state_machine.c

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/*
 *   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
 */
 
/**
 * @file src/lib/eap_aka_sim/state_machine.c
 * @brief Implement a common state machine for EAP-SIM, EAP-AKA, EAP-AKA'.
 *
 * @author Arran Cudbard-Bell (a.cudbardb@freeradius.org)
 *
 * @copyright 2021 Arran Cudbard-Bell (a.cudbardb@freeradius.org)
 * @copyright 2019 The FreeRADIUS server project
 * @copyright 2019 Network RADIUS (legal@networkradius.com)
 */
RCSID("$Id: 5099b23a5abfd3d0647ba3ee888aa30986a3fd81 $")
#include <freeradius-devel/eap/base.h>
#include <freeradius-devel/server/pair.h>
#include <freeradius-devel/unlang/interpret.h>
#include <freeradius-devel/unlang/module.h>
#include <freeradius-devel/util/rand.h>
 
#include "base.h"
#include "state_machine.h"
#include "attrs.h"
 
#ifndef EAP_TLS_MPPE_KEY_LEN
#  define EAP_TLS_MPPE_KEY_LEN     32
#endif
 
#define STATE(_x) static inline unlang_action_t state_ ## _x(unlang_result_t *p_result, \
                                                             module_ctx_t const *mctx, \
                                                             request_t *request)
 
#define STATE_GUARD(_x) static unlang_action_t guard_ ## _x(unlang_result_t *p_result, \
                                                            module_ctx_t const *mctx, \
                                                            request_t *request)
 
#define RESUME(_x) static inline unlang_action_t resume_ ## _x(unlang_result_t *p_result, \
                                                               module_ctx_t const *mctx, \
                                                               request_t *request)
 
#define STATE_NO_RESULT(_x) \
        static inline unlang_action_t state_ ## _x(UNUSED unlang_result_t *p_result, \
                                                   module_ctx_t const *mctx, \
                                                   request_t *request)
 
#define STATE_GUARD_NO_RESULT(_x) \
        static unlang_action_t guard_ ## _x(UNUSED unlang_result_t *p_result, \
                                            module_ctx_t const *mctx, \
                                            request_t *request)
 
#define STATE_TRANSITION(_x) guard_ ## _x(p_result, mctx, request)
 
#define CALL_SECTION(_x)        unlang_module_yield_to_section(&eap_aka_sim_session->section_result, \
                                                               request, \
                                                               inst->actions._x, \
                                                               RLM_MODULE_NOOP, \
                                                               resume_ ## _x, \
                                                               mod_signal, \
                                                               ~FR_SIGNAL_CANCEL, \
                                                               talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t))
 
/*
 *      Declare all state and guard functions to
 *      avoid ordering issues.
 */
STATE(eap_failure);
STATE_GUARD(eap_failure);
STATE(common_failure_notification);
STATE_GUARD(common_failure_notification);
STATE(eap_success);
STATE_GUARD(eap_success);
STATE(common_success_notification);
STATE_GUARD(common_success_notification);
STATE(common_reauthentication);
STATE_GUARD(common_reauthentication);
STATE(aka_challenge);
STATE_GUARD(aka_challenge);
STATE(sim_challenge);
STATE_GUARD(sim_challenge);
STATE_GUARD(common_challenge);
STATE(aka_identity);
STATE_GUARD(aka_identity);
STATE(sim_start);
STATE_GUARD(sim_start);
STATE_GUARD(common_identity);
STATE(init);
 
static fr_table_ptr_ordered_t const aka_sim_state_table[] = {
        { L("INIT"),                    NULL                                            },
 
        { L("EAP-IDENTITY"),            (void *)state_init                              },
        { L("SIM-START"),               (void *)state_sim_start                         },
        { L("AKA-IDENTITY"),            (void *)state_aka_identity                      },
 
        { L("SIM-CHALLENGE"),           (void *)state_sim_challenge                     },
        { L("AKA-CHALLENGE"),           (void *)state_aka_challenge                     },
 
        { L("SUCCESS-NOTIFICATION"),    (void *)state_common_success_notification       },
        { L("FAILURE-NOTIFICATION"),    (void *)state_common_failure_notification       },
 
        { L("REAUTHENTICATION"),        (void *)state_common_reauthentication           },
 
        { L("EAP-SUCCESS"),             (void *)state_eap_success                       },
        { L("EAP-FAILURE"),             (void *)state_eap_failure                       }
};
static size_t aka_sim_state_table_len = NUM_ELEMENTS(aka_sim_state_table);
 
/** Cancel a call to a submodule
 *
 * @param[in] mctx      UNUSED.
 * @param[in] request   The current request.
 * @param[in] action    to perform.
 */
static void mod_signal(module_ctx_t const *mctx, request_t *request, UNUSED fr_signal_t action)
{
        RDEBUG2("Request cancelled - Destroying session");
 
        /*
         *      Remove data from the request to
         *      avoid double free.
         */
        if (!fr_cond_assert(request_data_get(request, (void *)eap_aka_sim_state_machine_process, 0) == mctx->rctx)) return;
 
        talloc_free(mctx->rctx);
}
 
/** Warn the user that the rcode they provided is being ignored in this section
 *
 */
#define SECTION_RCODE_IGNORED \
do { \
        switch (eap_aka_sim_session->section_result.rcode) { \
        case RLM_MODULE_USER_SECTION_REJECT: \
                RWDEBUG("Ignoring rcode (%s)", \
                        fr_table_str_by_value(rcode_table, eap_aka_sim_session->section_result.rcode, "<invalid>")); \
                break; \
        default: \
                break; \
        } \
} while(0)
 
/** Trigger a state transition to FAILURE-NOTIFICATION if the section returned a failure code
 *
 */
#define SECTION_RCODE_PROCESS \
do { \
        if (after_authentication(eap_aka_sim_session)) { \
                switch (eap_aka_sim_session->section_result.rcode) { \
                case RLM_MODULE_REJECT:  \
                case RLM_MODULE_DISALLOW: \
                        eap_aka_sim_session->failure_type = FR_NOTIFICATION_VALUE_TEMPORARILY_DENIED; \
                        return STATE_TRANSITION(common_failure_notification); \
                case RLM_MODULE_NOTFOUND: \
                        eap_aka_sim_session->failure_type = FR_NOTIFICATION_VALUE_NOT_SUBSCRIBED; \
                        return STATE_TRANSITION(common_failure_notification); \
                case RLM_MODULE_INVALID: \
                case RLM_MODULE_FAIL: \
                        eap_aka_sim_session->failure_type = FR_NOTIFICATION_VALUE_GENERAL_FAILURE_AFTER_AUTHENTICATION;\
                        return STATE_TRANSITION(common_failure_notification); \
                default: \
                        break; \
                } \
        } else { \
                switch (eap_aka_sim_session->section_result.rcode) { \
                case RLM_MODULE_USER_SECTION_REJECT: \
                        REDEBUG("Section rcode (%s) indicates we should reject the user", \
                                fr_table_str_by_value(rcode_table, eap_aka_sim_session->section_result.rcode, "<INVALID>")); \
                        return STATE_TRANSITION(common_failure_notification); \
                default: \
                        break; \
                } \
        } \
} while(0)
 
/** Print debugging information, and write new state to eap_aka_sim_session->state
 *
 */
static inline CC_HINT(always_inline) void state_set(request_t *request,
                                                    eap_aka_sim_session_t *eap_aka_sim_session,
                                                    module_method_t new_state)
{
        module_method_t old_state = eap_aka_sim_session->state;
 
        if (new_state != old_state) {
                RDEBUG2("Changed state %s -> %s",
                        fr_table_str_by_value(aka_sim_state_table, (void *)old_state, "<unknown>"),
                        fr_table_str_by_value(aka_sim_state_table, (void *)new_state, "<unknown>"));
        } else {
                RDEBUG2("Reentering state %s",
                        fr_table_str_by_value(aka_sim_state_table, (void *)old_state, "<unknown>"));
        }
 
        eap_aka_sim_session->state = new_state;
}
#define STATE_SET(_new_state) state_set(request, talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t), state_ ## _new_state)
 
/** Determine if we're after authentication
 *
 */
static inline CC_HINT(always_inline) bool after_authentication(eap_aka_sim_session_t *eap_aka_sim_session)
{
        return eap_aka_sim_session->challenge_success || eap_aka_sim_session->reauthentication_success;
}
 
/** Print out the error the client returned
 *
 */
static inline CC_HINT(always_inline) void client_error_debug(request_t *request)
{
        fr_pair_t *vp;
 
        vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_client_error_code);
        if (!vp) {
                REDEBUG("Peer has not supplied a AT_ERROR_CODE");
        } else {
                REDEBUG("Peer rejected request with error: %i (%pV)", vp->vp_uint16, &vp->data);
        }
}
 
/** Sync up what identity we're requesting with attributes in the reply
 *
 */
static bool identity_req_set_by_user(request_t *request, eap_aka_sim_session_t *eap_aka_sim_session)
{
        bool            set_by_user = false;
 
        /*
         *      Check if the user included any of the
         *      ID req attributes.  If they did, use
         *      them to inform what we do next, and
         *      then delete them so they don't screw
         *      up any of the other code.
         */
        fr_pair_list_foreach(&request->reply_pairs, vp) {
                if (vp->da == attr_eap_aka_sim_permanent_id_req) {
                        eap_aka_sim_session->id_req = AKA_SIM_PERMANENT_ID_REQ;
                found:
                        set_by_user = true;
                        RDEBUG2("Previous section added reply.%pP, will request additional identity", vp);
                        fr_pair_delete(&request->reply_pairs, vp);
                }
                else if (vp->da == attr_eap_aka_sim_fullauth_id_req) {
                        eap_aka_sim_session->id_req = AKA_SIM_FULLAUTH_ID_REQ;
                        goto found;
                }
                else if (vp->da == attr_eap_aka_sim_any_id_req) {
                        eap_aka_sim_session->id_req = AKA_SIM_ANY_ID_REQ;
                        goto found;
                }
        }
 
        return set_by_user;
}
 
/** Based on the hint byte in the identity, add &Identity-Type and &Method-Hint attributes
 *
 */
static void identity_hint_pairs_add(fr_aka_sim_id_type_t *type_p, fr_aka_sim_method_hint_t *method_p,
                                    request_t *request, char const *identity)
{
        fr_aka_sim_id_type_t            type;
        fr_aka_sim_method_hint_t        method;
 
        /*
         *      Process the identity that we received.
         */
        if (fr_aka_sim_id_type(&type, &method,
                               identity, talloc_strlen(identity)) < 0) {
                RPWDEBUG2("Failed parsing identity, continuing anyway");
        }
 
        /*
         *      Map the output from the generic ID parser
         *      function to specific EAP-AKA internal
         *      attributes in the subrequest.
         */
        if (type != AKA_SIM_ID_TYPE_UNKNOWN) {
                fr_pair_t *vp = NULL;
 
                MEM(pair_update_request(&vp, attr_eap_aka_sim_identity_type) >= 0);
                switch (type) {
                case AKA_SIM_ID_TYPE_PERMANENT:
                        vp->vp_uint32 = FR_IDENTITY_TYPE_VALUE_PERMANENT;
                        break;
 
                case AKA_SIM_ID_TYPE_PSEUDONYM:
                        vp->vp_uint32 = FR_IDENTITY_TYPE_VALUE_PSEUDONYM;
                        break;
 
                case AKA_SIM_ID_TYPE_FASTAUTH:
                        vp->vp_uint32 = FR_IDENTITY_TYPE_VALUE_FASTAUTH;
                        break;
 
                default:
                        fr_assert(0);
                }
        }
 
        /*
         *      Map the output from the generic ID parser
         *      function to specific EAP-AKA internal
         *      attributes in the subrequest.
         */
        if (method != AKA_SIM_METHOD_HINT_UNKNOWN) {
                fr_pair_t *vp = NULL;
 
                MEM(pair_update_request(&vp, attr_eap_aka_sim_method_hint) >= 0);
                switch (method) {
                case AKA_SIM_METHOD_HINT_AKA_PRIME:
                        vp->vp_uint32 = FR_METHOD_HINT_VALUE_AKA_PRIME;
                        break;
 
                case AKA_SIM_METHOD_HINT_AKA:
                        vp->vp_uint32 = FR_METHOD_HINT_VALUE_AKA;
                        break;
 
                case AKA_SIM_METHOD_HINT_SIM:
                        vp->vp_uint32 = FR_METHOD_HINT_VALUE_SIM;
                        break;
 
                default:
                        fr_assert(0);
                }
        }
 
        if (type_p) *type_p = type;
        if (method_p) *method_p = method;
}
 
/** Add an Identity Request attribute to the reply
 *
 * Verify the progression of identity requests is valid.
 *
 * @param[in] request                   The current request.
 * @param[in] eap_aka_sim_session       The current eap_aka_sim_session.
 * @return
 *      - 0 on success.
 *      - -1 on failure (progression of identities was not valid).
 */
static int identity_req_pairs_add(request_t *request, eap_aka_sim_session_t *eap_aka_sim_session)
{
        fr_pair_t *vp;
 
        switch (eap_aka_sim_session->id_req) {
        /*
         *      This is allowed for EAP-SIM.
         *
         *      The EAP-SIM-Start packet gets used both for "version negotiation" and
         *      for request identities, so for EAP-SIM it's perfectly acceptable
         *      to send four Sim-Start packets:
         *
         *      - No ID
         *      - Any ID
         *      - Fullauth ID
         *      - Permanent ID
         *
         *      We need to represent the starting state as separate from no id req,
         *      so that we can catch potential loops in the identity statate machine
         */
        case AKA_SIM_NO_ID_REQ:
                if (eap_aka_sim_session->last_id_req != AKA_SIM_INIT_ID_REQ) {
                id_out_of_order:
                        REDEBUG("Cannot send %s, already sent %s",
                                fr_table_str_by_value(fr_aka_sim_id_request_table,
                                                      eap_aka_sim_session->id_req, "<INVALID>"),
                                fr_table_str_by_value(fr_aka_sim_id_request_table,
                                                      eap_aka_sim_session->last_id_req, "<INVALID>"));
                        return -1;
                }
                break;
 
        case AKA_SIM_ANY_ID_REQ:
                switch (eap_aka_sim_session->last_id_req) {
                case AKA_SIM_INIT_ID_REQ:
                case AKA_SIM_NO_ID_REQ:
                        break;
 
                default:
                        goto id_out_of_order;
                }
                MEM(pair_append_reply(&vp, attr_eap_aka_sim_any_id_req) >= 0);
                vp->vp_bool = true;
                break;
 
        case AKA_SIM_FULLAUTH_ID_REQ:
                switch (eap_aka_sim_session->last_id_req) {
                case AKA_SIM_INIT_ID_REQ:
                case AKA_SIM_NO_ID_REQ:         /* Not sent anything before */
                case AKA_SIM_ANY_ID_REQ:        /* Last request was for any ID, but the re-auth ID was bad */
                        break;
 
                default:
                        goto id_out_of_order;
                }
                MEM(pair_append_reply(&vp, attr_eap_aka_sim_fullauth_id_req) >= 0);
                vp->vp_bool = true;
                break;
 
        case AKA_SIM_PERMANENT_ID_REQ:
                switch (eap_aka_sim_session->last_id_req) {
                case AKA_SIM_INIT_ID_REQ:
                case AKA_SIM_NO_ID_REQ:         /* Not sent anything before */
                case AKA_SIM_ANY_ID_REQ:        /* Last request was for any ID, but the re-auth ID was bad */
                case AKA_SIM_FULLAUTH_ID_REQ:   /* ...didn't understand the pseudonym either */
                        break;
 
                default:
                        goto id_out_of_order;
                }
                MEM(pair_append_reply(&vp, attr_eap_aka_sim_permanent_id_req) >= 0);
                vp->vp_bool = true;
                break;
 
        default:
                fr_assert(0);
        }
 
        return 0;
}
 
/** Copy the incoming identity to the permanent identity attribute
 *
 * If the incoming ID really looks like a permanent ID, and we were
 * told it was a permanent ID, then (optionally) trim the first byte
 * to form the real permanent ID.
 *
 * Otherwise copy the entire incoming Identity to the
 * &session-state.Permanent-Identity attribute.
 *
 * @param[in] request           The current request.
 * @param[in] in                current identity.
 * @param[in] eap_type          The current eap_type.
 * @param[in] strip_hint        Whether to strip the hint byte off the permanent identity
 */
static int identity_to_permanent_identity(request_t *request, fr_pair_t *in, eap_type_t eap_type, bool strip_hint)
{
        fr_aka_sim_id_type_t            our_type;
        fr_aka_sim_method_hint_t        our_method, expected_method;
        fr_pair_t                       *vp;
 
        if (in->vp_length == 0) {
                RDEBUG2("Not processing zero length identity");
                return -1;
        }
 
        /*
         *      Not requested to strip hint, don't do anything
         *      fancy, just copy Identity -> Permanent-Identity.
         */
        if (!strip_hint) {
                MEM(pair_update_session_state(&vp, attr_eap_aka_sim_permanent_identity) >= 0);
                fr_pair_value_bstrndup(vp, in->vp_strvalue, in->vp_length, true);
                return 0;
        }
 
        switch (eap_type) {
        case FR_EAP_METHOD_SIM:
                expected_method = AKA_SIM_METHOD_HINT_SIM;
                break;
 
        case FR_EAP_METHOD_AKA:
                expected_method = AKA_SIM_METHOD_HINT_AKA;
                break;
 
        case FR_EAP_METHOD_AKA_PRIME:
                expected_method = AKA_SIM_METHOD_HINT_AKA_PRIME;
                break;
 
        default:
                return -1;
        }
 
        /*
         *      First, lets see if this looks like an identity
         *      we can process.
         *
         *      For now we allow all permanent identities no
         *      matter what EAP method.
         *
         *      This is because we could be starting a different
         *      EAP method to the one the identity hinted,
         *      but we still want to strip the first byte.
         */
        if ((fr_aka_sim_id_type(&our_type, &our_method, in->vp_strvalue, in->vp_length) < 0) ||
            (our_type != AKA_SIM_ID_TYPE_PERMANENT)) {
                MEM(pair_update_session_state(&vp, attr_eap_aka_sim_permanent_identity) >= 0);
                fr_pair_value_bstrndup(vp, in->vp_strvalue, in->vp_length, true);
 
                RDEBUG2("%s has incorrect hint byte, expected '%c', got '%c'.  "
                        "'hint' byte not stripped",
                        attr_eap_aka_sim_permanent_identity->name,
                        fr_aka_sim_hint_byte(AKA_SIM_ID_TYPE_PERMANENT, expected_method),
                        fr_aka_sim_hint_byte(our_type, our_method));
                RINDENT();
                RDEBUG2("session-state.%pP", vp);
                REXDENT();
        } else {
                /*
                 *      To get here the identity must be >= 1 and must have
                 *      had the expected hint byte.
                 *
                 *      Strip off the hint byte, and then add the permanent
                 *      identity to the output list.
                 */
                MEM(pair_update_session_state(&vp, attr_eap_aka_sim_permanent_identity) >= 0);
                fr_pair_value_bstrndup(vp, in->vp_strvalue + 1, in->vp_length - 1, true);
 
                RDEBUG2("Stripping 'hint' byte from %s", attr_eap_aka_sim_permanent_identity->name);
                RINDENT();
                RDEBUG2("session-state.%pP", vp);
                REXDENT();
        }
 
        return 0;
}
 
/** Check &control.checkcode matches &reply.checkcode
 *
 * @param[in] request   The current request.
 * @return
 *      - 1 if the check was skipped.
 *      - 0 if the check was successful.
 *      - -1 if the check failed.
 */
static int checkcode_validate(request_t *request)
{
        fr_pair_t               *peer_checkcode, *our_checkcode;
        /*
         *      Checkcode validation
         *
         *      The actual cryptographic calculations are
         *      done by the calling module, we just check
         *      the result.
         */
        our_checkcode = fr_pair_find_by_da(&request->control_pairs, NULL, attr_eap_aka_sim_checkcode);
        if (our_checkcode) {
                /*
                 *      If the peer doesn't include a checkcode then that
                 *      means they don't support it, and we can't validate
                 *      their view of the identity packets.
                 */
                peer_checkcode = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_checkcode);
                if (peer_checkcode) {
                        if (fr_pair_cmp(peer_checkcode, our_checkcode) == 0) {
                                RDEBUG2("Received AT_CHECKCODE matches calculated AT_CHECKCODE");
                                return 0;
                        } else {
                                REDEBUG("Received AT_CHECKCODE does not match calculated AT_CHECKCODE");
                                RHEXDUMP_INLINE2(peer_checkcode->vp_octets, peer_checkcode->vp_length, "Received");
                                RHEXDUMP_INLINE2(our_checkcode->vp_octets, our_checkcode->vp_length, "Expected");
                                return -1;
                        }
                /*
                 *      Only print something if we calculated a checkcode
                 */
                } else {
                        RDEBUG2("Peer didn't include AT_CHECKCODE, skipping checkcode validation");
                }
        }
        return 1;
}
 
/** Check &control.mac matches &reply.mac
 *
 * @param[in] request   The current request.
 * @return
 *      - 0 if the check was successful.
 *      - -1 if the check failed.
 */
static int mac_validate(request_t *request)
{
        fr_pair_t               *peer_mac, *our_mac;
        /*
         *      mac validation
         *
         *      The actual cryptographic calculations are
         *      done by the calling module, we just check
         *      the result.
         */
        our_mac = fr_pair_find_by_da(&request->control_pairs, NULL, attr_eap_aka_sim_mac);
        if (!our_mac) {
                REDEBUG("Missing control.%s", attr_eap_aka_sim_mac->name);
                return -1;
 
        }
 
        /*
         *      If the peer doesn't include a mac then that
         *      means they don't support it, and we can't validate
         *      their view of the identity packets.
         */
        peer_mac = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_mac);
        if (!peer_mac) {
                REDEBUG("Peer didn't include AT_MAC");
                return -1;
        }
 
        if (fr_pair_cmp(peer_mac, our_mac) != 0) {
                REDEBUG("Received AT_MAC does not match calculated AT_MAC");
                RHEXDUMP_INLINE2(peer_mac->vp_octets, peer_mac->vp_length, "Received");
                RHEXDUMP_INLINE2(our_mac->vp_octets, our_mac->vp_length, "Expected");
                return -1;
        }
 
        RDEBUG2("Received AT_MAC matches calculated AT_MAC");
        return 0;
}
 
/** Set the crypto identity from a received identity
 *
 */
static void crypto_identity_set(request_t *request, eap_aka_sim_session_t *eap_aka_sim_session,
                                uint8_t const *identity, size_t len)
{
        RDEBUG3("Setting cryptographic identity to \"%pV\"", fr_box_strvalue_len((char const *)identity, len));
 
        talloc_free(eap_aka_sim_session->keys.identity);
        eap_aka_sim_session->keys.identity_len = len;
        MEM(eap_aka_sim_session->keys.identity = talloc_memdup(eap_aka_sim_session, identity, len));
 
}
 
/** Resume after 'store session { ... }'
 *
 */
RESUME(store_session)
{
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        switch (eap_aka_sim_session->section_result.rcode) {
        /*
         *      Store failed.  Don't send fastauth id
         */
        case RLM_MODULE_USER_SECTION_REJECT:
                pair_delete_reply(attr_eap_aka_sim_next_reauth_id);
                break;
 
        default:
                break;
        }
 
        pair_delete_request(attr_eap_aka_sim_next_reauth_id);
 
        return eap_aka_sim_session->next(p_result, mctx, request);
}
 
/** Resume after 'store pseudonym { ... }'
 *
 * Stores session data if required.
 */
RESUME(store_pseudonym)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t                       *vp;
        fr_pair_t                       *new;
 
        switch (eap_aka_sim_session->section_result.rcode) {
        /*
         *      Store failed.  Don't send pseudonym
         */
        case RLM_MODULE_USER_SECTION_REJECT:
                pair_delete_reply(attr_eap_aka_sim_next_pseudonym);
                break;
 
        default:
                break;
        }
 
        eap_aka_sim_session->section_result.rcode = RLM_MODULE_NOOP;    /* Needed because we may call resume functions directly */
 
        pair_delete_request(attr_eap_aka_sim_next_pseudonym);
 
        /*
         *      Generate fast-reauth data if we
         *      find a next_reauth_id pair in the
         *      reply list.
         */
        vp = fr_pair_find_by_da_nested(&request->reply_pairs, NULL, attr_eap_aka_sim_next_reauth_id);
        if (vp) {
                /*
                 *      Generate a random fastauth string
                 */
                if (vp->vp_length == 0) {
                        char *identity;
 
                        if (!inst->ephemeral_id_length) {
                                RWDEBUG("Found empty Next-Reauth-Id, and told not to generate one.  "
                                        "Skipping store session { ... } section");
 
                                goto done;
                        }
 
                        MEM(identity = talloc_array(vp, char, inst->ephemeral_id_length + 2));
                        switch (eap_aka_sim_session->type) {
                        case FR_EAP_METHOD_SIM:
                                identity[0] = (char)ID_TAG_SIM_FASTAUTH;
                                break;
 
                        case FR_EAP_METHOD_AKA:
                                identity[0] = (char)ID_TAG_AKA_FASTAUTH;
                                break;
 
                        case FR_EAP_METHOD_AKA_PRIME:
                                identity[0] = (char)ID_TAG_AKA_PRIME_FASTAUTH;
                                break;
 
                        default:
                                break;
                        }
                        fr_rand_str((uint8_t *)identity + 1, inst->ephemeral_id_length, 'a');
                        identity[talloc_strlen(identity)] = '\0';
 
                        fr_value_box_bstrdup_buffer_shallow(NULL, &vp->data, NULL, identity, false);
                }
                MEM(pair_update_request(&new, attr_session_id) >= 0);
                fr_pair_value_memdup(new, (uint8_t const *)vp->vp_strvalue, vp->vp_length, vp->vp_tainted);
 
                MEM(eap_aka_sim_session->fastauth_sent = talloc_bstrndup(eap_aka_sim_session,
                                                                         vp->vp_strvalue, vp->vp_length));
 
                switch (eap_aka_sim_session->type) {
                /*
                 *      AKA and SIM use the original MK for session resumption.
                 */
                case FR_EAP_METHOD_SIM:
                case FR_EAP_METHOD_AKA:
                        fr_assert(eap_aka_sim_session->keys.mk_len >= AKA_SIM_MK_SIZE);
 
                        MEM(pair_update_session_state(&vp, attr_session_data) >= 0);
                        fr_pair_value_memdup(vp,
                                             eap_aka_sim_session->keys.mk, eap_aka_sim_session->keys.mk_len,
                                             false);
                        break;
                /*
                 *      AKA' KDF 1 generates an additional key k_re
                 *      which is used for reauthentication instead
                 *      of the MK.
                 */
                case FR_EAP_METHOD_AKA_PRIME:
                        fr_assert(eap_aka_sim_session->keys.mk_len >= AKA_PRIME_MK_REAUTH_SIZE);
 
                        MEM(pair_update_session_state(&vp, attr_session_data) >= 0);
                        fr_pair_value_memdup(vp,
                                             eap_aka_sim_session->keys.mk, AKA_PRIME_MK_REAUTH_SIZE,
                                             false);    /* truncates */
                        break;
 
                default:
                        fr_assert(0);
                        break;
                }
 
                /*
                 *      If the counter already exists in session
                 *      state increment by 1, otherwise, add the
                 *      attribute and set to zero.
                 */
                vp = fr_pair_find_by_da_nested(&request->session_state_pairs, NULL, attr_eap_aka_sim_counter);
                if (vp) {
                        vp->vp_uint16++;
                /*
                 *      Will get incremented by 1 in
                 *      reauthentication_send, so when
                 *      used, it'll be 1 (as per the standard).
                 */
                } else {
                        MEM(pair_append_session_state(&vp, attr_eap_aka_sim_counter) >= 0);
                        vp->vp_uint16 = 0;
                }
 
                return CALL_SECTION(store_session);
        }
 
        /*
         *      We didn't store any fast-reauth data
         */
done:
        return eap_aka_sim_session->next(p_result, mctx, request);
}
 
/** Implements a set of states for storing pseudonym and fastauth identities
 *
 * At the end of challenge or reauthentication rounds, the user may have specified
 * a pseudonym and fastauth identity to return to the supplicant.
 *
 * Call the appropriate sections to persist those values.
 *
 * @param[out] p_result                 Result of calling the module.
 * @param[in] mctx                      Module calling ctx.
 * @param[in] request                   the current request.
 * @param[in] eap_aka_sim_session       the EAP session
 * @param[in] next                      function to call after storing sessions and pseudonyms.
 */
static unlang_action_t session_and_pseudonym_store(unlang_result_t *p_result, module_ctx_t const *mctx,
                                                   request_t *request,
                                                   eap_aka_sim_session_t *eap_aka_sim_session,
                                                   module_method_t next)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        fr_pair_t                       *vp;
        fr_pair_t                       *new;
 
        if (!fr_cond_assert(next)) return STATE_TRANSITION(common_failure_notification);
 
        eap_aka_sim_session->next = next;
 
        eap_aka_sim_session->section_result.rcode = RLM_MODULE_NOOP; /* Reset the result code, as we may call resume functions directly */
 
        vp = fr_pair_find_by_da_nested(&request->reply_pairs, NULL, attr_eap_aka_sim_next_pseudonym);
        if (vp) {
                /*
                 *      Generate a random pseudonym string
                 */
                if (vp->vp_length == 0) {
                        char *identity;
 
                        if (!inst->ephemeral_id_length) {
                                RWDEBUG("Found empty Pseudonym-Id, and told not to generate one.  "
                                        "Skipping store pseudonym { ... } section");
 
                                return resume_store_pseudonym(p_result, mctx, request);
                        }
 
                        MEM(identity = talloc_array(vp, char, inst->ephemeral_id_length + 2));
                        fr_rand_str((uint8_t *)identity + 1, inst->ephemeral_id_length, 'a');
                        switch (eap_aka_sim_session->type) {
                        case FR_EAP_METHOD_SIM:
                                identity[0] = (char)ID_TAG_SIM_PSEUDONYM;
                                break;
 
                        case FR_EAP_METHOD_AKA:
                                identity[0] = (char)ID_TAG_AKA_PSEUDONYM;
                                break;
 
                        case FR_EAP_METHOD_AKA_PRIME:
                                identity[0] = (char)ID_TAG_AKA_PRIME_PSEUDONYM;
                                break;
 
                        default:
                                break;
                        }
                        identity[talloc_strlen(identity)] = '\0';
                        fr_value_box_bstrdup_buffer_shallow(NULL, &vp->data, NULL, identity, false);
                }
                MEM(pair_update_request(&new, attr_eap_aka_sim_next_pseudonym) >= 0);
                fr_pair_value_copy(new, vp);
 
                MEM(eap_aka_sim_session->pseudonym_sent = talloc_bstrndup(eap_aka_sim_session,
                                                                          vp->vp_strvalue, vp->vp_length));
                return CALL_SECTION(store_pseudonym);
        }
 
        return resume_store_pseudonym(p_result, mctx, request);
}
 
/** Resume after 'clear session { ... }'
 *
 */
RESUME(clear_session)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        pair_delete_request(attr_session_id);
 
        return eap_aka_sim_session->next(p_result, mctx, request);
}
 
/** Resume after 'clear pseudonym { ... }'
 *
 */
RESUME(clear_pseudonym)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        pair_delete_request(attr_eap_aka_sim_next_pseudonym);
 
        /*
         *      Clear session (if one was stored)
         */
        if (eap_aka_sim_session->fastauth_sent) {
                fr_pair_t *vp;
 
                pair_delete_request(attr_session_id);
 
                MEM(pair_update_request(&vp, attr_session_id) >= 0);
                fr_value_box_memdup(vp, &vp->data, NULL,
                                    (uint8_t *)eap_aka_sim_session->fastauth_sent,
                                    talloc_strlen(eap_aka_sim_session->fastauth_sent), true);
                TALLOC_FREE(eap_aka_sim_session->fastauth_sent);
 
                return CALL_SECTION(clear_session);
        }
 
        return eap_aka_sim_session->next(p_result, mctx, request);
}
 
/** Implements a set of states for clearing out pseudonym and fastauth identities
 *
 * If either a Challenge round or Reauthentication round fail, we need to clear
 * any identities that were provided during those rounds, as the supplicant
 * will have discarded them.
 *
 * @param[out] p_result                 Result of calling the module.
 * @param[in] mctx                      module calling ctx.
 * @param[in] request                   the current request.
 * @param[in] eap_aka_sim_session       the current EAP session
 * @param[in] next                      function to call after clearing sessions and pseudonyms.
 */
static unlang_action_t session_and_pseudonym_clear(unlang_result_t *p_result, module_ctx_t const *mctx,
                                                   request_t *request,
                                                   eap_aka_sim_session_t *eap_aka_sim_session,
                                                   module_method_t next)
{
        eap_aka_sim_process_conf_t *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
 
        if (!fr_cond_assert(next)) return STATE_TRANSITION(common_failure_notification);
 
        eap_aka_sim_session->next = next;
 
        eap_aka_sim_session->section_result.rcode = RLM_MODULE_NOOP;    /* Reset the result code, as we may call resume functions directly */
 
        /*
         *      Clear out pseudonyms (if we sent one)
         */
        if (eap_aka_sim_session->pseudonym_sent) {
                fr_pair_t *vp;
 
                MEM(pair_update_request(&vp, attr_eap_aka_sim_next_pseudonym) >= 0);
                fr_value_box_bstrdup_buffer(vp, &vp->data, NULL, eap_aka_sim_session->pseudonym_sent, true);
                TALLOC_FREE(eap_aka_sim_session->pseudonym_sent);
 
                return CALL_SECTION(clear_pseudonym);
        }
 
        return resume_clear_pseudonym(p_result, mctx, request);
}
 
/** Export EAP-SIM/AKA['] attributes
 *
 * Makes any internal data available as attributes in the response.
 * This allows test frameworks and the encoder to access any data they need without
 * needing to look at the eap_aka_session_t.
 */
static void common_reply(request_t *request, eap_aka_sim_session_t *eap_aka_sim_session, uint16_t subtype)
{
        fr_pair_t               *subtype_vp;
 
        /*
         *      Set the subtype to identity request
         */
        MEM(pair_update_reply(&subtype_vp, attr_eap_aka_sim_subtype) >= 0);
        subtype_vp->vp_uint16 = subtype;
 
        if (!eap_aka_sim_session->allow_encrypted) {
                fr_pair_list_foreach(&request->reply_pairs, vp) {
                        if (fr_dict_attr_common_parent(attr_eap_aka_sim_encr_data, vp->da, true)) {
                                RWDEBUG("Silently discarding reply.%pP: Encrypted attributes not "
                                        "allowed in this round", vp);
                                fr_pair_delete(&request->reply_pairs, vp);
                        }
                }
        }
}
 
static void CC_HINT(nonnull(1,2))
common_crypto_export(request_t *request, eap_aka_sim_session_t *eap_aka_sim_session,
                     uint8_t const *hmac_extra_request, size_t hmac_extra_request_len,
                     uint8_t const *hmac_extra_response, size_t hmac_extra_response_len)
{
        fr_pair_t *vp;
 
        /*
         *      Export keying material necessary for
         *      the encoder to encrypt and sign
         *      packets.
         */
        if (hmac_extra_request && hmac_extra_request_len) {
                MEM(pair_update_control(&vp, attr_eap_aka_sim_hmac_extra_request) >= 0);
                MEM(fr_pair_value_memdup(vp, hmac_extra_request, hmac_extra_request_len, true) == 0);
        }
 
        if (hmac_extra_response && hmac_extra_response_len) {
                MEM(pair_update_control(&vp, attr_eap_aka_sim_hmac_extra_response) >= 0);
                MEM(fr_pair_value_memdup(vp, hmac_extra_response, hmac_extra_response_len, true) == 0);
        }
 
        MEM(pair_update_control(&vp, attr_eap_aka_sim_k_aut) >= 0);
        MEM(fr_pair_value_memdup(vp,
                                 eap_aka_sim_session->keys.k_aut,
                                 eap_aka_sim_session->keys.k_aut_len,
                                 true) == 0);
 
        MEM(pair_update_control(&vp, attr_eap_aka_sim_k_encr) >= 0);
        MEM(fr_pair_value_memdup(vp,
                                 eap_aka_sim_session->keys.k_encr,
                                 sizeof(eap_aka_sim_session->keys.k_encr),
                                 true) == 0);
}
 
/** Called after 'store session { ... }' and 'store pseudonym { ... }'
 *
 */
static unlang_action_t common_reauthentication_request_send(unlang_result_t *p_result,
                                                            module_ctx_t const *mctx, request_t *request)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        /*
         *      Return reply attributes - AT_IV is handled automatically by the encoder
         */
        common_reply(request, eap_aka_sim_session, FR_SUBTYPE_VALUE_AKA_SIM_REAUTHENTICATION);
 
        /*
         *      9.5.  EAP-Request/SIM/Re-authentication
         *
         *      AT_MAC MUST be included.  No message-specific data is included in the
         *      MAC calculation.  See Section 10.14.
         *
         *      9.6.  EAP-Response/SIM/Re-authentication
         *
         *      The AT_MAC attribute MUST be included.  For
         *      EAP-Response/SIM/Re-authentication, the MAC code is calculated over
         *      the following data: EAP packet| NONCE_S
         *
         *      9.7.  EAP-Request/AKA-Reauthentication
         *
         *      The AT_MAC attribute MUST be included.  No message-specific data is
         *      included in the MAC calculation, see Section 10.15.
         *
         *      9.8.  EAP-Response/AKA-Reauthentication
         *
         *      The AT_MAC attribute MUST be included.  For
         *      EAP-Response/AKA-Reauthentication, the MAC code is calculated over
         *      the following data:  EAP packet| NONCE_S.
         */
        common_crypto_export(request, eap_aka_sim_session,
                             NULL, 0,
                             eap_aka_sim_session->keys.reauth.nonce_s,
                             sizeof(eap_aka_sim_session->keys.reauth.nonce_s));
 
        RETURN_UNLANG_HANDLED;
}
 
/** Called after 'store session { ... }' and 'store pseudonym { ... }'
 *
 */
static unlang_action_t aka_challenge_request_send(unlang_result_t *p_result, module_ctx_t const *mctx, request_t *request)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        /*
         *      Encode the packet - AT_IV is handled automatically
         *      by the encoder.
         */
        common_reply(request, eap_aka_sim_session, FR_SUBTYPE_VALUE_AKA_CHALLENGE);
 
        /*
         *      9.3.  EAP-Request/AKA-Challenge
         *
         *      AT_MAC MUST be included.  In EAP-Request/AKA-Challenge, there is no
         *      message-specific data covered by the MAC, see Section 10.15.
         *
         *      9.4.  EAP-Response/AKA-Challenge
         *
         *      The AT_MAC attribute MUST be included.  In
         *      EAP-Response/AKA-Challenge, there is no message-specific data covered
         *      by the MAC, see Section 10.15.
         */
        common_crypto_export(request, eap_aka_sim_session, NULL, 0, NULL, 0);
 
        RETURN_UNLANG_HANDLED;
}
 
/** Called after 'store session { ... }' and 'store pseudonym { ... }'
 *
 */
static unlang_action_t sim_challenge_request_send(unlang_result_t *p_result, module_ctx_t const *mctx, request_t *request)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        uint8_t                 sres_cat[AKA_SIM_VECTOR_GSM_SRES_SIZE * 3];
        uint8_t                 *p = sres_cat;
 
        /*
         *      Encode the packet - AT_IV is handled automatically
         *      by the encoder.
         */
        common_reply(request, eap_aka_sim_session, FR_SUBTYPE_VALUE_SIM_CHALLENGE);
 
        memcpy(p, eap_aka_sim_session->keys.gsm.vector[0].sres, AKA_SIM_VECTOR_GSM_SRES_SIZE);
        p += AKA_SIM_VECTOR_GSM_SRES_SIZE;
        memcpy(p, eap_aka_sim_session->keys.gsm.vector[1].sres, AKA_SIM_VECTOR_GSM_SRES_SIZE);
        p += AKA_SIM_VECTOR_GSM_SRES_SIZE;
        memcpy(p, eap_aka_sim_session->keys.gsm.vector[2].sres, AKA_SIM_VECTOR_GSM_SRES_SIZE);
 
        /*
         *      9.3.  EAP-Request/SIM/Challenge
         *
         *      The AT_MAC attribute MUST be included.  For
         *      EAP-Request/SIM/Challenge, the MAC code is calculated over the
         *      following data: EAP packet| NONCE_MT
         *
         *      9.4.  EAP-Response/SIM/Challenge
         *
         *      The AT_MAC attribute MUST be included.  For EAP-
         *      Response/SIM/Challenge, the MAC code is calculated over the following
         *      data: EAP packet| n*SRES
         */
        common_crypto_export(request, eap_aka_sim_session,
                             eap_aka_sim_session->keys.gsm.nonce_mt, sizeof(eap_aka_sim_session->keys.gsm.nonce_mt),
                             sres_cat, sizeof(sres_cat));
 
        RETURN_UNLANG_HANDLED;
}
 
/** Helper function to check for the presence and length of AT_SELECTED_VERSION and copy its value into the keys structure
 *
 * Also checks the version matches one of the ones we advertised in our version list,
 * which is a bit redundant seeing as there's only one version of EAP-SIM.
 */
static int sim_start_selected_version_check(request_t *request, eap_aka_sim_session_t *eap_aka_sim_session)
{
        fr_pair_t               *selected_version_vp;
 
        /*
         *      Check that we got an AT_SELECTED_VERSION
         */
        selected_version_vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_selected_version);
        if (!selected_version_vp) {
                REDEBUG("EAP-Response/SIM/Start does not contain AT_SELECTED_VERSION");
                return -1;
        }
 
        /*
         *      See if the selected version was in our list
         */
        {
                uint8_t selected_version[2];
                uint8_t *p, *end;
                bool found = false;
 
                p = eap_aka_sim_session->keys.gsm.version_list;
                end = p + eap_aka_sim_session->keys.gsm.version_list_len;
 
                selected_version[0] = (selected_version_vp->vp_uint16 & 0xff00) >> 8;
                selected_version[1] = (selected_version_vp->vp_uint16 & 0x00ff);
 
                while ((p + 2) <= end) {
                        if ((p[0] == selected_version[0]) && (p[1] == selected_version[1])) {
                                found = true;
 
                                /*
                                 *      Update our keying material
                                 */
                                eap_aka_sim_session->keys.gsm.version_select[0] = selected_version[0];
                                eap_aka_sim_session->keys.gsm.version_select[1] = selected_version[1];
                                break;
                        }
                        p += 2;
                }
 
                if (!found) {
                        REDEBUG("AT_SELECTED_VERSION (%u) does not match a value in our version list",
                                selected_version_vp->vp_uint16);
                        return -1;
                }
        }
 
        return 0;
}
 
/** Helper function to check for the presence and length of AT_NONCE_MT and copy its value into the keys structure
 *
 * Does not actually perform cryptographic validation of AT_NONCE_MT, this is done later.
 */
static int sim_start_nonce_mt_check(request_t *request, eap_aka_sim_session_t *eap_aka_sim_session)
{
        fr_pair_t       *nonce_mt_vp;
 
        /*
         *      Copy nonce_mt to the keying material
         */
        nonce_mt_vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_nonce_mt);
        if (!nonce_mt_vp) {
                REDEBUG("EAP-Response/SIM/Start does not contain AT_NONCE_MT");
                return -1;
        }
 
        if (nonce_mt_vp->vp_length != sizeof(eap_aka_sim_session->keys.gsm.nonce_mt)) {
                REDEBUG("AT_NONCE_MT must be exactly %zu bytes, not %zu bytes",
                        sizeof(eap_aka_sim_session->keys.gsm.nonce_mt), nonce_mt_vp->vp_length);
                return -1;
        }
        memcpy(eap_aka_sim_session->keys.gsm.nonce_mt, nonce_mt_vp->vp_octets,
               sizeof(eap_aka_sim_session->keys.gsm.nonce_mt));
 
        return 0;
}
 
/** FAILURE state - State machine exit point after sending EAP-Failure
 *
 * Should never actually be called. Is just a placeholder function to represent the FAILURE
 * termination state.  Could equally be a NULL pointer, but then on a logic error
 * we'd get a SEGV instead of a more friendly assert/failure rcode.
 */
STATE(eap_failure)
{
        if (!fr_cond_assert(request && mctx && mctx->rctx)) RETURN_UNLANG_FAIL; /* unused args */
 
        fr_assert(0);   /* Should never actually be called */
 
        RETURN_UNLANG_FAIL;
}
 
/** Resume after 'send EAP-Failure { ... }'
 *
 */
RESUME(send_eap_failure)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        if (!fr_cond_assert(mctx && mctx->rctx)) RETURN_UNLANG_FAIL;    /* unused args */
 
        SECTION_RCODE_IGNORED;
 
        RDEBUG2("Sending EAP-Failure");
 
        RETURN_UNLANG_REJECT;
}
 
/** Enter EAP-FAILURE state
 *
 */
STATE_GUARD(eap_failure)
{
        eap_aka_sim_process_conf_t *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        /*
         *      Free anything we were going to send out...
         */
        fr_pair_list_free(&request->reply_pairs);
 
        /*
         *      If we're failing, then any identities
         *      we sent are now invalid.
         */
        if (eap_aka_sim_session->pseudonym_sent || eap_aka_sim_session->fastauth_sent) {
                return session_and_pseudonym_clear(p_result, mctx,
                                                   request, eap_aka_sim_session, guard_eap_failure);
                                                   /* come back when we're done */
        }
 
        STATE_SET(eap_failure);
 
        return CALL_SECTION(send_eap_failure);
}
 
/** Resume after 'recv Failure-Notification-Ack { ... }'
 *
 * - Enter the EAP-FAILURE state.
 */
RESUME(recv_common_failure_notification_ack)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        SECTION_RCODE_IGNORED;
 
        /*
         *      Case 2 where we're allowed to send an EAP-Failure
         */
        return STATE_TRANSITION(eap_failure);
}
 
/** FAILURE-NOTIFICATION state - Continue the state machine after receiving a response to our EAP-Request/(AKA|SIM)-Notification
 *
 * - Continue based on received AT_SUBTYPE value:
 *   - EAP-Response/SIM-Client-Error - Call 'recv Failure-Notification-Ack { ... }'
 *   - Anything else, enter the FAILURE-NOTIFICATION state.
 */
STATE(common_failure_notification)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t                       *subtype_vp = NULL;
 
        subtype_vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_subtype);
        if (!subtype_vp) goto fail;
 
        switch (subtype_vp->vp_uint16) {
        case FR_SUBTYPE_VALUE_AKA_SIM_NOTIFICATION:
                RDEBUG2("Failure-Notification ACKed, sending EAP-Failure");
                return CALL_SECTION(recv_common_failure_notification_ack);
 
        default:
        fail:
                RWDEBUG("Failure-Notification not ACKed correctly, sending EAP-Failure anyway");
                return STATE_TRANSITION(eap_failure);
        }
}
 
/** Resume after 'send Failure-Notification { ... }'
 *
 * Ignores return code from send Failure-Notification { ... } section.
 */
RESUME(send_common_failure_notification)
{
        fr_pair_t               *vp, *notification_vp;
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx,
                                                                             eap_aka_sim_session_t);
 
        if (!fr_cond_assert(mctx)) RETURN_UNLANG_FAIL;  /* quiet unused warning */
 
        SECTION_RCODE_IGNORED;
 
        /*
         *      Allow the user to specify specific failure notification
         *      types.  We assume the user knows what they're doing and
         *      only toggle success and phase bits.
         *
         *      This allows custom notification schemes to be implemented.
         *
         *      If this is prior to authentication, valid values are:
         *      - FR_NOTIFICATION_VALUE_GENERAL_FAILURE
         *
         *      If this is after authentication, valid values are:
         *      - FR_NOTIFICATION_VALUE_GENERAL_FAILURE_AFTER_AUTHENTICATION
         *      - FR_NOTIFICATION_VALUE_TEMPORARILY_DENIED - User has been
         *        temporarily denied access to the requested service.
         *      - FR_NOTIFICATION_VALUE_NOT_SUBSCRIBED
         *        User has not subscribed to the requested service.
         */
        notification_vp = fr_pair_find_by_da(&request->reply_pairs, NULL, attr_eap_aka_sim_notification);
 
        /*
         *      Keep Notification, but remove everything else...
         */
        if (notification_vp) fr_pair_remove(&request->reply_pairs, notification_vp);
        fr_pair_list_free(&request->reply_pairs);
        if (notification_vp) fr_pair_append(&request->reply_pairs, notification_vp);
 
        /*
         *      Change the failure notification depending where
         *      we are in the eap_aka_state machine.
         */
        if (after_authentication(eap_aka_sim_session)) {
                if (!notification_vp) {
                        MEM(pair_append_reply(&notification_vp, attr_eap_aka_sim_notification) >= 0);
                        notification_vp->vp_uint16 = eap_aka_sim_session->failure_type; /* Default will be zero */
                }
 
                notification_vp->vp_uint16 &= ~0x4000;  /* Unset phase bit */
 
                /*
                 *      Include the counter attribute if we're failing
                 *      after a reauthentication success.
                 *
                 *      RFC 4187 Section #9.10
                 *
                 *      If EAP-Request/AKA-Notification is used on
                 *      a fast re-authentication exchange, and if
                 *      the P bit in AT_NOTIFICATION is set to zero,
                 *      then AT_COUNTER is used for replay protection.
                 *      In this case, the AT_ENCR_DATA and AT_IV
                 *      attributes MUST be included, and the
                 *      encapsulated plaintext attributes MUST include
                 *      the AT_COUNTER attribute.  The counter value
                 *      included in AT_COUNTER MUST be the same
                 *      as in the EAP-Request/AKA-Reauthentication
                 *      packet on the same fast re-authentication
                 *      exchange.
                 *
                 *      If the counter is used it should never be zero,
                 *      as it's incremented on first reauthentication
                 *      request.
                 */
                if (eap_aka_sim_session->reauthentication_success) {
                        MEM(pair_update_reply(&notification_vp, attr_eap_aka_sim_counter) >= 0);
                        notification_vp->vp_uint16 = eap_aka_sim_session->keys.reauth.counter;
                }
 
                /*
                 *      If we're after the challenge phase
                 *      then we need to include a MAC to
                 *      protect notifications.
                 */
                MEM(pair_update_reply(&vp, attr_eap_aka_sim_mac) >= 0);
                fr_pair_value_memdup(vp, NULL, 0, false);
        } else {
                /*
                 *      Only valid code is general failure
                 */
                if (!notification_vp) {
                        MEM(pair_append_reply(&notification_vp, attr_eap_aka_sim_notification) >= 0);
                        notification_vp->vp_uint16 = FR_NOTIFICATION_VALUE_GENERAL_FAILURE;
                /*
                 *      User supplied failure code
                 */
                } else {
                        notification_vp->vp_uint16 |= 0x4000;   /* Set phase bit */
                }
        }
        notification_vp->vp_uint16 &= ~0x8000;          /* In both cases success bit should be low */
 
        /*
         *      Send a response
         */
        common_reply(request, eap_aka_sim_session, FR_SUBTYPE_VALUE_AKA_SIM_NOTIFICATION);
 
        RETURN_UNLANG_HANDLED;
}
 
/** Enter the FAILURE-NOTIFICATION state
 *
 */
STATE_GUARD(common_failure_notification)
{
        eap_aka_sim_process_conf_t *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        /*
         *      If we're failing, then any identities
         *      we sent are now invalid.
         */
        if (eap_aka_sim_session->pseudonym_sent || eap_aka_sim_session->fastauth_sent) {
                return session_and_pseudonym_clear(p_result, mctx, request, eap_aka_sim_session,
                                                   guard_common_failure_notification); /* come back when we're done */
        }
 
        /*
         *      We've already sent a failure notification
         *      Now we just fail as it means something
         *      went wrong processing the ACK or we got
         *      garbage from the supplicant.
         */
        if (eap_aka_sim_session->state == state_common_failure_notification) {
                return STATE_TRANSITION(eap_failure);
        }
 
        /*
         *      Otherwise just transition as normal...
         */
        STATE_SET(common_failure_notification);
 
        return CALL_SECTION(send_common_failure_notification);
}
 
/** SUCCESS state - State machine exit point after sending EAP-Success
 *
 * Should never actually be called. Is just a placeholder function to represent the SUCCESS
 * termination state.  Could equally be a NULL pointer, but then on a logic error
 * we'd get a SEGV instead of a more friendly assert/failure rcode.
 */
STATE(eap_success)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        if (!fr_cond_assert(request && mctx && eap_aka_sim_session)) RETURN_UNLANG_FAIL;        /* unused args */
 
        fr_assert(0);   /* Should never actually be called */
 
        RETURN_UNLANG_FAIL;
}
 
/** Resume after 'send EAP-Success { ... }'
 *
 * Add MPPE keys to the request being sent to the supplicant
 *
 * The only work to be done is the add the appropriate SEND/RECV
 * attributes derived from the MSK.
 */
RESUME(send_eap_success)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        uint8_t                 *p;
 
        RDEBUG2("Sending EAP-Success");
 
        /*
         *      If this is true we're entering this state
         *      after sending a AKA-Success-Notification
         *
         *      Is seems like a really bad idea to allow the
         *      user to send a protected success to the
         *      supplicant and then force a failure using
         *      the send EAP-Success { ... } section.
         */
        if (eap_aka_sim_session->send_result_ind) {
                switch (eap_aka_sim_session->section_result.rcode) {
                case RLM_MODULE_USER_SECTION_REJECT:
                        RWDEBUG("Ignoring rcode (%s) from send EAP-Success { ... } "
                                "as we already sent a Success-Notification",
                                fr_table_str_by_value(rcode_table, eap_aka_sim_session->section_result.rcode, "<invalid>"));
                        RWDEBUG("If you need to force a failure, return an error code from "
                                "send Success-Notification { ... }");
                        break;
 
                default:
                        break;
                }
 
        /*
         *      But... if we're not working with protected
         *      success indication, this is the only
         *      opportunity the user has to force a failure at
         *      the end of authentication.
         */
        } else {
                SECTION_RCODE_PROCESS;
        }
 
        RDEBUG2("Adding attributes for MSK");
        p = eap_aka_sim_session->keys.msk;
        eap_add_reply(request->parent, attr_ms_mppe_recv_key, p, EAP_TLS_MPPE_KEY_LEN);
        p += EAP_TLS_MPPE_KEY_LEN;
        eap_add_reply(request->parent, attr_ms_mppe_send_key, p, EAP_TLS_MPPE_KEY_LEN);
 
        RETURN_UNLANG_OK;
}
 
/** Enter EAP-SUCCESS state
 *
 */
STATE_GUARD_NO_RESULT(eap_success)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        STATE_SET(eap_success);
 
        return CALL_SECTION(send_eap_success);
}
 
/** Resume after 'recv Success-Notification-Ack { ... }'
 *
 * - Enter the EAP-SUCCESS state.
 */
RESUME(recv_common_success_notification_ack)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        SECTION_RCODE_IGNORED;
 
        /*
         *      RFC 4187 says we ignore the contents of the
         *      next packet after we send our success notification
         *      and always send a success.
         */
        return STATE_TRANSITION(eap_success);
}
 
/** SUCCESS-NOTIFICATION state - Continue the state machine after receiving a response to our EAP-Request/(AKA|SIM)-Notification
 *
 * - Call 'recv Success-Notification-Ack { ... }'
 */
STATE_NO_RESULT(common_success_notification)
{
        eap_aka_sim_process_conf_t *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx,
                                                                             eap_aka_sim_session_t);
        /*
         *      Because the server uses the AT_NOTIFICATION code "Success" (32768) to
         *      indicate that the EAP exchange has completed successfully, the EAP
         *      exchange cannot fail when the server processes the EAP-AKA response
         *      to this notification.  Hence, the server MUST ignore the contents of
         *      the EAP-AKA response it receives to the EAP-Request/AKA-Notification
         *      with this code.  Regardless of the contents of the EAP-AKA response,
         *      the server MUST send EAP-Success as the next packet.
         */
        return CALL_SECTION(recv_common_success_notification_ack);
}
 
/** Resume after 'send Success-Notification { ... }'
 *
 */
RESUME(send_common_success_notification)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t               *vp;
 
        SECTION_RCODE_PROCESS;
 
        if (!fr_cond_assert(after_authentication(eap_aka_sim_session))) RETURN_UNLANG_FAIL;
 
        /*
         *      If we're in this state success bit is
         *      high phase bit is low.
         */
        MEM(pair_update_reply(&vp, attr_eap_aka_sim_notification) >= 0);
        vp->vp_uint16 = FR_NOTIFICATION_VALUE_SUCCESS;
 
        /*
         *      RFC 4187 section #9.10
         *
         *      If EAP-Request/AKA-Notification is used on
         *      a fast re-authentication exchange, and if
         *      the P bit in AT_NOTIFICATION is set to zero,
         *      then AT_COUNTER is used for replay protection.
         *      In this case, the AT_ENCR_DATA and AT_IV
         *      attributes MUST be included, and the
         *      encapsulated plaintext attributes MUST include
         *      the AT_COUNTER attribute.  The counter value
         *      included in AT_COUNTER MUST be the same
         *      as in the EAP-Request/AKA-Reauthentication
         *      packet on the same fast re-authentication
         *      exchange.
         *
         *      If the counter is used it should never be zero,
         *      as it's incremented on first reauthentication
         *      request.
         */
        if (eap_aka_sim_session->keys.reauth.counter > 0) {
                MEM(pair_update_reply(&vp, attr_eap_aka_sim_counter) >= 0);
                vp->vp_uint16 = eap_aka_sim_session->keys.reauth.counter;
        }
 
        /*
         *      Need to include an AT_MAC attribute so that
         *      it will get calculated.
         */
        MEM(pair_update_reply(&vp, attr_eap_aka_sim_mac) >= 0);
        fr_pair_value_memdup(vp, NULL, 0, false);
 
        /*
         *      Return reply attributes
         */
        common_reply(request, eap_aka_sim_session, FR_SUBTYPE_VALUE_AKA_SIM_NOTIFICATION);
 
        RETURN_UNLANG_HANDLED;
}
 
/** Enter the SUCCESS-NOTIFICATION state
 *
 */
STATE_GUARD_NO_RESULT(common_success_notification)
{
        eap_aka_sim_process_conf_t *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx,
                                                                             eap_aka_sim_session_t);
        STATE_SET(common_success_notification);
 
        return CALL_SECTION(send_common_success_notification);
}
 
/** Resume after 'recv Client-Error { ... }'
 *
 * - Enter the EAP-FAILURE state.
 */
RESUME(recv_common_client_error)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        SECTION_RCODE_IGNORED;
 
        return STATE_TRANSITION(eap_failure);
}
 
/** Resume after 'recv Reauthentication-Response { ... }'
 *
 * - If 'recv Reauthentication-Response { ... }' returned a failure
 *   rcode, enter the FAILURE-NOTIFICATION state.
 * - ...or call the EAP-Request/Reauthentication-Response function to act on the
 *   contents of the response.
 */
RESUME(recv_common_reauthentication_response)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        SECTION_RCODE_PROCESS;
 
        /*
         *      Validate mac
         */
        if (mac_validate(request) < 0) {
        failure:
                return STATE_TRANSITION(common_failure_notification);
        }
 
        /*
         *      Validate the checkcode
         */
        if (checkcode_validate(request) < 0) goto failure;
 
        /*
         *      Check to see if the supplicant sent
         *      AT_COUNTER_TOO_SMALL, if they did then we
         *      clear out reauth information and enter the
         *      challenge state.
         */
        if (fr_pair_find_by_da_nested(&request->request_pairs, NULL, attr_eap_aka_sim_counter_too_small)) {
                RWDEBUG("Peer sent AT_COUNTER_TOO_SMALL (indicating our AT_COUNTER value (%u) wasn't fresh)",
                        eap_aka_sim_session->keys.reauth.counter);
 
                fr_aka_sim_vector_umts_reauth_clear(&eap_aka_sim_session->keys);
                eap_aka_sim_session->allow_encrypted = false;
 
                return STATE_TRANSITION(aka_challenge);
        }
 
        /*
         *      If the peer wants a Success notification, and
         *      we included AT_RESULT_IND then send a success
         *      notification, otherwise send a normal EAP-Success.
         *
         *      RFC 4187 Section #6.2. Result Indications
         */
        if (eap_aka_sim_session->send_result_ind) {
                if (!fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_result_ind)) {
                        RDEBUG("We wanted to use protected result indications, but peer does not");
                        eap_aka_sim_session->send_result_ind = false;
                } else {
                        return STATE_TRANSITION(common_success_notification);
                }
        } else if (fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_result_ind)) {
                RDEBUG("Peer wanted to use protected result indications, but we do not");
        }
 
        eap_aka_sim_session->reauthentication_success = true;
 
        return STATE_TRANSITION(eap_success);
}
 
/** REAUTHENTICATION state - Continue the state machine after receiving a response to our EAP-Request/SIM-Start
 *
 * - Continue based on received AT_SUBTYPE value:
 *   - EAP-Response/(SIM|AKA)-Reauthentication - call 'recv Reauthentication-Response { ... }'
 *   - EAP-Response/(SIM|AKA)-Client-Error - call 'recv Client-Error { ... }' and after that
 *     send a EAP-Request/(SIM|AKA)-Notification indicating a General Failure.
 *   - Anything else, enter the FAILURE-NOTIFICATION state.
 */
STATE(common_reauthentication)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t                       *subtype_vp = NULL;
 
        subtype_vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_subtype);
        if (!subtype_vp) {
                REDEBUG("Missing AT_SUBTYPE");
                goto fail;
        }
 
        /*
         *      These aren't allowed in Reauthentication responses as they don't apply:
         *
         *      EAP_AKA_AUTHENTICATION_REJECT   - We didn't provide an AUTN value
         *      EAP_AKA_SYNCHRONIZATION_FAILURE - We didn't use new vectors.
         */
        switch (subtype_vp->vp_uint16) {
        case FR_SUBTYPE_VALUE_AKA_SIM_REAUTHENTICATION:
                /*
                 *      AT_COUNTER_TOO_SMALL is handled
                 *      in common_reauthentication_response_process.
                 */
                return CALL_SECTION(recv_common_reauthentication_response);
 
        /*
         *      Case 1 where we're allowed to send an EAP-Failure
         */
        case FR_SUBTYPE_VALUE_AKA_SIM_CLIENT_ERROR:
                client_error_debug(request);
 
                eap_aka_sim_session->allow_encrypted = false;
 
                return CALL_SECTION(recv_common_client_error);
        /*
         *      RFC 4187 says we *MUST* notify, not just
         *      send an EAP-Failure in this case.
         */
        default:
                REDEBUG("Unexpected subtype %pV", &subtype_vp->data);
        fail:
                eap_aka_sim_session->allow_encrypted = false;
 
                return STATE_TRANSITION(common_failure_notification);
        }
}
 
 
/** Send a EAP-Request/(AKA|SIM)-Reauthenticate message to the supplicant
 *
 */
static unlang_action_t common_reauthentication_request_compose(unlang_result_t *p_result,
                                                               module_ctx_t const *mctx,
                                                               request_t *request,
                                                               eap_aka_sim_session_t *eap_aka_sim_session)
{
        fr_pair_t               *vp;
        fr_pair_t               *kdf_id;
 
        /*
         *      Allow override of KDF Identity
         *
         *      Because certain handset manufacturers don't
         *      implement RFC 4187 correctly and use the
         *      wrong identity as input the the PRF/KDF.
         *
         *      Not seen any doing this for re-authentication
         *      but you never know...
         */
        kdf_id = fr_pair_find_by_da(&request->control_pairs, NULL, attr_eap_aka_sim_kdf_identity);
        if (kdf_id) {
                crypto_identity_set(request, eap_aka_sim_session,
                                    (uint8_t const *)kdf_id->vp_strvalue, kdf_id->vp_length);
                fr_pair_delete_by_da(&request->control_pairs, attr_eap_aka_sim_kdf_identity);
        }
 
        RDEBUG2("Generating new session keys");
 
        switch (eap_aka_sim_session->type) {
        /*
         *      The GSM and UMTS KDF_0 mutate their keys using
         *      and identical algorithm.
         */
        case FR_EAP_METHOD_SIM:
        case FR_EAP_METHOD_AKA:
                if (fr_aka_sim_vector_gsm_umts_kdf_0_reauth_from_attrs(request, &request->session_state_pairs,
                                                                       &eap_aka_sim_session->keys) != 0) {
                request_new_id:
                        switch (eap_aka_sim_session->last_id_req) {
                        /*
                         *      Got here processing EAP-Identity-Response
                         *      If this is the *true* reauth ID, then
                         *      there's no point in setting AKA_SIM_ANY_ID_REQ.
                         */
                        case AKA_SIM_INIT_ID_REQ:
                        case AKA_SIM_NO_ID_REQ:
                        case AKA_SIM_ANY_ID_REQ:
                                RDEBUG2("Composing EAP-Request/Reauthentication failed.  Clearing reply attributes and "
                                        "requesting additional Identity");
                                fr_pair_list_free(&request->reply_pairs);
                                eap_aka_sim_session->id_req = AKA_SIM_FULLAUTH_ID_REQ;
                                return STATE_TRANSITION(common_identity);
 
                        case AKA_SIM_FULLAUTH_ID_REQ:
                        case AKA_SIM_PERMANENT_ID_REQ:
                                REDEBUG("Last requested fullauth or permanent ID, "
                                        "but received, or were told we received (by policy), "
                                        "a fastauth ID.  Cannot continue");
                                return STATE_TRANSITION(common_failure_notification);
                        }
                }
                if (fr_aka_sim_crypto_kdf_0_reauth(&eap_aka_sim_session->keys) < 0) goto request_new_id;
                break;
 
        case FR_EAP_METHOD_AKA_PRIME:
                if (eap_aka_sim_session->kdf == enum_kdf_prime_with_ck_prime_ik_prime->vb_int16) {
                        if (fr_aka_sim_vector_umts_kdf_1_reauth_from_attrs(request, &request->session_state_pairs,
                                                                           &eap_aka_sim_session->keys) != 0) {
                                goto request_new_id;
                        }
                        if (fr_aka_sim_crypto_umts_kdf_1_reauth(&eap_aka_sim_session->keys) < 0) goto request_new_id;
                } else {
                        fr_assert(0);
                }
                break;
 
        default:
                fr_assert(0);
                break;
        }
 
        if (RDEBUG_ENABLED3) fr_aka_sim_crypto_keys_log(request, &eap_aka_sim_session->keys);
 
        /*
         *      Indicate we'd like to use protected success messages
         *      with AT_RESULT_IND
         *
         *      Use our default, but allow user override too.
         */
        vp = fr_pair_find_by_da(&request->reply_pairs, NULL, attr_eap_aka_sim_result_ind);
        if (vp) eap_aka_sim_session->send_result_ind = vp->vp_bool;
 
        /*
         *      RFC 5448 says AT_BIDDING is only sent in the challenge
         *      not in reauthentication, so don't add that here.
         */
 
         /*
          *     Add AT_NONCE_S
          */
        MEM(pair_update_reply(&vp, attr_eap_aka_sim_nonce_s) >= 0);
        fr_pair_value_memdup(vp, eap_aka_sim_session->keys.reauth.nonce_s,
                             sizeof(eap_aka_sim_session->keys.reauth.nonce_s), false);
 
        /*
         *      Add AT_COUNTER
         */
        MEM(pair_update_reply(&vp, attr_eap_aka_sim_counter) >= 0);
        vp->vp_uint16 = eap_aka_sim_session->keys.reauth.counter;
 
        /*
         *      need to include an empty AT_MAC attribute so that
         *      the mac will get calculated.
         */
        MEM(pair_update_reply(&vp, attr_eap_aka_sim_mac) >= 0);
        fr_pair_value_memdup(vp, NULL, 0, false);
 
        /*
         *      We've sent the challenge so the peer should now be able
         *      to accept encrypted attributes.
         */
        eap_aka_sim_session->allow_encrypted = true;
 
        return session_and_pseudonym_store(p_result, mctx, request, eap_aka_sim_session,
                                           common_reauthentication_request_send);
}
 
/** Resume after 'send Reauthentication-Request { ... }'
 *
 */
RESUME(send_common_reauthentication_request)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        switch (eap_aka_sim_session->section_result.rcode) {
        /*
         *      Failed getting the values we need for resumption
         *      Request a different identity.
         */
        default:
                switch (eap_aka_sim_session->last_id_req) {
                /*
                 *      Got here processing EAP-Identity-Response
                 *      If this is the *true* reauth ID, then
                 *      there's no point in setting AKA_SIM_ANY_ID_REQ.
                 */
                case AKA_SIM_INIT_ID_REQ:
                case AKA_SIM_NO_ID_REQ:
                case AKA_SIM_ANY_ID_REQ:
                        RDEBUG2("Previous section returned (%s), clearing reply attributes and "
                                "requesting additional identity",
                                fr_table_str_by_value(rcode_table, eap_aka_sim_session->section_result.rcode, "<INVALID>"));
                        fr_pair_list_free(&request->reply_pairs);
                        eap_aka_sim_session->id_req = AKA_SIM_FULLAUTH_ID_REQ;
 
                        return STATE_TRANSITION(common_identity);
 
                case AKA_SIM_FULLAUTH_ID_REQ:
                case AKA_SIM_PERMANENT_ID_REQ:
                default:
                        break;
                }
                REDEBUG("Last requested Full-Auth-Id or Permanent-Identity, "
                        "but received a Fast-Auth-Id.  Cannot continue");
        failure:
                return STATE_TRANSITION(common_failure_notification);
 
        /*
         *      Policy rejected the user
         */
        case RLM_MODULE_REJECT:
        case RLM_MODULE_DISALLOW:
                goto failure;
 
        /*
         *      Everything looks ok, send the EAP-Request/reauthentication message
         *      After storing any new pseudonyms or session information.
         */
        case RLM_MODULE_NOOP:
        case RLM_MODULE_OK:
        case RLM_MODULE_UPDATED:
                return common_reauthentication_request_compose(p_result, mctx, request, eap_aka_sim_session);
        }
}
 
/** Resume after 'load pseudonym { ... }'
 *
 */
RESUME(load_pseudonym)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        pair_delete_request(attr_eap_aka_sim_next_reauth_id);
 
        /*
         *      Control attributes required could have been specified
         *      in another section.
         */
        if (!inst->actions.load_pseudonym) {
        next_state:
                return eap_aka_sim_session->next(p_result, mctx, request);
        }
 
        switch (eap_aka_sim_session->section_result.rcode) {
        /*
         *      Failed resolving the pseudonym
         *      request a different identity.
         */
        default:
                switch (eap_aka_sim_session->last_id_req) {
                case AKA_SIM_INIT_ID_REQ:
                case AKA_SIM_NO_ID_REQ:
                case AKA_SIM_ANY_ID_REQ:
                case AKA_SIM_FULLAUTH_ID_REQ:
                        RDEBUG2("Previous section returned (%s), clearing reply attributes and "
                                "requesting additional identity",
                                fr_table_str_by_value(rcode_table, eap_aka_sim_session->section_result.rcode, "<INVALID>"));
                        fr_pair_list_free(&request->reply_pairs);
                        eap_aka_sim_session->id_req = AKA_SIM_FULLAUTH_ID_REQ;
                        return STATE_TRANSITION(common_identity);
 
                case AKA_SIM_PERMANENT_ID_REQ:
                        REDEBUG("Last requested a Permanent-Identity, but received a Pseudonym.  Cannot continue");
                failure:
                        return STATE_TRANSITION(common_failure_notification);
                }
                break;
 
        /*
         *      Policy rejected the user
         */
        case RLM_MODULE_REJECT:
        case RLM_MODULE_DISALLOW:
                goto failure;
 
        /*
         *      Everything OK
         */
        case RLM_MODULE_OK:
        case RLM_MODULE_UPDATED:
                goto next_state;
        }
 
        goto failure;
}
 
/** Resume after 'load session { ... }'
 *
 */
RESUME(load_session)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        pair_delete_request(attr_session_id);
 
        /*
         *      Control attributes required could have been specified
         *      in another section.
         */
        if (!inst->actions.load_session) goto reauthenticate;
 
        switch (eap_aka_sim_session->section_result.rcode) {
        /*
         *      Failed getting the values we need for resumption
         *      Request a different identity.
         */
        default:
                switch (eap_aka_sim_session->last_id_req) {
                /*
                 *      Got here processing EAP-Identity-Response
                 *      If this is the *true* reauth ID, then
                 *      there's no point in setting AKA_SIM_ANY_ID_REQ.
                 */
                case AKA_SIM_INIT_ID_REQ:
                case AKA_SIM_NO_ID_REQ:
                case AKA_SIM_ANY_ID_REQ:
                        RDEBUG2("Previous section returned (%s), clearing reply attributes and "
                                "requesting additional identity",
                                fr_table_str_by_value(rcode_table, eap_aka_sim_session->section_result.rcode, "<INVALID>"));
                        fr_pair_list_free(&request->reply_pairs);
                        eap_aka_sim_session->id_req = AKA_SIM_FULLAUTH_ID_REQ;
                        return STATE_TRANSITION(common_identity);
 
                case AKA_SIM_FULLAUTH_ID_REQ:
                case AKA_SIM_PERMANENT_ID_REQ:
                        REDEBUG("Last requested Full-Auth-Id or Permanent-Identity, "
                                "but received a Fast-Auth-Id.  Cannot continue");
                        return STATE_TRANSITION(common_failure_notification);
                }
                break;
 
        /*
         *      Policy rejected the user
         */
        case RLM_MODULE_REJECT:
        case RLM_MODULE_DISALLOW:
        reject:
                return STATE_TRANSITION(common_failure_notification);
 
        /*
         *      Everything OK
         */
        case RLM_MODULE_OK:
        case RLM_MODULE_UPDATED:
        reauthenticate:
                return CALL_SECTION(send_common_reauthentication_request);
        }
 
        goto reject;
}
 
/** Enter the REAUTHENTICATION state
 *
 */
STATE_GUARD_NO_RESULT(common_reauthentication)
{
        eap_aka_sim_process_conf_t *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t               *vp = NULL;
 
        STATE_SET(common_reauthentication);
 
        /*
         *      Add the current identity as session_id
         *      to make it easier to load/store things from
         *      the cache module.
         */
        MEM(pair_update_request(&vp, attr_session_id) >= 0);
        fr_pair_value_memdup(vp, eap_aka_sim_session->keys.identity, eap_aka_sim_session->keys.identity_len, true);
 
        return CALL_SECTION(load_session);
}
 
/** Resume after 'recv Synchronization-Failure { ... }'
 *
 * - If 'recv Synchronization-Failure { ... }' returned a failure
 *   rcode, enter the FAILURE-NOTIFICATION state.
 * - ...or if no 'recv Synchronization-Failure { ... }' section was
 *   defined, then enter the FAILURE-NOTIFICATION state.
 * - ...or if the user didn't provide a new SQN value in &control.SQN
 *   then enter the FAILURE-NOTIFICATION state.
 * - ...or enter the AKA-CHALLENGE state.
 */
RESUME(recv_aka_synchronization_failure)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t                       *vp;
 
        SECTION_RCODE_PROCESS;
 
        /*
         *      If there's no section to handle this, then no resynchronisation
         *      can't have occurred and we just send a reject.
         *
         *      Similarly, if we've already received one synchronisation failure
         *      then it's highly likely whatever user configured action was
         *      configured was unsuccessful, and we should just give up.
         */
        if (!inst->actions.recv_aka_synchronization_failure || eap_aka_sim_session->prev_recv_sync_failure) {
        failure:
                return STATE_TRANSITION(common_failure_notification);
        }
 
        /*
         *      We couldn't generate an SQN and the user didn't provide one,
         *      so we need to fail.
         */
        vp = fr_pair_find_by_da(&request->control_pairs, NULL, attr_sim_sqn);
        if (!vp) {
                REDEBUG("No control.SQN value provided after resynchronisation, cannot continue");
                goto failure;
        }
 
        /*
         *      RFC 4187 Section #6.3.1
         *
         *      "if the peer detects that the
         *      sequence number in AUTN is not correct, the peer responds with
         *      EAP-Response/AKA-Synchronization-Failure (Section 9.6), and the
         *      server proceeds with a new EAP-Request/AKA-Challenge."
         */
        return STATE_TRANSITION(aka_challenge);
}
 
/** Resume after 'recv Authentication-Reject { ... }'
 *
 * - Enter the FAILURE-NOTIFICATION state.
 */
RESUME(recv_aka_authentication_reject)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        SECTION_RCODE_IGNORED;
 
        /*
         *      Case 2 where we're allowed to send an EAP-Failure
         */
        return STATE_TRANSITION(eap_failure);
}
 
/** Resume after 'recv Challenge-Response { ... }'
 *
 * - If the previous section returned a failure rcode, enter the FAILURE-NOTIFICATION state.
 * - ...or call a function to process the contents of the AKA-Challenge message.
 *
 * Verify that MAC, and RES match what we expect.
 */
RESUME(recv_aka_challenge_response)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t               *vp = NULL;
 
        SECTION_RCODE_PROCESS;
 
        /*
         *      Validate mac
         */
        if (mac_validate(request) < 0) {
        failure:
                return STATE_TRANSITION(common_failure_notification);
        }
 
        /*
         *      Validate the checkcode
         */
        if (checkcode_validate(request) < 0) goto failure;
 
        vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_res);
        if (!vp) {
                REDEBUG("AT_RES missing from challenge response");
                goto failure;
        }
 
        if (vp->vp_length != eap_aka_sim_session->keys.umts.vector.xres_len) {
                REDEBUG("Received RES' length (%zu) does not match calculated XRES' length (%zu)",
                        vp->vp_length, eap_aka_sim_session->keys.umts.vector.xres_len);
                goto failure;
        }
 
        if (fr_digest_cmp(vp->vp_octets, eap_aka_sim_session->keys.umts.vector.xres, vp->vp_length)) {
                REDEBUG("Received RES does not match calculated XRES");
                RHEXDUMP_INLINE2(vp->vp_octets, vp->vp_length, "RES  :");
                RHEXDUMP_INLINE2(eap_aka_sim_session->keys.umts.vector.xres,
                                eap_aka_sim_session->keys.umts.vector.xres_len, "XRES :");
                goto failure;
        }
 
        RDEBUG2("Received RES matches calculated XRES");
 
        eap_aka_sim_session->challenge_success = true;
 
        /*
         *      If the peer wants a Success notification, and
         *      we included AT_RESULT_IND then send a success
         *      notification, otherwise send a normal EAP-Success.
         *
         *      RFC 4187 Section #6.2. Result Indications
         */
        if (eap_aka_sim_session->send_result_ind) {
                if (!fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_result_ind)) {
                        RDEBUG("We wanted to use protected result indications, but peer does not");
                        eap_aka_sim_session->send_result_ind = false;
                } else {
                        return STATE_TRANSITION(common_success_notification);
                }
        } else if (fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_result_ind)) {
                RDEBUG("Peer wanted to use protected result indications, but we do not");
        }
 
        return STATE_TRANSITION(eap_success);
}
 
/** AKA-CHALLENGE state - Continue the state machine after receiving a response to our EAP-Request/SIM-Challenge
 *
 * - Continue based on received AT_SUBTYPE value:
 *   - EAP-Response/AKA-Challenge - call 'recv Challenge-Response { ... }'.
 *   - EAP-Response/AKA-Authentication-Reject - call 'recv Authentication-Reject { ... }'  and after that
 *     send a EAP-Request/SIM-Notification indicating a General Failure.
 *   - EAP-Response/AKA-Synchronization-Failure - call 'recv Synchronization-Failure { ... }'.
 *   - EAP-Response/AKA-Client-Error - call 'recv Client-Error { ... }' and after that
 *     send a EAP-Request/AKA-Notification indicating a General Failure.
 *   - Anything else, enter the FAILURE-NOTIFICATION state.
 */
STATE(aka_challenge)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t                       *subtype_vp = NULL;
        fr_pair_t                       *vp;
 
        subtype_vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_subtype);
        if (!subtype_vp) {
                REDEBUG("Missing AT_SUBTYPE");
                goto fail;
        }
 
        switch (subtype_vp->vp_uint16) {
        case FR_SUBTYPE_VALUE_AKA_CHALLENGE:
                return CALL_SECTION(recv_aka_challenge_response);
 
        /*
         *      Case 2 where we're allowed to send an EAP-Failure
         */
        case FR_SUBTYPE_VALUE_AKA_AUTHENTICATION_REJECT:
                eap_aka_sim_session->allow_encrypted = false;
                return CALL_SECTION(recv_aka_authentication_reject);
 
        case FR_SUBTYPE_VALUE_AKA_SYNCHRONIZATION_FAILURE:
        {
                uint64_t        new_sqn;
 
                eap_aka_sim_session->allow_encrypted = false;
 
                vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_auts);
                if (!vp) {
                        REDEBUG("EAP-Response/AKA-Synchronisation-Failure missing AT_AUTS");
                failure:
                        return STATE_TRANSITION(common_failure_notification);
                }
 
                switch (fr_aka_sim_umts_resync_from_attrs(&new_sqn,
                                                          request, vp, &eap_aka_sim_session->keys)) {
                /*
                 *      Add everything back that we'll need in the
                 *      next challenge round.
                 */
                case 0:
                        MEM(pair_append_control(&vp, attr_sim_sqn) >= 0);
                        vp->vp_uint64 = new_sqn;
 
                        MEM(pair_append_control(&vp, attr_sim_ki) >= 0);
                        fr_pair_value_memdup(vp, eap_aka_sim_session->keys.auc.ki,
                                             sizeof(eap_aka_sim_session->keys.auc.ki), false);
 
                        MEM(pair_append_control(&vp, attr_sim_opc) >= 0);
                        fr_pair_value_memdup(vp, eap_aka_sim_session->keys.auc.opc,
                                             sizeof(eap_aka_sim_session->keys.auc.opc), false);
                        break;
 
                case 1: /* Don't have Ki or OPc so something else will need to deal with this */
                        break;
 
                default:
                case -1:
                        goto failure;
                }
 
                return CALL_SECTION(recv_aka_synchronization_failure);
        }
 
        /*
         *      Case 1 where we're allowed to send an EAP-Failure
         */
        case FR_SUBTYPE_VALUE_AKA_SIM_CLIENT_ERROR:
                client_error_debug(request);
 
                eap_aka_sim_session->allow_encrypted = false;
 
                return CALL_SECTION(recv_common_client_error);
 
        /*
         *      RFC 4187 says we *MUST* notify, not just
         *      send an EAP-Failure in this case.
         */
        default:
                REDEBUG("Unexpected subtype %pV", &subtype_vp->data);
        fail:
                eap_aka_sim_session->allow_encrypted = false;
                goto failure;
        }
}
 
/** Resume after 'send Challenge-Request { ... }'
 *
 */
RESUME(send_aka_challenge_request)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t               *vp;
        fr_aka_sim_vector_src_t src = AKA_SIM_VECTOR_SRC_AUTO;
 
        fr_pair_t               *kdf_id;
 
        SECTION_RCODE_PROCESS;
 
        /*
         *      Allow override of KDF Identity
         *
         *      Because certain handset manufacturers don't
         *      implement RFC 4187 correctly and use the
         *      wrong identity as input the the PRF/KDF.
         */
        kdf_id = fr_pair_find_by_da(&request->control_pairs, NULL, attr_eap_aka_sim_kdf_identity);
        if (kdf_id) {
                crypto_identity_set(request, eap_aka_sim_session,
                                    (uint8_t const *)kdf_id->vp_strvalue, kdf_id->vp_length);
                fr_pair_delete_by_da(&request->control_pairs, attr_eap_aka_sim_kdf_identity);
        }
 
        RDEBUG2("Acquiring UMTS vector(s)");
 
        if (eap_aka_sim_session->type == FR_EAP_METHOD_AKA_PRIME) {
                /*
                 *      Copy the network name the user specified for
                 *      key derivation purposes.
                 */
                vp = fr_pair_find_by_da(&request->reply_pairs, NULL, attr_eap_aka_sim_kdf_input);
                if (vp) {
                        talloc_free(eap_aka_sim_session->keys.network);
                        eap_aka_sim_session->keys.network = talloc_memdup(eap_aka_sim_session,
                                                                          (uint8_t const *)vp->vp_strvalue,
                                                                          vp->vp_length);
                        eap_aka_sim_session->keys.network_len = vp->vp_length;
                } else {
                        REDEBUG("No network name available, can't set AT_KDF_INPUT");
                failure:
                        return STATE_TRANSITION(common_failure_notification);
                }
 
                /*
                 *      We don't allow the user to specify
                 *      the KDF currently.
                 */
                MEM(pair_update_reply(&vp, attr_eap_aka_sim_kdf) >= 0);
                vp->vp_uint16 = eap_aka_sim_session->kdf;
        }
 
        /*
         *      Get vectors from attribute or generate
         *      them using COMP128-* or Milenage.
         */
        if (fr_aka_sim_vector_umts_from_attrs(request, &request->control_pairs,
                                              &eap_aka_sim_session->keys, &src) != 0) {
                REDEBUG("Failed retrieving UMTS vectors");
                goto failure;
        }
 
        /*
         *      Don't leave the AMF hanging around
         */
        if (eap_aka_sim_session->type == FR_EAP_METHOD_AKA_PRIME) pair_delete_control(attr_sim_amf);
 
        /*
         *      All set, calculate keys!
         */
        switch (eap_aka_sim_session->type) {
        default:
        case FR_EAP_METHOD_SIM:
                fr_assert(0);   /* EAP-SIM has its own Challenge state */
                break;
 
        case FR_EAP_METHOD_AKA:
                fr_aka_sim_crypto_umts_kdf_0(&eap_aka_sim_session->keys);
                break;
 
        case FR_EAP_METHOD_AKA_PRIME:
                if (eap_aka_sim_session->kdf == enum_kdf_prime_with_ck_prime_ik_prime->vb_int16) {
                        fr_pair_t *ck_prime_vp;
                        fr_pair_t *ik_prime_vp;
 
                        /*
                         *      When control.CK-Prime / control.IK-Prime are
                         *      supplied (e.g. by a 3GPP HSS over SWx which performs
                         *      the RFC 5448 / TS 33.402 transform itself), read them
                         *      from those attributes and skip the local Annex A
                         *      derivation in fr_aka_sim_crypto_umts_kdf_1().
                         *
                         *      The helper returns 1 when neither attribute is set
                         *      (normal local-derivation path) and -1 when the inputs
                         *      are present but invalid (mismatched pair or wrong
                         *      length).  Only the -1 case is a real error.
                         */
                        ck_prime_vp = fr_pair_find_by_da(&request->control_pairs, NULL,
                                                         attr_eap_aka_sim_ck_prime);
                        ik_prime_vp = fr_pair_find_by_da(&request->control_pairs, NULL,
                                                         attr_eap_aka_sim_ik_prime);
 
                        if (fr_aka_sim_vector_umts_ck_ik_prime_from_attrs(request,
                                                                          ck_prime_vp, ik_prime_vp,
                                                                          &eap_aka_sim_session->keys) < 0) {
                                goto failure;
                        }
                        fr_aka_sim_crypto_umts_kdf_1(&eap_aka_sim_session->keys);
                } else {
                        fr_assert(0);
                }
        }
        if (RDEBUG_ENABLED3) fr_aka_sim_crypto_keys_log(request, &eap_aka_sim_session->keys);
 
        /*
         *      Indicate we'd like to use protected success messages
         *      with AT_RESULT_IND
         *
         *      Use our default, but allow user override too.
         */
        vp = fr_pair_find_by_da(&request->reply_pairs, NULL, attr_eap_aka_sim_result_ind);
        if (vp) eap_aka_sim_session->send_result_ind = vp->vp_bool;
 
        /*
         *      These attributes are only allowed with
         *      EAP-AKA', protect users from themselves.
         */
        if (eap_aka_sim_session->type == FR_EAP_METHOD_AKA) {
                pair_delete_reply(attr_eap_aka_sim_kdf_input);
                pair_delete_reply(attr_eap_aka_sim_kdf);
        }
 
        /*
         *      Okay, we got the challenge! Put it into an attribute.
         */
        MEM(pair_update_reply(&vp, attr_eap_aka_sim_rand) >= 0);
        fr_pair_value_memdup(vp, eap_aka_sim_session->keys.umts.vector.rand, AKA_SIM_VECTOR_UMTS_RAND_SIZE, false);
 
        /*
         *      Send the AUTN value to the client, so it can authenticate
         *      whoever has knowledge of the Ki.
         */
        MEM(pair_update_reply(&vp, attr_eap_aka_sim_autn) >= 0);
        fr_pair_value_memdup(vp, eap_aka_sim_session->keys.umts.vector.autn, AKA_SIM_VECTOR_UMTS_AUTN_SIZE, false);
 
        /*
         *      need to include an AT_MAC attribute so that it will get
         *      calculated.
         */
        MEM(pair_update_reply(&vp, attr_eap_aka_sim_mac) >= 0);
        fr_pair_value_memdup(vp, NULL, 0, false);
 
        /*
         *      We've sent the challenge so the peer should now be able
         *      to accept encrypted attributes.
         */
        eap_aka_sim_session->allow_encrypted = true;
 
        return session_and_pseudonym_store(p_result, mctx, request, eap_aka_sim_session, aka_challenge_request_send);
}
 
/** Enter the AKA-CHALLENGE state
 *
 */
STATE_GUARD(aka_challenge)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t                       *vp;
 
        /*
         *      If we've sent either of these identities it
         *      means we've come here form a Reauthentication-Request
         *      that failed.
         */
        if (eap_aka_sim_session->pseudonym_sent || eap_aka_sim_session->fastauth_sent) {
                return session_and_pseudonym_clear(p_result, mctx, request,
                                                   eap_aka_sim_session, guard_aka_challenge);
                                                   /* come back when we're done */
        }
 
        STATE_SET(aka_challenge);
 
        /*
         *      Set some default attributes, giving the user a
         *      chance to modify them.
         */
        switch (eap_aka_sim_session->type) {
        case FR_EAP_METHOD_AKA_PRIME:
        {
                uint8_t         amf_buff[2] = { 0x80, 0x00 };   /* Set the AMF separation bit high */
 
                /*
                 *      Toggle the AMF high bit to indicate we're doing AKA'
                 */
                MEM(pair_update_control(&vp, attr_sim_amf) >= 0);
                fr_pair_value_memdup(vp, amf_buff, sizeof(amf_buff), false);
 
                /*
                 *      Use the default network name we have configured
                 *      and send it to the peer.
                 */
                if (inst->network_name &&
                    !fr_pair_find_by_da(&request->reply_pairs, NULL, attr_eap_aka_sim_kdf_input)) {
                        MEM(pair_append_reply(&vp, attr_eap_aka_sim_kdf_input) >= 0);
                        fr_pair_value_bstrdup_buffer(vp, inst->network_name, false);
                }
        }
                break;
 
        default:
                break;
 
        }
 
        /*
         *      Set the defaults for protected result indicator
         */
        if (eap_aka_sim_session->send_result_ind &&
            !fr_pair_find_by_da(&request->reply_pairs, NULL, attr_eap_aka_sim_result_ind)) {
                MEM(pair_append_reply(&vp, attr_eap_aka_sim_result_ind) >= 0);
                vp->vp_bool = true;
        }
 
        return CALL_SECTION(send_aka_challenge_request);
}
 
/** Resume after 'recv Challenge-Response { ... }'
 *
 * - If the previous section returned a failure rcode, enter the FAILURE-NOTIFICATION state.
 * - ...or call a function to process the contents of the SIM-Challenge message.
 *
 * Verify that MAC, and RES match what we expect.
 */
RESUME(recv_sim_challenge_response)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        uint8_t                 sres_cat[AKA_SIM_VECTOR_GSM_SRES_SIZE * 3];
        uint8_t                 *p = sres_cat;
 
        SECTION_RCODE_PROCESS;
 
        memcpy(p, eap_aka_sim_session->keys.gsm.vector[0].sres, AKA_SIM_VECTOR_GSM_SRES_SIZE);
        p += AKA_SIM_VECTOR_GSM_SRES_SIZE;
        memcpy(p, eap_aka_sim_session->keys.gsm.vector[1].sres, AKA_SIM_VECTOR_GSM_SRES_SIZE);
        p += AKA_SIM_VECTOR_GSM_SRES_SIZE;
        memcpy(p, eap_aka_sim_session->keys.gsm.vector[2].sres, AKA_SIM_VECTOR_GSM_SRES_SIZE);
 
        /*
         *      Validate mac
         */
        if (mac_validate(request) < 0) return STATE_TRANSITION(common_failure_notification);
 
        eap_aka_sim_session->challenge_success = true;
 
        /*
         *      If the peer wants a Success notification, and
         *      we included AT_RESULT_IND then send a success
         *      notification, otherwise send a normal EAP-Success.
         */
        if (eap_aka_sim_session->send_result_ind) {
                if (!fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_result_ind)) {
                        RDEBUG("We wanted to use protected result indications, but peer does not");
                        eap_aka_sim_session->send_result_ind = false;
                } else {
                        return STATE_TRANSITION(common_success_notification);
                }
        } else if (fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_result_ind)) {
                RDEBUG("Peer wanted to use protected result indications, but we do not");
        }
 
        return STATE_TRANSITION(eap_success);
}
 
/** SIM-CHALLENGE state - Continue the state machine after receiving a response to our EAP-Request/SIM-Challenge
 *
 * - Continue based on received AT_SUBTYPE value:
 *   - EAP-Response/SIM-Challenge - call 'recv Challenge-Response { ... }'.
 *   - EAP-Response/SIM-Client-Error - call 'recv Client-Error { ... }' and after that
 *     send a EAP-Request/SIM-Notification indicating a General Failure.
 *   - Anything else, enter the FAILURE-NOTIFICATION state.
 */
STATE(sim_challenge)
{
        eap_aka_sim_process_conf_t *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t      *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t                  *subtype_vp = NULL;
 
        subtype_vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_subtype);
        if (!subtype_vp) {
                REDEBUG("Missing AT_SUBTYPE");
                goto fail;
        }
 
        switch (subtype_vp->vp_uint16) {
        case FR_SUBTYPE_VALUE_SIM_CHALLENGE:
                return CALL_SECTION(recv_sim_challenge_response);
 
        /*
         *      Case 1 where we're allowed to send an EAP-Failure
         */
        case FR_SUBTYPE_VALUE_AKA_SIM_CLIENT_ERROR:
                client_error_debug(request);
 
                eap_aka_sim_session->allow_encrypted = false;
 
                return CALL_SECTION(recv_common_client_error);
 
        /*
         *      RFC 4186 says we *MUST* notify, not just
         *      send an EAP-Failure in this case.
         */
        default:
                REDEBUG("Unexpected subtype %pV", &subtype_vp->data);
        fail:
                eap_aka_sim_session->allow_encrypted = false;
 
                return STATE_TRANSITION(common_failure_notification);
        }
}
 
/** Resume after 'send Challenge-Request { ... }'
 *
 */
RESUME(send_sim_challenge_request)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        fr_pair_t               *vp;
        fr_aka_sim_vector_src_t src = AKA_SIM_VECTOR_SRC_AUTO;
 
        fr_pair_t               *kdf_id;
 
        SECTION_RCODE_PROCESS;
 
        /*
         *      Allow override of KDF Identity
         *
         *      Because certain handset manufacturers don't
         *      implement RFC 4187 correctly and use the
         *      wrong identity as input the the PRF/KDF.
         */
        kdf_id = fr_pair_find_by_da(&request->control_pairs, NULL, attr_eap_aka_sim_kdf_identity);
        if (kdf_id) {
                crypto_identity_set(request, eap_aka_sim_session,
                                    (uint8_t const *)kdf_id->vp_strvalue, kdf_id->vp_length);
                fr_pair_delete_by_da(&request->control_pairs, attr_eap_aka_sim_kdf_identity);
        }
 
        RDEBUG2("Acquiring GSM vector(s)");
        if ((fr_aka_sim_vector_gsm_from_attrs(request, &request->control_pairs, 0,
                                              &eap_aka_sim_session->keys, &src) != 0) ||
            (fr_aka_sim_vector_gsm_from_attrs(request, &request->control_pairs, 1,
                                              &eap_aka_sim_session->keys, &src) != 0) ||
            (fr_aka_sim_vector_gsm_from_attrs(request, &request->control_pairs, 2,
                                              &eap_aka_sim_session->keys, &src) != 0)) {
                REDEBUG("Failed retrieving SIM vectors");
                RETURN_UNLANG_FAIL;
        }
 
        fr_aka_sim_crypto_gsm_kdf_0(&eap_aka_sim_session->keys);
 
        if (RDEBUG_ENABLED3) fr_aka_sim_crypto_keys_log(request, &eap_aka_sim_session->keys);
 
        /*
         *      Indicate we'd like to use protected success messages
         *      with AT_RESULT_IND
         *
         *      Use our default, but allow user override too.
         */
        vp = fr_pair_find_by_da(&request->reply_pairs, NULL, attr_eap_aka_sim_result_ind);
        if (vp) eap_aka_sim_session->send_result_ind = vp->vp_bool;
 
        /*
         *      Okay, we got the challenges! Put them into attributes.
         */
        MEM(pair_append_reply(&vp, attr_eap_aka_sim_rand) >= 0);
        fr_pair_value_memdup(vp, eap_aka_sim_session->keys.gsm.vector[0].rand, AKA_SIM_VECTOR_GSM_RAND_SIZE, false);
 
        MEM(pair_append_reply(&vp, attr_eap_aka_sim_rand) >= 0);
        fr_pair_value_memdup(vp, eap_aka_sim_session->keys.gsm.vector[1].rand, AKA_SIM_VECTOR_GSM_RAND_SIZE, false);
 
        MEM(pair_append_reply(&vp, attr_eap_aka_sim_rand) >= 0);
        fr_pair_value_memdup(vp, eap_aka_sim_session->keys.gsm.vector[2].rand, AKA_SIM_VECTOR_GSM_RAND_SIZE, false);
 
        /*
         *      need to include an AT_MAC attribute so that it will get
         *      calculated.
         */
        MEM(pair_update_reply(&vp, attr_eap_aka_sim_mac) >= 0);
        fr_pair_value_memdup(vp, NULL, 0, false);
 
        /*
         *      We've sent the challenge so the peer should now be able
         *      to accept encrypted attributes.
         */
        eap_aka_sim_session->allow_encrypted = true;
 
        return session_and_pseudonym_store(p_result, mctx,request, eap_aka_sim_session, sim_challenge_request_send);
}
 
/** Enter the SIM-CHALLENGE state
 *
 */
STATE_GUARD(sim_challenge)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t                       *vp;
 
        /*
         *      If we've sent either of these identities it
         *      means we've come here form a Reauthentication-Request
         *      that failed.
         */
        if (eap_aka_sim_session->pseudonym_sent || eap_aka_sim_session->fastauth_sent) {
                return session_and_pseudonym_clear(p_result, mctx, request,
                                                   eap_aka_sim_session, guard_sim_challenge);
                                                   /* come back when we're done */
        }
 
        STATE_SET(sim_challenge);
 
        /*
         *      Set the defaults for protected result indicator
         */
        if (eap_aka_sim_session->send_result_ind &&
            !fr_pair_find_by_da(&request->reply_pairs, NULL, attr_eap_aka_sim_result_ind)) {
                MEM(pair_append_reply(&vp, attr_eap_aka_sim_result_ind) >= 0);
                vp->vp_bool = true;
        }
 
        return CALL_SECTION(send_sim_challenge_request);
}
 
/** Enter the SIM-CHALLENGE or AKA-CHALLENGE state
 *
 * Called by functions which are common to both the EAP-SIM and EAP-AKA state machines
 * to enter the correct challenge state.
 */
STATE_GUARD(common_challenge)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        switch (eap_aka_sim_session->type) {
        case FR_EAP_METHOD_SIM:
                return STATE_TRANSITION(sim_challenge);
 
        case FR_EAP_METHOD_AKA:
        case FR_EAP_METHOD_AKA_PRIME:
                return STATE_TRANSITION(aka_challenge);
 
        default:
                break;
        }
 
        fr_assert(0);
        RETURN_UNLANG_FAIL;
}
 
/** Resume after 'recv Identity-Response { ... }' or 'recv AKA-Identity { ... }'
 *
 * - If the previous section returned a failure rcode, enter the FAILURE-NOTIFICATION state.
 * - ...or call a function to process the contents of the AKA-Identity message, mainly the AT_IDENTITY value.
 * - If the message does not contain AT_IDENTITY, then enter the FAILURE-NOTIFICATION state.
 * - If the user requested another identity, re-enter the AKA-Identity state.
 * - ...or continue based on the value of &Identity-Type which was added by #aka_identity,
 *   and possibly modified by the user.
 *   - Fastauth - Enter the REAUTHENTICATION state.
 *   - Pseudonym - Call 'load pseudonym { ... }'
 *   - Permanent - Enter the CHALLENGE state.
 */
RESUME(recv_aka_identity_response)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        bool                            user_set_id_req;
        fr_pair_t                       *identity_type;
 
        SECTION_RCODE_PROCESS;
 
        /*
         *      See if the user wants us to request another
         *      identity.
         *
         *      If they set one themselves don't override
         *      what they set.
         */
        user_set_id_req = identity_req_set_by_user(request, eap_aka_sim_session);
        if ((eap_aka_sim_session->section_result.rcode == RLM_MODULE_NOTFOUND) || user_set_id_req) {
                if (!user_set_id_req) {
                        switch (eap_aka_sim_session->last_id_req) {
                        case AKA_SIM_ANY_ID_REQ:
                                eap_aka_sim_session->id_req = AKA_SIM_FULLAUTH_ID_REQ;
                                break;
 
                        case AKA_SIM_FULLAUTH_ID_REQ:
                                eap_aka_sim_session->id_req = AKA_SIM_PERMANENT_ID_REQ;
                                break;
 
                        case AKA_SIM_NO_ID_REQ:         /* We always request an ID in AKA-Identity unlike SIM-Start */
                        case AKA_SIM_INIT_ID_REQ:       /* Should not happen */
                                fr_assert(0);
                                FALL_THROUGH;
 
                        case AKA_SIM_PERMANENT_ID_REQ:
                                REDEBUG("Peer sent no usable identities");
                                return STATE_TRANSITION(common_failure_notification);
 
                        }
                        RDEBUG2("Previous section returned (%s), requesting next most permissive identity (%s)",
                                fr_table_str_by_value(rcode_table, eap_aka_sim_session->section_result.rcode, "<INVALID>"),
                                fr_table_str_by_value(fr_aka_sim_id_request_table,
                                                      eap_aka_sim_session->id_req, "<INVALID>"));
                }
                return STATE_TRANSITION(aka_identity);
        }
 
        /*
         *      If the identity looks like a fast re-auth id
         *      run fast re-auth, otherwise do fullauth.
         */
        identity_type = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_identity_type);
        if (identity_type) switch (identity_type->vp_uint32) {
        case FR_IDENTITY_TYPE_VALUE_FASTAUTH:
                return STATE_TRANSITION(common_reauthentication);
 
        /*
         *      It's a pseudonym, which now needs resolving.
         *      The resume function here calls aka_challenge_enter
         *      if pseudonym resolution went ok.
         */
        case FR_IDENTITY_TYPE_VALUE_PSEUDONYM:
                eap_aka_sim_session->next = guard_aka_challenge;
                return CALL_SECTION(load_pseudonym);
 
        default:
                break;
        }
 
        return STATE_TRANSITION(aka_challenge);
}
 
/** AKA-IDENTITY state - Continue the state machine after receiving a response to our EAP-Request/AKA-Identity
 *
 * - Continue based on received AT_SUBTYPE value:
 *   - EAP-Response/AKA-Identity - call either 'recv Identity-Response { ... }' or if
 *     provided 'recv AKA-Identity-Response { ... }'. The idea here is that the
 *     EAP-Identity-Response is really the first round in identity negotiation and
 *     there's no real value distinguishing between the first round and subsequent
 *     rounds, but if users do want to run different logic, then give them a way of
 *     doing that.
 *   - EAP-Response/AKA-Client-Error - call 'recv Client-Error { ... }' and after that
 *     send a EAP-Request/SIM-Notification indicating a General Failure.
 *   - Anything else, enter the FAILURE-NOTIFICATION state.
 */
STATE(aka_identity)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t                       *subtype_vp = NULL;
 
        subtype_vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_subtype);
        if (!subtype_vp) {
                REDEBUG("Missing AT_SUBTYPE");
                goto fail;
        }
 
        switch (subtype_vp->vp_uint16) {
        /*
         *      This is the subtype we expect
         */
        case FR_SUBTYPE_VALUE_AKA_IDENTITY:
        {
                fr_pair_t               *id;
                fr_aka_sim_id_type_t    type;
 
                id = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_identity);
                if (!id) {
                        /*
                         *  9.2.  EAP-Response/Identity
                         *
                         *  The peer sends EAP-Response/Identity in response to a valid
                         *  EAP-Request/Identity from the server.
                         *  The peer MUST include the AT_IDENTITY attribute.  The usage of
                         *  AT_IDENTITY is defined in Section 4.1.
                         */
                        REDEBUG("EAP-Response/Identity does not contain AT_IDENTITY");
                        return STATE_TRANSITION(common_failure_notification);
                }
 
                /*
                 *      Add ID hint attributes to the request to help
                 *      the user make policy decisions.
                 */
                identity_hint_pairs_add(&type, NULL, request, id->vp_strvalue);
                if (type == AKA_SIM_ID_TYPE_PERMANENT) {
                        identity_to_permanent_identity(request, id,
                                                       eap_aka_sim_session->type,
                                                       inst->strip_permanent_identity_hint);
                }
 
                /*
                 *      Update cryptographic identity
                 */
                crypto_identity_set(request, eap_aka_sim_session,
                                    (uint8_t const *)id->vp_strvalue, id->vp_length);
 
                return unlang_module_yield_to_section(&eap_aka_sim_session->section_result,
                                                      request,
                                                      inst->actions.recv_aka_identity_response ?
                                                                inst->actions.recv_aka_identity_response:
                                                                inst->actions.recv_common_identity_response,
                                                      RLM_MODULE_NOOP,
                                                      resume_recv_aka_identity_response,
                                                      mod_signal,
                                                      ~FR_SIGNAL_CANCEL,
                                                      eap_aka_sim_session);
        }
 
        /*
         *      Case 1 where we're allowed to send an EAP-Failure
         *
         *      This can happen in the case of a conservative
         *      peer, where it refuses to provide the permanent
         *      identity.
         */
        case FR_SUBTYPE_VALUE_AKA_SIM_CLIENT_ERROR:
                client_error_debug(request);
 
                return CALL_SECTION(recv_common_client_error);
 
        default:
                /*
                 *      RFC 4187 says we *MUST* notify, not just
                 *      send an EAP-Failure in this case.
                 */
                REDEBUG("Unexpected subtype %pV", &subtype_vp->data);
        fail:
                return STATE_TRANSITION(common_failure_notification);
        }
}
 
/** Resume after 'send Identity-Request { ... }'
 *
 * There are three types of user identities that can be implemented
 * - Permanent identities such as 0123456789098765@myoperator.com
 *   Permanent identities can be identified by the leading zero followed by
 *   by 15 digits (the IMSI number).
 * - Ephemeral identities (pseudonyms).  These are identities assigned for
 *   identity privacy so the user can't be tracked.  These can identities
 *   can either be generated as per the 3GPP 'Security aspects of non-3GPP accesses'
 *   document section 14, where a set of up to 16 encryption keys are used
 *   to reversibly encrypt the IMSI. Alternatively the pseudonym can be completely
 *   randomised and stored in a datastore.
 * - A fast resumption ID which resolves to data used for fast resumption.
 *
 * In order to perform full authentication the original IMSI is required for
 * forwarding to the HLR. In the case where we can't match/decrypt the pseudonym,
 * or can't perform fast resumption, we need to request the full identity from
 * the supplicant.
 *
 */
RESUME(send_aka_identity_request)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        SECTION_RCODE_PROCESS;
 
        /*
         *      Update eap_aka_sim_session->id_req in case the the
         *      user set attributes in `send Identity-Request { ... }`
         *      Also removes all existing id_req attributes
         *      from the reply.
         */
        identity_req_set_by_user(request, eap_aka_sim_session);
 
        /*
         *      Select the right type of identity request attribute
         *
         *      Implement checks on identity request order described
         *      by RFC4187 section #4.1.5.
         *
         *      The internal state machine should always handle this
         *      correctly, but the user may have other ideas...
         */
        if (identity_req_pairs_add(request, eap_aka_sim_session) < 0) {
                return STATE_TRANSITION(common_failure_notification);
        }
        eap_aka_sim_session->last_id_req = eap_aka_sim_session->id_req; /* Record what we last requested */
 
        /*
         *      Encode the packet
         */
        common_reply(request, eap_aka_sim_session, FR_SUBTYPE_VALUE_AKA_IDENTITY);
 
        RETURN_UNLANG_HANDLED;
}
 
/** Enter the AKA-IDENTITY state
 *
 */
STATE_GUARD_NO_RESULT(aka_identity)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        STATE_SET(aka_identity);
 
        /*
         *      If we have an send_aka_identity_request section
         *      then run that, otherwise just run the normal
         *      identity request section.
         */
        return unlang_module_yield_to_section(&eap_aka_sim_session->section_result,
                                              request,
                                              inst->actions.send_aka_identity_request ?
                                                        inst->actions.send_aka_identity_request:
                                                        inst->actions.send_common_identity_request,
                                              RLM_MODULE_NOOP,
                                              resume_send_aka_identity_request,
                                              mod_signal,
                                              ~FR_SIGNAL_CANCEL,
                                              eap_aka_sim_session);
}
 
/** Resume after 'recv Identity-Response { ... }' or 'recv SIM-Start { ... }'
 *
 * - If the previous section returned a failure rcode, enter the FAILURE-NOTIFICATION state.
 * - ...or call a function to process the contents of the SIM-Start message, mainly the AT_IDENTITY value.
 * - If the message does not contain AT_IDENTITY, then enter the FAILURE-NOTIFICATION state.
 * - If the user requested another identity, re-enter the SIM-START state.
 * - ...or continue based on the value of &Identity-Type which was added by #sim_start,
 *   and possibly modified by the user.
 *   - Fastauth
 *     - If AT_NONCE_MT or AT_SELECTED_VERSION are present, enter the FAILURE-NOTIFICATION state.
 *     - ...or enter the REAUTHENTICATION state.
 *   - Pseudonym - Verify selected version and AT_NONCE_MT, then call 'load pseudonym { ... }'
 *   - Permanent - Verify selected version and AT_NONCE_MT, then enter the CHALLENGE state.
 */
RESUME(recv_sim_start_response)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        bool                            user_set_id_req;
        fr_pair_t                       *identity_type;
 
        SECTION_RCODE_PROCESS;
 
        /*
         *      See if the user wants us to request another
         *      identity.
         *
         *      If they set one themselves don't override
         *      what they set.
         */
        user_set_id_req = identity_req_set_by_user(request, eap_aka_sim_session);
        if ((eap_aka_sim_session->section_result.rcode == RLM_MODULE_NOTFOUND) || user_set_id_req) {
                if (!user_set_id_req) {
                        switch (eap_aka_sim_session->last_id_req) {
                        case AKA_SIM_NO_ID_REQ: /* Should not happen */
                                eap_aka_sim_session->id_req = AKA_SIM_ANY_ID_REQ;
                                break;
 
                        case AKA_SIM_ANY_ID_REQ:
                                eap_aka_sim_session->id_req = AKA_SIM_FULLAUTH_ID_REQ;
                                break;
 
                        case AKA_SIM_FULLAUTH_ID_REQ:
                                eap_aka_sim_session->id_req = AKA_SIM_PERMANENT_ID_REQ;
                                break;
 
                        case AKA_SIM_INIT_ID_REQ:       /* Should not happen */
                                fr_assert(0);
                                FALL_THROUGH;
 
                        case AKA_SIM_PERMANENT_ID_REQ:
                                REDEBUG("Peer sent no usable identities");
                        failure:
                                return STATE_TRANSITION(common_failure_notification);
                        }
                        RDEBUG2("Previous section returned (%s), requesting next most permissive identity (%s)",
                                fr_table_str_by_value(rcode_table, eap_aka_sim_session->section_result.rcode, "<INVALID>"),
                                fr_table_str_by_value(fr_aka_sim_id_request_table,
                                                      eap_aka_sim_session->id_req, "<INVALID>"));
                }
                return STATE_TRANSITION(sim_start);
        }
 
        /*
         *      If the identity looks like a fast re-auth id
         *      run fast re-auth, otherwise do fullauth.
         */
        identity_type = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_identity_type);
        if (identity_type) switch (identity_type->vp_uint32) {
        case FR_IDENTITY_TYPE_VALUE_FASTAUTH:
                /*
                 *  RFC 4186 Section #9.2
                 *
                 *  The AT_NONCE_MT attribute MUST NOT be included if the AT_IDENTITY
                 *  with a fast re-authentication identity is present for fast
                 *  re-authentication
                 */
                if (fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_nonce_mt)) {
                        REDEBUG("AT_NONCE_MT is not allowed in EAP-Response/SIM-Reauthentication messages");
                        return STATE_TRANSITION(common_failure_notification);
                }
 
                /*
                 *  RFC 4186 Section #9.2
                 *
                 *  The AT_SELECTED_VERSION attribute MUST NOT be included if the
                 *  AT_IDENTITY attribute with a fast re-authentication identity is
                 *  present for fast re-authentication.
                 */
                if (fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_selected_version)) {
                        REDEBUG("AT_SELECTED_VERSION is not allowed in EAP-Response/SIM-Reauthentication messages");
                        return STATE_TRANSITION(common_failure_notification);
                }
 
                return STATE_TRANSITION(common_reauthentication);
 
        /*
         *      It's a pseudonym, which now needs resolving.
         *      The resume function here calls aka_challenge_enter
         *      if pseudonym resolution went ok.
         */
        case FR_IDENTITY_TYPE_VALUE_PSEUDONYM:
                if (sim_start_selected_version_check(request, eap_aka_sim_session) < 0) goto failure;
                if (sim_start_nonce_mt_check(request, eap_aka_sim_session) < 0) goto failure;
 
                eap_aka_sim_session->next = guard_sim_challenge;
                return CALL_SECTION(load_pseudonym);
 
        /*
         *      If it's a permanent ID, copy it over to
         *      the session state list for use in the
         *      store pseudonym/store session sections
         *      later.
         */
        case FR_IDENTITY_TYPE_VALUE_PERMANENT:
                if (sim_start_selected_version_check(request, eap_aka_sim_session) < 0) goto failure;
                if (sim_start_nonce_mt_check(request, eap_aka_sim_session) < 0) goto failure;
 
                FALL_THROUGH;
        default:
                break;
        }
 
        return STATE_TRANSITION(sim_challenge);
}
 
/** SIM-START state - Continue the state machine after receiving a response to our EAP-Request/SIM-Start
 *
 * - Continue based on received AT_SUBTYPE value:
 *   - EAP-Response/SIM-Start - call either 'recv Identity-Response { ... }' or if
 *     provided 'recv SIM-Start-Response { ... }'. The idea here is that the
 *     EAP-Identity-Response is really the first round in identity negotiation and
 *     there's no real value distinguishing between the first round and subsequent
 *     rounds, but if users do want to run different logic, then give them a way of
 *     doing that.
 *   - EAP-Response/SIM-Client-Error - call 'recv Client-Error { ... }' and after that
 *     send a EAP-Request/SIM-Notification indicating a General Failure.
 *   - Anything else, enter the FAILURE-NOTIFICATION state.
 */
STATE(sim_start)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t                       *subtype_vp = NULL;
 
        subtype_vp = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_subtype);
        if (!subtype_vp) {
                REDEBUG("Missing AT_SUBTYPE");
                goto fail;
        }
        switch (subtype_vp->vp_uint16) {
        case FR_SUBTYPE_VALUE_SIM_START:
        {
                eap_session_t           *eap_session = eap_session_get(request->parent);
                fr_pair_t               *id;
                fr_aka_sim_id_type_t    type;
 
                id = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_identity);
                if (!id && (eap_aka_sim_session->id_req != AKA_SIM_NO_ID_REQ)) {
                        /*
                         *  RFC 4186 Section #9.2
                         *
                         *  The peer sends EAP-Response/SIM/Start in response to a valid
                         *  EAP-Request/SIM/Start from the server.
                         *
                         *  If and only if the server's EAP-Request/SIM/Start includes one of the
                         *  identity-requesting attributes, then the peer MUST include the
                         *  AT_IDENTITY attribute.  The usage of AT_IDENTITY is defined in
                         *  Section 4.2.
                         *  The peer MUST include the AT_IDENTITY attribute.  The usage of
                         *  AT_IDENTITY is defined in Section 4.1.
                         */
                        REDEBUG("EAP-Response/SIM/Start does not contain AT_IDENTITY");
                        return STATE_TRANSITION(common_failure_notification);
                }
 
                /*
                 *      Add ID hint attributes to the request to help
                 *      the user make policy decisions.
                 */
                if (id) {
                        identity_hint_pairs_add(&type, NULL, request, id->vp_strvalue);
                        if (type == AKA_SIM_ID_TYPE_PERMANENT) {
                                identity_to_permanent_identity(request, id,
                                                               eap_aka_sim_session->type,
                                                               inst->strip_permanent_identity_hint);
                        }
 
                        /*
                         *      Update cryptographic identity
                         *
                         *      We only do this if we received a new identity.
                         */
                        crypto_identity_set(request, eap_aka_sim_session,
                                            (uint8_t const *)id->vp_strvalue, id->vp_length);
                /*
                 *      If there's no additional identity provided, just
                 *      use eap_session->identity again...
                 */
                } else {
                        /*
                         *      Copy the EAP-Identity into our Identity
                         *      attribute to make policies easier.
                         */
                        MEM(pair_append_request(&id, attr_eap_aka_sim_identity) >= 0);
                        fr_pair_value_bstrdup_buffer(id, eap_session->identity, true);
 
                        /*
                         *      Add ID hint attributes to the request to help
                         *      the user make policy decisions.
                         */
                        identity_hint_pairs_add(&type, NULL, request, eap_session->identity);
 
                        if (type == AKA_SIM_ID_TYPE_PERMANENT) {
                                identity_to_permanent_identity(request, id,
                                                               eap_aka_sim_session->type,
                                                               inst->strip_permanent_identity_hint);
                        }
                }
 
                return unlang_module_yield_to_section(&eap_aka_sim_session->section_result,
                                                      request,
                                                      inst->actions.recv_sim_start_response?
                                                                inst->actions.recv_sim_start_response:
                                                                inst->actions.recv_common_identity_response,
                                                      RLM_MODULE_NOOP,
                                                      resume_recv_sim_start_response,
                                                      mod_signal,
                                                      ~FR_SIGNAL_CANCEL,
                                                      eap_aka_sim_session);
        }
 
        /*
         *      Case 1 where we're allowed to send an EAP-Failure
         *
         *      This can happen in the case of a conservative
         *      peer, where it refuses to provide the permanent
         *      identity.
         */
        case FR_SUBTYPE_VALUE_AKA_SIM_CLIENT_ERROR:
                client_error_debug(request);
 
                return CALL_SECTION(recv_common_client_error);
 
        default:
                /*
                 *      RFC 4187 says we *MUST* notify, not just
                 *      send an EAP-Failure in this case.
                 */
                REDEBUG("Unexpected subtype %pV", &subtype_vp->data);
        fail:
                return STATE_TRANSITION(common_failure_notification);
        }
}
 
/** Resume after 'send Start { ... }'
 *
 * Send a EAP-Request/SIM-Start message to the supplicant
 *
 * There are three types of user identities that can be implemented
 * - Permanent identities such as 0123456789098765@myoperator.com
 *   Permanent identities can be identified by the leading zero followed by
 *   by 15 digits (the IMSI number).
 * - Ephemeral identities (pseudonyms).  These are identities assigned for
 *   identity privacy so the user can't be tracked.  These can identities
 *   can either be generated as per the 3GPP 'Security aspects of non-3GPP accesses'
 *   document section 14, where a set of up to 16 encryption keys are used
 *   to reversibly encrypt the IMSI. Alternatively the pseudonym can be completely
 *   randomised and stored in a datastore.
 * - A fast resumption ID which resolves to data used for fast resumption.
 *
 * In order to perform full authentication the original IMSI is required for
 * forwarding to the HLR. In the case where we can't match/decrypt the pseudonym,
 * or can't perform fast resumption, we need to request the full identity from
 * the supplicant.
 */
RESUME(send_sim_start)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t               *vp;
        uint8_t                 *p, *end;
 
        SECTION_RCODE_PROCESS;
 
        p = eap_aka_sim_session->keys.gsm.version_list;
        end = p + sizeof(eap_aka_sim_session->keys.gsm.version_list);
        eap_aka_sim_session->keys.gsm.version_list_len = 0;
 
        /*
         *      If the user provided no versions, then
         *      just add the default (1).
         */
        if (!(fr_pair_find_by_da(&request->reply_pairs, NULL, attr_eap_aka_sim_version_list))) {
                MEM(pair_append_reply(&vp, attr_eap_aka_sim_version_list) >= 0);
                vp->vp_uint16 = EAP_SIM_VERSION;
        }
 
        /*
         *      Iterate over the the versions adding them
         *      to the version list we use for keying.
         */
        for (vp = fr_pair_list_head(&request->reply_pairs);
             vp;
             vp = fr_pair_list_next(&request->reply_pairs, vp)) {
                if (vp->da != attr_eap_aka_sim_version_list) continue;
 
                if ((end - p) < 2) break;
 
                /*
                 *      Store as big endian
                 */
                *p++ = (vp->vp_uint16 & 0xff00) >> 8;
                *p++ = (vp->vp_uint16 & 0x00ff);
                eap_aka_sim_session->keys.gsm.version_list_len += sizeof(uint16_t);
        }
 
        /*
         *      Update eap_aka_sim_session->id_req in case the the
         *      user set attributes in `send Identity-Request { ... }`
         *      Also removes all existing id_req attributes
         *      from the reply.
         */
        identity_req_set_by_user(request, eap_aka_sim_session);
 
        /*
         *      Select the right type of identity request attribute
         *
         *      Implement checks on identity request order described
         *      by RFC4186 section #4.2.5.
         *
         *      The internal state machine should always handle this
         *      correctly, but the user may have other ideas...
         */
        if (identity_req_pairs_add(request, eap_aka_sim_session) < 0) {
                return STATE_TRANSITION(common_failure_notification);
        }
        eap_aka_sim_session->last_id_req = eap_aka_sim_session->id_req; /* Record what we last requested */
 
        common_reply(request, eap_aka_sim_session, FR_SUBTYPE_VALUE_SIM_START);
 
        RETURN_UNLANG_HANDLED;
}
 
/** Enter the SIM-START state
 *
 */
STATE_GUARD_NO_RESULT(sim_start)
{
        eap_aka_sim_process_conf_t *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t      *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        STATE_SET(sim_start);
 
        return unlang_module_yield_to_section(&eap_aka_sim_session->section_result,
                                              request,
                                              inst->actions.send_sim_start_request ?
                                                        inst->actions.send_sim_start_request:
                                                        inst->actions.send_common_identity_request,
                                              RLM_MODULE_NOOP,
                                              resume_send_sim_start,
                                              mod_signal,
                                              ~FR_SIGNAL_CANCEL,
                                              eap_aka_sim_session);
}
 
/** Enter the SIM-START or AKA-IDENTITY state
 *
 * Called by functions which are common to both the EAP-SIM and EAP-AKA state machines
 * to enter the correct Identity-Request state.
 */
STATE_GUARD(common_identity)
{
        eap_aka_sim_session_t   *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
 
        switch (eap_aka_sim_session->type) {
        case FR_EAP_METHOD_SIM:
                return STATE_TRANSITION(sim_start);
 
        case FR_EAP_METHOD_AKA:
        case FR_EAP_METHOD_AKA_PRIME:
                return STATE_TRANSITION(aka_identity);
 
        default:
                break;
        }
 
        fr_assert(0);
        RETURN_UNLANG_FAIL;
}
 
/** Resume after 'recv Identity-Response { ... }'
 *
 * - Perform the majority of eap_aka_sim_session_t initialisation.
 * - If 'recv Identity-Response { ... }' returned a failure rcode, enter the FAILURE-NOTIFICATION state.
 * - ...or continue based on the identity hint byte in the AT_IDENTITY value or EAP-Identity-Response value:
 *   - If identity is a pseudonym, call load pseudonym { ... }.
 *   - If identity is a fastauth identity, enter the REAUTHENTICATE state.
 *   - If identity is a permanent identity, enter the CHALLENGE state.
 */
RESUME(recv_common_identity_response)
{
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t                       *eap_type, *method, *identity_type;
        fr_aka_sim_method_hint_t        running, hinted;
 
        SECTION_RCODE_PROCESS;
 
        /*
         *      Ignore attempts to change the EAP-Type
         *      This must be done before we enter
         *      the submodule.
         */
        eap_type = fr_pair_find_by_da(&request->control_pairs, NULL, attr_eap_type);
        if (eap_type) RWDEBUG("Ignoring control.EAP-Type, this must be set *before* the EAP module is called");
 
        method = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_method_hint);
 
        /*
         *      Set default configuration, we may allow these
         *      to be toggled by attributes later.
         */
        eap_aka_sim_session->send_result_ind = inst->protected_success;
        eap_aka_sim_session->id_req = AKA_SIM_NO_ID_REQ;        /* Set the default */
 
        /*
         *      Unless AKA-Prime is explicitly disabled,
         *      use it... It has stronger keying, and
         *      binds authentication to the network.
         */
        switch (eap_aka_sim_session->type) {
        case FR_EAP_METHOD_SIM:
                RDEBUG2("New EAP-SIM session");
 
                running = AKA_SIM_METHOD_HINT_SIM;
 
                eap_aka_sim_session->type = FR_EAP_METHOD_SIM;
                eap_aka_sim_session->mac_md = EVP_sha1();
                break;
 
        case FR_EAP_METHOD_AKA:
                RDEBUG2("New EAP-AKA session");
 
                running = AKA_SIM_METHOD_HINT_AKA;
 
                eap_aka_sim_session->type = FR_EAP_METHOD_AKA;
                eap_aka_sim_session->mac_md = EVP_sha1();
                break;
 
        case FR_EAP_METHOD_AKA_PRIME:
                RDEBUG2("New EAP-AKA' session");
 
                running = AKA_SIM_METHOD_HINT_AKA_PRIME;
 
                eap_aka_sim_session->type = FR_EAP_METHOD_AKA_PRIME;
                eap_aka_sim_session->kdf = enum_kdf_prime_with_ck_prime_ik_prime->vb_int16;
                eap_aka_sim_session->mac_md = EVP_sha256();
                break;
 
        default:
                fr_assert(0);
                RETURN_UNLANG_FAIL;
        }
 
        /*
         *      Warn the user if the selected identity
         *      does not match what's hinted.
         */
        if (method) {
                switch (method->vp_uint32) {
                case FR_METHOD_HINT_VALUE_AKA_PRIME:
                        hinted = AKA_SIM_METHOD_HINT_AKA_PRIME;
                        break;
 
                case FR_METHOD_HINT_VALUE_AKA:
                        hinted = AKA_SIM_METHOD_HINT_AKA;
                        break;
 
                case FR_METHOD_HINT_VALUE_SIM:
                        hinted = AKA_SIM_METHOD_HINT_SIM;
                        break;
 
                default:
                        hinted = running;
                        break;
                }
 
                if (hinted != running) {
                        RWDEBUG("EAP-Identity hints that EAP-%s should be started, but we're attempting EAP-%s",
                                fr_table_str_by_value(fr_aka_sim_id_method_table, hinted, "<INVALID>"),
                                fr_table_str_by_value(fr_aka_sim_id_method_table, running, "<INVALID>"));
                }
        }
 
        /*
         *      Unless the user has told us otherwise We always
         *      start by requesting any ID initially as we can
         *      always negotiate down.
         */
        if (!identity_req_set_by_user(request, eap_aka_sim_session)) {
                if (eap_aka_sim_session->section_result.rcode == RLM_MODULE_NOTFOUND) {
                        eap_aka_sim_session->id_req = AKA_SIM_ANY_ID_REQ;
                        RDEBUG2("Previous section returned (%s), requesting additional identity (%s)",
                                fr_table_str_by_value(rcode_table, eap_aka_sim_session->section_result.rcode, "<INVALID>"),
                                fr_table_str_by_value(fr_aka_sim_id_request_table,
                                                      eap_aka_sim_session->id_req, "<INVALID>"));
                } else if (inst->request_identity != AKA_SIM_NO_ID_REQ) {
                        eap_aka_sim_session->id_req = inst->request_identity;
                        RDEBUG2("Requesting additional identity (%s)",
                                fr_table_str_by_value(fr_aka_sim_id_request_table,
                                                      eap_aka_sim_session->id_req, "<INVALID>"));
                }
        }
 
        /*
         *      For EAP-SIM we _always_ start with a SIM-Start
         *      for "version negotiation" even if we don't need
         *      another identity.
         */
        if (eap_aka_sim_session->type == FR_EAP_METHOD_SIM) return STATE_TRANSITION(sim_start);
 
        /*
         *      User may want us to always request an identity
         *      initially.  The RFCs says this is also the
         *      better way to operate, as the supplicant
         *      can 'decorate' the identity in the identity
         *      response.
         *
         *      For EAP-AKA/EAP-AKA' unless we've been configured
         *      to always request the identity or it was set
         *      dynamically, we can save a round of EAP and just
         *      jump straight into the challenge.
         */
        if (eap_aka_sim_session->id_req != AKA_SIM_NO_ID_REQ) return STATE_TRANSITION(common_identity);
 
        /*
         *      If the identity looks like a fast re-auth id
         *      run fast re-auth, otherwise do a fullauth.
         */
        identity_type = fr_pair_find_by_da(&request->request_pairs, NULL, attr_eap_aka_sim_identity_type);
        if (identity_type) switch (identity_type->vp_uint32) {
        case FR_IDENTITY_TYPE_VALUE_FASTAUTH:
                return STATE_TRANSITION(common_reauthentication);
 
        /*
         *      It's a pseudonym, which now needs resolving.
         *      The resume function here calls aka_challenge_enter
         *      if pseudonym resolution went ok.
         */
        case FR_IDENTITY_TYPE_VALUE_PSEUDONYM:
                eap_aka_sim_session->next = guard_common_challenge;
                return CALL_SECTION(load_pseudonym);
 
        case FR_IDENTITY_TYPE_VALUE_PERMANENT:
        default:
                break;
        }
 
        return STATE_TRANSITION(common_challenge);
}
 
/** Enter the EAP-IDENTITY state
 *
 * - Process the incoming EAP-Identity-Response
 * - Start EAP-SIM/EAP-AKA/EAP-AKA' state machine optionally calling 'recv Identity-Response { ... }'
 */
STATE(init)
{
        eap_session_t                   *eap_session = eap_session_get(request->parent);
        eap_aka_sim_process_conf_t      *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t           *eap_aka_sim_session = talloc_get_type_abort(mctx->rctx, eap_aka_sim_session_t);
        fr_pair_t                       *vp;
        fr_aka_sim_id_type_t            type;
 
        /*
         *      Verify we received an EAP-Response/Identity
         *      message before the supplicant started sending
         *      EAP-SIM/AKA/AKA' packets.
         */
        if (!eap_session->identity) {
                REDEBUG("All SIM or AKA exchanges must begin with a EAP-Response/Identity message");
                return STATE_TRANSITION(common_failure_notification);
        }
 
        /*
         *      Copy the EAP-Identity into our Identity
         *      attribute to make policies easier.
         */
        MEM(pair_append_request(&vp, attr_eap_aka_sim_identity) >= 0);
        fr_pair_value_bstrdup_buffer(vp, eap_session->identity, true);
 
        /*
         *      Add ID hint attributes to the request to help
         *      the user make policy decisions.
         */
        identity_hint_pairs_add(&type, NULL, request, eap_session->identity);
        if (type == AKA_SIM_ID_TYPE_PERMANENT) {
                identity_to_permanent_identity(request, vp, eap_session->type,
                                               inst->strip_permanent_identity_hint);
        }
 
        /*
         *      Set the initial crypto identity from
         *      the EAP-Identity-Response
         */
        crypto_identity_set(request, eap_aka_sim_session,
                            (uint8_t const *)eap_session->identity,
                            talloc_strlen(eap_session->identity));
 
        return CALL_SECTION(recv_common_identity_response);
}
 
/** Zero out the eap_aka_sim_session when we free it to clear knowledge of secret keys
 *
 * @param[in] eap_aka_sim_session       to free.
 * @return 0
 */
static int _eap_aka_sim_session_free(eap_aka_sim_session_t *eap_aka_sim_session)
{
        memset(eap_aka_sim_session, 0, sizeof(*eap_aka_sim_session));
        return 0;
}
 
/** Resumes the state machine when receiving a new response packet
 *
 */
unlang_action_t eap_aka_sim_state_machine_process(unlang_result_t *p_result, module_ctx_t const *mctx, request_t *request)
{
        eap_aka_sim_process_conf_t *inst = talloc_get_type_abort(mctx->mi->data, eap_aka_sim_process_conf_t);
        eap_aka_sim_session_t *eap_aka_sim_session = request_data_reference(request,
                                                                            (void *)eap_aka_sim_state_machine_process,
                                                                            0);
        module_ctx_t our_mctx = *mctx;
 
        /*
         *      A new EAP-SIM/AKA/AKA' session!
         */
        if (!eap_aka_sim_session) {
 
                /*
                 *      Must be allocated in the NULL ctx as this will
                 *      need to persist over multiple rounds of EAP.
                 */
                MEM(eap_aka_sim_session = talloc_zero(NULL, eap_aka_sim_session_t));
                talloc_set_destructor(eap_aka_sim_session, _eap_aka_sim_session_free);
 
                /*
                 *      Add new session data to the request
                 *      We only ever need to do this once as it's restored
                 *      during the next round of EAP automatically.
                 *
                 *      It will also be freed automatically if the request
                 *      is freed and persistable data hasn't been moved
                 *      into the parent.
                 */
                if (unlikely(request_data_add(request, (void *)eap_aka_sim_state_machine_process, 0,
                                              eap_aka_sim_session, true, true, true) < 0)) {
                        RPEDEBUG("Failed creating new EAP-SIM/AKA/AKA' session");
                        RETURN_UNLANG_FAIL;
                }
                eap_aka_sim_session->type = inst->type;
 
                our_mctx.rctx = eap_aka_sim_session;
 
                return state_init(p_result, &our_mctx, request);
        }
 
        /*
         *      This function is called without a resume ctx as it's the
         *      entry point for each new round of EAP-AKA.
         */
        our_mctx.rctx = eap_aka_sim_session;
 
        if (!fr_cond_assert(eap_aka_sim_session->state)) RETURN_UNLANG_FAIL;
 
        return eap_aka_sim_session->state(p_result, &our_mctx, request);
}