
if (this->handle == NULL)
|
|
{
|
|
DBG1(DBG_IKE, "unable to open SIM reader '%s'", SIM_READER_LIB);
|
|
free(this);
|
|
return NULL;
|
|
}
|
|
switch (role)
|
|
{
|
|
case EAP_PEER:
|
|
name = SIM_READER_ALG;
|
|
break;
|
|
case EAP_SERVER:
|
|
name = SIM_READER_GET_TRIPLET;
|
|
break;
|
|
default:
|
|
free(this);
|
|
return NULL;
|
|
}
|
|
symbol = dlsym(this->handle, name);
|
|
if (symbol == NULL)
|
|
{
|
|
DBG1(DBG_IKE, "unable to open SIM function '%s' in '%s'",
|
|
name, SIM_READER_LIB);
|
|
dlclose(this->handle);
|
|
free(this);
|
|
return NULL;
|
|
}
|
|
switch (role)
|
|
{
|
|
case EAP_SERVER:
|
|
this->public.eap_method_interface.initiate = (status_t(*)(eap_method_t*,eap_payload_t**))server_initiate;
|
|
this->public.eap_method_interface.process = (status_t(*)(eap_method_t*,eap_payload_t*,eap_payload_t**))server_process;
|
|
this->get_triplet = symbol;
|
|
this->type = EAP_REQUEST;
|
|
break;
|
|
case EAP_PEER:
|
|
this->public.eap_method_interface.initiate = (status_t(*)(eap_method_t*,eap_payload_t**))peer_initiate;
|
|
this->public.eap_method_interface.process = (status_t(*)(eap_method_t*,eap_payload_t*,eap_payload_t**))peer_process;
|
|
this->alg = symbol;
|
|
this->type = EAP_RESPONSE;
|
|
rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
|
|
if (!rng)
|
|
{
|
|
DBG1(DBG_IKE, "unable to generate NONCE for EAP_SIM");
|
|
free(this);
|
|
return NULL;
|
|
}
|
|
rng->allocate_bytes(rng, NONCE_LEN, &this->nonce);
|
|
rng->destroy(rng);
|
|
break;
|
|
default:
|
|
free(this);
|
|
return NULL;
|
|
}
|
|
this->public.eap_method_interface.get_type = (eap_type_t(*)(eap_method_t*,u_int32_t*))get_type;
|
|
this->public.eap_method_interface.is_mutual = (bool(*)(eap_method_t*))is_mutual;
|
|
this->public.eap_method_interface.get_msk = (status_t(*)(eap_method_t*,chunk_t*))get_msk;
|
|
this->public.eap_method_interface.destroy = (void(*)(eap_method_t*))destroy;
|
|
|
|
this->hasher = lib->crypto->create_hasher(lib->crypto, HASH_SHA1);
|
|
this->prf = lib->crypto->create_prf(lib->crypto, PRF_FIPS_SHA1_160);
|
|
this->signer = lib->crypto->create_signer(lib->crypto, AUTH_HMAC_SHA1_128);
|
|
if (!this->hasher || !this->prf || !this->signer)
|
|
{
|
|
DBG1(DBG_IKE, "initiating EAP-SIM failed, FIPS-PRF/SHA1 not supported");
|
|
destroy(this);
|
|
return NULL;
|
|
}
|
|
return &this->public;
|
|
}
|
|
|
|
/*
|
|
* Described in header.
|
|
*/
|
|
eap_sim_t *eap_sim_create_server(identification_t *server,
|
|
identification_t *peer)
|
|
{
|
|
return eap_sim_create_generic(EAP_SERVER, server, peer);
|
|
}
|
|
|
|
/*
|
|
* Described in header.
|
|
*/
|
|
eap_sim_t *eap_sim_create_peer(identification_t *server,
|
|
identification_t *peer)
|
|
{
|
|
return eap_sim_create_generic(EAP_PEER, server, peer);
|
|
}
|
|
|