Annotation of embedaddon/strongswan/src/libcharon/plugins/eap_aka_3gpp/eap_aka_3gpp_provider.c, revision 1.1

1.1     ! misho       1: /*
        !             2:  * Copyright (C) 2008-2009 Martin Willi
        !             3:  * HSR Hochschule fuer Technik Rapperswil
        !             4:  *
        !             5:  * This program is free software; you can redistribute it and/or modify it
        !             6:  * under the terms of the GNU General Public License as published by the
        !             7:  * Free Software Foundation; either version 2 of the License, or (at your
        !             8:  * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
        !             9:  *
        !            10:  * This program is distributed in the hope that it will be useful, but
        !            11:  * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
        !            12:  * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
        !            13:  * for more details.
        !            14:  */
        !            15: /*
        !            16:  * Copyright (C) 2015 Thomas Strangert
        !            17:  * Polystar System AB, Sweden
        !            18:  *
        !            19:  * Permission is hereby granted, free of charge, to any person obtaining a copy
        !            20:  * of this software and associated documentation files (the "Software"), to deal
        !            21:  * in the Software without restriction, including without limitation the rights
        !            22:  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
        !            23:  * copies of the Software, and to permit persons to whom the Software is
        !            24:  * furnished to do so, subject to the following conditions:
        !            25:  *
        !            26:  * The above copyright notice and this permission notice shall be included in
        !            27:  * all copies or substantial portions of the Software.
        !            28:  *
        !            29:  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
        !            30:  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
        !            31:  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
        !            32:  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
        !            33:  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
        !            34:  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
        !            35:  * THE SOFTWARE.
        !            36:  */
        !            37: 
        !            38: #include "eap_aka_3gpp_provider.h"
        !            39: 
        !            40: #include <daemon.h>
        !            41: 
        !            42: typedef struct private_eap_aka_3gpp_provider_t private_eap_aka_3gpp_provider_t;
        !            43: 
        !            44: /**
        !            45:  * Private data of an eap_aka_3gpp_provider_t object.
        !            46:  */
        !            47: struct private_eap_aka_3gpp_provider_t {
        !            48: 
        !            49:        /**
        !            50:         * Public eap_aka_3gpp_provider_t interface.
        !            51:         */
        !            52:        eap_aka_3gpp_provider_t public;
        !            53: 
        !            54:        /**
        !            55:         * AKA functions
        !            56:         */
        !            57:        eap_aka_3gpp_functions_t *f;
        !            58: 
        !            59:        /**
        !            60:         * time based SQN, we use the same for all peers
        !            61:         */
        !            62:        uint8_t sqn[AKA_SQN_LEN];
        !            63: };
        !            64: 
        !            65: /** Authentication management field, AMF, as defined in 3GPP TS 33.102 V12.2.0
        !            66:  *
        !            67:  * The 16 bits in the AMF are numbered from "0" to "15" where bit "0" is
        !            68:  * the most significant bit and bit "15" is the least significant bit.
        !            69:  * Bit "0" is called the "AMF separation bit". It is used for the purposes
        !            70:  * of EPS (Evolved Packet System) and is specified in
        !            71:  * -   TS 33.401 [28] for E-UTRAN access to EPS;
        !            72:  * -   TS 33.402 [29] for non-3GPP access to EPS.
        !            73:  * Bits "1" to "7" are reserved for future standardization use.
        !            74:  * Bits "1" to "7" shall be set to 0 while not yet specified for a particular use.
        !            75:  * Bits "8" to "15" can be used for proprietary purposes.
        !            76:  */
        !            77: static const uint8_t amf[AKA_AMF_LEN] = {0x80, 0x00};
        !            78: 
        !            79: METHOD(simaka_provider_t, get_quintuplet, bool,
        !            80:        private_eap_aka_3gpp_provider_t *this, identification_t *id,
        !            81:        char rand[AKA_RAND_LEN], char xres[AKA_RES_MAX], int *xres_len,
        !            82:        char ck[AKA_CK_LEN], char ik[AKA_IK_LEN], char autn[AKA_AUTN_LEN])
        !            83: {
        !            84:        rng_t *rng;
        !            85:        uint8_t maca[AKA_MAC_LEN], ak[AKA_AK_LEN], k[AKA_K_LEN], opc[AKA_OPC_LEN];
        !            86: 
        !            87:        /* generate RAND: we use a RNG already registered as f0(). */
        !            88:        rng = lib->crypto->create_rng(lib->crypto, RNG_WEAK);
        !            89:        if (!rng || !rng->get_bytes(rng, AKA_RAND_LEN, rand))
        !            90:        {
        !            91:                DBG1(DBG_IKE, "generating RAND for AKA failed");
        !            92:                DESTROY_IF(rng);
        !            93:                return FALSE;
        !            94:        }
        !            95:        rng->destroy(rng);
        !            96:        DBG3(DBG_IKE, "generated rand %b", rand, AKA_RAND_LEN);
        !            97: 
        !            98:        if (!eap_aka_3gpp_get_k_opc(id, k, opc))
        !            99:        {
        !           100:                DBG1(DBG_IKE, "no EAP key found for %Y to authenticate with AKA", id);
        !           101:                return FALSE;
        !           102:        }
        !           103:        DBG4(DBG_IKE, "EAP key found for id %Y, using K %b and OPc %b", id, k,
        !           104:                 AKA_K_LEN, opc, AKA_OPC_LEN);
        !           105: 
        !           106:        /* generate MAC and XRES, CK, IK, AK */
        !           107:        if (!this->f->f1(this->f, k, opc, rand, this->sqn, amf, maca) ||
        !           108:            !this->f->f2345(this->f, k, opc, rand, xres, ck, ik, ak))
        !           109:        {
        !           110:                return FALSE;
        !           111:        }
        !           112:        *xres_len = AKA_RES_LEN;
        !           113: 
        !           114:        /* create AUTN = (SQN xor AK) || AMF || MAC */
        !           115:        memcpy(autn, this->sqn, AKA_SQN_LEN);
        !           116:        memxor(autn, ak, AKA_AK_LEN);
        !           117:        memcpy(autn + AKA_SQN_LEN, amf, AKA_AMF_LEN);
        !           118:        memcpy(autn + AKA_SQN_LEN + AKA_AMF_LEN, maca, AKA_MAC_LEN);
        !           119:        DBG3(DBG_IKE, "AUTN %b", autn, AKA_AUTN_LEN);
        !           120: 
        !           121:        chunk_increment(chunk_create(this->sqn, AKA_SQN_LEN));
        !           122: 
        !           123:        return TRUE;
        !           124: }
        !           125: 
        !           126: METHOD(simaka_provider_t, resync, bool,
        !           127:        private_eap_aka_3gpp_provider_t *this, identification_t *id,
        !           128:        char rand[AKA_RAND_LEN], char auts[AKA_AUTS_LEN])
        !           129: {
        !           130:        uint8_t *sqn, *macs;
        !           131:        uint8_t aks[AKA_AK_LEN], k[AKA_K_LEN], opc[AKA_OPC_LEN], amfs[AKA_AMF_LEN],
        !           132:                        xmacs[AKA_MAC_LEN];
        !           133: 
        !           134:        if (!eap_aka_3gpp_get_k_opc(id, k, opc))
        !           135:        {
        !           136:                DBG1(DBG_IKE, "no EAP key found for %Y to authenticate with AKA", id);
        !           137:                return FALSE;
        !           138:        }
        !           139:        DBG4(DBG_IKE, "EAP key found for id %Y, using K %b and OPc %b", id, k,
        !           140:                 AKA_K_LEN, opc, AKA_OPC_LEN);
        !           141: 
        !           142:        /* get SQNms out of the AUTS the card created as:
        !           143:         * AUTS = (SQNms xor AKS) || MAC-S */
        !           144:        sqn = auts;
        !           145:        macs = auts + AKA_SQN_LEN;
        !           146:        if (!this->f->f5star(this->f, k, opc, rand, aks))
        !           147:        {
        !           148:                return FALSE;
        !           149:        }
        !           150:        memxor(sqn, aks, AKA_AK_LEN);
        !           151: 
        !           152:        /* generate resync XMAC-S... */
        !           153:        memset(amfs, 0, AKA_AMF_LEN);
        !           154:        if (!this->f->f1star(this->f, k, opc, rand, sqn, amfs, xmacs))
        !           155:        {
        !           156:                return FALSE;
        !           157:        }
        !           158:        /* ...and compare it with the card's MAC-S */
        !           159:        if (!memeq_const(xmacs, macs, AKA_MAC_LEN))
        !           160:        {
        !           161:                DBG1(DBG_IKE, "received MACS does not match XMACS");
        !           162:                DBG3(DBG_IKE, "MACS %b XMACS %b",
        !           163:                         macs, AKA_MAC_LEN, xmacs, AKA_MAC_LEN);
        !           164:                return FALSE;
        !           165:        }
        !           166:        /* update stored SQN to received SQN + 1 */
        !           167:        memcpy(this->sqn, sqn, AKA_SQN_LEN);
        !           168:        chunk_increment(chunk_create(this->sqn, AKA_SQN_LEN));
        !           169:        return TRUE;
        !           170: }
        !           171: 
        !           172: METHOD(eap_aka_3gpp_provider_t, destroy, void,
        !           173:        private_eap_aka_3gpp_provider_t *this)
        !           174: {
        !           175:        free(this);
        !           176: }
        !           177: 
        !           178: /**
        !           179:  * See header
        !           180:  */
        !           181: eap_aka_3gpp_provider_t *eap_aka_3gpp_provider_create(
        !           182:                                                                                                eap_aka_3gpp_functions_t *f)
        !           183: {
        !           184:        private_eap_aka_3gpp_provider_t *this;
        !           185: 
        !           186:        INIT(this,
        !           187:                .public = {
        !           188:                        .provider = {
        !           189:                                .get_triplet = (void*)return_false,
        !           190:                                .get_quintuplet = _get_quintuplet,
        !           191:                                .resync = _resync,
        !           192:                                .is_pseudonym = (void*)return_null,
        !           193:                                .gen_pseudonym = (void*)return_null,
        !           194:                                .is_reauth = (void*)return_null,
        !           195:                                .gen_reauth = (void*)return_null,
        !           196:                        },
        !           197:                        .destroy = _destroy,
        !           198:                },
        !           199:                .f = f,
        !           200:        );
        !           201:        /* use an offset to accept clock skew between client/server without resync */
        !           202:        eap_aka_3gpp_get_sqn(this->sqn, SQN_TIME_OFFSET);
        !           203: 
        !           204:        return &this->public;
        !           205: }

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