eap_fast.h

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#pragma once
/*
 *   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.
 *
 *   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.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
 
/**
 * $Id: d54b0f868ec1ca17a463661d313027a7d1598bb5 $
 * @file eap_fast.h
 * @brief Function declarations and packet structures
 *
 * @author Alexander Clouter (alex@digriz.org.uk)
 *
 * @copyright 2016 Alan DeKok (aland@freeradius.org)
 * @copyright 2016 The FreeRADIUS server project
 */
RCSIDH(eap_fast_h, "$Id: d54b0f868ec1ca17a463661d313027a7d1598bb5 $")
 
#include <freeradius-devel/eap/tls.h>
#include <freeradius-devel/radius/radius.h>
#include <freeradius-devel/util/chap.h>
 
#define EAP_FAST_VERSION                        1
 
#define EAP_FAST_KEY_LEN                        64
#define EAP_EMSK_LEN                            64
#define EAP_FAST_SKS_LEN                        40
#define EAP_FAST_SIMCK_LEN                      40
#define EAP_FAST_CMK_LEN                        20
 
#define EAP_FAST_TLV_MANDATORY                  0x8000
#define EAP_FAST_TLV_TYPE                       0x3fff
 
#define EAP_FAST_FATAL_ERROR                    2000
#define EAP_FAST_ERR_TUNNEL_COMPROMISED         2001
#define EAP_FAST_ERR_UNEXPECTED_TLV             2002
 
#define EAP_FAST_TLV_RESULT_SUCCESS             1
#define EAP_FAST_TLV_RESULT_FAILURE             2
 
typedef enum {
        EAP_FAST_TLS_SESSION_HANDSHAKE = 0,
        EAP_FAST_AUTHENTICATION,
        EAP_FAST_CRYPTOBIND_CHECK,
        EAP_FAST_PROVISIONING,
        EAP_FAST_COMPLETE
} eap_fast_stage_t;
 
typedef enum {
        EAP_FAST_UNKNOWN = 0,
        EAP_FAST_PROVISIONING_ANON,
        EAP_FAST_PROVISIONING_AUTH,
        EAP_FAST_NORMAL_AUTH
} eap_fast_auth_type_t;
 
typedef enum {
        PAC_TYPE_TUNNEL = 1,    // 1
        PAC_TYPE_MACHINE_AUTH,  // 2
        PAC_TYPE_USER_AUTHZ,    // 3
        PAC_TYPE_MAX
} eap_fast_pac_type_t;
 
#define PAC_KEY_LENGTH          32
#define PAC_A_ID_LENGTH         16
#define PAC_I_ID_LENGTH         16
#define PAC_A_ID_INFO_LENGTH    32
 
typedef struct {
        uint16_t                        type;
        uint16_t                        length;
} CC_HINT(__packed__) eap_fast_pac_attr_hdr_t;
 
typedef struct {
        eap_fast_pac_attr_hdr_t         hdr;
        uint32_t                        data;   // secs since epoch
} CC_HINT(__packed__) eap_fast_pac_attr_lifetime_t;
 
typedef struct {
        eap_fast_pac_attr_hdr_t         hdr;
        uint8_t                         data[PAC_A_ID_LENGTH];
} CC_HINT(__packed__) eap_fast_pac_attr_a_id_t;
 
typedef struct {
        eap_fast_pac_attr_hdr_t         hdr;
        uint8_t                         data[PAC_I_ID_LENGTH];
} CC_HINT(__packed__) eap_fast_pac_attr_i_id_t;
 
typedef struct {
        eap_fast_pac_attr_hdr_t         hdr;
        uint8_t                         data[PAC_A_ID_INFO_LENGTH];
} CC_HINT(__packed__) eap_fast_pac_attr_a_id_info_t;
 
typedef struct {
        eap_fast_pac_attr_hdr_t         hdr;
        uint16_t                        data;
} CC_HINT(__packed__) eap_fast_pac_attr_pac_type_t;
 
typedef struct {
        eap_fast_pac_attr_hdr_t         hdr;
        uint8_t                         data[PAC_KEY_LENGTH];
} CC_HINT(__packed__) eap_fast_pac_attr_pac_key_t;
 
typedef struct {
        eap_fast_pac_attr_pac_type_t    type;
        eap_fast_pac_attr_lifetime_t    lifetime;
        eap_fast_pac_attr_pac_key_t     key;
} CC_HINT(__packed__) eap_fast_attr_pac_opaque_plaintext_t;
 
typedef struct {
        eap_fast_pac_attr_hdr_t         hdr;
        unsigned char                   aad[PAC_A_ID_LENGTH];
        unsigned char                   iv[EVP_MAX_IV_LENGTH];
        unsigned char                   tag[EVP_GCM_TLS_TAG_LEN];
        uint8_t                         data[sizeof(eap_fast_attr_pac_opaque_plaintext_t) * 2]; // space for EVP
} CC_HINT(__packed__) eap_fast_attr_pac_opaque_t;
 
typedef struct {
        eap_fast_pac_attr_hdr_t         hdr;
        eap_fast_pac_attr_lifetime_t    lifetime;
        eap_fast_pac_attr_a_id_t        a_id;
        eap_fast_pac_attr_a_id_info_t   a_id_info;
        eap_fast_pac_attr_pac_type_t    type;
} CC_HINT(__packed__) eap_fast_attr_pac_info_t;
 
typedef struct {
        eap_fast_pac_attr_pac_key_t     key;
        eap_fast_attr_pac_info_t        info;
        eap_fast_attr_pac_opaque_t      opaque; // has to be last!
} CC_HINT(__packed__) eap_fast_pac_t;
 
/* RFC 4851, Section 4.2.8 - Crypto-Binding TLV */
typedef struct {
        uint16_t tlv_type;
        uint16_t length;
        uint8_t reserved;
        uint8_t version;
        uint8_t received_version;
        uint8_t subtype;
        uint8_t nonce[32];
        uint8_t compound_mac[20];
} CC_HINT(__packed__) eap_tlv_crypto_binding_tlv_t;
 
typedef enum eap_fast_tlv_crypto_binding_tlv_subtype_t {
        EAP_FAST_TLV_CRYPTO_BINDING_SUBTYPE_REQUEST = 0,        // 0
        EAP_FAST_TLV_CRYPTO_BINDING_SUBTYPE_RESPONSE            // 1
} eap_fast_tlv_crypto_binding_tlv_subtype_t;
 
/* RFC 5422: Section 3.3 - Key Derivations Used in the EAP-FAST Provisioning Exchange */
typedef struct {
        uint8_t session_key_seed[EAP_FAST_SKS_LEN];
        uint8_t server_challenge[MD5_DIGEST_LENGTH];
        uint8_t client_challenge[MD5_DIGEST_LENGTH];
} CC_HINT(__packed__) eap_fast_keyblock_t;
 
typedef struct {
        fr_pair_t               *username;
 
        bool                    authenticated;
 
        int                     mode;
        eap_fast_stage_t        stage;
        eap_fast_keyblock_t     *keyblock;
        uint8_t                 *s_imck;
        uint8_t                 *cmk;
        int                     imck_count;
        struct {
                uint8_t         mppe_send[MD5_DIGEST_LENGTH];
                uint8_t         mppe_recv[MD5_DIGEST_LENGTH];
        } CC_HINT(__packed__)   isk;
        uint8_t                 *msk;
        uint8_t                 *emsk;
 
        int                     default_method;
        int                     default_provisioning_method;
 
        fr_time_delta_t         pac_lifetime;
        char const              *authority_identity;
        uint8_t const           *a_id;
        uint8_t const           *pac_opaque_key;
 
        struct {
                uint8_t                 *key;
                eap_fast_pac_type_t     type;
                fr_time_t               expires;
                bool                    expired;
                bool                    send;
        }                       pac;
 
        bool                    result_final;
 
#ifdef WITH_PROXY
        bool            proxy_tunneled_request_as_eap;  //!< Proxy tunneled session as EAP, or as de-capsulated
                                                        //!< protocol.
#endif
        char const      *virtual_server;
} eap_fast_tunnel_t;
 
extern HIDDEN fr_dict_attr_t const *attr_eap_tls_require_client_cert;
extern HIDDEN fr_dict_attr_t const *attr_eap_type;
extern HIDDEN fr_dict_attr_t const *attr_ms_chap_challenge;
extern HIDDEN fr_dict_attr_t const *attr_ms_chap_peer_challenge;
extern HIDDEN fr_dict_attr_t const *attr_proxy_to_realm;
 
extern HIDDEN fr_dict_attr_t const *attr_eap_message;
extern HIDDEN fr_dict_attr_t const *attr_eap_msk;
extern HIDDEN fr_dict_attr_t const *attr_eap_emsk;
extern HIDDEN fr_dict_attr_t const *attr_freeradius_proxied_to;
extern HIDDEN fr_dict_attr_t const *attr_ms_mppe_send_key;
extern HIDDEN fr_dict_attr_t const *attr_ms_mppe_recv_key;
extern HIDDEN fr_dict_attr_t const *attr_user_name;
extern HIDDEN fr_dict_attr_t const *attr_user_password;
 
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_crypto_binding;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_eap_payload;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_error;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_intermediate_result;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_nak;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_a_id;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_a_id_info;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_acknowledge;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_i_id;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_info_a_id;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_info_a_id_info;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_info_i_id;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_info_pac_lifetime;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_info_pac_type;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_info_tlv;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_key;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_lifetime;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_opaque_i_id;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_opaque_pac_key;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_opaque_pac_lifetime;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_opaque_pac_type;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_opaque_tlv;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_tlv;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_pac_type;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_result;
extern HIDDEN fr_dict_attr_t const *attr_eap_fast_vendor_specific;
extern HIDDEN fr_dict_t const *dict_eap_fast;
 
/*
 *      Process the FAST portion of an EAP-FAST request.
 */
void eap_fast_tlv_append(fr_tls_session_t *tls_session, fr_dict_attr_t const *da, bool mandatory,
                         int length, const void *data) CC_HINT(nonnull);
fr_radius_packet_code_t eap_fast_process(request_t *request, eap_session_t *eap_session, fr_tls_session_t *tls_session) CC_HINT(nonnull);
 
/*
 *      A bunch of EAP-FAST helper functions.
 */
ssize_t         eap_fast_decode_pair(TALLOC_CTX *ctx, fr_pair_list_t *out, fr_dict_attr_t const *parent,
                                     uint8_t const *data, size_t data_len,
                                     UNUSED void *decode_ctx);